Advanced alkaline reactive precursors

Abstract

Methods of processing earth materials to make alkaline reactive materials for polysialate system formation are described herein. An earth material is selected to use for forming a polysialate system based on elemental composition of the earth material. The earth material is subjected to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity. Recycled cementitious materials can be used as ingredients for polysialate systems.

Description

ADVANCED ALKALINE REACTIVE PRECURSORSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority benefit of United States Provisional Patent Application Serial Numbers 63 / 661 ,260, filed 18 June 2024, 63 / 727,771 , filed 4 December 2024, and 63 / 799,109, filed 2 May 2025, each of which is entirely incorporated herein by reference.FIELD

[0002] This application for patent relates to polysialate systems. More particularly the invention relates to the use of advanced precursors for making alkaline reactive materials and polysialate systems.BACKGROUND

[0003] Geopolymers, a type of alkaline reactive material, are a class of inorganic materials that are formed by chemical reaction of various aluminosilicates, oxides, and silicates to form an amorphous three-dimensional framework cement-like structure. The term geopolymer was proposed and first used by J. Davidovits. His work is described in Davidovits, J: “Synthesis of New High-Temperature GeoPolymers for Reinforced Plastics / Composites.' Society of Plastics Engineers, IUPAC International Symposium on Macromolecules, Stockholm (1976). Geopolymers are polymers of aluminum, silicon, and oxygen which form an aluminosilicate matrix having repeated tetrahedral arrangements of aluminum, oxygen, and silicon atoms. Such polysialate polymers can include other entrapped components, which may or may not be chemically bonded to the aluminosilicate matrix. Other terms have been used to describe materials synthesized utilizing a similar chemistry, such as alkaline reactive cement, geocement, alkali-bonded ceramic, inorganic polymer, and hydroceramic. Generally, the polymeric portions of such materials can be termed polysialates, and the polymerization reaction that makes them can be referred to as a polysialation reaction.

[0004] Polysialates have been investigated for use in several applications, including as concrete systems within the construction industry, as refractory materials and as encapsulants for hazardous and radioactive waste streams. Such polymers are also recognized as being rapid setting and hardening materials. They exhibit superior hardness and chemical stability. The preparation of polysialates generally involves mixing a blend of reactive solid materials and activating the polymerization reaction by adding, or preparing in-situ, an alkaline solution. Typically, the initial slurry mixture is then applied and allowed to harden in place. In construction, faster hardening is usually valued, while in well construction for the hydrocarbon exploration and production industry, cementitious materials are deployed in a well to provide wall strength and isolation. Deployment of cementitious materials to a well requires the precursor slurry be pumpable into the well before the precursor begins to harden.

[0005] Conventionally, precursors for making polysialates are waste products such as slags and ashes, byproducts of combustion or other thermal processes that contain oxidized aluminum and oxidized silicon. Systems made from such raw materials have traditionally been called geopolymers. Polysialates generally have the advantage that a wide range of properties can be accessed by adjusting the mixture of materials in the precursor. Due to the sizes and morphologies of the materials used to make such polymers, the precursors can be more flexible in composition than for traditional cementitious materials.

[0006] The materials conventionally used to make geopolymers are, however, variable in their composition, particle size distribution, and morphology, and exhibit a limited range of some properties such as specific gravity. Precursor materials for making polysialates are needed that are more predictable and selective than conventional materials.SUMMARY

[0007] Embodiments described herein provide a method, comprising selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; and subjecting the earth material to achemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity.

[0008] Other embodiments described herein provide a method, comprising selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; subjecting the earth material to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity; and adding up to about 20% by weight of a recycled cementitious material to the alkaline reactive precursor.

[0009] Other embodiments described herein provide a method, comprising selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; subjecting the earth material to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity; adding up to about 20% by weight of a recycled cementitious material to the alkaline reactive precursor; dispersing the alkaline reactive precursor in an activating solution to form a pumpable polymerization precursor; pumping the polymerization precursor to a target location; and allowing the polymerization precursor to harden into a polysialate system.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figs. 1 -20 are schematic cross-sectional views depicting various embodiments of alkaline reactive precursors that can be made using processes described herein.

[0011] Fig. 21 is a graph showing a relationship between specific gravity and content of various crystalline domains for alumina and silica materials according to embodiments described herein.DETAILED DESCRIPTION

[0012] In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it may be understood by those skilled in the art that the methods of the present disclosure may be practiced withoutthese details and that numerous variations or modifications from the described embodiments may be possible.

[0013] At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation — specific decisions are made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. In addition, the composition used / disclosed herein can also comprise some components other than those cited. In the summary of the disclosure and this detailed description, each numerical value should be read once as modified by the term "about" (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. The term “about” should be understood as any amount or range within 10% of the recited amount or range (for example, a range from about 1 to about 10 encompasses a range from 0.9 to 11 ). Also, in the summary and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each possible number along the continuum between about 1 and about 10. Furthermore, one or more of the data points in the present examples may be combined together, or may be combined with one of the data points in the specification to create a range, and thus include each possible value or number within this range. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to a few specific data points, it is to be understood that inventors appreciate and understand that any data points within the range are to be considered to have been specified, and that inventors possessed knowledge of the entire range and the points within the range.

[0014] Regarding chemical formulas, it should be noted that measurements may not conform precisely to the chemical formulas described herein due to varioussources of error that can affect real-world testing. The chemical formulas described herein should therefore be understood as expressing the nominal chemical makeup of compounds, where real-world testing may show close, but not exact, conformity to the formulas.

[0015] As used herein, “embodiments” refers to non-limiting examples disclosed herein, whether claimed or not, which may be employed or present alone or in any combination or permutation with one or more other embodiments. Each embodiment disclosed herein should be regarded both as an added feature to be used with one or more other embodiments, as well as an alternative to be used separately or in lieu of one or more other embodiments. It should be understood that no limitation of the scope of the claimed subject matter is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the application as illustrated therein as would normally occur to one skilled in the art to which the disclosure relates are contemplated herein.

[0016] Aluminosilicate polymer materials, also known as polysialates, can be formed using specially prepared materials comprising oxidized aluminum, oxidized silicon, and optionally oxidized calcium to yield narrowly targeted properties of precursor mixtures and the resulting polymer materials. Oxidized aluminum materials that can be used in the methods herein can include oxidized aluminum having chemical formula AEOx, where x is about 3, for example 2.9 to 3.1 , or 2.95 to 3.05, or 2.99 to 3.01. That is, the oxidized aluminum can be aluminum oxide, but the aluminum oxide can be oxygen depleted, oxygen rich, or oxygen balanced (3 oxygen atoms for every 2 aluminum atoms). The reactant material can include an aluminum hydroxide material having the general formula AIOaHb where b can be a small number representing hydrogen impurities or b can be a number close to a such that a ratio of b / a is near 1 , for example 0.95 to 1.05. Where the ratio of b / a is not exactly 1 , the aluminum hydroxide material may be hydrogen-depleted aluminum hydroxide or hydrogen-enriched aluminum hydroxide. The oxygen content a is a number near 3, for example 2.95 to 3.05. The hydrogen content may be near 3, for example 2.95 to 3.05, or may be lower or higher if hydrogen content departs substantially from the normally stoichiometric ratio for aluminum hydroxide. The reactant material caninclude oxidized silicon having chemical formula SiOy, where y is about 2, for example 1.9 to 2.1 , or 1.95 to 2.05, or 1.99 to 2.01. That is, the oxidized silicon can be silica or silicon oxide, but the silica or silicon oxide can be oxygen depleted, oxygen rich, or oxygen balanced (2 oxygen atoms for every silicon atom).

[0017] An oxidized aluminum material usable for the polymerization precursors herein can be a homogeneous material, having substantially constant or consistent composition and structure throughout the material, or the oxidized aluminum can be a heterogeneous material having varying composition and structure throughout the material. For example, the oxidized aluminum can be a mixture of aluminum and aluminum oxide, for example an aluminum powder mixed with an aluminum oxide powder. In another case, the oxidized aluminum can be a particulate material of oxide-coated aluminum particles. Likewise, the oxidized silicon material can be homogeneous or heterogeneous. An example of a heterogeneous oxidized silicon material is a mixture of silicon powder and silicon oxide powder or a particulate material of oxide-coated silicon particles.

[0018] Aluminosilicate materials having the general formula AlaSibOcHd can also be used as raw materials for polysialates. Such materials can be obtained from previously hardened cementitious materials, which may be recycled polysialate materials or recycled cement materials, aluminosilicate glasses, and the like. These materials can also be naturally occurring minerals such as andalusite, kyanite, sillimanite, kaolinite, mullite, and the like, or man-made materials such as blast furnace slags and aluminosilicate glasses. Ratios of a, b, c, and d are generally in ranges shown in Table 1.Table 1 - Composition of Aluminosilicate Materials

[0019] Recycled polysialate materials generally contain polysialate, or may be entirely polysialate, so they will typically have composition within the ranges shown in Table 1 . Recycled cements will generally have significant quantities of calcium and silicon, and may also have some aluminum and other elements, such as iron, in smaller quantities. Recycled cementitious materials, in particular, may have certain quantities of non-native iron from construction materials, such as rebar, originally deployed with the cementitious material and included, at least in part, in the recycled cementitious material. The recycled cementitious material can also have small amounts of other metal ions, such as magnesium and sodium, chemically bonded into the polymer chain, and other ions within the system but not chemically bonded in the polymer chain.

[0020] The materials used herein to make precursors for alkaline reactive polysialation can be modified through chemomechanical processes to render the materials alkaline reactive. In general, the chemomechanical process includes application of mechanical energy to the aluminum-, silicon-, and oxygen-containing materials, optionally with application of thermal energy in any suitable form, to yield alkaline reactive aluminosilicate materials, and optionally other materials in the composition, that have selected characteristics such as particle size, particle size distribution, particle morphology, degree of crystallinity, and chemical composition. The processes described herein transform the precursor materials using sizing and forming processes to yield raw materials having a selected specific gravity, particle size, particle size distribution, degree of crystallinity or amorphous content and morphology for optimal use to make alkaline reactive precursors and polymer systems having selected properties.

[0021] The materials used herein can be pre-conditioned, for example by exposure to thermal processing of any suitable sort, such as combustion or electrical heating. Alternately, or additionally, the sizing and forming processes herein used torender the materials in polymerization-suitable form can also activate, or increase activation of, the oxidized aluminum and oxidized silicon materials, and can be concurrently used with thermal energy from combustion or electrical heating.

[0022] A variety of solid materials can be used in forming polysialate systems. Alkali activators used to activate the polymerization reaction can be solid materials that are blended with the materials generally containing aluminum, silicon, and oxygen to make a dry blend. Solid activators, such as alkali metal salts, for example oxides, hydroxides, peroxides, silicates, orthosilicates, metasilicates, pyrosilicates, hexafluorosilicates, carbonates, sulfates, sulfites, phosphates, oxalates, fluorides, iodates, and molybdates can be used along with alkaline earth metal hydroxides, oxides, carbonates, and / or peroxides as co-agents to form a high pH aqueous medium for reacting the aluminum, silicon, and oxygen in the polymerization reactants. Where the polymerization reactant materials have metal oxides such as calcium oxide in significant quantities, the alkali metal salts can be used without additional alkaline earth metal co-agents can be omitted. The oxidized aluminum and silicon materials are dispersed into an aqueous medium, along with the alkali activators, to form a polysialate precursor that is then deployed to a target location and hardened into a polysialate system.

[0023] Conventional cements, such as Portland cement, can also be used as alkali activators. A conventional cement powder can be mixed with polysialation reactants in a quantity of up to about 10 percent by weight of the total solid polymerization reactant blend to provide alkali activation for the polysialation reaction. Additional cement can also be used in the mixture, but the additional cement is generally thought to react to form hydrated cement domains within the hardened product, resulting in a cement-polysialate mixture or alloy. Depending on how much cement or aluminosilicate reactants are used in the mixture, the final product may have continuous cement domains with dispersed discrete polysialate domains and / or continuous polysialate domains with dispersed discrete cement domains. In polysialate made using a low concentration of cement as an activator, optionally along with other alkali activators, some calcium atoms from the cement may join the polysialate matrix and occupy coordinating positions in the matrix together with thesilicon oxygen and aluminum atoms. In some cases, a calcium containing polysialate matrix may result.

[0024] Generally, aluminum oxide; aluminum hydroxide; silica flour; clays such as illite, montmorillonite, smectites, hectorites, and kaolinites; bauxites; feldspars; granite, diorite, volcanic, ash, weathered granite, diorite, volcanic, ash, and other similar natural rocks, quartz; sand; silt; waste and recycled glasses and ceramics such as waste soda glass, waste e-glass, and waste ceramic residues; drill cuttings; kiln dust; mica; waste fiberglass insulation; waste silicon and / or aluminum; mine tailings; gangue; and silica sand can be activated and used as ingredients to make an alkaline reactive precursor described herein. Where silica is used as a reactant, the silica may be crystalline silica, or amorphous silica, nanocrystalline silica, or fume silica. Despite lower reactivity, use of crystalline silica can help in achieving precursor characteristics such as pumpability, solids fraction, density or specific gravity, viscosity, and the like. Crystalline silica having particle size from 1 -50 pm can be useful to tune particle size distribution of the precursor mixture. Other materials that can be used with, or instead of, the materials listed above include silica fume, colloidal silica, silica flour, water glass, metasilicates, orthosilicates, calcium hydroxide, calcium oxide, sodium carbonates, alumina, water, and soda ash. Such materials can, in some cases, be used to target certain properties of a polysialate precursor, or eventual polysialate system, when used with other materials listed above.

[0025] Herein, cementitious materials such as previously hardened cements and polysialate systems, when recycled and grinded to the right size, can be used as raw materials in polysialate precursors. Cementitious materials such as previously hardened cements and polysialate systems, when recycled and grinded to the right size, and optionally chemomechanically treated, can also be used as raw materials in polysialate precursors. Such materials can function as activators, raising the pH of the polysialate precursor, and / or as polymerization reactants. In some cases, the recycled cementitious materials can be used as the only activator in the polysialate precursor. In other cases, the recycled cementitious materials can be used with other activators.

[0026] The recycled cementitious materials herein can be solid materials recovered from prior construction, for example from demolished buildings, bridges, pavements, and other structures. Solid polysialate systems recovered from prior uses can also be used as a raw material for a new polysialate precursor. The solid, previously set, cementitious materials are rendered in a form that is usable in a polysialate raw material blend. Generally, the recycled cementitious materials are subjected to a sizing process to make the materials blendable as a powder or particle mixture.

[0027] The recycled cementitious materials can be subjected to a chemomechanical process. For example, a recycled cementitious material can be subjected to any of the chemomechanical processes described herein before being used as a raw material for a polysialate precursor. Thus, a recycled cementitious material can be mixed with an earth material, where both the recycled cementitious material and the earth material are selected based on their properties, such as chemical composition, density or specific gravity, particle size distribution, morphology, and the like, to form a mixture, and the mixture can then be subjected to chemomechanical processing to form a polysialate raw material. In another case, a selected earth material can be subjected to a first chemomechanical process, a recycled cementitious material can be subjected to a second chemomechanical process, and the two processed materials mixed together to form a polysialate raw material. Thus, the recycled cementitious material can be subjected to chemomechanical processing together with an earth material or separately and independently from the earth material.

[0028] Precursor materials can be selected, and processed, to target a composition, morphology distribution, slurry density, specific gravity or density of solids, particle size distribution, crystallinity and amorphous or glass content, and specific surface area profile for an alkaline reactive precursor blend based on desired properties of the blend and based on desired properties of the eventual set polysialate system. In many cases, a precursor having D10 (dimensional size limit of 10% by weight of all particles in the precursor) of 0.5 pm, D50 (dimensional size limit of 50% by weight of all particles in the precursor ) of 10 pm, and D90 (dimensional size limitof 90% by weight of all particles in the precursor) of 30 to 50 pm is useful to balance fluid properties of the precursor within workable ranges. Likewise, a precursor having specific surface area of 1 -10 m2 / g provides workable fluid properties. Higher specific surface areas, with lower particle sizes, can lead to excessive water entrapment by the solid materials of the precursor, causing high viscosity and difficulty moving the polymerization precursor to a target setting location. Low concentrations of particles having high specific surface area, for example concentration of particles having specific surface area of 18-25 m2 / g that are below about 20%, can be used to tune overall performance of the polymerization precursor. Particles can be milled or ground to reduce particle size and increase specific surface area. Particles can also be sintered to increase particle size and reduce specific surface area. Mixtures of small and large particles, and mixture of particles having different particle size distributions, can be used to achieve an overall particle size and specific surface area profile for an alkaline reactive precursor.

[0029] Recycled cementitious materials may be used to tailor the particle size distribution of a polysialate raw material blend. In addition to the recycled cementitious materials, other solid polysialate raw materials are used in such blends. Recycled cementitious materials can be sized, based on the particle size distribution of other materials in the solid blend, to provide particle size polydispersity to improve rheological properties of a polysialate precursor so that the precursor can be pumped to a desired location for hardening.

[0030] Generally, recycled cementitious materials can be used for the methods herein in amounts of up to about 65% by weight of the dry polysialate precursor mixture, such as from about 0.1 % to about 65%, about 10% to about 50%, for example about 30%. The amount of recycled cementitious material use may depend on slurry density of the polysialate precursor blend to be used. Lower density slurries may be able to use higher amounts of recycled cementitious materials, as a proportion of the dry polysialate precursor. In some cases, a low amount of recycled cementitious material, such as 0.1 % to 20% by weight of the dry polysialate precursor, for example 5% to 15% by weight of the dry polysialate precursor, is used. In other cases, a moderate amount, such as 20% to 40% by weight of the drypolysialate precursor, for example 25% to 35% by weight of the dry polysialate precursor, is used. In still other cases, high amounts, such as 40% to 65% by weight of the dry polysialate precursor, for example 50% to 60% by weight of the dry polysialate precursor, is used. Systems using recycled cementitious materials, as described herein, can be hardened to develop suitable compressive strength for most applications that use cementitious materials. Such systems will develop compressive strength of at least about 100 psi, such as at least about 250 psi, for example at least about 500 psi.

[0031] The chemical composition of an alkaline reactive precursor can be selected to achieve properties for the precursor, a polymerization precursor made by adding an alkaline solution to the alkaline reactive precursor, and for the set polysialate system derived from the precursor. In general, the composition of the precursor can be expressed as a percentage of the oxides of the metals present in the precursor. Elemental composition to be adjusted or selected to achieve precursor or set product properties include but are not limited to Si, Al, Fe, Ca, Mg, Na, K, Ti, Fe, B, Zr, and S. A desired elemental composition can be achieved by selected raw materials with a known elemental composition. For instance, precursors having a low concentration (such as below 5%, below 10%, below 15%, below 20%) of alkaline earth metals such as calcium and or magnesium, added as calcium oxide or magnesium oxide, may have increased resistance to attack by CO2. In other cases, precursors having a high concentration of boron, and or iron, added as boron oxide or iron oxide (such as more than 0.5%, more than 1 %, more than 2%, more than 5% or more than 10%), can reduce precursor reactivity to avoid flash setting of the precursor in high temperature environments. Such properties can be predicted or selectively provided by choosing a suitable elemental composition.

[0032] The chemical composition and the degree of crystallinity of a solid raw material will alter the density (or specific gravity) of the solid raw material. Solid raw materials having different specific gravity are used in different situations. For instance, with deep, highly pressurized reservoirs, requiring high density fluids to counteract said reservoir pressures, a high specific gravity material (for example close to or greater than 2,500 kg / m3) can be useful in a polymerization precursor totransport the precursor to the desired location and polymerize it in place. In such cases, it can be useful to add solid raw materials having high specific gravity (for example greater than 2,750 kg / m3, or greater than 2,900 kg / m3, or greater than 3,000 kg / m3, or greater than 3,100 kg / m3, or greater than 3,200 kg / m3, or greater than 3,300 kg / m3, or greater than 3,500 kg / m3, or higher) to reduce the solids volume fraction needed to achieve a target polymerization precursor slurry density and improve pumpability. On the other hand, with shallow, very depleted reservoirs having low fracture gradient, requiring low density fluids to avoid exceeding the formation stress and prevent undesired fracturing of said reservoir, polymerization precursor specific gravity can be lower (for example close to or less than 1 ,400 kg / m3). In such cases, it can be useful to provide solid raw materials having low specific gravity (for example less than 2,500 kg / m3, or less than 2,400 kg / m3, or less than 2,300 kg / m3, or less than 2,200 kg / m3, or less than 2,000 kg / m3, or less than 1 ,800 kg / m3, or less than 1 ,600 kg / m3, or lower) to increase the solids volume fraction at the lower target slurry density and improve set material properties.

[0033] Given the limited range of specific gravity of the commercially available aluminosilicates (fly ash F, fly ash C, Metakaolin, Ground Granulated Blast Furnace Slag, other no steel slags, synthetic aluminosilicates, calcined clays, volcanic ash, recycled glass, and the like), which are typically higher than 2,200 kg / m3, and typically less than 3,100 kg / m3it is often helpful to achieve alkaline reactive precursors having a broader specific gravity range, such as between 1 ,600 kg / m3or lower and 3,500 kg / m3or higher, and methods to manufacture such products.

[0034] Morphology of the solids in the polymerization precursor can affect the reactivity of the polymerization precursor, and / or the final mechanical properties of the set polysialate or polysialate system. For instance, adding fibers, platelet materials, or both that have dimensions smaller than a particle size of reactive particles in the polymerization precursor (thus giving rise to separate domains within the set polymer that can become entrapped within the polymer matrix) can provide improved mechanical properties such as higher modulus and / or ductility to the set material derived from polymerizing the precursor. The fibers can be glass, carbon, sepiolite, attapulgite, or palygorskite fibers, or combination thereof. The plateletmaterials can be any type of mica, muscovite, lepidolite, biotite, glauconite, phlogopite, or other materials with a flat structure due to exfoliation or synthesis such as slate, graphite, or graphene, or any combination thereof.

[0035] Precursor morphology can also be adjusted to obtain structures having a higher level or roundness ( / .e. a low quantity of sharp edges) or a lower level of roundness (i.e. a higher quantity of sharp edges). That is, components of the precursor having high angularity can be adjusted to have lower angularity. Precursor morphology can also be adjusted to obtain structures having a higher level of dimensional uniformity ( / .e. three orthogonal axial dimensions being similar), or a lower level of dimensional uniformity ( / .e.one or two orthogonal axial dimensions being very different from a third such dimension). That is, components of the precursor having low dimensional uniformity can be adjusted to have higher dimensional uniformity. Generally, the angularity and dimensional uniformity of a particle can be determined according to the Krumbein and Sloss method set forth in API RP60. In addition, the angularity of a particle can be determined by optical methods, by visually rating, or measuring the radius of curvature, which reflect the sharpness or roundness of the edges Dimensional uniformity of a particle can be expressed as sphericity, which can be determined by measuring radii of the particle along three different orthogonal axis.

[0036] Components having heterogeneous composition can be added to alkaline reactive precursors to provide various properties for the set material resulting from polymerizing the precursor. For instance, particles having highly reactive sites on the surface, such as surfaces having high concentration of calcium oxide may be useful for precursors that are to be polymerized in low temperatures, while a low calcium oxide content in the inner part of the particle could result in higher CO2 and acid resistance for the set material. In other cases, particles with high strength crystalline oxides, such as silicone oxide or zirconium oxide, hematite, and / or ilmenite, in the inner part of each particle and high content of amorphous silicon-aluminum oxide on the surface of each particle can provide high strength, with high reactivity and good adhesion. Hence the crystallinity or amorphous content of the reactive fraction of the precursor may be different than the overall precursor.

[0037] The particle size distribution of the precursor can be selected or adjusted to improve precursor properties such as gelation control, fluid loss control, viscosity, and set time. The composition of the particles of the precursor in one size range can be the same as, or different from, that of particles in another size range. Also, the morphology of the particles in each size range can be the same as, or different from the morphology of particles in a different size range. In one case, large particles having high dimensional uniformity and angularity can be used in a precursor to provide packing behavior that reduces fluid loss. In another case, particles having low angularity and high dimensional uniformity can reduce gelation behavior of a precursor. In another case, large particles having high dimensional uniformity and high angularity can be combined with small particles having low angularity and high dimensional uniformity in a precursor to provide improved fluid loss while minimizing gelation. In another case, large particles having a core of high specific gravity material (e.g. rich in titanium oxide, iron oxide, zirconium oxide, manganese oxide, barite, celestine, and / or crystalline silica) and a shell of highly reactive amorphous aluminosilicate can provide a polymerization precursor having reduced solid volume fraction along with improved gelation and fluid loss control. Many other cases where alkaline reactive precursors have particles of different composition, morphology, density or specific gravity, particle size, crystallinity, amorphous or glass content, and specific surface area, or distributions and / or profiles, can be envisioned.

[0038] The degree of crystallinity of the precursor (or the degree of amorphous, or glass material, i.e. the non-crystalline content of precursor and or reactive fraction of the precursor) can be selected or adjusted to achieve target properties of precursors and set materials obtained by polymerization of such precursors. The degree of crystallinity of an aluminosilicate, or other alkaline reactive precursor, can be measured using X-ray diffraction methods, which can determine the type and amounts of crystalline minerals in a sample. The degree of crystallinity expresses percentage of the material mass that is in the form of an ordered crystal structure. The content of glass or amorphous domain indicates what percentage of the material mass is not in the form of an ordered crystal structure. Materials having ordered crystal structure are referred to as “crystalline,” while materials with little or no ordered crystal structure are referred to as “amorphous” or “glass” materials. Materials canhave structures that are intermediate between totally amorphous and totally crystalline, which can take many forms including different discrete domains having different amounts of ordered structure. For inorganic materials with a given chemical composition susceptible of forming ordered crystal structures, the degree of crystallinity can be altered by transitioning the material from a high temperature liquidus state permitting at least some material flowability or deformability (for instance but not limited to a melt, or near-melt state) where the atoms are movable and can orient in space, to a low temperature state where the atoms are no longer movable, at a preselected rate. In general, slow cooling will favor the generation of highly crystalline materials, whereas very fast cooling (sometimes also called “quenching”) will often favor formation of highly amorphous or glassy materials. The result of a particular cooling regime depends on properties of the material, but without limitation, examples of slow cooling rates are 60°C / hour, 30°C / hour, 20°C / hour, 10°C / hour, or 5°C / hour. Examples of very fast cooling rates or quenching rates are 4000°C / s, 3000°C / s, 2000°C / s, 1500°C / s, 1000°C / s, 250°C / s, 100°C / s, 60°C / s, or 30°C / s. Also, in general, a particle having reactive aluminosilicate material can have up to about 90% by weight non-reactive material or material that is slow to react.

[0039] Thus, a particle can have highly crystalline domains, for example 80-100% crystallinity, dispersed within a substantially amorphous aluminosilicate material, for example having crystallinity less than about 30%. Such a particle can have average crystallinity of up to 75%, but can still be reactive in an alkaline solution, with higher crystallinity materials needing more alkalinity to achieve a given reaction rate. Crystalline domains having 30%, 50%, or 70% crystallinity can also be dispersed within a substantially amorphous body, and such structures can be made by mixing process steps that form materials having different levels of crystallinity and / or including highly crystalline species in the solids mixture for chemomechanical processing. Predominantly amorphous domains having 100%, 95%, or 90% amorphous content may also be dispersed within a substantially crystalline body, and such structures can be made by selecting compositions that do not crystalline or are slow to crystallize, and or mixing process steps that form materials having different levels of crystallinity and / or including highly crystalline species in the solids mixture for chemomechanical processing.

[0040] In laboratory conditions, it is possible to determine a cooling rate to form minerals having a target crystallinity, a minimum crystallinity, or a maximum crystallinity, and therefore to control the degree of crystallinity, or the amorphous degree, or the glass content of the material. Controlled crystallization experiments can be performed, for example, using a calorimeter, which may be a differential scanning calorimeter, with or without modulation, in connection with X-Ray diffraction testing. Additional thermal transition information can be obtained by means of a thermo-mechanical analyzer (TMA), potentially combined with a thermo-gravimetric analysis (TGA). Depending on the chemical nature of materials to be processed, processing temperatures for chemomechanical processing can be selected so that some materials can be substantially or completely molten, or can undergo thermal transitions such as dehydroxylation, whereas the crystalline structure of other materials can remain substantially unaffected.

[0041] At the industrial scale, crystallinity of a material can be controlled by cooling a material from at least a near-melt state. Such cooling can be performed by thermally contacting a controlled flow or quantity of a material with a controlled flow or quantity of a cooling medium at temperatures, and for a time, selected to achieve a target cooling rate of the material. The cooling medium can be liquid or gas, and may be, or include water, air, nitrogen, CO2, syngas, methane, uncombusted hydrocarbon, or other gas or liquid media. The industrial process can include multiple stages of thermal contact between the material and a cooling medium. An industrial scale cooling process can be designed based on laboratory results using sound chemical engineering design practices known to those of skill in the art. Scale-up can include performing pilot scale experiments, and multiphysics mathematical modelling and simulations of the process. Controlled crystallization processes can also include annealing operations, which generally maintain the material at an intermediate temperature for a time selected to accomplish certain atomic organizations or orientations within the material to aid achievement of the final crystallinity configuration of the material. Controlling crystalline configuration of a polymer precursor material can affect the morphology, and the reactivity of the precursor.

[0042] In general, cooling proceeds from the surface of a particle inward toward the center of the particle. Where the particle has a uniform composition, thermal flux within the particle can be substantially uniform and thermal transition rates within the particle can be angularly isotropic with only the radial coordinate defining thermal transition within the particle. Where the particle has non-uniform composition, thermal transition within the particle will be more complex. For a given locality within a particle undergoing a cooling transition, the thermal transition rate and composition at the locality will determine how the atoms behave, and will determine the final degree of crystallinity at the locality. Where the particle has a uniform composition, a thermal transition treatment can be performed on the particle that quickly cools localities of the particle near the surface while more slowly cooling localities of the particle near the center thereof, leading to a particle having a surface region with low crystallinity and a core region with higher crystallinity. A particle having less uniform composition subjected to a measured, intermediate, thermal transition rate can result in a cooled particle having domains of more and less crystalline structure in a complex arrangement. In some cases, the final particle may have surface domains that vary widely in crystallinity such that a mixture of particles treated using such methods can result in some Janus particles and / or multidomain particles. Such treatments can be designed using particles of known composition to deploy in an industrial setting where particles matching the known composition are to be found.

[0043] Together with other parameters such as chemical composition, density or specific gravity, morphology, surface area, and particle size distribution amongst others, the degree of crystallinity can have a large effect, by itself with other parameters constant, on reactivity of an polysialate precursor. In general for a given chemical composition, morphology, surface area, and particle size distribution, aluminosilicates, and precursors that have very low degree of crystallinity (such as less than 20%, less than 10% or less than 5%), or that have high amorphous content or glass content (such as more than 80%, more than 90% or more than 95%) are more reactive in alkaline reactive polymerization reactions than aluminosilicates, and other precursors, that have high degree of crystallinity (such as higher than 20%, higher than 40%, higher than 60% or higher than 80%), or that have low amorphous content of glass content (such as less than 80%, less than 60%, less than 40% orless than 20%). Controlling the degree of crystallinity or the amorphous or glass content of the precursor can be helpful to achieve a pumpable precursor that has a controlled setting profile in multiple operating conditions. For example, one polysialate precursor can be exposed to different temperatures during pumping, setting, and operating, represented by surface temperature, bottom hole circulating temperature, and bottom hole static temperature. The many factors described herein for formulating a polymer precursor can be used to select mechanical properties and reactivity of the precursor with different environmental conditions in mind.

[0044] For instance, in order to pump and set a polymerization precursor in relatively low temperature conditions, such as close to 0°C, close to 5 °C, close to 10 °C, close to 15 °C, close to 20 °C, or any temperature below ambient temperature, frequently encountered in artic operations, shallow wells in cold climates, or in annuli next to shallow formations in off-shore or deepwater wells, high reactivity of the polymerization precursor can be helpful. As described above, high reactivity can be achieved in a polymerization precursor by providing solids having a very low degree of crystallinity, such as less than 20%, 10%, or 5%, or high content of glassy or amorphous domains, such as higher than 80%, 90%, or 95% in the reactive fraction of the precursor. High precursor reactivity will enable setting within a suitable time at such low temperatures, when formulated using appropriate concentrations of activators, accelerators, dispersants, fluid loss additive, and other additives.

[0045] Likewise, in order to pump and set a polymerization precursor in relatively high temperature conditions, such as higher than 110 °C, higher than 120 °C, higher than 140 °C, higher than 150 °C, higher than 170 °C, or higher than 200 °C, frequently encountered in deep hot reservoirs and formations, or geothermal wells, low reactivity of the polymerization precursor prevents premature or flash setting of the precursor. Low precursor reactivity can be achieved by providing a high degree of crystallinity, such as higher than 20%, 40%, 60%, or 80%, or low content of glassy or amorphous domains, such as lower than 80%, 60%, 40%, or 20% in the reactive fraction. Low precursor reactivity will enable setting within a suitable time, after the polymerization precursor has been deployed to a target location, at such high temperatures, when formulated using appropriate concentrations of activators, retarders, dispersants,fluid loss additive, and other specialty additives. In general, it is useful to obtain any of the waste and / or recycled aluminum-silicon-oxygen products listed above as a starting ingredient to make a polymer precursor to reduce general environmental burden, although any of the materials herein containing aluminum, silicon, and oxygen can be a starting ingredient. Elemental composition of the selected material is understood using suitable analytical techniques. Adjuvant materials, such as aluminum, alumina, silicon, silica, or other materials can be added as needed to achieve a selected elemental composition for the polymerization precursor. Morphology of the selected materials is also ascertained using known suitable techniques to determine, for example, degree of crystallinity in the material. Finally, particle size distribution and specific surface area of the materials are ascertained, also using known suitable techniques. Using different materials with different known compositions, morphologies, particle size distributions, and specific surface areas can selectively and, to an extent, independently target all such properties for the polymerization precursor and resulting polysialate or polysialate system. Additionally, using processes described herein, morphology, particle size distribution, and specific surface area can be adjusted.

[0046] Alternatively, methods of precursor pre-sizing, pre-blending, preprocessing, pre-compressing, pre-sintering can be used to reach various target morphologies of the polymerization precursor after the material has been subjected to the chemomechanical process. Such methods may encompass sizing two raw materials to similar or different particle size distributions, pre-blending, pre-sintering, or pre-compressing the sized particles into a preformed structure with domains of the different raw materials, and then subjecting the preformed structure to the chemomechanical process.

[0047] In addition to changes to the degree of crystallinity of the various domains, as a result of the thermal process the materials will be subjected to during the chemomechanical process, placement of such domains in the polymerization precursor is also controlled by the chemical composition of the raw materials and their thermal properties. For instance, the viscosity of the molten and near-molten domains of various materials changes with temperature. The interfacial tensionbetween various molten and near-molten materials in flowable conditions (including the interfacial tension with external gas and external liquid domains) may cause some material domains to collect at or near the particle gas interface, while other material domains collect further from the gas particle interface. It is expected that for a set of initial raw material compositions, and pre-processed morphology, given varying chemomechanical conditions, time dependent morphologies and properties will arise. For example, where a mostly amorphous aluminosilicate and a potentially crystallizable aluminosilicate, the two materials having different composition, liquid viscosities, and interfacial properties, are mixed in a liquid state to form a precursor, the domains of the liquidus will seek a minimum interfacial energy state. Given enough stable time in the liquid state, the material exhibiting lowest gas-liquidus interfacial energy would collect at the external boundary of the particles, and the material exhibiting highest liquidus-gas interfacial energy would collect inside the particles. Kinetic effects will interact with thermodynamic effects to determine the particle morphology achieved during a chemomechanical process. Such kinetic effects include the relative viscosity and mobility of the liquid materials, the relative heat transfer rate, the rates of crystallization, the size of the original domains, and particle size distribution, the viscosity of the materials in the non-liquid state, and the time and temperatures the materials will be exposed to conditions where liquid state is maintained, and the time and temperature the materials will be exposed to conditions where crystallization, and annealing may occur. In most cases herein, materials are exposed to short residence time at transformative conditions in a chemomechanical process, so thermodynamic equilibrium will seldom be achieved. The materials treated according to such processes would be expected to freeze into complex intermediate morphologies, making the selection of the original state significant when aiming to achieve a given morphology of the polymerization precursor after the chemomechanical process is completed.

[0048] The solid materials described above are processed to yield an alkaline reactive precursor dry solid blend. Processing generally adjusts the number of reactive chemical sites in the material, creates new and unique combinations of materials at the microscopic level, and adjusts morphology, particle size distribution, and specific surface area of the material. Using such processes not only broadensthe available ingredients that can be used to make polysialates, but also allows the properties of the polymerization precursor, and the eventual polymer to be selectively controlled. For example, processing precursors to achieve a desired alkaline reactivity can result in a desired setting time, hardening time, and final hardness ( / .e. compressive strength) of a polysialate system. Processing to achieve a desired particle size distribution can result in a desired viscosity and / or density of a polymerization precursor mixture, and can also affect dissolution time of reactants in an alkaline solution. Combining different materials with aluminum-silicon-oxygen materials can broaden the processing windows available to achieve certain effects. Such practices can provide flexibility to adjust the need for additive materials such as viscosifiers and surfactants in the precursor mixture.

[0049] In one method, the solid materials to be used to make a polysialate system are processed in a chemomechanical activation tool, such as a grinder or mill, to reorder atoms in the materials and create alkaline reactive species, render the material in a particle size distribution suitable for target precursor and polymer properties, and render the material in a specific surface area distribution suitable for precursor and polymer properties. Planetary ball mills, rod mills, and the like can be used for such processing. For example, a source of aluminum, such as alumina, and a source of silicon, such as crystalline and / or amorphous silica, selected to achieve a target ratio of silicon to aluminum in a polymer precursor blend, can be provided to a ball mill and processed until a target particle size distribution and specific surface area profile is reached. A source of calcium, such as calcium oxide and / or calcium hydroxide, or even elemental calcium itself, can be added to provide a target calcium content. In another example, an aluminosilicate material deficient in one or more elements of interest can be added to a ball mill along with a second ingredient rich in the one or more elements of interest to achieve a target elemental composition. The material can be processed using the ball mill until a target morphology, particle size distribution, and specific surface area profile are reached.

[0050] Chemomechanical activation can be performed in a reactive environment to achieve a target activation of materials for polymerization. For example, a ball mill, as described above, can be operated under an oxygen-containing environment tofacilitate an oxygen reaction that adds oxygen to the materials being made alkaline reactive. The ball mill can also be operated under a pressure selected to facilitate removal of volatile species, or only certain volatile species depending on vapor pressure. In another embodiment, the materials to be subjected to activation processing and / or sizing can be wetted with water to form a mud or slurry prior to activation. The activation can bring the mixture to a reactive state that can produce hydroxyl groups to react with the metals and metalloid materials in the blend to enhance activation. In another embodiment, activation processing and sizing can be performed in a medium that minimizes impact on the materials being activated. For example, the materials to be activated can be wetted using a hydrocarbon fluid such as kerosene or mineral oil prior to activation processing.

[0051] Thus, in one case, an earth material, or mixture of earth materials, containing aluminum, oxygen, and silicon, and potentially including a recycled cementitious material, is disposed in a chemomechanical processor and processed to yield an alkaline reactive dry precursor mixture. Processing conditions are selected to achieve a desired alkali reactivity, particle size distribution, density or specific gravity, and specific surface area or surface area profile. The earth material, or mixture of earth materials, is selected to achieve a desired composition, for example a desired elemental composition. Any of the ingredients described above can be used to form the dry alkaline reactive precursor mixture. In some cases, it can be convenient to use locally sourced materials for mixing a polymerization precursor. Materials can be locally sourced and locally processed to make a polymerization precursor specifically tailored to a particular local use. Composition tuning materials, such as aluminum rich materials, silicon rich materials, calcium rich materials, and the like, can be used in small quantities to tailor the elemental profile of the precursor. Likewise, morphology and / or particle size tuning materials can also be used in small quantities to tailor the physical properties of the precursor. In some cases, tuning materials can tune multiple features, such as composition and morphology profile. Processing conditions can be used, along with such tuning materials, to achieve very specific precursor properties. One example of a tuning material is metakaolin, which can adsorb too much water if used in too large a quantity, but can provide tuning of elemental and physical properties in smaller quantities.

[0052] In some cases, the chemomechanical processing can be performed under, or within, a controlled atmosphere. Composition of the atmosphere can be controlled to add or remove atoms from the solids being processed. Temperature of the atmosphere can also be controlled to add or remove thermal energy from the solids being processed. Thus, for example, milling energy for a chemomechanical process can be selected to increase temperature of the solids to an intermediate temperature, not high enough to perform a desired chemical transformation of the solid material, and thermal energy can be added to the solid material by an atmosphere at a controlled, elevated temperature to complete the chemical transformation of the material. The thermal energy can be added using a burner or furnace to combust fuel. The combustion effluent can be directly used to add thermal energy, or the combustion effluent can be used to heat a gas or gas mixture to be provided to the chemomechanical process. Electric heating, and other suitable forms of heating, can also be used to heat a gas or gas mixture to be provided to the chemomechanical process. When the gas mixture is combustible, ignition of the gas can further enhance the chemomechanical treatment by accelerating the heating process, or increasing the temperature that can be reached by the precursor. In this way, a thermally controlled atmosphere can also be controlled to have a desired composition, as noted above, to achieve a target compositional transformation of the solids being processed. Such methods can improve thermal uniformity of processing the solids where thermal transport within the bulk of the solid material is insufficient to provide a desired uniformity of thermal processing. Where finely calibrated thermal processing of particles is desired to achieve certain structures within the particles, such methods can improve control over the thermal state of the particles being processed.

[0053] The resulting alkaline reactive precursor is then disposed in a high pH solution to form a polymerization precursor and activate a polysialation reaction. The polymerization precursor is then disposed at a target location and allowed to harden. In some cases, disposing the polymerization precursor at the target location involves pumping the polymerization precursor. In such cases, the polymerization precursor will be formulated to contain enough liquid to make the precursor pumpable. Polymerization precursors formulated using the disclosed alkaline reactiveprecursors are generally considered pumpable when the polymerization precursor produces a dial reading of less than 300 using a Couette viscometer equipped with an R1 B1 F1 rotor:bob:spring configuration at a 300 rpm rotation rate. By selecting processing conditions, for the solid raw materials, that achieve a desired alkaline reactivity, the dilution effect of making a polymerization precursor with enough liquid to be pumpable can be substantially offset by increasing reactivity of the solid precursors.

[0054] The chemomechanical process can be tailored to independently adjust particle size distribution of the dry alkaline reactive precursor mixture. For example, where more than one ingredient is to be processed, a first ingredient can be added to the chemomechanical processor at a first time and a second ingredient can be added to the processor at a second time different from the first time. Adding the ingredients at different times provides for different processing times of the ingredients, which can be used to render different particle sizes and structures. Await time between adding the first ingredient and adding the second ingredient can be selected to result in a desired particle size distribution. For example, a larger wait time allows the first ingredient to be further reduced in particle size before processing the second ingredient, so that particle sizes of the first and second ingredients are more divergent and particle size distribution of the resulting dry alkaline reactive precursor is broader.

[0055] Chemomechanical activation can also be performed using an extrusion process, which can be performed under reactive or non-reactive atmosphere and / or target pressure, as described above, and / or using liquid media to enhance processing in various ways. Extrusion can also be performed to liquefy, or partially liquefy, the solid materials of the precursor blend in order to adjust morphology, particle size distribution, and specific surface area profile. An extruder can be charged with a mixture of solids to be activated into an alkaline reactive material. The extruder can be operated to reduce the particle size of the solid to a target range. The extruder can be operated to liquefy the solids, at least partially. A solid material that is selected to liquefy in the extruder may be included with the solid material of the precursorblend. For example, a low-melting salt can be added to the blend to liquefy during the chemomechanical process.

[0056] In an extrusion process, a single extruder can be used to treat earth materials, or multiple extruders can be used, in series or parallel configuration, to make the earth materials alkaline reactive. In some cases, co-extrusion of two or more materials can be used to treat materials to make them alkaline reactive, where for example the treatment condition of one material is different from that of another material. Thus, a first material and a second material can be co-extruded at different extrusion conditions to produce a mixture, upon exiting the extruders. In general single screw extruders or twin extruders may be used to produce the alkaline reactive precursors.

[0057] Like milling, extrusion can be practiced using a controlled environment. Oxygen can be injected into the extruder barrel to add oxygen to the materials during extrusion. Other gases can also be injected to achieve other compositional effect. The extruder, or extruders, can be heated or cooled using external or internal contact with thermal fluids. For example, a jacket around the outside of the extrusion barrel can carry a thermal fluid to heat or cool the material within the extrusion barrel. Likewise, a conduit can be disposed along a central axis of the extrusion barrel to carry a thermal fluid for internally heating or cooling the material within the extrusion barrel. Heating and cooling, in this way, can be combined in stages where such heat history can be advantageous for targeting morphological, particle size, or surface area properties.

[0058] An extrusion process can be performed as a flash extrusion to activate materials in ways that are similar, in some respects, to flash calcination. Extrusion can heat and liquefy materials to be activated within the extruder. The materials can be blended with a material to be volatilized upon exiting the extruder. For example, the materials can be wetted with water before charging to the extruder. Additionally, or alternately, a low-melting salt can be used to liquefy during the extrusion and to flash upon exiting the extruder. Extrusion of the wet solids can produce steam within the extruder as the solids are liquefied. Upon being forced through a small die, the steam can flash and atomize the liquefied solid, which quickly freezes into particleshaving very small particle size and high specific surface area. Likewise, extrusion using a low-melting salt, or other suitable low-melting material, can produce a liquid that, upon being forced through a small die, will flash freeze into particles having very small particle size and high specific surface area. Such a process can be performed for all or part of a material to be activated for polymerization. For example, where the particle size distribution needs smaller particles, and the surface area profile needs increased specific surface area, a predetermined portion of the polymer precursor material can be subjected to flash extrusion, as described above, so that when the flashed material is blended with material activated by other means, the particle size distribution and surface area profile of the blend achieve a target.

[0059] An extrusion process can also be staged to achieve a desired particle size distribution and / or morphology distribution and / or surface area profile. For example, using one extruder, a first ingredient can be charged to the extruder at a first axial location and a second ingredient can be charged to the extruder at a second axial location. One or both of the first ingredient and the second ingredient can be wet, for example with water or hydrocarbon, or dry. The first and second axial locations can be selected to provide extruder residence times for the two ingredients that result in processing the ingredients to yield desired particle size, morphology, and surface area profiles of the mixture exiting the extruder. A similar staged extrusion process can be performed using a plurality of extruders in series configuration, where a first ingredient is charged to a first extruder, which produces an intermediate material that is charged to a second extruder, and a second ingredient can be charged to the second extruder along with the intermediate material. In this way, the first ingredient is subject to processing in two extruders while the second ingredient is subject to processing in only one extruder. Other staged configurations of extrusion, or other chemomechanical processing, can be used, and extrusion can be mixed with milling and grinding in a chemomechanical process.

[0060] In general, harder and more crystalline materials may need more chemomechanical processing to achieve desired reactivity, particle size distribution, morphology, and specific surface area than less crystalline and amorphous materials. Hardness of materials can be ascertained as Shore hardness. Crystallinity can beascertained using crystallinity analyses such as x-ray diffraction and x-ray crystallography. Such analyses can be used to prescribe chemomechanical processing time and conditions for a desired outcome. Thus, in a staged chemomechanical process, a first ingredient having a first crystallinity and / or hardness is processed in a first stage and in a second stage, and a second ingredient having a second crystallinity and / or hardness is processed in the second stage, where the second crystallinity and / or hardness is less than the first crystallinity and / or hardness. In some cases, the second ingredient may be amorphous or substantially amorphous.

[0061] In some cases such harder and more crystalline materials such as crystalline silica, crystalline alumina, mullite, hematite, ilmenite, barite, celestine, gypsum, and the like can be added to the chemomechanical process with the ultimate goal of having a certain fraction of such solids, at the selected particle size, or at a particle size resulting from the chemomechanical process, remain substantially as crystalline components of the alkaline reactive precursor. Such crystalline components can become domains within larger particles in some processes. In other processes, such components can remain discrete particles within the mixture. Such particles and amalgamations can have different properties in a polymerization precursor and in the hardened polysialate system.

[0062] Additives can also be added to the chemomechanical process. In general, additives that are used in alkaline reactive precursor blends include accelerators, retarders, density modifiers, anti-foam agents, defoamers, silica, fluid-loss control additives, viscosifiers, dispersants, expanding agents, anti-settling additives and combinations thereof. These additives are generally unreactive in polysialation reactions, but can affect the progress of such reactions. Depending on sensitivity of the additive to chemomechanical processing, and any advantageous effects from subjecting the additive to chemomechanical processing, the additive may be added early in processing, at the very end of processing just to mix the additive with the precursor mixture, or at any time between. Some of these additives have mechanical strength sufficient to undergo at least some sizing processes described herein, along with alkaline reactive materials. Other additives with low decomposition temperaturesand / or thermoplastic properties can be added to the dry polysialate precursor after sizing, or can be added to the pumpable polysialate precursor after addition of water. More than one of the additives mentioned above can be included in a polysialate precursor. Thus, a polysialate precursor can contain additives and other materials that are unreactive in polysialation reactions or that affect the progress of such reactions. Solid materials that are additives can also be sized to have a particle size distribution that helps achieve target particle size distribution in a precursor blend.

[0063] A chemomechanical activation process can be performed in stages. For example, a first material can be subjected to a first chemomechanical activation operation. After the first chemomechanical operation is discontinued, a second chemomechanical operation can be performed on the first material. The second chemomechanical operation can be the same as the first chemomechanical operation, can be different by adjusting the conditions of the process, or the second chemomechanical operation can be a different type of operation from the first chemomechanical operation. A second material can be added between the first chemomechanical operation and the second chemomechanical operation. For example, the first material can be a clay material, which can be subjected to a first type of chemomechanical operation, and then the second material can be a calcium containing material, such as a limestone material, can be added and a second chemomechanical operation performed on the mixture. In such cases, the clay material and the limestone material can be expected to provide different morphology, particle size distribution, and specific surface area profile following the stage chemomechanical operation, along with different elemental compositions, to achieve target precursor and set polymer properties.

[0064] As noted above, the activator materials that result in a high pH solution when water is added can be added to the precursor mixture during chemomechanical processing. The activators used herein can include an alkali metal or alkaline earth metal hydroxide, such as NaOH, KOH, Ca(OH)2, Sr(OH)2, Mg(OH)2 and / or Ba(OH)2; or alkaline earth metal oxide, such as CaO, SrO, MgO and / or BaO or a combination thereof, or alkaline earth metal peroxide, such as MgO2 and CaO2 or a combination thereof; or an alkali metal salt such as a metal carbonate M2CO3, metal sulphateM2SO4, metal sulphite M2SO3, metal phosphate M3PO4, metal oxalate M2C2O4, metal silicate M2xSiyO2y+x where x is 1 , 2, or 3 and y is 1 or 2 (for example silicates, metasilicates, orthosilicates, and pyrosilicates), metal fluoride MF, metal hexafluorosilicate M2SiFe, metal iodate MIO3, metal molybdate M2MOO4, where M can be Li, Na, K, Rb, or Cs, where such salts can have a combination of different metals and a combination of different anions. Lime and hydrated lime are examples of materials that contain calcium oxide and / or calcium hydroxide. Hydrogenated metal salts, such as MHCO3, MHSO4, MHPO4, MHC2O4, M2HPO4, MH2PO4, and MHSO3 can also be used, alone or in combination with other activators described herein, where M is alkali metal as listed above. These activators raise pH in a precursor upon addition of water such that the alkaline reactive species in the precursor composition dissolve and begin to polymerize. Any of these solid activators can be added to the solid precursor mixture at a suitable time before, during, or after chemomechanical processing, or any combination thereof. Conventional cement materials can also be used as activators, as noted above.

[0065] The solid activators described above are typically added in a quantity that is 2 to 40 parts per hundred based on the weight of the dry precursor particulate blend, for example 4 to 20 parts per hundred or 4 to 40 parts per hundred based on the weight of the total dry precursor particulate blend. The solid activator content of the precursor composition is selected to provide enough pump time, after water is added to form an alkaline solution, for deploying the precursor composition to a target location while also achieving acceptable compressive strength after passage of a requisite time period such as 24 hours.

[0066] The activators described herein can be added as a dry material to a dry polysialate precursor, which can contain recycled cementitious materials. Alternately, or additionally, the activators can be provided in water or alkaline solution and / or dispersion that is mixed with the dry polysialate precursor to form a pumpable polysialate precursor composition. Where the activators are used as dry materials, the activators are typically used in a quantity that is 2 to 40 parts per hundred based on the weight of the dry polysialate precursor, for example 4 to 20 parts per hundred or 4 to 40 parts per hundred based on the weight of the dry polysialate precursor toresult in a suitable thickening time, for example time to achieve 70 Bearden consistency units of at least about 2 hours.

[0067] Retarders and accelerators can be used to influence thickening time of polysialate precursors made according to the descriptions herein. Retarders such as sodium pentaborate decahydrate, borax, sucrose, boric acid, lignosulphonates, sodium glucoheptonate, tartaric acid, citric acid, or phosphorus containing compounds such as phosphoric acid, salts thereof, or mixtures thereof can be added to an alkaline reactive precursor particulate mixture in amounts of 0.01 to 5 part per hundred by weight of the total particulate precursor mixture. The retarders above can be added before, during, or after chemomechanical processing, or any combination thereof. The amount of retardation of the polymerization reaction, and the setting of the precursor, depends on the type of raw materials used for the precursor and the type and relative quantity of retarder used. Adding too much retarder reagent to an alkaline reactive precursor can cause the precursor to remain unhardened by interfering with the polymerization reaction so the precursor does not set.

[0068] Accelerators can also be added to an alkaline reactive precursor particulate mixture in amounts up to about 0.01 -10, such as 1-5, parts per hundred weight of the total particulate precursor mixture. The amount of acceleration of the polymerization reaction, and the setting of the precursor, depends on the type of raw materials used for the precursor and the type and relative quantity of accelerating reagent used. Adding too much accelerator to a polymerization precursor can cause the precursor to thicken too quickly making it difficult to deploy the precursor to target locations. Accelerators can be added before, during, or after chemomechanical processing.

[0069] In some cases, alkali metal salts can be used as accelerators in alkaline reactive precursor blends. Materials such a sodium chloride and lithium chloride can act as accelerators in some cases. Where such materials are to be used as accelerators, these materials can also be added to the precursors during chemomechanical processing, for example by extrusion, to form a liquidus during the extrusion process. As described above, such processes can be used to flash the precursor mixture, upon exiting an extruder, to provide very small particles with veryhigh specific surface area. If particle size distribution and specific surface area of such materials fall outside a desired range, other additives can be added at particle sizes and specific surface areas to broaden the range and profile of the mixture.

[0070] Alkaline reactive precursors for use in well lining applications typically are mixed into a slurry that has a slurry density range from 0.84 g / cm3(7 Ibm / gal) to 2.87 g / cm3(24 Ibm / gal), such as 1 .32 g / cm3(11 Ibm / gal) to 2.4 g / cm3(20 Ibm / gal) or 1 .32 g / cm3(11 Ibm / gal) to 2.16 g / cm3(18 Ibm / gal), for example 1 .36 g / cm3(11 .3 Ibm / gal) to 1 .90 g / cm3(15.8 Ibm / gal). The slurry density can be influenced by quantity of water added and / or by adding density modifiers. Slurry density is the bulk density of the pumpable polysialate precursor formed by adding water to a dry polysialate precursor. Slurry density is generally influenced by the amount of liquid added to the dry polysialate precursor, but can be modified using the density modifiers herein. Water typically makes up from about 20% by weight to about 60% by weight of an alkaline reactive precursor. Density modifiers can include density increasing particles and density lowering particles. Low-density particles may be added to the dry precursor particulate mixture to achieve lower slurry densities for a given amount of water added, or heavy particles may be added to achieve higher slurry densities. The lightweight or low-density particles may have densities lower than 2 g / cm3, or lower than 1.3 g / cm3. Examples include hollow glass or ceramic microspheres (cenospheres), plastic particles such as polypropylene beads, rubber particles, uintaite (sold as GILSONITE™), vitrified shale, petroleum coke or coal or combinations thereof. The lightweight particles may be present in the compositions at concentrations between about 0.05 kg / L and 0.6 kg / L (20 Ib / bbl and 200 Ib / bbl). The particle size range of the low-density particles may be between about 38 .m and 3350 j m (6 mesh and 400 mesh). The heavy particles typically may have densities exceeding 2 g / cm3, more than 3 g / cm3, or more than 4 g / cm3, and up to 5 g / cm3. Examples include hematite, barite, ilmenite, silica (e.g. crystalline silica sand), crushed granite, limestone, dolostone, calcite, marble, and also manganese tetroxide commercially available under the trade names of Micro Max™ and MicroMax FF™. Many of these density additives, particularly those in particulate form, can be added at any suitable time before, during, or after chemomechanical processing, or anycombination thereof.

[0071] Density modifiers such as hollow glass or ceramic microspheres and plastic or rubber particles which may be excessively sensitive to chemomechanical processing conditions in some cases, can be added after chemomechanical processing. Where such modifiers are at least relatively insensitive to the processing conditions, they may be added at a suitable time before or during the processing, or any combination thereof.

[0072] The fluid-loss control agent may comprise a latex. The latex may be an alkali-swellable latex. The latex may be present in the compositions at a concentration between 0.02 L / L and 0.3 L / L or between 0.05 L / L and 0.15 L / L. The latex material may be added at a suitable time before, during, or after chemomechanical processing, or any combination thereof. The latex may be added as a solid material to the dry polysialate precursor, and / or the latex may be dispersed or dissolved in the water or alkaline solution added to the dry polysialate precursor to make a pumpable polysialate precursor. The latex polymer can be, for example, a rubber material such as styrene-butadiene rubber, natural rubber, nitrile rubber, neoprene rubber, and other vinyl polymers. Other fluid-loss control additives, such as carboxymethyl cellulose, polyanionic cellulose, and / or other water soluble or water dispersible polymers can also be used.

[0073] Viscosifiers may comprise diutan gum having a molecular weight higher than about 1 x 106. The diutan gum may be present at a concentration between 0.14 g / L and 1 .4 g / L (0.05 Ibm / bbl and 0.5 Ibm / bbl). In some cases, viscosifiers are present in the dry alkaline reactive precursor at a concentration of 0.04-5% by weight of the total dry precursor. Other viscosifiers may comprise a polysaccharide material, which may be a biopolymer. Suitable polysaccharide biopolymers can include welan gum, xanthan gum, a polyanionic cellulose (PAC), a carboxymethylcellulose (CMC), and combinations thereof. One or more polysaccharide materials, which may be biopolymers, may be present at a concentration between 0.14 g / L and 1.4 g / L (0.05 Ibm / bbl and 0.5 Ibm / bbl). The molecular weight of the polysaccharide material, which may be a biopolymer, may be between 100,000 and 1 ,000,000. Such materials may be added at a suitable time before, during, or after chemomechanical processing, orany combination thereof, where the processing conditions will not interfere with the function of the viscosifiers, for example by decomposing the viscosifiers. Addition time of such viscosifiers can be selected to avoid any modification of the viscosifier by the chemomechanical processing conditions. Alternately, or additionally, addition time of the viscosifiers, or a portion thereof, can be selected to achieve specific modifications and / or reactions of the viscosifiers.

[0074] Carboxylic acids including gluconic acid and soluble salts thereof, glucoheptonic acid and soluble salts thereof, tartaric acid and soluble salts thereof, citric acid and soluble salts thereof, glycolic acid and soluble salts thereof, lactic acid and soluble salts thereof, formic acid and soluble salts thereof, acetic acid and soluble salts thereof, proprionic acid and soluble salts thereof, oxalic acid and soluble salts thereof, malonic acid and soluble salts thereof, succinic acid and soluble salts thereof, adipic acid and soluble salts thereof, malic acid and soluble salts thereof, nicotinic acid and soluble salts thereof, benzoic acid and soluble salts thereof, and ethylenediamine tetraacetic acid (EDTA) and soluble salts thereof may be included in the compositions as retarders or dispersants or both. Phosphoric acids may be present for the same purpose. Salts of these acids may also be employed. These materials may be present in the compositions at concentrations between 0.5 g / L and 10 g / L, or between 1 g / L and 5 g / L. These materials can be added at a suitable time before, during, or after chemomechanical processing, or any combination thereof, and may be added at a time selected to avoid any alteration of the additives or to achieve specific modifications and / or reactions of the additives.

[0075] Expanding agents may comprise calcium sulphate hemihydrate, metal oxides such as MgO or combinations thereof. The expanding agents may be present in the compositions at concentrations between 0.01 kg / L and 0.2 kg / L of the polymerization precursor, or between 0.05 and 0.1 kg / L. These materials can be added at a suitable time before, during, or after chemomechanical processing, or any combination thereof. These materials can be subjected to sizing operations to contribute to the polydispersity of the particle size distribution of the dry polysialate precursor. These materials can be added to the dry polysialate precursor, or to the water and / or alkaline solution used to mix with the dry polysialate precursor, or both.

[0076] Anti-foaming agents and defoamers can be glycol materials such as propylene glycol and polyethylene glycol. Dispersants such as polynaphthalene sulfonate, acetone formaldehyde sulfonate, melamine formaldehyde sulfonate, and polycarboxylates are commonly used and can be used in the compositions herein.

[0077] Particle sizes between about 0.1 pm and about 100 pm, such as between about 1 pm and about 40 pm, are generally preferred in alkaline reactive precursor mixtures. Specific surface area of particles in such precursor mixtures are generally preferred in a range of about 0.5 m2 / g to about 10 m2 / g. When particle size distribution of an alkaline reactive precursor mixture is too large, and specific surface area too low, the precursor material might be insufficiently reactive. When particle size distribution is too narrow, and specific surface area too high, the precursor material may be difficult to blend into a pumpable precursor. Specific surface area that is too high can also cause alkaline reactive precursors to begin gelling too early.

[0078] A chemomechanical process to form alkaline reactive materials may be controlled by monitoring the physical state and chemical reactivity of the polymerization precursor materials. Physical state of the precursor materials can be monitored using x-ray crystallographic and similar X-ray diffractive methods along with particle size analyses such as mesh tests. Distribution of reactive species can be monitored using micrographic methods such as optical microscopy, scanning electron microscopy and elemental analysis via x-ray techniques such as energy dispersive x-ray spectroscopes. Other spectrographic methods, such as FTIR and mass spectroscopy can also be used to ascertain elemental analysis and distribution of reactive species in the precursor before, during, or after chemomechanical treatment, or any combination thereof. An alkaline reactive precursor that has undergone treatment using chemomechanical processing can be analyzed for alkaline reactivity using wet chemical methods such as Frattini test, lime consumption, acid base titrations, time of set in standardized formulations and test conditions, or set material compressive strength in standardized formulations and test conditions, and the like. Such methods can be used to adjust chemomechanical processes for rendering precursor materials alkaline reactive.

[0079] In one aspect density control solids can be chemomechanically coprocessed with aluminum-silicon-oxygen materials to form an alkaline reactive precursor for forming a polysialate system. Oxide particles and / or sulfate particles, such as any of the density modification materials described herein, can be added to a solids mixture to form a premix that can be treated to achieve thermal transformation of the aluminum-, silicon-, and oxygen-containing materials in the premix into an alkaline reactive precursor. The type and quantity of such particles to be added can be determined by the target slurry density to be achieved in the precursor. Performing chemomechanical processing on a premix of reactants and density control solids achieves intimate mixture of the materials that forms a superhomogeneous alkaline reactive precursor with all particles having a similar density and morphology such that heavier particles are slow to separate. In some cases, heavier particles that merely have particle size distribution generally similar to that of lighter particles in the mixture can improve stability of the mixture. In other cases, the heavier particles can be amalgamated in part with lighter particles and materials to form substantially inseparable particles of more and less dense material, providing maximum homogeneity and mix stability. Such methods minimize the potential size of non-reactive domains in the polymerization precursor and allows for minimal solid volume fraction to achieve a desired slurry density or an polysialate or polysialate system with desired properties. Testing methods such as those detailed in API RP 10B-2 for slurry stability including free fluid and static sedimentation, as well as other proprietary tests related to solid blend stability are commonly used to determine the relative stability of a slurry, and by induction, the potential for gravity segregation of solids. Where all particles of superhomogeneous precursors have similar density or specific gravity such as per this disclosure, slurry stability is improved, compared to alternative slurries where particles of different types of solids of different specific gravities are used. Other measurements such as powder rheology can also be performed to demonstrate enhanced stability of the disclosed superhomogenous precursors compared to using mixtures of particles of different types of solids of different specific gravities.

[0080] Solid materials such as FesO4 (known as iron (II, III) oxide), FeSO4 (ferrous sulfate or iron(ll) sulfate), strontium sulfate, and barium sulfate can beadvantageously used as density control solids in a chemomechanically processed, homogenized alkaline reactive material. These materials can be used with materials, and mixtures of materials, containing aluminum, silicon, and oxygen such as natural pozzolans and silicates, for example hectorites, smectites, and kaolinites, cements and byproducts thereof, aluminosilicate glasses, and waste materials such as blast furnace slags and fly ashes. Crystalline silica, and crystalline alumina may be used. The aluminosilicate materials are mixed with the density control materials to make a premix, but depending on desired particle size change, process characteristics, and processing needed to achieve a desired morphology in the aluminosilicate structure, the materials may be added sequentially to the chemomechanical process to provide different processing times and chemomechanical histories for different materials. For example, harder materials such as barium sulfate can be processed for a time that is longer than softer materials in order to reduce particle size of the harder materials to a target particle size for the precursor mixture. Likewise, harder materials can be processed using more severe processing conditions, and then processing conditions can be moderated when softer materials are added to the pre-processed harder materials. Thus, a density control material such as iron(ll) oxide can be pre- processed for a pre-processing time, or at pre-processing conditions, to reduce particle size of the density control material, and then aluminum-silicon-oxygen materials can be added and processing conditions optionally changed to achieve a mixture having desired particle size distribution and aluminosilicate morphology.

[0081] It is generally desired, using the processes described herein, to control ( / .e. enhance or moderate) precursor reactivity to achieve an aluminosilicate mixture that has a low degree of crystallinity (at least in the fraction that is intended to react quickly). Lower crystallinity aluminosilicate materials are generally more reactive in alkaline environments. Reactivity of a specific mixture depends on alkalinity of the environment, as well as composition, crystallinity, and particle size of the aluminosilicate material. Smaller particle sizes and more amorphous materials are generally more susceptible to hydration and are therefore more reactive, but higher pH environments can hydrate even moderately crystalline materials, especially if particle size is low.

[0082] Recycled cementitious materials may have different reactivity, and different aluminum, silicon, calcium, and oxygen containing reactants also have different reactivity depending on composition, particle size, and crystallinity. It is believed that the reactivity of the recycled cementitious material depends, at least, on the alkalinity of the recycled material, so many cements having high alkalinity may be more reactive as recycled raw materials than most polysialate materials. Reactivity of the recycled cementitious materials results in pH of the polysialate precursor mixture, and to the extent that the recycled cementitious material results in a pH that is too low, additional activators can be added as needed. It is notable that more reactive (amorphous, small particle size) polysialate raw materials, such as GGBS, may be usable with recycled cementitious materials, as activator, that give rise to lower pH, such as 9-10. Such raw materials may be able to polymerize to suitable degree using some recycled polysialate materials. Less reactive raw materials may need more reactive recycled materials, such as high-calcium cements, potentially mixed with other activators.

[0083] Types of recycled cements that can be used as activator and / or reactant in a polysialate precursor include cements made according to American Petroleum Institute standards (“API cements”) and cements made according to other standards (“non-API cements”). Previously hardened Portland cement can be used as a recycled cementitious material for the methods herein. Class G cement can also be used as a recycled cementitious material for the methods herein. Types of recycled polysialate systems that can be used include those made using aluminosilicates such as GGBS, fly ash, and metakaolin. In general, recycled cementitious materials having high lime or Portlandite content are useful. In some cases, recycled cementitious materials may also have unreacted activators that can be useful. The polysialate system materials used as recycled cementitious materials are polymeric materials containing one or more polymers of aluminum, silicon, and oxygen, i.e. polysialates. The recycled cement materials are mainly calcium silicate polymers. Recycled cementitious materials have different inherent alkalinity, and so will contribute different alkalinity to a polysialate precursor. For example, some recycled cementitious materials have calcium oxide, calcium hydroxide, and / or activators that were unreacted when the cementitious material was first hardened. Such materialsmay have useful calcium oxide content for subsequent use as a polysialate raw material. These recycled cementitious materials can also be mixed, for example to target a desired reactivity or solution pH. These recycled cementitious materials can also be used to provide particle size polydispersity where other raw materials used in a polysialate precursor lack sufficient polydispersity to provide a pumpable mixture when dispersed in water to a target slurry density. A separate chemomechanical treatment of the recycled cementitious materials can also be performed. The recycled cementitious materials described can also be mixed with aluminosilicate precursors prior to subjecting the mixture to chemomechanical processing. A combination of any of the recycled cementitious materials described above can also be used.

[0084] Polysialate raw materials that can be used with recycled cementitious materials in a polysialate precursor include (but are not limited to) ASTM Class C fly ash, ASTM Class F fly ash, fly ash not classified by ASTM, volcanic ash, volcanic glass, slag, ferrous slag, ferroalloy slag, non ferrous slag, such as copper slag, nickel slag, tin slag, zinc slag, and the like, blast furnace slag, basic oxygen furnace slag, electric arc furnace slag, and ground slags, such as ground blastfurnace slag, ground granulated blast furnace slag (GGBS), diatomaceous earths, pumice, and calcined clays, which may be partially or fully calcined clays (metakaolin is a partially calcined clay), aluminum-containing silica fume, natural aluminosilicate, feldspars, which may be dehydrated, alumina and silica sols, synthetic aluminosilicate glass powder, zeolite, scoria, allophone, bentonite, pumice, red mud, which may be calcined. These materials are mostly aluminum, silicon, and oxygen containing materials that may be, or may include, aluminosilicate materials. Other materials that can be used are ashes produced by combustion of some forest or agricultural industry by-products commonly known as biomass ash, or more specifically biomass fly ash, from various sources such as witchgrass ash, walnut shell ash, rice husk ash, and the like. The more commonly used aluminosilicate materials are fly ash, metakaolin and blast furnace slag. In addition, alumina and silica may be added separately, for example as a blend of bauxite and silica fume. Thus, an alumina-silica mixture can be used with recycled cementitious materials to make a polysialate system. Silica materials such as soda-lime glass dust, borosilicate glass dust, microsilica, fumed silica,precipitated silica, nanosilica, or a combination thereof, can be used with alumina sources and with aluminosilicate sources.

[0085] It should be noted that some of the aluminosilicate sources mentioned above, such as GGBS and ASTM Class C fly ash, also contain calcium oxide, so these materials can also be considered activator sources. Suitable aluminosilicate sources for purposes here can have at least 2%, at least 7%, at least 12%, at least 18%, or at least 25% by weight calcium oxide. These aluminosilicate sources become reactive when placed in strongly alkaline environments with recycled cementitious materials, typically at pH greater than 11. The aluminosilicate sources described above react with recycled cementitious materials under such conditions to form polysialate systems. As noted above, in some cases the recycled cementitious material can have compounds such as calcium oxide and calcium hydroxide, along with previously unreacted activators, that raise pH of the water mixture. Binder components such as Portland cement, kaolin, GGBS, fly ash, bauxite, aluminum oxide, and aluminum hydroxide can also be included.

[0086] The processing methods herein can blend aluminum-silicon-oxygen materials, potentially along with density control materials, and can transform chemically diverse mixtures of aluminum, silicon and oxygen into materials that are substantially aluminosilicate in chemical structure and partially, substantially, or completely amorphous in morphology. To make such transformation, the processing methods herein increase temperature of the aluminum, silicon, and oxygen in the mixture to activate atomic rearrangements of the materials. In some cases, the processing may soften and / or melt the aluminum, silicon, and oxygen materials in the mixture. The processing conditions may also soften and / or melt some of the density control materials listed above. Softening and melting the materials facilitates atomic and morphological changes that increase alkaline reactivity of aluminosilicate materials. The processing conditions herein also reduce angularity or particles in the mixture and reduce particle size variation in the mixture.

[0087] The chemomechanical process, or processes, used to treat the premix of aluminosilicate material and density control material can be configured to create some particles that are combinations of alkaline reactive aluminosilicate material withdensity control particles. The processing conditions may be selected to melt, partially melt, or soften some materials in the mixture and not others. For example, where barium sulfate is used as a density control material in a mixture of aluminum-, silicon- , and oxygen-containing materials, the processing conditions may be selected to increase a temperature within the mixture to a value that results in softening or melting of the materials containing aluminum, silicon, and oxygen while the barium sulfate, having much higher melting point, does not soften. The barium sulfate may be ground in the milling action to reduce its particle size without melting, while the materials containing aluminum, silicon and oxygen soften and / or melt, flow or agglomerate together, and form aluminosilicate particles having low crystallinity. Depending on processing time of the various materials, a very narrow particle size distribution can be achieved using materials of different hardness and melting points, resulting in a highly stable, superhomogeneous mixture that has very small non- reactive domains. Whilst increasing the specific gravity of the polymerization precursor is often desirable, and most examples described herein rely on density control materials, at least to some extent, that have higher specific gravity than the reactive aluminosilicates in the precursors, it is possible to use density control materials that have lower specific gravity than the reactants. Such materials can include pumice, organic polymers, carbon black, graphite, coke, coal, asphalt, wax, natural resins, gilsonite, uintaite, glass beads, cenospheres, and the like. Polymerization precursors having specific gravities ranging between 1 ,400 Kg / m3and 2,400 Kg / m3can be obtained by chemomechanically combining reactive low crystallinity aluminosilicate precursor raw materials with low specific gravity density control materials such as those described above. Multiple density control materials having high and low specific gravity can be used. For example, a plurality of density control materials having higher specific gravity than the aluminosilicate reactants can be used in one polymerization precursor. Likewise, a plurality of density control materials having lower specific gravity than the aluminosilicate reactants can be used in one polymerization precursor. Likewise, a plurality of density control materials having higher and lower specific gravity than the aluminosilicate reactants can be used in one polymerization precursor.

[0088] Using such methods, an alkaline reactive solid mixture can be created that is up to 60% or up to 70% or up to 80% or up to 90% by weight non-reactive solids, but which will, nonetheless, react in alkaline conditions to form a hard polysialate. Thus, the alkaline reactive solid mixture, a precursor for polymerization, can be at least 50% by weight, or 75% by weight, non-reactive material. Generally, using exclusively high specific gravity density control materials in combination with aluminosilicate raw materials, the processes described herein can be used to form an alkaline reactive solid mixture that has up to 90% non-reactive solids, with precise targeting of mixture bulk density from 2,200 kg / m3to 3,500 kg / m3and particle size distribution such that D50 is between 5 pm and 50 pm and D90 is between 10 pm and 400 pm, where water, or an aqueous mixture can be added together with other solids and additives to create a polymerization precursor mixture with viscosity from 100 cP to 400 cP and slurry density from 1 ,200 kg / m3to 2,500 kg / m3. Generally, using exclusively low specific gravity density control materials in combination with aluminosilicate raw materials the processes described herein can be used to form an alkaline reactive solid mixture that has up to 90% non-reactive solids, with precise targeting of mixture bulk density from 1 ,400 kg / m3to 2,400 kg / m3and particle size distribution such that D50 is between 5 pm and 50 pm and D90 is between 10 pm and 400 pm, where water, or an aqueous mixture can be added to create a polymerization precursor mixture with viscosity from 100 cP to 400 cP and slurry density from 0,800 kg / m3to 1 ,400 kg / m3. Generally, using combinations of density control materials selecting these from low specific gravity density control materials and high specific gravity density control materials in combination with aluminosilicate raw materials the processes described herein can be used to form an alkaline reactive solid mixture that has up to 90% non-reactive solids, with precise targeting of mixture bulk density from 1 ,400 kg / m3to 3,500 kg / m3and particle size distribution such that D50 is between 5 pm and 50 pm and D90 is between 10 pm and 400 pm, where water, or an aqueous mixture can be added to create a polymerization precursor mixture with viscosity from 100 cP to 400 cP and slurry density from 0,800 kg / m3to 2,500 kg / m3. Limiting the breadth of particle size distribution by coprocessing aluminosilicate and density control materials, for example such that D90- D50 (the subtractive difference between D90 and D50) is less than about 50 pm, forexample less than 20 pm, reduces the tendency for the dense particles to settle and separate within the mixture, improving mixture stability and homogeneity. As described above, amalgamating more dense particles with less dense particles can further increase stability and homogeneity. Superhomogeneous alkaline reactive mixtures lead to polysialates with very consistent properties. By varying the type and amount of density control material and the processing conditions, substantially independent control of all such properties is achievable in a polymerization precursor, which can be nonetheless pumpable, enabling excellent control of compressive strength and density of the hardened polymer over very broad ranges. In other cases having particles with a very broad particle size distribution can be advantageous with respect to gelation and viscosity reduction.

[0089] In a process that mixes a relatively hard density control material, such as barium sulfate or strontium sulfate, with an aluminosilicate material or mixture, a preprocessing operation that may include grinding can be performed in which the density control material is subjected to chemomechanical processing that softens, partially melts, or fully melts the density control material in the absence of aluminosilicate material. The chemomechanical pre-process can deliver mechanical, electrical, and / or thermal energy sufficient to soften and / or melt the density control material to achieve a desired structure and morphology of the density control material, mainly particle size and angularity. Upon conclusion of the pre-process, aluminosilicate material can be added and processing conditions altered to provide suitable processing of the mixture to achieve an aggregate condition of the mixture. Thus, the pre-process may increase a temperature of the density control material to a temperature near 1 ,700°C to melt and / or soften a density control material such as barium sulfate, and thereafter processing conditions can be moderated, after adding aluminosilicate materials, to raise the temperature of the aluminosilicate materials to 1 ,000°C, or another temperature suited to softening and / or melting the aluminosilicate materials. The aluminosilicate materials can be mixed with the hot density control materials to provide energy for increasing the temperature of the aluminosilicate materials so that less energy is needed to complete treatment of the aluminosilicate materials to make them alkaline reactive. In one example of such a process, density control material can be pre-processed using mechanical energy,with thermal energy added using a heat source to raise the temperature of the density control material to a first target temperature selected to soften or melt the density control material, at least in part. The density control material can be processed for a processing time at the target temperature, where the processing time is selected to provide a desired residence time at the target temperature for reconfiguring the structure of the density control material. At the conclusion of the pre-processing, the addition of thermal energy can be reduced or discontinued, and the aluminosilicate material added to the pre-processed density control material to form a mixture. The mixture can be processed using less energetic conditions, for example with no added thermal energy, to complete treatment of the mixture and yield an alkaline reactive, superhomogeneous mixture that has a target density.

[0090] The processes described herein can achieve alkaline reactive materials having diverse particle structures. Figs. 1-20 are schematic cross-sectional views depicting various embodiments of alkaline reactive precursors that can be prepared using processes described herein. The figures schematically represent arrangements and morphologies of particles as if in vertical cross-section, where in Fig. 1 , two particles are shown, a large amorphous aluminosilicate particle 101 and a small crystalline density control particle 102, as can be achieved by simple admixing of two materials. The materials in Fig. 1 may be materials that were processed according to methods herein to give specific particle sizes, and particle size distribution, for a target mixture stability. Fig. 2 shows a small amorphous aluminosilicate particle 201 in admixture with a large crystalline density control particle 202. Fig. 3 shows a medium-sized amorphous aluminosilicate particle 301 admixed with a medium-sized crystalline density control particle. The mixtures of Figs. 1-3 could be achieved by at least partially co-processing of the crystalline and amorphous materials using a process configured to achieve the depicted particle sizes, where such processes do not create conditions conducive to combining or amalgamating particles.

[0091] Figs. 4-6 show particles that can be made by a chemomechanical process that can combine particles having different characteristics. For example, a process that melts aluminosilicate materials and does not melt density control materials can yield particles that are a combination of a density control material and an alkalinereactive aluminosilicate material. Such particles may have the structure of core-shell particles that have a dense core material surrounded, or partially surrounded, by a less dense alkaline reactive aluminosilicate material. Fig. 4 shows a particle structure having a large amorphous aluminosilicate shell 401 surrounding a small crystalline density control core 402. Fig. 5 shows a particle having a small, or thin, amorphous aluminosilicate shell 501 surrounding a large crystalline density control core 502. Fig. 6 shows a large amorphous aluminosilicate shell 601 partially surrounding a crystalline density control particle 602. The particle of Fig. 6 is an amalgamation of amorphous aluminosilicate material with crystalline density control material that results in a Janus particle having surface domains with different density and crystallinity characteristics.

[0092] The particles illustrated in Figs. 4-6 can be made by co-processing aluminosilicate materials with higher-melting density control materials using processing conditions that melt, or partially melt, the aluminosilicate materials to combine the materials into the combination particles shown in the figures. The materials can be subjected to different processing times to achieve the different particle sizes shown. If the structures of Figs. 4 and 5 are desired, where aluminosilicate material completely or mostly surrounds the density control particle, processing conditions can be selected to melt the aluminosilicate material into a liquidus state that can flow around the density control particles to create a shell. Generally higher temperatures and more severe processing conditions can achieve such effects. Where the Janus particle structure of Fig. 6 is desired, melting or softening the aluminosilicate material to a malleable or deformable state that does not flow as much can join the particles as shown in Fig. 6.

[0093] In some cases, multiple particles can be attached, adhered, and / or amalgamated in complex structures. Fig. 7 shows a plurality of small crystalline density control cores 702 dispersed within an amorphous aluminosilicate body 701. Fig. 8 shows an amorphous aluminosilicate body 801 attached or amalgamated to, and partially surrounding, two crystalline density control lobes 802. Fig. 9 shows an amorphous aluminosilicate body 901 completely surrounding a plurality of small crystalline density control particles 902 that are dispersed throughout thealuminosilicate body 901. Here, the dispersion depicted is substantially uniform, but the crystalline particles can be non-uniform ly dispersed within the aluminosilicate body in other cases. The particles shown in Figs. 7 and 9 have uniform amorphous aluminosilicate surfaces with heterogeneous interiors. The structures shown in Figs. 7 and 9 can be made by co-processing aluminosilicate and higher-melting density control materials in a chemomechanical process with conditions to bring the aluminosilicate material to a liquidus state. The process may be operated to reduce particle size of the density control materials such that a plurality of such materials can disperse within a fluid aluminosilicate medium to form the particle structures of Figs. 7 and 9. Alternately, the density control material can be at least partially pre- processed to bring the particle size thereof to a target level before co-processing with the aluminosilicate material. As with the structure of Fig. 6, the structure of Fig. 8 can be achieved by bringing the aluminosilicate material to less-flowable state.

[0094] Figs. 10-12 show particles with heterogeneous surfaces. Fig. 10 shows an amorphous aluminosilicate body 1001 with a plurality of small crystalline density control particles 1002 decorating the surface of the aluminosilicate body 1001. This particle has a heterogeneous surface with a uniform interior. Fig. 11 shows a particle, made of two materials, in which an amorphous aluminosilicate body 1101 is joined with a first plurality of small crystalline density control particles 1102 decorating the surface of the particle and a second plurality of small crystalline density control particles 1103, having the same chemical nature as particles 1102, dispersed within the interior of the aluminosilicate body 1101. In this case, the first particles 1102 have a first chemical nature and the second particles 1103 have a second chemical nature that is the same as the first chemical nature. The particle of Fig. 11 is thus a substantially uniform mixture of crystalline bodies of a first material with a second material that is an amorphous material, the particle having similar surface and interior heterogeneity. Fig. 12 shows a particle made of three materials, an amorphous aluminosilicate body 1201 , with a first plurality of small crystalline density control particles 1202 having a first chemical nature decorating the surface of the aluminosilicate body 1201 , and a second plurality of small crystalline density control particles 1203 having a second chemical nature different from the first chemical nature dispersed throughout the interior of the aluminosilicate body 1201. Thestructure of Fig. 10 can be achieved by co-processing large aluminosilicate particles with small crystalline density control particles using chemomechanical processing that softens the surface of the aluminosilicate particles such that the density control particles stick to the surface of the aluminosilicate particles. The structure of Figs. 11 and 12 can be made by using the homogenizing process that makes the particle of Fig. 9 followed by the surface coating process that makes the particle of Fig. 10. For Fig. 12, the third material is introduced into the process that makes the structure of Fig. 10.

[0095] Other particle structures can be made, using the methods herein, in which an aluminosilicate body having different domains, optionally with different characteristics, are joined with density control particles. The particles shown in Figs. 13-15 have aluminosilicate bodies with characteristics of composition and / or morphology that vary according to a pattern. Fig. 13 shows a medium-sized amorphous aluminosilicate body 1301 that is joined with a plurality of small crystalline density control particles 1302, wherein the density control particles are dispersed within the body 1301 and protrude through the surface of the body 1301. In some cases, the density control particles are dispersed within, and decorate the surface of, the body 1301. The combined structure of the body 1301 and the particles 1302 is completely surrounded by an outer amorphous aluminosilicate transition shell 1303 which is, in turn, completely surrounded by an outer amorphous aluminosilicate shell 1304. Each of the materials 1301 , 1303, and 1304 are aluminosilicate materials that may have different composition, structure, or both. For example, each of the materials 1301 , 1303, and 1304 may have the same crystallinity, or different crystallinity, and each of the materials 1301 , 1303, and 1304 may have compositions that are indistinguishable, or may have slightly-to-somewhat different elemental compositions.

[0096] Fig. 14 shows a particle with five different domains having a medium-sized amorphous aluminosilicate body 1401 , completely surrounded by an outer amorphous aluminosilicate transition shell 1402 and an outer amorphous aluminosilicate shell 1403, with two large density control particles 1404 attached. Fig. 15 shows a medium-sized amorphous aluminosilicate body 1501 , completelysurrounded by an outer amorphous aluminosilicate transition shell 1502 and an outer amorphous aluminosilicate shell 1503, with a plurality of small crystalline density control particles 1504 decorating the surface. Fig. 16 shows a particle having two different domains, a medium-sized amorphous aluminosilicate body 1601 , completely surrounded by a large outer density control material 1602. The outer density control material may be partially crystalline, or amorphous with a higher density than the inner body 1601. Fig 17. shows a homogenous particle 1701 where two raw materials, at least one being an aluminosilicate material of lower specific gravity, have been exposed to a chemomechanical process and have intermixed to form a single domain having intermediate specific gravity, and potentially having a low degree of crystallinity, and lower reactivity than the aluminosilicate.

[0097] The high specific gravity domains in structures in Fig 1 -17 have been described as having high crystallinity. In some cases, however, it may be advantageous to prevent the formation of crystalline domains altogether. A high specific gravity domain, for example, might not have high crystallinity, but due to the chemomechanical process conditions separate domains may arise that have different chemical compositions resulting in morphologies with different relative specific gravity. Such structures can still provide a wider range of reactivity and specific gravity for polymerization precursor embodiments.

[0098] The particle structures and arrangements shown in Figs. 1 -17 are just a few examples of structures that could result from the chemomechancial processes described herein. For example, another particle structure that can result is an amorphous mixture, at the atomic level, of aluminosilicate material with density control material where the density control material has a melting point that is relatively close to that of the aluminosilicate material. FeSCk, for example, has a relatively low melting point of 680°C. Co-processing such a material with aluminosilicate materials can result in a solid solution of the aluminosilicate and density control materials or an amorphous agglomeration of an aluminosilicate particle and a density control particle.

[0099] Fig. 18A is a processing diagram that shows the result of some chemomechanical processes. Two raw materials 1810 and 1820 of different chemical composition, specific gravity, and potential for crystallization are each pre-milled indesignated hammer mills 1812 and 1822. Raw material 1810 is a low density reactive aluminosilicate with little tendency to crystallize at low temperatures and using fast quenching, and 1820 is a high density, potentially crystalline raw material which can provide high density, low reactivity, domains. Pre-milling the two materials 1810 and 1812 reduces particle size of the materials to preselected particle size distributions yielding precursors 1814, and 1824 respectively. Here, the precursor 1814 is milled to a larger particle size than the precursor 1824. In this case, the particles are ground to particle sizes between a first size and a second size, where the second size is about 10 times the first size and the second size is similar to a particle size of a final alkali activate precursor particle size to be created by the process of Fig. 18A. A preselected mass or volume fraction of particles 1814 and particles 1824 are admixed using a suitable process 1816, and their respective volume fractions are homogenized to give an intimate mixture of particles 1826, from the material 1814, and particles 1827, from the material 1817, which substantially surround the particles 1826 to form agglomerated alkaline reactive precursor particles having similar sizes and morphologies with narrow particle size distribution. The agglomerates can be subjected to an agglomerate process 1818, which can include compaction, sintering, adhesion and other additional agglomeration treatments. The agglomerate process 1818 may include partial intermixing of nearly liquidus interfaces of the various materials, surface to surface contact between the various materials with no intimate intermixing, and surface-gas-surface contact points between the various materials, so that particles 1828 of ground material 1810, are in intimate contact with particles 1829 of ground material 1820, and with other particles 1828 of ground material 1810, while particles 1829 of ground material 1820 are in intimate contact with particles 1828 of ground material 1810, and with other particles 1829 of ground material 1820. The chemomechanical processes depicted in Fig. 18A can be low temperature chemomechancial processes, and can be followed by other higher temperature chemomechanical processes described in connection with Fig. 18B.

[0100] Fig. 18B is a processing diagram that shows results of other chemomechanical processes. In Fig. 18B, the pre-adhered, or pre-sintered agglomerates of particles 1828 of ground material 1810, and particles 1829 of ground material 1820 (Fig. 18A), are subjected to a first chemomechanical process thatraises a temperature of the processed material to a near-melt temperature of the raw material 1810, bringing the particles 1828 to a molten or pre-molten state. The shape of the particles 1828 is partially modified at the higher temperatures, forming a lower energy rounder domain 1830, whereas the particles 1829 of the raw material 1820 are substantially unmodified but may be increasingly adhered or sintered as particles 1831. Modification of the particles 1830 continues so long as the particles 1830 are maintained at or above a liquidus temperature of the raw material 1810 and below a melt temperature of the raw material 1820, increasing the agglomeration, sintering, and rounding of the particles 1830 while the shape and nature of the particles 1831 remains essentially unchanged. After a requisite duration, the particles 1830 can merge to form a domain 1832 of the raw material 1810, which is agglomerated with, and partially surrounded by, the particles 1833. If at this stage as part of the chemomechanical process, the hot particles having a single domain 1832 of the molten raw material 1810, sintered and entrapping particles 1833, were to be quenched from the temperature at which the transformations into domains 1832 and 1833 were achieved, a polymerization precursor structure with a low density, highly reactive large amorphous domain 1834 may be obtained, with a plurality of high density potentially crystalline particles 1835 attached to the amorphous domain 1834. Such a precursor can be highly alkaline reactive because a substantial fraction of the precursor particle area can be exposed to the alkaline aqueous environment. Such particles can also have high specific gravity that can be approximated by mass or volume average of the specific gravities of the raw materials 1810 and 1820, embodied by the domains 1834 and 1835. While some of the resulting precursor particles may aggregate or agglomerate during the cooling process due to static electricity, ineffective transporting gas flow, or mechanical aggregation, the particles would otherwise be expected to have a particle size, and distribution, near a target size by selecting chemomechanical processing conditions configured to achieve time and temperature characteristics to yield particles of the target size. Such aggregates can be separated by minimal mechanical processing. It should be noted, that because the precursor particles generated comprise low density domains 1834 and high density domains 1835 intimately sintered, such precursor particles will not segregate by gravity into phases during storage, transport, pneumatic transportmixture into a polymerization precursor, as blends of particles of raw material 1810, and 1820 would.

[0101] If rather than quenching the hot precursor obtained having reached the stage where a single domain 1832, is molten, sintered and entrapping particles 1833, the chemomechancial process were to be continued by increasing the temperature to a value above a liquidus temperature of the raw material 1820, the amorphous domain 1832 would approach a pseudospherical morphology 1840, and the domains 1833 would also begin to deform, and potentially sinter with each other, into rounded particles 1841. The rounded particles 1841 , in at least a partially liquidus and mobile state, would further embed into the amorphous domain 1840, which is substantially liquid at such temperatures, driven by minimization of interfacial energy between the domains and surrounding gas or liquid domains, and governed by the respective viscosities of the two materials.

[0102] Given understanding of the composition and morphology of the raw materials 1810 and 1820 to be subjected together to a chemomechanical process, process conditions can be selected to provide a thermodynamic and kinetic history that can achieve domain morphologies with a target shapes, crystallinity, adhesion, and dispersion. Mechanical and thermal energy can be configured and applied to cause the different materials to undergo selected thermodynamic and kinetic transformations to achieve any of the particle shapes and morphologies described herein, which can, in turn, be selected to achieve target particle size, particle size distribution, and alkaline reactivity characteristics for a polysialation reaction.

[0103] The processes depicted in Fig. 18B are the result of time and temperature history that gives rise to increasing liquidus and agglomeration of materials. If, at any point in the processes depicted in Fig. 18B, a quench were initiated, low density reactive domains of aluminosilicate 1842, 1844, 1846, or 1848 would be formed respectively at each of the stages depicted in Figure 18B. Similarly, high density reactive domains of aluminosilicate 1843, 1845, 1847, or 1849 would be formed. Such particles can have a cord that is a density control material and at least a partial shell that is an alkaline reactive aluminosilicate material. Further duration at high temperature process conditions can achieve further rounding of the high densitydomain 1849 to form a Janus particle with low density molten domain 1850 and high density molten or pre-molten domain 1851 , where interfacial tension between domains 1849 and 1848 are larger than interfacial tensions between domain 1849 and the ambient material (gas or liquid). Where interfacial tension between aluminosilicate domains 1849 and 1848 are lower, a core-shell structure can result where a low density amorphous core domain 1854 is surrounded by a high density shell domain 1855. Such structures can be substantially frozen by quenching at appropriate times and using appropriate cooling rates. A different time-temperature history can lead to opposite core-shell structures having a high density core domain 1877 surrounded by a low density shell domain 1876. In such cases, chemomechanical processes can be selected to maintain a temperature above a melting temperature of the low density domain 1840 and just at or above the liquidus temperature of the high density domain 1841 , allowing more time for relative movement and reshaping of the adhered domains. Rounded high density domains 1861 can migrate into the low density molten domain 1860 by Bernoulli forces to form a particle having high density domains dispersed within a low density domain that has a homogeneous surface. Further increasing temperature of such a particle can lead to coalescence of the dispersed high density domains 1861 into larger high density domains 1871 and 1873, and further duration can lead to formation of a single high density domain 1875 within a larger low density domain 1874. Quenching at any point in these processes can yield particles having a wide range of morphologies and alkaline reactivities with independently-selectable specific gravities.

[0104] The passage above describes materials that are substantially immiscible. Partial or complete miscibility between the materials could result in more homogeneous particle structures, such as the structure of Fig. 17. Time and temperature history can be selected that results in partial to complete homogenization of the particles, leading to another class of structures characterized by different compositions and gradations of compositions at different locations within the particle, along with different morphologies.

[0105] In some cases of chemomechanical processing, the mechanical stresses particles will be subjected to during heating and cooling, especially during quenchsituations may give rise to other effects. If two domains with different liquidus temperatures or glass transition temperatures have substantially different specific volumes, stresses during cooling can generate fractures within one or both the solid domains, or adhesive failures in between the two solid domains or between amorphous and crystalline domains of a single phase. In some cases, such stresses may be used to provide pathways for activator exposure to enhance reactivity.

[0106] Figs. 19A, B, and C qualitatively show inorganic polymerization reactive paths that can be utilized for some of the structures of precursor particles, as depicted in Fig. 1 -1 Sin a polymerization reaction. Three general pathways are depicted in a stylized format. Fig. 19A depicts a precursor particle structure similar to that depicted in Fig 11 with a different ratio of the domains 1101 , 1102, and 1103. In Fig 19A, the exterior particle interface 1910 between the aqueous phase and a reactive, substantially non crystalline, low specific gravity aluminosilicate domain 1912 is presented. Fig. 19A also depicts the exterior particle interface 1914, between the aqueous phase and a non-reactive, substantially crystalline, high density domain 1916. Fig 19A also depicts the interface 1918 between a non-reactive, substantially crystalline, high density domain 1916 and the reactive, substantially non crystalline, low density aluminosilicate domain 1912. Such aluminosilicate features a composition where silicon oxide, aluminum oxide and calcium oxide are preeminently concentrated metal oxides. Fig. 19A also depicts water molecules 1920, that can migrate across the interface 1910, and absorb into the bulk particle of the reactive, substantially non crystalline, low density aluminosilicate domain 1912, through a substantially uninterrupted diffusive path 1922, and potentially react with calcium oxide in the bulk, to yield calcium hydroxide Ca(OH)2 molecules, 1924. Also depicted in Fig.19A, polymerization activating hydroxyl ions OH 1926, present in the aqueous phase may also migrate across the interface 1910, and absorb into the bulk of the reactive, substantially non crystalline, low density aluminosilicate domain 1912, through a substantially uninterrupted diffusive path 1928, and potentially react with silicon oxide in the bulk, to yield silicate ions, SiOs 1930, and or with aluminum oxide in the bulk, to yield aluminate ions, AIO2 1932. The presence of these reactions and ions in the aluminosilicate domain 1912 activates a polysialation reaction through migration of hydroxyl ions, silicate ions, and aluminate ions along substantiallyuninterrupted diffusive paths 1934, 1936, and or 1938 within the domain 1912 and across the interface 1910. In this case, the majority of the external particle interface is between the aqueous liquid and the reactive aluminosilicate domain 1912, which can be considered a fast reactive path due to high ion mobility through the interface 1910 and within the domain 1912.

[0107] Fig. 19B depicts a precursor particle structure similar to that of Fig 11 , also with a different ratio of the domains 1101 , 1102, and 1103. IFig 19B also shows an exterior particle interface 1940 between the aqueous phase and a reactive, substantially non crystalline, low density aluminosilicate domain 1942. Fig. 19B also shows an exterior particle interface 1944 between the aqueous phase and a non- reactive, substantially crystalline, high density domain 1946. Fig 19B also shows an interface 1948 between the domain 1946 and the domain 1942. As in Fig. 19A, the aluminosilicate material is a composition of concentrated silicon, aluminum, and calcium oxides. Fig. 19B also depicts water molecules 1950 that can migrate across the interface 1940 and absorb into the bulk of the domain 1942, but along a more tortuous path 1952 than the path 1922 of Fig. 19A. The water molecules 1950 can react with calcium oxide in the domain 1942 to yield calcium hydroxide Ca(OH)2 molecules, 1954. As also depicted in Fig.19A, polymerization activating hydroxyl ions OH- 1956 present in the aqueous phase may also migrate across the interface 1940 and absorb into the domain 1942, also along a more tortuous diffusive path 1958. The hydroxyl ions can react with silicon and aluminum oxide in the domain 1942 to yield silicate ions, SiOs', 1960, and aluminate ions, AIO2', 1962, respectively. As above, these ions participate in polysialation by the migration of hydroxyl ions, silicate ions, and aluminate ions, through more tortuous diffusive paths 1964, 1966, and or 1968 respectively within the domain 1942 and across the interface 1940. It is thought likely that ion diffusion, migration and transport within the high density domains is slow or zero, and in any event much slower than within the domain 1942 making the tortuous paths through the domain 1942 or along the interface 1948, energetically preferred. In this case, the majority of the external particle interface is between the liquid and the substantially crystalline, high density domains 1946. A small fraction of the external particle interface is between the liquid and the low density aluminosilicate domain 1942, resulting in a less favorable migration path for ions through the externalparticle interface. Additionally, because the ion migration paths 1952, 1958, 1964, 1966, and 1968 are more tortuous, the particle depicted in Fig. 19B is expected to be less reactive than the particle depicted in Fig. 19A, other characteristics of the particles being substantially the same.

[0108] Fig. 19C depicts a precursor particle structure similar to that of Fig 16, with a different ratio of domains 1601 , 1602. In Fig 19C, the exterior particle interface 1970 between the aqueous phase and a reactive, substantially non crystalline, low density aluminosilicate domain 1972 is virtually non-existent. Fig. 19C also shows essentially all the exterior particle interface 1974 between the aqueous phase and a non- reactive, substantially crystalline, high density domain 1976. Fig 19C also shows an interface 1978 between the domain 1976 and domain 1972. Here, water molecules 1980 cannot easily migrate across the tiny interface 1970. To enter the reactive domain 1972, then, the water molecules must diffuse, migrate, or transport through an extremely difficult path 1982 amongst the crystalline domains 1976, where the water molecules 1980 can react to form calcium hydroxide Ca(OH)2 molecules, 1984. Also, polymerization activating hydroxyl ions OH 1986, present in the aqueous phase cannot easily migrate across the tiny interface 1970, and must also transport through the extremely difficult path 1988 to reach the reactive domain 1972. Due to the extremely difficult transport pathways at the surface of the particle shown in Fig. 19C, the particle of Fig. 19C would be expected to have much lower reactivity that the particles of Figs. 19A and 19B, other characteristics being substantially the.

[0109] The heterogenous precursor particles depicted in Fig.1 to 17 are described above as having to two different mineral domains, one a low specific gravity reactive aluminosilicate with a suitable chemical composition and a degree of crystallinity low enough to allow for acceptable reactivity, and at least a second domain of potentially the same chemical composition but a different specific gravity, and potentially a different degree of crystallinity, where the at least second phase is placed heterogeneously with respect to the first domain to yield a particle with heterogeneous composition and / or morphology. In general, average precursor specific gravity and reactivity can be balanced and adjusted by targeting the composition and specific gravity of the reactive aluminosilicate domain, the non-reactive domain, or both and by manufacturing either or both as a 100% amorphous domain, or a partially crystalline domain, where each domain can have the same degree of crystallinity or different degrees of crystallinity.

[0110] Reactivity of a given precursor in a polysialation reaction depends on temperature, generally increasing at higher temperature and decreasing at lower temperature. Fig. 20 shows a qualitative polymerization reactivity diagram for precursor particles with various morphologies and domains. For this diagram, polymerization temperature, activator type and concentrations, dispersant, viscosifier, and other additives are equal, precursor PSD, and the solid volume fraction in the slurry are invariant. A higher than 95% amorphous content is assumed for the reactive aluminosilicate domains, and a higher than 80% crystallinity is assumed for the high specific gravity non-reactive domains. The chemical composition of all domains having amorphous content of 95% or more is assumed to be the same, and the chemical composition of all domains having crystallinity of 80% or more is assumed to be the same. The relative position of the particle precursor morphologies 2000 to 2070 in the diagram reflects the expected polymerization reactivity, higher reactivity is to be observed for particles situated higher relative to the vertical axis, with precursor morphology 2000 being the most reactive, and precursor morphology 2070 the least reactive. The relative position of the particle precursor morphologies 2000 to 2070 on the horizontal axis reflects the total amorphous content of the particle, with precursor morphology 2000 having the highest amorphous content, and precursor morphology 2070 having the lowest amorphous content. Parameters such as the overall crystallinity of the precursor, or the overall specific gravity of the precursor decrease as the amorphous content increases.

[0111] As shown in Fig. 20, the highest polymerization reactivity is expected from the precursor morphology 2000 where only a single amorphous domain 2001 is exposed to the reaction environment. Similar but potentially slightly lower reactivity will be expected from a core-shell precursor morphology 2010 having a shell amorphous domain 2011 exposed to the reaction environment while the non-reactive core 2012 is not exposed to the reaction environment. Also similar but potentiallyslightly lower reactivity will be expected from a “grape” precursor morphology 2020, where only the amorphous shell domain 2021 is exposed to the reaction environment while the non-reactive “seeds 2022, small high specific gravity crystalline domains, are not exposed to the reaction environment. Lower reactivity will be expected of a Janus precursor morphology 2030, where only about one third of the area of the amorphous domain 2031 is exposed to the reaction environment while the external non-reactive domain 2032 shields a portion of the surface area of the reactive domain from the reaction environment.

[0112] Increasingly shielding the reactive domain from the reaction environment is expected to reduce reactivity of the precursor particle in a polysialation reaction. A substantially lower reactivity will be expected, for example, from a trilobu lar precursor morphology 2040 where only less than half of the area of the amorphous domain 2041 is exposed to the reaction environment while the two external non-reactive domains 2042 shield portions of the surface area of the reactive domain 2041 from the reaction environment. An even substantially lower reactivity will be expected from a precursor morphology 2050 having a plurality of small non-reactive domains 2052 decorating the exterior surface of the reactive domain such that only a small fraction of the area of the reactive amorphous domain 2051 is directly exposed to the reaction environment. The non-reactive internal domains 2053 will also reduce reactivity of the particle overall as they will shield portions of the reactive domain 2051 when the non-reactive internal domains 2053 are exposed to the reaction environment as the amorphous material 2051 hydrates and moves into the fluid mixture. The lowest reactivity is expected from the inverse core-shell precursor morphology 2060 where only a non-reactive shell crystalline domain 2062 is exposed to the reaction environment while the core 2061 remains reactive but is substantially entirely shielded from the reaction environment resulting in poor ion mobility and transport. Finally the precursor morphology 2070, comprising exclusively a single non-reactive domain 2072, will generally not engage in polysialation.

[0113] In such processes, particles of size 10 to 300 microns, such as 20 to 100 microns, can have an alkaline reactive coating that is 5 to 20 microns thick. In some cases, the coating is an alkaline reactive coating on a non-reactive particle. Thecoating can be entirely alkaline reactive material, or the coating may include smaller particles of non-reactive material. The coating, in these cases, can be a full coating around the entire outer surface of a core particle, or the coating may be a partial coating over a portion of the outer surface of a core particle. Such particles will polymerize in alkaline environments to yield a polysialate matrix with finely interspersed small domains having higher density. Such materials and processes minimize the solid volume fraction needed in a polymerization precursor to achieve, after the precursor is formulated and hardened, a target hardness (e.g. compressive strength) in a polysialate system, while minimizing the risk of gravity and / or size segregation resulting from admixing solids of different density and size as shown in Figs. 1 -3.

[0114] In some cases, the alkaline reactive material may consist of parts having high crystallinity and parts having low crystallinity. For example, in all the cases described above, the alkaline reactive material, after thermal treatment, may have amorphous domains and crystalline domains, all of which can vary in crystallinity from essentially zero, to low crystallinity, to moderate crystallinity, to high crystallinity. For example, an alkaline reactive material can have crystalline domains, such as particles, dispersed in or interspersed with amorphous, or low crystallinity, domains, which may also be particles or may be a coating or otherwise continuous domain surrounding, or partially surrounding crystalline domains, such as particles. Depending on the processing temperature and the quenching temperature, two raw materials of different chemical composition, and density, one of which is prone to crystallizing, which are processed at temperatures exceeding a melt temperature of both materials, may be cooled quickly to obtained particles having separate domains of different density, which may also be potentially with intermixed domains of chemical composition different than the original chemical composition of both materials without forming crystalline domains.

[0115] In the cases where aluminosilicate materials and density control materials are co-processed, alkaline reactive materials having diverse crystallinity domains can be formed by processing different volumes of aluminosilicate materials for different times and / or at different conditions. For example, a mixture of a first volume ofalum inosilicate material with a density control material can be treated in a chemomechanical process for a first time at first processing conditions, and then a second volume of aluminosilicate material can be added to the mixture to form a second mixture, which can be treated in the chemomechanical process for a second time at second processing conditions. In such cases, the longer processing time of the first volume of aluminosilicate material will result in more transformation for the first volume than the second volume. In the cases when the two volumes of aluminosilicate have two different chemical compositions, and depending on the chemomechanical process conditions, a third aluminosilicate domain can result from the co-melting of the first volume of aluminosilicate material and the second volume of aluminosilicate material. In such processes, third and fourth volumes can be sequentially added and processed, if desired, and so on reasonably limited only by the ability to subdivide the aluminosilicate material into a plurality of volumes for sequential addition to the chemomechanical process.

[0116] The chemomechanical treatments of mixed aluminosilicate materials and density control materials described above can be followed by low severity mechanical processing, if desired, to further adjust particle sizes in an alkaline reactive precursor. For example, in some cases above where the aluminosilicate materials have been softened and / or melted, particles can agglomerate during quenching. In such cases, low intensity grinding or milling can be performed to break up agglomerates and generally reduce the particle size distribution further.

[0117] The polysialate systems and alkaline reactive precursors described herein can be used for any application where the properties of a polysialate can be advantageous. The materials described herein can be used for subterranean applications, like cementing a wellbore, as well as surface applications, such as construction and civil engineering projects. The wellbore may be for a hydrocarbon well or other purposes.

[0118] In some embodiments, the wellbore may be used for carbon capture, utilization, and storage (CCUS) and / or for recovery and use of geothermal energy. Geothermal energy is a promising source of renewable energy that captures energy from heat generated or stored within the earth. For example, geothermal energy maybe used to perform climate control (e.g., heating, cooling) for structures (e.g., buildings) using heat pumps and / or to generate electricity (e.g., by heating water to generate steam and drive a turbine with the steam). The wellbores described herein may be used to circulate a working fluid that exchanges heat within the earth formation through which the wellbore extends. The working fluid may be circulated to the surface where a surface heat exchanger is used to transfer thermal energy to another fluid used to generate electricity and / or for climate control. After the thermal energy is transferred from the working fluid in the surface heat exchanger, the working fluid is circulated back to the earth formation to continue the cycle. In geothermal wells it is possible that thermally conductive cementitious materials could be preferred in some of the casing strings, over other more insulating cement materials. In these cases, the use of polymerization precursors with morphologies as those disclosed herein, where aluminosilicates are combined through chemomechanical process with different specific gravity materials that can enhance the thermal conductivity of the set organic polymer sheath may be advantageous. Raw materials such as graphite, graphene, carbon nanotubes, hematite, and substantially un-oxidized metal domains of iron, copper, aluminum, steel, tin, bronze, chromium, manganese, vanadium, tungsten, molybdenum, and the like could be used to enhance the thermal conductivity of the set inorganic material by admixing them with aluminosilicate precursors when preparing the polymerization precursor, as per Fig. 1 , 2 and 3. It is expected that a more intimate contact between the reactive aluminosilicate and the thermally conductive raw material could be achieved if these raw materials could be appropriately pre-conditioned and premixed with the aluminosilicate raw materials, and be subjected to chemomechanical processing to achieve precursor morphologies such as depicted in Fig. 4 to 17.

[0119] CCUS facilitates the capture, use, and / or storage of carbon (e.g., carbon dioxide), which has a goal of achieving carbon neutrality and / or net zero carbon emissions (NZE). Carbon capture may include the capture of carbon dioxide from large point sources, such as power plants, refineries, cement plants, other industrial processing plants, or other industrial facilities that use fossil fuels, biomass fuels, or other fuels that generate carbon dioxide. The captured carbon dioxide may be converted into valuable products such as, for example, ethanol, sustainable aviationfuel, chemicals, mineral aggregates, and / or other products. Alternatively, the carbon dioxide may be stored in geologic formations, such as in depleted hydrocarbon reservoirs. The carbon dioxide may be introduced into the earth formation through a wellbore. In the earth formation, the carbon in the carbon dioxide may be dispersed in an aqueous phase and stored as carbon dioxide, may be stored in mineral form (e.g., as a carbonate, such as calcium carbonate, magnesium carbonate, iron(ll) carbonate), or as another form of carbon.

[0120] For wellbore applications involving exposure to CO2 in gas, liquid or supercritical form, such as CCUS, or CO2 driven Enhance Oil recovery EOR applications, or even geothermal applications, it may be useful to manufacture and utilize polymerization precursors comprising at least a fraction of material that will remain in a separate substantially non-reactive phase during setting but will be at least partially reactive with carbon dioxide, bicarbonate ions, and or carbonic acid after setting to form a carbonate material that can reduce the permeability of the set polysialate system. For instance the presence of small concentrations of metallic ions that can form carbonate salts, such as Fe2+, Ca2+, Mg2+, Sr2+, Ba2+, Zn2+, Co2+, Ni2+, Cu2+, and the like, in any of the polymerization precursors described herein can provide such carbonate-forming capability. Such materials can be included in any of the domains of a heterogeneous precursor particle, as described above. Usable materials having such metallic ions can be oxides, nitrates, sulfates, sulfites, thiosulfates, bisulfites, persulphates, phosphates, hydroxyphosphates, phosphites, hydroxyphosphites, formates, acetates, oxalates, lactates, phthalates, and other sparsely soluble organic salts of said metal ions. Reactivity of such salts with carbon dioxide, bicarbonate and carbonate ions to yield metal carbonates can be evaluated in laboratory conditions, and salts achieving the appropriate rate of reaction may be chosen, where in the set polysialate system the metal ion is displaced from the original salt anion to the carbonate anion.

[0121] Precursors can be prepared that comprise multiple different inorganic domains. After a chemo-mechanical treatment described herein is completed, a precursor may comprise at least a first reactive aluminosilicate domain having a first preselected concentration of metals Si, Al, Fe, Ca, Mg, Na, B, Ti, (as for exampleoxide, sulfide, sulfate, etc), with a known specific gravity, and a known crystallinity (or amorphous content). The precursor may comprise a second moderately reactive aluminosilicate domain having a second preselected concentration of metals Si, Al, Fe, Ca, Mg, Na, B, Ti, as above, with a higher crystallinity (or lower amorphous content) and as a result a higher specific gravity. As described above, the higher crystallinity of the second domain would be expected to result in lower reactivity with alkali activators, and in an increased specific gravity of the precursor. The increased crystallinity can be provided by crystalline silica, crystalline alumina, crystalline mullite, crystalline hematite, and combinations thereof. The specific gravity of silicon oxide SiO2varies from about 2,196 kg / m3for amorphous silica to about 2,648 kg / m3for crystalline silica. The specific gravity of aluminum oxide AI2O3 varies from about 2,100 to 3,500 kg / m3for to about 3,987 kg / m3for crystalline aluminum oxide (corundum). The specific gravity of mullite, an aluminosilicate material having chemical formula Al4+2xSi2-2xO -x, where x is between 0.17 and 0.59, is from about 3,000 kg / m3to about 3,100 kg / m3. The specific gravity of hematite, Fe2Os is from about 4,900 kg / m3to about 5,300 kg / m3. These materials can be advantageously used for independent control of specific gravity and reactivity of polysialate precursors.

[0122] For low temperature applications, such as conductor casing, and surface casing in deep water wells, where the expected circulating temperature will be close to 0-5 °C, tending to decrease polysialation reactivity, precursors having low crystallinity, or high amorphous content, such as greater than 90% or 95% amorphous content, can at least partially counteract the reduction in reactivity caused by low temperatures. For high temperature applications, such as deep hot reservoirs (above 100 °C), use of more crystalline precursors, for example precursors having less than 90%, for example less than 80%, amorphous content, can mitigate the reaction acceleration from the high temperatures. Likewise, for very high temperature applications, such as geothermal wells, with deep hot reservoirs (above 200 °C), precursor having even lower amorphous content, such as less than 70%, can be advantageous

[0123] Higher degrees of crystallinity, and / or high specific gravity are required toachieve larger increases of specific gravity in multi-domain precursors like those described above. The specific gravity of an aluminosilicate domain has a direct relationship with crystallinity of the domain. Thus, a partially crystalline aluminosilicate domain will have higher specific gravity than an amorphous domain of the same composition. The same is true of silica and alumina materials. An aluminosilicate precursor of homogeneous composition can, therefore, have domains of different crystallinity that influence the specific gravity of the precursor. As noted above, an amorphous aluminosilicate precursor can also include a domain of high crystallinity and / or high specific gravity material of a different composition to influence the specific gravity of the precursor. The specific gravity of the precursor is a volumetric average of the specific gravities of the individual domains of the precursor. The following examples illustrate how properties of a polysialation precursor can be selected by controlling properties of the raw materials.

[0124] Numerical Example 1 : In order to formulate a polysialation precursor using a 100% amorphous single domain calcium rich monodisperse aluminosilicate raw material having average specific gravity 3,140 kg / m3, at a slurry density of 14 pound per gallon (1 ,680 kg / m3), a Solid Volume Fraction of 32% is required. A precursor formulated in such a way will be pumpable (viscosity below 300 cP), and will show no gelation.

[0125] Numerical Example 2: In order to formulate a polymerization precursor using the same material at a slurry density of 16 pound per gallon (1 ,920 kg / m3), a Solid Volume Fraction of 43% is required. This precursor would also be pumpable (viscosity below 300 cP), and would likely show no gelation.

[0126] Numerical Example 3: In order to formulate a polymerization precursor using the same material at a slurry density of 18 pound per gallon (2,160 kg / m3), a Solid Volume Fraction of 54% is required. This precursor likely will not be pumpable (because viscosity likely would not be below 300 cP), and would be expected to show gelation. Were the crystallinity of such single domain raw material increased at the expense of somewhat reduced reactivity (see Fig. 20), specific gravity of the raw material would increase moderately. For instance, replacing 8% equivalent AI2O3 and 21 % equivalent SiC>2, by weight, with crystalline alumina and crystalline silica, thespecific gravity of the raw material would increase by 380 kg / m3due to the higher specific gravity of the crystalline versus amorphous materials. For an aluminosilicate raw material having 16% alumina and 42% silica, such replacement would reduce amorphous content of the raw material by 50%.

[0127] If the average crystallinity of a one domain monodisperse aluminosilicate particle were increased by including a homogenously distributed hematite second domain, thus reducing the proportional content of amorphous silica and amorphous alumina (e.g. amorphous aluminosilicate) in the particle, specific gravity of the particle can be increased substantially. For instance, if 8% of equivalent AI2O3 and 21 % of equivalent SiCh were replaced, in such a particle, by crystalline hematite, the specific gravity of the particle would increase by 640 kg / m3. For an aluminosilicate particle with 16% alumina and 42% silica, amorphous content would decrease by 50% by addition of the hematite. Such a particle would exhibit reduced alkaline reactivity by adding the non-reactive hematite to the particle, so such particles would not be expected to polymerize in all conditions, notably at low temperature or with low activator concentrations.

[0128] Fig. 21 is a graph 2100 that shows specific gravity of a particle as a function of composition, specifically of amorphous alumina, amorphous silica, and crystalline hematite. The increase in specific gravity of a particle containing 16% AI2O3 and 42% SiO2 is estimated where crystallinity of the alumina and silica is increased, at 2102, and as hematite is added at 2104. While specific gravity of the particle rises as amorphous alumina and / or silica are replaced by crystalline alumina and / or silica, increase in specific gravity is greater if amorphous alumina and / or silica are replaced by crystalline hematite due to the higher specific gravity of hematite. The graph 2100 uses specific gravities for amorphous alumina and silica of 2,100 kg / m3and 2,196 kg / m3respectively, specific gravities for crystalline alumina and silica of 3,987 kg / m3and 2,648 kg / m3respectively, and specific gravity for crystalline hematite of 5,300 kg / m3.

[0129] Numerical Example 4: In order to formulate polymerization precursor using a 50% amorphous single domain (i.e. small, highly dispersed crystalline components) calcium rich monodisperse aluminosilicate raw material having averagespecific gravity 3,520 kg / m3, (i.e. 380 kg / m3denser than the aluminosilicate raw material of Example 3) in a polymerization precursor having a slurry density of 18 pound per gallon (2,160 kg / m3), a Solid Volume Fraction of 46% is required. A polymerization precursor formulated in such a way with typical additive and activator concentrations may be pumpable (viscosity below 300 cP), would not be expected to exhibit gelation, but might not reach acceptable compressive strength in some cases (particularly at low temperatures, for example) due to insufficient reactivity.

[0130] Numerical Example 5: in order to formulate a polymerization precursor using a 50% amorphous single domain calcium rich monodisperse aluminosilicate precursor having average specific gravity 3,780 kg / m3, (i.e. 640 kg / m3more dense than the aluminosilicate of example 3) at a slurry density of 18 pound per gallon (2,160 kg / m3), a Solid Volume Fraction of 43 % is required. A polymerization precursor formulated in such a way with typical additive and activator concentrations will be pumpable (viscosity below 300 cP), and will not exhibit gelation, but might not reach acceptable compressive strength. A raw material like this could be made in a core-shell configuration, so not as a single domain but in two domains as shown in Fig. 4, by using an amorphous core material having 16% by weight of AI2O3 and 42% by weight of SiO? representing 68% of the total volume of the core material. The shell material could then be any mineral material, potentially including aluminosilicate material and other materials, having any desired crystallinity and specific gravity. The shell thickness, in this case, would be about 30% of the radius of the precursor.

[0131] Numerical Example 6: A core-shell raw material particle having 34% of its volume occupied by a core material made of 100% crystalline silica and alumina, and a 66% of its volume occupied by a shell material made of 100% amorphous aluminosilicate can be formulated as a two-domain, and therefore heterogeneous, calcium rich monodisperse aluminosilicate raw material. Such raw material particles would have average specific gravity of 3.520 kg / m3, (i.e. 380 kg / m3more dense than the aluminosilicate of example 3). Forming a polymerization precursor using such particles at a slurry density of 18 pound per gallon (2,160 kg / m3), would require a Solid Volume Fraction of 46%. A polymerization precursor formulated in such a way with typical additive and activator concentrations may be pumpable (viscosity below300 cP), would not be expected to exhibit gelation, and would likely result in a workable polymer because the particle shells would be expected to have sufficient reactivity in an alkaline environment.

[0132] Numerical Example 7: If a core-shell raw material like that of Example 6, but using crystalline hematite as the core material were made into a two-domain heterogeneous calcium rich monodisperse aluminosilicate raw material, such raw material would have a specific gravity of 3.780 kg / m3, (i.e. 640 kg / m3more dense than the aluminosilicate of example 3). Use of such raw material in a polymerization precursor having a slurry density of 18 pound per gallon (2,160 kg / m3), a Solid Volume Fraction of 43 % is required. A polymerization precursor formulated in such a way with typical additive and activator concentrations may be pumpable (viscosity below 300 cP), would not be expected to exhibit gelation, and would likely result in a workable polymer due to reactivity of the shell material in alkaline solution.

[0133] The examples above shown how the methods described above can be used to independently vary reactivity and specific gravity of polysialation precursors to provide polymerization precursors that are pumpable, that have sufficient slurry density for deployment in a well setting, and that result in polymers having a desired compressive strength. As the examples show, polysialation raw materials having an amorphous external surface but enclosing a crystalline core of selected specific gravity can be used to tailor the specific gravity of the raw material with minimal impact on alkaline reactivity. Such methods can be used to independently vary slurry density of a polymerization precursor without impact on viscosity, pumpability, and gelling potential of the precursor.

[0134] The raw materials described herein are generally made using materials that have been previously treated to form a material suitable for chemomechanical processing into polysialation raw materials. In some cases, aluminosilicate materials can be used that have been pre-polymerized to a selected extent to provide certain properties. For example, a prepolymer can be made that has a selected specific gravity and chemical composition, and such prepolymer can be used as a raw material for a subsequent polysialation reaction, potentially adding other raw materials.

[0135] A first polymer, which can be a prepolymer, is made using a first polymerization precursor comprising an aluminosilicate raw material. The polymerization precursor may be pumpable or might not be pumpable since the resulting polymer is not intended for deployment to a remote location. The first polymerization precursor can include additives selected to provide properties of the first polymer that are advantageous for forming a second polymer using the first polymer as raw material. The first polymerization precursor is allowed to polymerize, fully or partially to any desired degree, to form a raw material to be used in a subsequent polymerization. The degree of polymerization of the first polymer can be controlled by stopping the reaction after a selected time, for example by desiccating the reaction mixture (removing water removes the ionic species driving the polymerization reaction).

[0136] After formation of the first polymer is complete, the first polymer is rendered into a polysialation raw material by griding, milling, or otherwise sizing the first polymer. It should be noted that such methods can be used to form raw materials that can be useful in a CRETE system with other raw materials. For example, a prepolymer, having any desired polymerization extent, can be rendered to a larger particle size, averaging, for example, 50 pm. Such prepolymer can be used as a first aluminosilicate raw material having large particle size, along with a second aluminosilicate material having small particle size, such as metakaolin. It is known that polymerization precursor using metakaolin as the only aluminosilicate raw material become very viscous with increasing solid volume fraction due to very small particle size. Use of a prepolymer having large particle size can mitigate the viscosity effects of the small particle size of metakaolin. Making a prepolymer using metakaolin in a setting that does not require pumping a polymerization precursor, and then sizing the prepolymer to provide larger particles, can be a way to make a pumpable polymerization precursor, using only metakaolin, having higher solid volume fraction (and therefore reactivity and eventual polymer compression strength) than is typically possible using only metakaolin as a raw material.

[0137] In other cases, a prepolymer can be made using reactive and non-reactive materials. Such prepolymers can provide more complete incorporation of non-reactive species into an eventual polymer by creating chemical bonds between reactive and non-reactive species in a prepolymer for use in forming the final polymer. As above, the prepolymer is formulated and allowed to harden to any selected degree, and then the prepolymer is sized for use in a polymerization slurry as a raw material. In such cases, the prepolymer can be rendered into particles having reactive aluminosilicate material chemically bonded to small non-reactive domains, similar to the particles shown in Figs. 1 -12. In this way, particles having a selected average reactivity and specific gravity, determined by the composition of the prepolymer, can be size-selected for use in a polymerization precursor having target properties for easy deployment in a well setting.

[0138] Prepolymers can be sized in different ways. A brick of hardened concrete, cement, or clay can be ground or milled to any desired extent. Alternately, a precursor, which may be a polymerization precursor (i.e. a polysialation precursor or a cement precursor) or merely a wet precursor (i.e. not having substantial alkalinity), can be processed into a useful shape. The precursor can be a flowable material or a dough or sol-gel material. For example, such precursor can be formed into a sheet, allowed to harden or dry, and then crumbled and / or ground or milled into a size selected particle distribution. In another example, such precursor can be extruded and droplets of the precursor dropped onto a belt or into a medium for further processing. On the belt, the precursor, potentially prepolymerized to a selected extent, can be desiccated to stop any polymerization reaction. In some cases, the prepolymer can be shaped, for example by molding or rolling during prepolymerization. A precursor dough, for example, can be processed in a paddle tank to form spherules of any desired size.

[0139] Thus, generally speaking, a first polymer is formed from a first polymerization precursor comprising an alkaline reactive material, such as an aluminosilicate or cement material. The first polymerization precursor is allowed to harden, optionally using any suitable technique to size and / or shape the polymerization precursor during hardening. Polymerization of the first polymerization precursor may be allowed to proceed to completion, or may be stopped at a desired degree by desiccating the polymerization precursor.

[0140] The first polymer, made to any desired degree of polymerization, and thus compressive strength, is formed into a polymerization raw material for subsequent use in a second polymerization precursor. In this way, the first polymer is a prepolymer. The second polymerization precursor includes the first polymer as a raw material, along with any other desired reactive, non-reactive, additive, and activator species. The second polymerization precursor may be made as a pumpable material, according to the methods described above, advantageously using the first polymer to provide pumpability in ways not achievable with conventional raw materials. The second polymerization precursor is deployed to a target location and allowed to harden into a second polymer having target properties.

[0141] In some cases, shaped particles can be used as non-reactive particles in the methods described herein. Proppant particles, for example, are often made of ceramic materials, such as aluminosilicate materials. Such particles are available in large particle sizes and size distributions, and may be shaped. Such particles can be used as crystalline materials along with amorphous aluminosilicate materials as described herein. Thus, a polysialation raw material particle can be made using small aluminosilicate particles, which may be a powder, along with aluminosilicate, or non- reactive, proppant particles using the methods described herein.

[0142] Regarding use of recycled cementitious materials, Table 1 below shows polysialate precursors made using recycled cementitious materials using GGBS as an aluminosilicate reactant, and polysialate systems made from such precursors. In Examples 1 -3, percentage for GGBS is by volume of blend and other percentages are by weight of blend. In Examples 4 and 5, percentage of recycled polysialate is by volume of blend and other percentages are by weight of blend. Defoamer quantities are gallons per sack.Table 1 - Polysialate Systems Using Recycled Cementitious Materials. Condition:150F curing in water bath

[0143] The preceding description has been presented with reference to present embodiments. Persons skilled in the art and technology to which this disclosure pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this present disclosure. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.

Claims

CLAIMSWe claim:

1. A method, comprising: selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; and subjecting the earth material to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity.

2. The method of claim 1 , wherein the earth material comprises a recycled cementitious material.

3. The method of claim 1 , wherein the chemomechanical process is a first chemomechanical process, and further comprising adding to the alkaline reactive precursor, or to the earth material, a recycled cementitious material that has been subjected to a second chemomechanical process.

4. The method of any of claims 1 to 3, further comprising dispersing the alkaline reactive precursor in an activating solution to form a polymerization precursor, pumping the polymerization precursor to a target location, and allowing the polymerization precursor to harden into a polysialate system.

5. The method of any of claims 1 to 4, wherein the chemomechanical process comprises applying a combination of mechanical energy and thermal energy to the earth material.

6. The method of any of claims 1 to 5, further comprising adding to the alkaline reactive precursor an additive selected from the group consisting of an accelerator, a retarder, a density control material, an anti-foam agent, a defoamer, silica, a fluidloss control additive, a viscosifier, a dispersant, an expanding agent, an anti-settling additive and combinations thereof.

7. The method of any of claims 1 to 6, wherein the earth material, the recycled cementitious material, or both are also selected based on particle size distribution,morphology, crystallinity, specific gravity, specific surface area, or a combination thereof.

8. The method of any of claims 1 to 7, further comprising adding a tuning material to achieve a target particle size distribution, morphology, crystallinity, specific gravity, specific surface area, or a combination thereof.

9. The method of any of claims 2-8, wherein the recycled cementitious material comprises a previously hardened cement, a polysialate material, or both.

10. A method, comprising: selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; subjecting the earth material to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity; and adding up to about 20% by weight of a recycled cementitious material to the alkaline reactive precursor.

11. The method of claim 10, further comprising dispersing the alkaline reactive precursor in an activating solution to form a polymerization precursor, pumping the polymerization precursor to a target location in a well, and allowing the polymerization precursor to harden into a polysialate system at the target location.

12. The method of any of claims 1 to 10, further comprising selecting a density control material having a density for yielding a polymerization precursor having a target slurry density to mix with the earth material to form a premix; and subjecting the premix to a chemomechanical process to form the alkaline reactive precursor having a target physical form, bulk density and alkaline reactivity.

13. The method of any of claims 1 to 12, further comprising mixing with the earth material a density control material, wherein the chemomechanical processing is configured to yield particles of the alkaline reactive precursor each of which is a combination of aluminosilicate material and density control material.

14. The method of claim 13, wherein the particles have a core that is a density control material and at least a partial shell that is alkaline reactive aluminosilicate material.

15. A method, comprising: selecting an earth material to use for forming a polysialate system based on elemental composition of the earth material; subjecting the earth material to a chemomechanical process to form an alkaline reactive precursor having a target physical form and alkaline reactivity; adding up to about 20% by weight of a recycled cementitious material to the alkaline reactive precursor; dispersing the alkaline reactive precursor in an activating solution to form a pumpable polymerization precursor; pumping the polymerization precursor to a target location; and allowing the polymerization precursor to harden into a polysialate system.

16. The method of any of claims 1 to 15, wherein the chemomechanical process is configured to yield a particle size distribution of the alkaline reactive precursor wherein the D90 particle size minus the D50 particle size is no more than about 10 pm.

17. The method of any of claims 1 to 16, wherein a density control material is combined with the earth material to form a mixture and the mixture is subjected to the chemomechanical process to form particles of the alkaline reactive precursor each of which is a combination of aluminosilicate material and density control material.

18. The method of any of claims 1 to 17, wherein the alkaline reactive precursor has a particle size distribution with D90 not more than about 500 pm.

19. The method of any of claims 1 to 18, wherein the alkaline reactive precursor contains about 5% to about 15% by weight of a recycled cementitious material.

20. The method of any of claims 2 to 19, wherein the recycled cementitious material comprises iron.

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