METHOD FOR DETERMINING A FORMULATION FOR A CONSTRUCTION BINDER

Abstract

The invention relates to a method (100) for determining a formulation for a construction binder, said construction binder comprising at least one by-product from a lithium concentration process, said method being implemented by a computer device comprising a calculation module (16), said method comprising: - a receiving step (130a), by the calculation module (16), of a measured value of at least one physicochemical property of the at least one by-product from a lithium concentration process; and - a selection step (150), by the calculation module (16), of a quantity of the at least one by-product from a lithium concentration process and a quantity of at least one complementary composition to form a construction binder; said at least one complementary composition being selected from: at least one precursor, a deflocculating polymer, an alkaline activation composition and a raw clay matrix.Figure to be published with the abbreviation: figure 1.

Description

Title of the invention: METHOD FOR DETERMINING A FORMULATION FOR A CONSTRUCTION BINDER technical field

[0001] The invention relates to the field of construction materials and more particularly to the valorization of by-products from industry. In particular, the invention relates to a method for determining a formulation for a construction binder, a method for preparing a construction binder, a construction binder, a construction material, and a suitable system. Previous technique

[0002] Below, we describe the prior art known from which the invention was developed.

[0003] The construction sector contributes significantly to global greenhouse gas emissions, accounting for approximately 37% of the total. This high percentage is largely due to the production and use of high-emission materials such as cement, steel, and aluminum.

[0004] Thus, cement production is a major contributor to carbon emissions in the construction sector, primarily due to the energy-intensive nature of its production process and the chemical reactions involved in manufacturing clinker, the main component of cement. The challenge lies in reducing the carbon footprint of cement without compromising its performance or significantly increasing its costs. Some of the proposed strategies include improving the energy efficiency of transformation processes, using alternative fuels, and adopting new technologies for clinker production. However, most studies focus on reducing the clinker content of cement by replacing it with additional cementitious materials such as fly ash, calcined clays, rice husk ash, or blast furnace slag.

[0005] The use of these additional cementitious materials, such as fly ash, a by-product of coal combustion, and blast furnace slag, a by-product of steelmaking, in cement production offers a dual advantage: reducing the carbon footprint of cement and solving waste disposal problems. In particular, these materials can at least partially replace clinker in cement, thereby reducing overall energy consumption and CO2 emissions associated with cement production.

[0006] However, for some of these additional cementitious materials, availability remains limited, and for others, the footprint of the final construction material is not sufficiently reduced. Therefore, the search for alternative components and precursors for low-carbon cement involves exploring new materials that can be used in the manufacture of low-carbon and circular cement.

[0007] It has recently been shown that the incorporation of lithium concentration by-products (e.g., Lithium Slag) could confirm the potential of LS to serve as an additional cementitious material (Gou H et al., Cementitious and Geopolymer Composites with Lithium Slag Incorporation. Materials. 2024; 17(1):142. https: / / doi.org / 10.3390 / mal7010142). The use of these by-products could be part of a circular economy approach in which waste or lithium concentration by-products are used to reduce the use of materials with a high or moderate carbon footprint in construction, such as clinker or metakaolins.

[0008] However, the use of these lithium concentration by-products in construction binders has resulted in cements with variable compressive strengths and drying shrinkage problems. Therefore, there is a need for the development of composite mixtures with lithium concentration by-products that optimize compressive, flexural, and tensile strengths, as well as shrinkage. To this end, a first step is to develop a method for determining optimized compositions for construction binders incorporating these lithium concentration by-products. Summary of the invention

[0009] The invention aims to overcome these drawbacks. The following presents a simplified summary of selected aspects, embodiments, and examples of the present invention in order to provide a basic understanding of the invention. However, this summary does not constitute an exhaustive overview of all aspects, embodiments, and examples of the invention. Its sole purpose is to present selected aspects, embodiments, and examples of the invention in a concise form as an introduction to the more detailed description of the aspects, embodiments, and examples of the invention that follows the summary.

[0010] The invention relates in particular to a method for determining a formulation for a construction binder, said construction binder comprising at least one by-product from a lithium concentration process, said method being implemented by a computer device comprising a calculation module, said method comprising:

[0011] - a step of receiving, by the calculation module, a measured value of at least a physicochemical property of at least one by-product from a lithium concentration process; and

[0012] - a step of selecting, by the calculation module, a quantity of at least one by-product from a lithium concentration process and a quantity of at least one complementary composition to form a construction binder; said at least one complementary composition being selected from: at least one precursor, a deflocculating polymer, an alkaline activation composition and a raw clay matrix.

[0013] While the use of lithium concentration by-products is in its early stages, the applicant has developed a process enabling the determination of a construction binder formulation taking advantage of the characteristics of this by-product while complementing its shortcomings with complementary compositions.

[0014] This makes it possible to generate a composition with mechanical characteristics adapted to the requirements of the construction sector.

[0015] According to other optional features of the process, the latter may optionally include one or more of the following features, alone or in combination: - at least one by-product from a lithium concentration process is from a lithium hydroxide or lithium carbonate preparation process. - at least one by-product from a lithium concentration process has a D50 less than or equal to 20pm. - at least one by-product from a lithium concentration process has a D90 less than or equal to 100pm. - the by-product from a lithium concentration process is a composition containing at least 35% SiO2. - the by-product from a lithium concentration process is a composition comprising at least 15% by weight of A12O3. - The by-product from a lithium concentration process is a composition containing at least 20% by weight of CaCO3. Preferably, at least one by-product from a lithium concentration process is a composition containing at least 50% by weight of CaCO3. In particular, the CaCO3 is in powder form. - at least one by-product from a lithium concentration process is a composition containing at most 2% by weight of lithium, preferably at most 1.75% by weight of lithium, more preferably at most 1.5% by weight of lithium. lithium weight and even more preferably at most 1.25% by weight of lithium. At least one by-product from a lithium concentration process has a sulfur trioxide (SO3) content of 15% or less by weight, preferably 12% or less by weight, more preferably 10% or less by weight, and even more preferably 8% or less by weight. This improves the long-term stability of the construction material. At least one by-product from a lithium concentration process has an amorphous phase content greater than or equal to 15%, preferably greater than or equal to 20%, more preferably greater than or equal to 25%, and even more preferably greater than or equal to 30%. This improves the performance of the construction binder. At least one by-product from a lithium concentration process is mixed with a deflocculating polymer; preferably, the mixing of the at least one by-product from a lithium concentration process and the deflocculating polymer is carried out before mixing with any other complementary compositions. This improves the performance of the construction binder, particularly when the by-product from a lithium concentration process is added at a concentration above 20% by weight of the construction binder, preferably starting at a concentration above 30% by weight relative to the dry weight of the construction binder. The reference values ​​include correlations between measured values ​​of at least one physicochemical property of at least one by-product from a lithium concentration process, and quantities of complementary compositions adapted to said by-product from a lithium concentration process. This mixture partially replaces resources with a high or moderate carbon footprint that are usually used in construction binders (e.g., clinker, blast furnace slag, etc.). Comparison to reference values ​​corresponds to the use of a trained learning model. The selected quantities lead to a construction binder formulation with a mass concentration of lithium less than or equal to 1%, preferably less than or equal to 0.75%, more preferably less than or equal to 0.5%, and even more preferably less than or equal to 0.25%. The selected quantities lead to a construction binder formulation with a mass concentration of A12O3 greater than or equal to 5%, preferably greater than or equal to 7%, more preferably greater than or equal to 8%, and even more preferably greater than or equal to 9%. The selected quantities lead to a construction binder formulation with a mass concentration of A12O3 less than or equal to 15%, preferably less than or equal to 14%. The selected quantities lead to a construction binder formulation with a mass concentration of SiO2 greater than or equal to 20%, preferably greater than or equal to 25%, more preferably greater than or equal to 30%. The selected quantities lead to a construction binder formulation with a CaO mass concentration greater than or equal to 35%, preferably greater than or equal to 40%, more preferably greater than or equal to 42%. The selected quantities lead to a construction binder formulation with a CaO mass concentration less than or equal to 60%, preferably greater than or equal to 57%, more preferably greater than or equal to 55%. The selected quantities lead to a construction binder formulation with a mass concentration of MgO less than or equal to 5%, preferably less than or equal to 4%, more preferably less than or equal to 3%. The selected quantities lead to a construction binder formulation with a mass concentration of Fe2O3 less than or equal to 5%, preferably less than or equal to 4%, more preferably less than or equal to 3%. at least one complementary composition includes at least one precursor selected from: slags such as blast furnace slags, steel slags, cupola slags; fly ash, natural pozzolans, silica fume, micronized limestone fillers, micronized siliceous fillers such as glass powder, siliceous fillers, synthetic vaterite, diatomaceous earth, ground slag or combinations thereof; preferably selected from: blast furnace slags, micronized limestone filler; vaterite such as micrometric or nanometric vaterite; or combinations thereof. - at least one complementary composition includes at least one raw clay matrix relative to the dry weight of construction binder.

[0016] According to a second object, the invention relates to a construction binder that can be obtained by the process according to the invention, characterized in that it comprises at least one by-product from a lithium concentration process, and at least one complementary composition, the at least one complementary composition being selected from a precursor, a deflocculating polymer, a raw clay matrix and / or an alkaline activation composition.

[0017] Depending on other optional characteristics of the binder, the latter may optionally include one or more of the following characteristics, alone or in combination: - It has a mass concentration of CaO less than or equal to 60% relative to the dry weight of construction binder. - it has a mass concentration of A12O3 greater than or equal to 5% relative to the dry weight of construction binder. - it has a mass concentration of MgO less than or equal to 5% relative to the dry weight of construction binder. - It includes at least one raw clay matrix, preferably at least 10% by weight of raw clay matrix. Brief description of the drawings

[0018] Other features and advantages of the invention will be better understood from the following description and with reference to the accompanying drawings, given by way of illustration and not limitation.

[0019] [Fig-1] Fig. 1 represents a method for determining a formulation for construction binder comprising at least one by-product from a lithium concentration process.

[0020] [Fig.2] Fig.2 represents a method for preparing a construction binder according to the invention.

[0021] [Fig.3] Fig.3 represents a method for preparing a construction material according to the invention.

[0022] [Fig.4] Fig.4 represents a system for preparing a construction binder according to the invention.

[0023] The figures do not necessarily respect the scales, particularly in thickness, for illustrative purposes.

[0024] Aspects of the present invention are described with reference to flowcharts and / or functional diagrams of processes, devices (systems) and computer program products according to embodiments of the invention.

[0025] In the figures, flowcharts and functional diagrams illustrate the architecture, functionality, and operation of possible implementations of computer program systems, processes, and products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams can represent a system, device, module, or code, which comprises one or more executable instructions for implementing the specified logical function(s). In some implementations, the functions associated with the blocks may appear in a different order than that shown in the figures. For example, two blocks shown successively may, in fact, be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order, depending on the functionality involved.Each block in the schematic diagrams and / or flowchart, and combinations of blocks in the schematic diagrams and / or flowchart, can be implemented by special hardware systems that perform the specified functions or actions, or carry out combinations of special hardware and computer instructions. Description of the implementation methods

[0026] Below, we describe a summary of the invention and the associated vocabulary, before presenting the disadvantages of the prior art, and finally showing in more detail how the invention remedies them.

[0027] In the following description, the term "binder" can be understood as a formulation that ensures the agglomeration of materials, particularly during the setting and subsequent hardening of a construction material. Thus, it specifically ensures the agglomeration of sand and other constituents of the construction material with the constituents of the binder. The binder according to the invention is, in particular, a hydraulic binder, meaning that hardening occurs upon contact with water.

[0028] The term “formulation” can be defined as the values ​​of the contents of the different components of a composition.

[0029] The term “composition” can be defined as any entity composed of a single, nearly pure compound or a mixture of several components. This entity may be in various physical forms, including but not limited to suspensions, solutions, or in solid form, including powder. The composition can be characterized by its specific formulation, including the proportions of its constituents, its physicochemical properties, and its manufacturing process. The expression “complementary composition” can be defined as the entity or entities that combine with the by-product of a lithium concentration process to form a construction binder.

[0030] The term "by-product" in the context of the invention may refer to a secondary product, composition, or material that is produced or isolated during an industrial process such as, for example, the extraction, purification, transformation, production, concentration, or destruction of a primary product. It is generally not the primary objective of the process and may have characteristics or values ​​different from those of the primary product.

[0031] The expression "by-product of a lithium concentration process" in the context of the invention therefore refers to a by-product obtained during the concentration and processing of lithium. A by-product of a lithium concentration process can exhibit various physical and chemical characteristics associated with the numerous processes developed within the nascent lithium processing industry. It can correspond to a by-product obtained at any stage of a process aimed at obtaining more concentrated lithium.

[0032] For the purposes of this invention, a "flocculant," "flocculant," "flocculant polymer," or "flocculating agent" may refer to a compound capable of dissociating aggregates and colloids, particularly those in aqueous suspension. Flocculant agents have, for example, been used in drilling or oil extraction to make clay more fluid and facilitate extraction or drilling.

[0033] The term "alkaline activation composition" means any composition whose function is to accelerate the dispersion of an aluminosilicate source promoting the formation of stable hydrates with low solubility and the formation of a compact structure with these hydrates, thereby increasing the mechanical resistance of materials incorporating such an activation composition.

[0034] The term "clay matrix," as used in the invention, may refer to one or more rock materials based on hydrated silicates or aluminosilicates with a lamellar structure, said clay matrix being composed of fine particles generally resulting from the alteration of silicates with a three-dimensional framework, such as feldspars. A clay matrix may thus comprise a mixture of such rock materials, which may, for example, consist of kaolinite, illite, smectite, bentonite, chlorite, vermiculite, or mixtures thereof. Furthermore, a clay matrix may include silts.

[0035] For the purposes of this invention, the expression "raw clay matrix" can refer to a clay matrix that has not undergone a calcination step. For example, this corresponds to a clay matrix that has not been subjected to a temperature rise exceeding 300°C, preferably exceeding 200°C, and more preferably exceeding 150°C. Indeed, the raw clay matrix may undergo a heating-drying step requiring a temperature rise generally approximately equal to or less than 150°C but no calcination stage. A raw clay matrix may preferably include a mixture of rock materials which may for example include kaolinite, illite, smectite, micas such as muscovite, bentonite, chlorite, vermiculite, or mixtures thereof, as well as silts.

[0036] The expression "physicochemical property", particularly when referring to a product, can correspond in the sense of the invention to the properties which result from both the physical state and the chemical composition of the product.

[0037] The expression "particle size profile" in the sense of the invention, can correspond to the distribution of particles of a composition as a function of the relative weight importance of the different classes of particles identified by their size (e.g. diameter).

[0038] The term "reference value" in the context of the invention may refer to one or more predetermined values ​​which, in combination with measured values, allow for the determination of complementary quantities and compositions suitable for the formation of a construction binder. The reference values ​​serve as a guide and may take, for example, the form of an algorithm, a machine learning model, limit values, or nomograms.

[0039] The expression "% by weight" in relation to a composition, binder, or construction material should be understood as a proportion relative to the dry weight of the composition, binder, or site-mixed concrete. The dry weight corresponds to the weight before the addition of water, for example, necessary for the formation of a construction material.

[0040] The expression "dry mixture" in the context of the invention can refer to the act of mixing one or more components without the addition of water or any other liquid. Advantageously, the moisture content of a dry mixture does not exceed 5% H2O and preferably 3% H2O, more preferably 2% H2O.

[0041] The expression "learning model" can correspond, in the sense of the invention, in the context of artificial intelligence and machine learning, to a mathematical structure or an algorithm designed to learn patterns or behaviors from data measured or entered into a database.

[0042] Construction binder manufacturing processes generally have a significant environmental footprint. Methods have been proposed to reduce this impact, including the use of lithium concentration by-products. However, considerable variability can be observed in the performance of the resulting construction binders.

[0043] In response to this observation, the applicant has developed a new solution for determining a formulation for a low-carbon construction binder. Advantageously, the construction binder will exhibit good mechanical properties such as that low shrinkage and high compressive strength at early age and at 28 days. As detailed later, the solution developed is based on the definition of a composition incorporating at least one by-product from a lithium concentration process and complementary compounds, in suitable quantities to generate a binder meeting the requirements of the trade.

[0044] Thus, according to a first aspect and as illustrated in [Fig. 1], the invention relates to a method 100 for determining a formulation for a construction binder comprising at least one by-product from a lithium concentration process. Preferably, a method 100 for determining a formulation for a construction binder, said construction binder comprising at least one by-product from a lithium concentration process according to the invention, is implemented by a computer device comprising a calculation module 16.

[0045] As illustrated in [Fig.1], the process comprises: a receiving step 130a of a measured value of at least one physicochemical property of at least one by-product from a lithium concentration process; and a selection step 150 of a suitable quantity of at least one complementary composition to be combined with at least one by-product.

[0046] The at least one by-product from a lithium concentration process may correspond to any by-product generated during a lithium concentration process. In particular, the at least one by-product from a lithium concentration process may be derived from a process for preparing lithium hydroxide or lithium carbonate with a high level of purity. For example, a by-product in this process may correspond to lithium slag, lithium carbonates, sands and limestones, or lithium silicates.

[0047] Generally, the by-product used in the context of the present invention will have a low lithium content. For example, a by-product used in the context of the present invention will contain less than 5% lithium by dry weight. It may contain at most 2% lithium by weight, preferably at most 1.75% lithium by weight, more preferably at most 1.5% lithium by weight, and even more preferably at most 1.25% lithium by weight.

[0048] The by-product from a lithium concentration process may have a composition comprising at least 35% SiO2. The by-product from a lithium concentration process may have a composition comprising at least 15% by weight of Al2O3.

[0049] In addition, the by-product from a lithium concentration process may correspond to a composition comprising at least 20% by weight of CaCO3, preferably at least 50% by weight of CaCO3.

[0050] Advantageously, the by-product generated during (or resulting from) a lithium concentration process is used in solid form, for example in the form of a powder.

[0051] In particular, at least one by-product from a lithium concentration process has a D50 of less than or equal to 50 µm, preferably less than or equal to 40 µm, and more preferably less than or equal to 20 µm. Furthermore, at least one by-product from a lithium concentration process has a D90 of less than or equal to 200 µm, preferably a D90 of less than or equal to 150 µm, and more preferably a D90 of less than or equal to 100 µm.

[0052] As described, the present invention aims to combine a lithium concentration by-product with one or more complementary compositions to form a construction binder.

[0053] At least one complementary composition may be selected from: at least one precursor, a deflocculating polymer, an alkaline activation composition and / or a raw clay matrix;

[0054] At least one complementary composition may include a precursor.

[0055] The precursor can be selected from: slags such as blast furnace slags, steel mill slags, cupola slags; fly ash, natural pozzolans, silica fumes, micronized calcareous fillers, micronized siliceous fillers such as glass powder, siliceous fillers, synthetic vaterite, diatomaceous earth, crushed slags or combinations thereof.

[0056] Advantageously, the precursor can be selected from: blast furnace slags, micronized calcareous filler; vaterite such as micrometric or nanometric vaterite; or combinations thereof.

[0057] In the invention, when the precursor is present, it may be present at a content of at least 1% by weight of the construction binder, preferably at a content of at least 10% by weight of the construction binder, and even more preferably at a content of at least 15% by weight of the construction binder. Furthermore, preferably, the construction binder according to the invention comprises at most 25% by weight of precursor, and even more preferably at most 20% by weight of precursor.

[0058] Thus, in particular, a construction binder according to the invention can comprise between 1% and 25% by weight of precursor, preferably between 10% and 25% by weight of precursor, more preferably between 10% and 20% by weight of precursor.

[0059] Furthermore, the precursor according to the present invention may comprise a calcined clay. The calcined clay may be a raw clay material which has previously undergone heat treatment, preferably at a temperature of at least 450°C and at most 900°C, or in a "flash" calcination process according to Anglo-Saxon terminology at temperatures between 600°C and 900°C.

[0060] Preferably, the calcined clay material is dehydroxylated into an amorphous material while the formation of high-temperature aluminosilicate crystalline phases such as mullite is prevented. The calcined clay matrix is ​​preferably amorphous and has pozzolanic activity.

[0061] The calcined clay matrix can be formed with all the clay matrices mentioned in this description. The calcined clay matrix may comprise, by way of non-limiting example, at least one mineral species selected from: Metakaolin, Metalillite, and / or Metamontmorillonite. Preferably, the clay matrix that has been calcined comprises kaolinite and / or illite. Thus, preferably, the calcined clay matrix consists of metakaolin or metalillite.

[0062] Preferably the calcined clay matrix is ​​a flashed clay matrix, such as, for example, metakaolin obtained from a flash calcination.

[0063] At least one complementary composition may comprise a raw clay matrix.

[0064] Within the framework of the invention, a raw clay matrix may, for example, comprise at least one mineral species selected from: Illite, Kaolinite, Smectite, Vermiculite, Chlorite, Montmorillonites, Muscovite, Halloysite, Sepiolite, and Palygorskite.

[0065] Preferably, the raw clay matrix may comprise at least two types of clay selected from: Illite, Kaolinite, Smectite, Vermiculite, Chlorite, Montmorillonite, Muscovite, Halloysite, Sepiolite, Interstratified clays, Pyrophyllite, Talcs, Serpentines, and Palygorskite. This includes so-called interstratified clays, which are complex combinations of several clays. Even more preferably, the raw clay matrix may comprise at least one mineral species selected from: Kaolinite, Illite, Smectite, Palygorskite, Sepiolite, Chlorite, Montmorillonite, and Vermiculite.

[0066] Table 1 below presents the chemical characteristics of these mineral species. [Tables 1] Matrix Clayey Raw Type of clay Composition Illite (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] Smectite (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2, n H2O Kaolinite Al2Si2O5(OH)4 Vermiculite (Mg,Ca)oj7(Mg,Fe,Al)6(Al,Si)8022(OH)4j n H2O Chlorite (Fe,Mg,Al)6(Si,Al)4O10(OH)8 Muscovite KAl2(AlSi3O10) (OH,F)2 Halloysite Al2Si2O5(OH)4 Sepiolite Mg4Si6O15(OH)2, n H2O Palygorskite (Mg,Al,Fe3+)5[Si8O20](OH)2 (OH2)4n H2O

[0067] According to a preferred embodiment, a binder for a building material according to the invention may comprise at least two different types of clays and may comprise smectite (Smectite, Bentonite, Montmorillonite), kaolinite, and / or illite.

[0068] The type of clay can be determined by methods known to those skilled in the art, for example, after specific sample preparation using the oriented slide method (see Thiry et al. - 2013 - Technique for preparing clay minerals for analysis by X-ray diffraction and introduction to the interpretation of diagrams). In particular, X-ray diffractometry can be used. For example, the following conditions can be used: - Equipment: Diffractometer, for example a BRUKER D8 ADVANCE (Bragg-Brentano geometry); for example with the following settings: Copper Tube (X Kal ~ 1.54 Å) Generator power: 40 kV, 40 mA; Primary optics: fixed slit 0.16°; Soller slit 2.5°; Secondary optics: Soller slit 2.5°; LynXeye XE-T detector - Acquisition parameters: Scanning from 4 to 90°20; Scanning speed of 0.03°20 / second, Counting time: 480 seconds per step; Rotating sample.

[0069] A construction binder according to the invention may comprise at least 5% by weight of raw clay matrix relative to the dry weight of construction binder, preferably at least 10% by weight of raw clay matrix, more preferably at least 15% by weight of raw clay matrix, even more preferably at least 20% by weight of raw clay matrix relative to the dry weight of construction binder.

[0070] A construction binder may comprise at most 50% by weight of raw clay matrix relative to the dry weight of construction binder, preferably at most 40% by weight. weight of raw clay matrix relative to the dry weight of construction binder, more preferably at most 30% by weight of raw clay matrix relative to the dry weight of construction binder, even more preferably at most 20% by weight of raw clay matrix relative to the dry weight of construction binder.

[0071] A construction binder according to the invention may comprise from 5% to 50% by weight of raw clay matrix relative to the dry weight of construction binder, preferably from 5% to 40% by weight of raw clay matrix relative to the dry weight of construction binder, preferably from 5% to 30% by weight of raw clay matrix relative to the dry weight of construction binder and even more preferably from 10% to 30% by weight of raw clay matrix relative to the dry weight of construction binder.

[0072] Advantageously, the raw clay matrix may have a D50 less than or equal to 200 pm, preferably less than or equal to 150 pm, more preferably less than or equal to 100 pm, even more preferably less than or equal to 80 pm.

[0073] At least one complementary composition may include a deflocculating polymer. The presence of one or more deflocculating polymers may improve the performance of the material formed from the construction binder. Many compounds can act as deflocculating polymers, many of which are generally known to those skilled in the art.

[0074] In the context of the invention, a construction binder may comprise an organic deflocculating agent, advantageously a deflocculating polymer. According to the present invention, an organic deflocculating polymer comprises at least one carbon atom and preferably at least one carbon-oxygen bond.

[0075] The deflocculant polymer may be a non-ionic surfactant such as a polyoxyethylene ether. The polyoxyethylene ether may, for example, be selected from: a poly(oxyethylene) lauryl ether. The deflocculant polymer may also be an anionic agent such as an anionic surfactant. In particular, the anionic agent may be selected from: alkylaryl sulfonates, amino alcohols, carbonates, silicates, fatty acids, humates (e.g., sodium humates), carboxylic acids, lignosulfonates (e.g., sodium lignosulfonates), polyacrylates, phosphates or polyphosphates such as sodium hexametaphosphate, sodium tripolyphosphate, sodium orthophosphate, carboxymethylcelluloses, and mixtures thereof.

[0076] The deflocculant polymer can also be a polyacrylate. It can then be selected, for example, from sodium polyacrylate and ammonium polyacrylate.

[0077] The deflocculating polymer may also be an amine selected, for example, from: 2-amino-2-methyl-l-propanol; mono-, di- or tri-ethanolamine, the isopropanolamines (l-Amino-2-propanol, diisopropanolamine, triisopropanolamine) and N-alkyl ethanolamines.

[0078] Preferably, the deflocculating polymer is selected from: a lignosulfonate (e.g., sodium lignosulfonate), a polyacrylate, a humate, and mixtures thereof.

[0079] Preferably, the deflocculating polymer is selected from: a lignosulfonate (e.g. sodium lignosulfonate), a polyacrylate, a humate, a polycarboxylate such as an ether polycarboxylate, and mixtures thereof.

[0080] More preferably, the deflocculating polymer comprises a humate, a lignosulfonate and / or a polyacrylate.

[0081] Alternatively, the deflocculating polymer may be a mixture of compounds, such as a mixture comprising at least two compounds selected from: non-ionic surfactant, anionic agent, polyacrylate, amine and organophosphorus compound.

[0082] However, the invention cannot be limited to the deflocculant polymers mentioned above; any type of deflocculant polymer known to a person skilled in the art can be used in place of the aforementioned deflocculant polymers.

[0083] The deflocculant polymer is preferably in the form of a salt. The deflocculant polymers usable according to the present invention may be in solid or liquid form.

[0084] In particular, the deflocculating agent, preferably the deflocculating polymer, represents at least 0.05% by weight of the construction binder, preferably at least 0.1% by weight of the construction binder, preferably at least 0.25% by weight of the construction binder, more preferably at least 0.5% by weight of the construction binder, more preferably at least 0.5% by weight of the construction binder, even more preferably at least 0.8% by weight of the construction binder and for example at least 1% by weight of the construction binder.

[0085] Furthermore, the deflocculating agent, preferably the deflocculating polymer, represents at most 5% by weight of the construction binder, preferably at most 4% by weight of the construction binder, more preferably at most 3% by weight of the construction binder, and even more preferably at most 2% by weight of the construction binder. Indeed, an excessively high concentration is not necessary to form a material with advantageous mechanical properties.

[0086] In particular, the deflocculating agent, preferably the deflocculating polymer, represents between 0.05% and 5% by weight of the construction binder, preferably between 0.1% and 4% by weight of the construction binder, more preferably between 0.25% and 3% by weight of the construction binder, even more preferably between 0.5% and 2% by weight of the construction binder, and even more preferably between 0.8% and 2% by weight of the construction binder and even more preferably between 0.9% and 2% by weight of the construction binder.

[0087] Advantageously, the deflocculating polymer is pre-mixed with the by-product from a lithium concentration process. This makes it possible to improve the performance of the construction binder, particularly when the by-product from a lithium concentration process is added at a concentration greater than 20% by weight of the construction binder, preferably from a concentration greater than 30% by weight relative to the dry weight of the construction binder.

[0088] At least one complementary composition may include an alkaline activation composition.

[0089] Preferably, the alkaline activation composition can be selected from: clinker, CEM I, lime, silicates such as sodium silicate, carbonates such as sodium carbonate, or combinations thereof. Advantageously, the activator comprises clinkers.

[0090] Furthermore, a construction binder according to the invention may comprise at least 5% by weight of alkaline activation composition relative to the dry weight of the construction binder, preferably at least 10%, more preferably at least 15%, and even more preferably at least 20% by weight of activator(s) relative to the dry weight of the construction binder.

[0091] A construction binder according to the invention may comprise at most 55% by weight of alkaline activation composition relative to the dry weight of the construction binder, preferably at most 50%, more preferably at most 45%, and even more preferably at most 40% by weight of activator(s) relative to the dry weight of the construction binder.

[0092] A construction binder according to the invention may comprise from 5% to 55% by weight of activator(s) relative to the dry weight of the construction binder, preferably from 10% to 50%, more preferably from 15% to 45%, and even more preferably from 20% to 40% by weight of activator(s) relative to the dry weight of the construction binder.

[0093] Preferably, the construction binder comprises at least 20% by weight of CEM I as an activator relative to the dry weight of construction binder.

[0094] One of the features of the present invention is to combine a lithium concentration process by-product with complementary compositions to achieve target values ​​on certain constituents of the construction binder.

[0095] The selection step 150 of a quantity of at least one by-product from a lithium extraction process and of a quantity of at least one complementary composition is carried out by a calculation module configured for this purpose.

[0096] Selection step 150 may advantageously include an analysis of input data (such as received data) to determine the optimal quantities of the constituents of a construction binder to achieve optimal final quantities. Furthermore, this may be based on optimal ratios between essential chemical elements based on predefined criteria reflecting the quantities and ratios expected to achieve the desired performance characteristics of the binder.

[0097] Thus, advantageously, the selection step 150 makes it possible to obtain a formulation which, when implemented during the preparation of a construction binder, makes it possible to obtain defined performance characteristics. This relates in particular to mechanical performance such as mechanical strength and shrinkage. In particular, the selected quantities can determine the formulation of the construction binder, and the process according to the invention can allow for optimization of the formulation of an alkaline construction binder.

[0098] In particular, the calculation module will be able to establish comparisons between the measured value(s) of physicochemical properties and reference values. This comparison can be carried out using predetermined charts or expert rules. The comparison is followed by a selection of suitable values ​​for the quantities of the different constituents to meet the predefined reference values.

[0099] Alternatively, this comparison can be performed by a computational algorithm configured to select complementary compositions and suitable quantities. This computational algorithm may have been built from different learning models, including partitioning models, supervised or unsupervised. An unsupervised statistical learning model may, for example, be selected from an unsupervised Gaussian mixture model, a hierarchical clustering agglomerative (HCG), or a hierarchical clustering divisive (HCG). A supervised statistical learning model may, for example, be selected from kernel methods (e.g., Large Margin Separators - Support Vector Machines (SVMs), Kernel Ridge Regression) described, for example, in Burges, 1998 (Data Mining and Knowledge Discovery).A Tutorial on Support Vector Machines for Pattern Recognition), ensemble methods (e.g., Bagging, Boosting, Decision Trees, Random Forests) described, for example, in Brieman, 2001 (Machine Learning. Random Forests), or neural networks described, for example, in Rosenblatt, 1958 (The Perceptron: A Probabilistic Model for Information Storage and Organization in the Brain). Preferably, the previously calibrated computational algorithm was obtained by implementing a supervised learning statistical method.

[0100] Advantageously, the method may include a step of creating a correlation between the received measured values ​​in order to calibrate a calculation algorithm. This correlation step, based on measured values, makes it possible to build a calculation algorithm from a statistical learning model.

[0101] In particular, during the selection stage, the complementary compositions and the quantities of by-product and complementary compositions are selected so that the construction binder has, in relation to its dry weight: - a mass concentration of lithium less than or equal to 1%, preferably less than or equal to 0.75%, more preferably less than or equal to 0.5%, and even more preferably less than or equal to 0.25%. - a mass concentration of A12O3 greater than or equal to 5%, preferably greater than or equal to 7%, more preferably greater than or equal to 8%, and even more preferably greater than or equal to 9%. - a mass concentration of A12O3 less than or equal to 15%, preferably less than or equal to 14%. - a mass concentration of SiO2 greater than or equal to 20%, preferably greater than or equal to 25%, more preferably greater than or equal to 30%. - a mass concentration of CaO greater than or equal to 35%, preferably greater than or equal to 40%, more preferably greater than or equal to 42%. - a mass concentration of CaO less than or equal to 60%, preferably greater than or equal to 57%, more preferably greater than or equal to 55%. - a mass concentration of MgO less than or equal to 5%, preferably less than or equal to 4%, more preferably less than or equal to 3%. - a mass concentration of Fe2O3 less than or equal to 5%, preferably less than or equal to 4%, more preferably less than or equal to 3%.

[0102] Furthermore, as illustrated in [Fig. 1], a process according to the invention may further comprise: a supply step 110 of the by-product from a lithium concentration process; a measurement step 120a of at least one physicochemical property of the by-product from a lithium concentration process; a measurement step 120b of at least one physicochemical property of at least one complementary composition; a reception step 130b of at least one physicochemical value of at least one complementary composition; an acquisition step 140 of at least one reference value; a selection step 160 of a quantity of additives to be added to the construction binder formulation.

[0103] A determination method 100 according to the present invention may include a step of selecting a quantity of at least one additive to the construction binder formulation. The selection step 160 of at least one additive allows the construction binder formulation to be completed.

[0104] Additives may, for example, be molecules known to improve the performance of construction binders. An additive will generally be present at a mass concentration of 10% or less by weight of the dry weight of the construction binder. Preferably, the additive(s) will be present at a cumulative content of 8% or less, more preferably 7% or less, and even more preferably 6% or less, for example, 5% or less.

[0105] Additives can for example be selected from: amines (such as triethanolamine, triisopropanolamine, or hydroxyethyldiethylenetriamine), glycol-based compounds (such as monoethylene glycol, ethylene glycol, diethylene glycol, propylene glycol), phenolic compounds, glycerol, sodium stearate, sodium gluconate, or calcium nitrate.

[0106] According to another aspect, the invention relates to a construction binder.

[0107] In particular, the invention relates to a construction binder that can be obtained by the process for preparing a construction binder according to the invention. Preferably, the invention relates to a construction binder obtained by the process for preparing a construction binder according to the invention.

[0108] A construction binder according to the present invention shall have the characteristic of comprising at least one lithium concentration by-product. A construction binder according to the invention may also have the characteristic of having been prepared according to the formulation selected within the framework of a selection process according to the present invention. Beyond this preparation characteristic, as described in the detailed description of the formulation selection process for these advantageous embodiments, a construction binder according to the invention may have specific contents for certain chemical elements enabling it to achieve high performance despite the presence of a lithium concentration by-product.

[0109] The following characteristics are given for a binder in its dry state, preferably dehydrated. That is to say, it preferably has a water content of less than 5%, more preferably less than 3%, and more preferably less than or equal to 2%.

[0110] Preferably, a construction binder according to the present invention has a CaO content of 60% or less. More preferably, a construction binder according to the present invention has a CaO content of 57% or less. Even more preferably, a construction binder according to the present The invention has a CaO content of 55% or less. However, the applicant has also identified minimum CaO concentrations for obtaining construction binders with good properties. Thus, a construction binder according to the present invention has a CaO content of 35% or more. More preferably, a construction binder according to the present invention has a CaO content of 40% or more. Even more preferably, a construction binder according to the present invention has a CaO content of 42% or more.

[0111] Preferably, a construction binder according to the present invention has a SiO2 content greater than or equal to 20%. More preferably, a construction binder according to the present invention has a SiO2 content greater than or equal to 25%. Even more preferably, a construction binder according to the present invention has a SiO2 content greater than or equal to 30%.

[0112] Preferably, a construction binder according to the present invention has a Li content (in any form) greater than or equal to 0.1%. More preferably, a construction binder according to the present invention has a Li content (in any form) greater than or equal to 0.2%. Even more preferably, a construction binder according to the present invention has a Li content (in any form) greater than or equal to 0.4%, for example 0.6% by weight relative to the dry weight of the construction binder.

[0113] Lithium can be present in the form of LiO, LiCO3, LiOH, LiClO4, LiSO4, Li3PO4, LiCl. The lithium concentration can be measured by ICP-MS.

[0114] Preferably, a construction binder according to the present invention has an Al₂O₃ content of 15% or less. More preferably, a construction binder according to the present invention has an Al₂O₃ content of 14% or less. Preferably, a construction binder according to the present invention has an Al₂O₃ content of 5% or more. More preferably, a construction binder according to the present invention has an Al₂O₃ content of 7% or more. Even more preferably, a construction binder according to the present invention has an Al₂O₃ content of 8% or more, for example, 9% or more. The Al₂O₃ concentration can be measured by X-ray fluorescence.

[0115] Preferably, a construction binder according to the present invention has an MgO content of 5% or less. More preferably, a construction binder according to the present invention has a preferred MgO content of 4% or less. Even more preferably, a construction binder according to the present invention has a preferred MgO content of 3% or less. The MgO concentration can be measured by X-ray fluorescence.

[0116] Preferably, a construction binder according to the present invention has an Fe2O3 content of 5% or less. More preferably, a construction binder according to the present invention has an Fe2O3 content of 4% or less. Even more preferably, a construction binder according to the present invention has an Fe2O3 content of 3% or less. The Fe2O3 concentration can be measured by X-ray fluorescence.

[0117] According to another aspect, the invention relates to a method for preparing a construction material obtained from a construction binder according to the invention.

[0118] As illustrated in [Fig. 3], the process 300 for preparing a construction material may include a step 310a of supplying a construction binder, and a step 310b of supplying water, aggregates, and / or fillers. Furthermore, the process will include a step 320 of mixing the construction binder with the water, aggregates, and / or fillers. The addition of water will conventionally be at a concentration of between 0.4 and 0.6 by dry weight of the construction binder.

[0119] Thus, according to another aspect, the invention relates to a construction material obtained from a construction binder according to the invention.

[0120] A construction material according to the present invention may comprise aggregates. Typically, aggregates may be natural aggregates, artificial aggregates, or recycled aggregates.

[0121] Aggregates may also include mineral aggregates, i.e., mainly composed of mineral matter, and / or plant aggregates, i.e., mainly composed of matter of plant origin. Aggregates may also include marine aggregates, i.e., mainly composed of organic or inorganic matter from the seabed, such as siliceous aggregates and / or calcareous substances (e.g., maerl and shell sands).

[0122] Mineral aggregates can, for example, correspond to sand, gravel, pebbles, fillers (or fine materials), powders, fossilized waste and combinations thereof.

[0123] Plant aggregates may, for example, consist of wood (chips or fibers), hemp, straw, hemp shives, miscanthus, sunflower, cattail, maize, flax, rice husks, wheat husks, rapeseed, seaweed, bamboo, cellulose wadding, defibrated fabric and combinations thereof

[0124] In particular, when the building material according to the invention comprises plant aggregates, said material preferably comprises at least 0.1% by weight of plant aggregates, preferably at least 0.2% by weight of plant aggregates, more preferably at least 0.5% by weight of plant aggregates, and even more preferably at least 0.7% by weight of plant aggregates.

[0125] In another aspect, the invention relates to a system 1 for preparing a construction binder. A system 1 according to the present invention can be specially configured to obtain a construction binder from a process 200 for preparing a construction binder according to the present invention.

[0126] A system for preparing a construction binder according to the present invention may include a calculation module 16 as well as: a by-product tank 10, a complementary composition tank 11, an additive tank 12, a mixing device 13, one or more carrier(s) 14, and / or one or more means 15 for detecting at least one physicochemical property.

[0127] In particular, a system 1 according to the present invention may include reservoirs 10, 11, 12 for containing the various constituents of the construction binder formulation. Thus, a system 1 may include at least one reservoir 10 for containing a by-product from a lithium concentration process. A system 1 according to the invention may also include at least one reservoir 11 for containing a complementary composition; advantageously, the system 1 includes at least one reservoir 11 for each of the different components of the complementary composition, for example, one reservoir 11 for containing at least one precursor, one reservoir 11 for the raw clay matrix, one reservoir 11 for the alkaline activation composition, and / or one reservoir 11 for the deflocculating polymer. Advantageously, the reservoirs 10, 11, 12 may be selected from: a tank, a container, a tub, or a silo.

[0128] A system 1 according to the present invention may further include a mixing device 13. A mixing device 13 allows the various constituents of the construction binder formulation to be mixed. A mixing device 13 may be selected from: a powder mixer; a ribbon mixer; a concentric ribbon mixer; a plow mixer; a horizontal mixer. The mixer may be continuous or batch.

[0129] A system 1 according to the present invention may include one or more conveyor(s) 14. A conveyor 14 allows, for example, the conveying of a quantity of at least one by-product from a lithium concentration process, at least one complementary composition and / or at least one additive to the mixing device 13. Advantageously, each tank 10, 11, 12 is connected to the mixing device 13 by a conveyor 14 which is specific to it.

[0130] A conveyor 14 can be selected from flexible or rigid pipes, belts, conveyors, or screws. Furthermore, in combination with the conveyor(s) 14, the system 1 can include pumps, valves, solenoid valves, and flow restrictors. In particular, the flow restrictors can be arranged in functional switching with the conveyor(s) 14 to independently regulate the quantity of each of the ingredients distributed to the mixing device 13.

[0131] Furthermore, the system 1 according to the invention may include at least one measuring means 15 for at least one physicochemical property. Advantageously, the system 1 according to the invention includes at least one measuring means 15 per reservoir 10, 11, 12. Thus, at least one measuring means is capable of performing at least one measurement of at least one physicochemical property of at least one by-product from a lithium concentration process, at least one complementary composition, and / or at least one additive. Such a measuring means 15 may, for example, be a pH meter, an X-ray diffractometer, a conductivity meter, an electron microscope, a mercury porosimeter, a spectrofluorometer, an ICP-MS, an HPLC-MS, a GC-MS, a specific surface area measurement by the BET method, a particle size analyzer, or a rheometer.

[0132] A system 1 according to the invention may include a computing module 16 capable of, preferably configured to, implement a computer program configured to perform: - a receiving step of a measured value of at least one physicochemical property of a by-product from a lithium concentration process, of at least one complementary composition and / or of at least one additive; - a step of selecting a quantity of at least one by-product from a lithium concentration process to form a construction binder and, - a step of selecting at least one complementary composition or at least one complementary composition and at least one additive, to form a construction binder on the basis of a comparison of the measured value(s) to reference values. Alternatively, a system 1 according to the invention may include a calculation module 16 suitable for, preferably configured to, receive a construction binder formulation comprising a quantity of by-product from a lithium concentration process.

[0133] In addition, a calculation module 16 can control the conveyor(s) 14. For example, the calculation module 16 can control the conveyor(s) so that they transport an appropriate quantity of the various constituents required for the construction binder formulation, according to the reference value(s). Also, a calculation module 16 can control the mixing device 13.

[0134] The invention can be the subject of numerous variations and applications other than those described above. In particular, unless otherwise indicated, the various structural and functional features of each of the embodiments described above should not be considered as combined and / or closely and / or inextricably linked to one another, but rather as mere juxtapositions. Furthermore, the structural and / or functional features of the various embodiments described above may be the subject, in whole or in part, of any different juxtaposition or any different combination.

Claims

Demands

1. A method (100) for determining a formulation for a construction binder, said construction binder comprising at least one by-product from a lithium concentration process, said method being implemented by a computer device comprising a calculation module (16), said method comprising: - a receiving step (130a), by the calculation module (16), of a measured value of at least one physicochemical property of at least one by-product from a lithium concentration process; and - a selection step (150), by the calculation module (16), of a quantity of at least one by-product from a lithium concentration process and a quantity of at least one complementary composition to form a construction binder; said at least one complementary composition comprising at least one deflocculating polymer, and / or a raw clay matrix.

2. A method (100) for determining according to claim 1, characterized in that at least one by-product from a lithium concentration process is from a lithium hydroxide or lithium carbonate preparation process.

3. Method (100) of determination according to any one of the preceding claims, characterized in that at least one by-product from a lithium concentration process has a D50 less than or equal to 20pm.

4. Method (100) of determination according to any one of the preceding claims, characterized in that at least one by-product from a lithium concentration process has a D90 less than or equal to 100pm.

5. A method (100) for determining a construction binder formulation according to any one of the preceding claims, characterized in that the by-product from a lithium concentration process is a composition comprising at least 35% SiO2.

6. A method (100) for determining a formulation for a construction binder according to any one of the preceding claims, characterized in that the by-product obtained from a method lithium concentration is a composition containing at least 15% by weight of A12O3.

7. A method (100) for determining a construction binder formulation according to any one of the preceding claims, characterized in that at least one by-product from a lithium concentration process is a composition comprising at most 2% by weight of lithium.

8. A method (100) for determining according to any one of the preceding claims, characterized in that at least one by-product from a Lithium concentration process has a sulfur trioxide (SO3) content of less than or equal to 15% by weight.

9. A method (100) for determining lithium concentration according to any one of the preceding claims, characterized in that at least one by-product from a lithium concentration process has an amorphous phase content greater than or equal to 15%

10. Method (100) of determination according to any one of the preceding claims, characterized in that at least one by-product from a Lithium concentration process is mixed with a deflocculating polymer, the mixing between at least one by-product from a Lithium concentration process and the deflocculating polymer is carried out before mixing with any other complementary composition.

11. A method (100) for determining a formulation for a construction binder according to claim 1, characterized in that it further comprises a step of acquiring at least one reference value and in that the reference value or values ​​include correlations between measured values ​​of at least one physicochemical property of at least one by-product from a lithium concentration process on the one hand and quantities of complementary compositions adapted to said by-product from a lithium concentration process on the other hand.

12. Method (100) of determination according to claim 11, characterized in that it further comprises comparisons between the measured value(s) of physicochemical properties with reference values ​​and in that the comparison to reference values ​​corresponds to the use of a trained learning model.

13. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of lithium less than or equal to 1%.

14. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of A12O3 greater than or equal to 5%.

15. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of A12O3 less than or equal to 15%.

16. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of SiO2 greater than or equal to 20%.

17. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of CaO greater than or equal to 35%.

18. A method (100) for determining according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of CaO less than or equal to 60%

19. Method (100) of determination according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation having a mass concentration of MgO less than or equal to 5%.

20. A method (100) for determining according to any one of the preceding claims, characterized in that the selected quantities lead to a construction binder formulation exhibiting a mass concentration of Fe2O3 less than or equal to 5%.

21. A method (100) for determining according to any one of the preceding claims, characterized in that at least one complementary composition comprises at least one precursor selected from: slags such as blast furnace slags, steel slags, cupola slags; fly ash, natural pozzolans, silica fume, micronized limestone fillers, micronized siliceous fillers such as glass powder, siliceous fillers, synthetic vaterite, diatomaceous earth, ground slag or combinations thereof; preferably selected from: blast furnace slags, micronized limestone filler; vaterite such as micrometric or nanometric vaterite; or combinations thereof.

22. Method (100) of determination according to any one of the preceding claims, characterized in that at least one complementary composition is further selected from at least one precursor and one alkaline activation composition.

23. A process (200) for preparing a construction binder, said process for preparing the construction binder comprising a mixing step between at least one by-product from a lithium concentration process and at least one complementary composition according to a construction binder composition of the selection process (100) according to claims 1 to 22.

24. Construction binder capable of being obtained by the process of preparing a construction binder according to the preceding claim, characterized in that it comprises at least one by-product from a lithium concentration process, and at least one complementary composition, the at least one complementary composition comprising at least one raw clay matrix, preferably at least 10% by weight of raw clay matrix relative to the dry weight of construction binder and / or a deflocculating polymer.

25. Construction binder according to claim 24 characterized in that it comprises a mass concentration of CaO less than or equal to 60% relative to the dry weight of construction binder.

26. Construction binder according to any one of claims 24 or 25 characterized in that it comprises a mass concentration of A12O3 greater than or equal to 5% relative to the dry weight of construction binder.

27. ​​Construction binder according to any one of claims 24 to 26, characterized in that it comprises a mass concentration of MgO less than or equal to 5% relative to the dry weight of construction binder.

28. Construction binder according to any one of claims 24 to 27, characterized in that at least one additional composition can be further selected from a precursor, and / or an alkaline activation composition.

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