System and method for generating a powdered material

Abstract

A system and method for generating a pozzolanic powder material, or ground glass pozzolan, also referred to as GGP, from silica-based waste materials (recycled glass) wherein at least 90% (±2%) of the pozzolanic particles of the GGP have a particle size of about 20 µm (±2 µm) and / or less. In an embodiment the powder material may have a mean pozzolanic particle size of 5 µm ± 2µm). The system may include an impact mill that incorporates a conical inner liner and corresponding rotor that includes grinding elements; and the inner liner and grinding elements are composed of a ceramic-metallic material. A cementitious mixture according to aspects of the invention including a combination of OPC and GGP may comprise between about 10% to about 25% by weight of GGP wherein least 90% (±2%) of the pozzolanic particles of the GGP have a particle size of about 20 µm (±2 µm) and / or less.

Description

SYSTEM AND METHOD FOR GENERATING A POWDERED MATERIALCross-Reference to Related Applications

[0001] This application is an international application, which claims the benefit of United States provisional application serial no. 63 / 702,700, filed October 3, 2024. The entire contents of each of this application is hereby incorporated by reference as if fully set forth herein.Background

[0002] The invention disclosed herein relates generally to the comminution and micronization of preferably waste or recyclable materials to an ultra-fine powder material. More specifically, the invention relates to generating pozzolanic powder materials or ground glass pozzolan (GGP) from silica-based waste materials.

[0003] Pozzolan is a finely divided siliceous or siliceous and aluminous material that reacts chemically with slaked lime at ordinary temperature and in the presence of moisture to form a strong slow-hardening cement. Pozzolanic powder materials can be generated from naturally occurring materials and / or artificial (man-made) materials. For example, feedstocks used for generating powder material may include reclaimed fly ash, various types of slags, including lithium slag, foundry sand, stamps sands (e.g. derived from copper mining tailings). In addition, crystalline structured silica, such as glass that have amorphous forms, may be used for generating pozzolanic powder materials

[0004] It is known to use pozzolanic powder material as a supplemental cementitious material (SCM). To that end, GGP, a promising supplementary cementitious material (SCM), has emerged as a solution.

[0005] Cement and concrete are intertwined to the point that the terms are often used interchangeably. Concrete is the material that persons interact with every day - in the structure of our homes, offices and hospitals, supporting our bridges and infrastructure; while cement is the “glue” that binds the ingredients of concrete together. Cement is a fine powder made by crushing, then heating, limestone or chalk, with a few other natural materials such as clay or shale. Today, Portland clinker-based cement, first developed in the beginning of the 1800s, is the most common type of cement in use. The ground basematerials are heated in a rotating kiln to a temperature of up to l,450°C or as hot as volcanic lava.

[0006] In comparison, concrete is a mixture of cement, water, and aggregates (e.g., sand, gravel, and crushed stone) and often includes small amounts of admixtures for performance enhancements. The exact ratios and mix of aggregates used depend on how the concrete is intended to be used. One of concrete’s key assets is its versatility. Concrete is used in a variety of ways to solve the many needs of societies - shelter, housing, providing clean water and sanitation, transport, business and commerce.

[0007] According to the Global Cement and Concrete Association (GCCA), the cement industry contributes approximately 7% of global anthropogenic carbon dioxide (CO2) emissions. Considering this fact and the essential role of cement in concrete construction and infrastructure development, the industry has spearheaded research to minimize the environmental impact of cement production and support sustainability efforts.

[0008] One approach towards reducing the carbon footprint of the cement industry involves the replacement of cement in concrete mixtures with SCMs such as silica fume, metakaolin, fly ash and / or slag. These materials, also called pozzolans, chemically react with lime to form additional cementitious compounds and enhance the strength and durability of concrete. They not only lower the total embodied energy and carbon footprint of concrete but also lower the total cost of the concrete and increase sustainability within the construction industry, since the materials either occur naturally (metakaolin) or come from by-products of other industrial processes (silica fume, fly ash and slag). The cement industry has also accepted Ground Glass Pozzolans (GGPs) as another SCM type that can contribute to significantly lower use of cement in a concrete mixture. These materials can be blended with other SCM material to improve aesthetics, costs and mechanical properties of concrete systems.

[0009] GGP is an environmentally sustainable material, produced by finely grinding recycled glass into a powdery form. It serves as a SCM in concrete, contributing to stronger and more durable concrete mixtures. GGP is derived from various post-consumer waste glass sources, involving processes such as collection, cleaning, crushing, and ultra-fine grinding. The adoption of recycled glass as a pozzolan aligns with sustainable constructionpractices, offering a viable solution for glass waste management and reducing the environmental footprint associated with concrete production.

[0010] The ASTM C 1866 standard specifies the requirements for ground glass pozzolans used in concrete. This standard encompasses ground glass from different sources like container glass, plate glass, and E-glass, and outlines necessary chemical and physical properties for concrete applications. GGP can be derived from various sources of postconsumer waste or recycled glass. The process typically involves collecting the waste glass, cleaning and crushing it into fine particles, and then grinding it into an ultra-fine powder. Using recycled glass as a pozzolan not only provides a sustainable solution for managing glass waste but also contributes to reducing the environmental impact associated with concrete production. This utilization of recycled materials aligns with sustainable construction practices and can enhance the overall eco-friendliness of building projects.

[0011] Micronization, which is the mechanical reduction of materials, is commonly used in various industries such as pharmaceuticals, chemicals, food, and cosmetics. Micronization may add functionality to a particle by altering its physical and chemical properties. Some ways in which micronization enhances the functionality of particles include (1) increased surface area; (2) improved dispersion and mixing; (3) enhanced bioavailability; (4) altered physical properties (5) tailored release profiles. Overall, micronization enables improved interaction with the surrounding environment, enhanced solubility, better dispersion, and controlled release, enhancing performance and functionality in various applications. To control the distribution of micronized particle sizes, air classification is employed. An air classifier can precisely, predictably, and efficiently sort micronized particles by size, shape, and mass, resulting in precise product cuts. From the resultant cuts, different product performance profiles can be created to optimize SCM to the specific needs of a project.Summary of the Invention

[0012] The ASTM Cl 866 provides the standard specification for GGP use in concrete including particle size of 45 pm; however, micronization systems are not available produce a pozzolanic powder material that has a particle size distribution that is less than 45 pm. The inventors, on the other hand, have developed a system and method for generating a pozzolanic powder material, or ground glass pozzolan, also referred to as GGP, from silica- based waste materials (recycled glass) wherein at least 90% (±2%) of the pozzolanicparticles of the GGP have a particle size of about 20 pm (±2 pm) and / or less. In some embodiments the system and method may produce GGP having a particle size wherein at least 90% (±2%) of the pozzolanic particles of the GGP have a particle size of about 10 pm (±2 pm) and / or; and, in some embodiments, the system an and method may produce GGP wherein at least 90% (±2%) of the pozzolanic particles of the GGP have a particle size of about 5 pm (±2 pm) and / or less. Embodiments of the system and method may produce GGP where at less than 50% (±2%) of the particles are 5 pm or less. In an embodiment the powder material may have a mean pozzolanic particle size of 5 pm ±2pm. In an embodiment, at least 95% of the pozzolanic particles have a particle size with a mean particle size of about 5 pm.

[0013] The system for generating pozzolanic powder material from feedstock of silica- based waste materials, may comprise an impact mill (a first grinding mill) including a rotor mounted within a housing. The rotor includes a central hub and a plurality of radially projecting shelves axially spaced relative to the rotor and central hub. The shelves are dimensioned to define a conical shape, and the rotor is operatively connected to a motor to rotate about a common rotational axis of the rotor and hub.

[0014] Grinding mills, other than an impact mill may be used, for example, the term grinding mill may include for example, a vortex mill, a disk mill or jet mill.

[0015] In addition, the system and impact mill include a conically shaped inner liner mounted to the housing and the inner liner may have a serrated surface facing the rotor, and the inner liner is preferably composed of a ceramic-metallic material. A plurality of grinding elements are mounted along a periphery of a respective rotor shelf and each grinding element has a grinding surface facing the inner liner and spaced from the inner liner. Each grinding element may be composed of a ceramic-metallic material and the face of one or more of the grinding elements includes a plurality of parallel troughs and veins.

[0016] The inner liner and grinding elements define a conically shaped grinding gap therebetween within the housing and the grinding gap is in fluid flow communication with an opening through a top of the rotor housing and through which a feedstock is input. The feedstock includes silica-based waste material such as recycled glass.

[0017] An air classifier is provided in fluid communication with the impact mill and grinding gap via an output of the impact mill to receive ground glass pozzolanic material(GGP) generated in the mill by grinding of the feedstock. The air classifier is configured to separate the GGP material according to a threshold particle size (a first particle size threshold), wherein GGP particles that are equal to or less than the threshold particle size are output relative to the air classifier to a first silo via a first classifier output and particles of the GGP that are greater than the threshold particle size are returned to the impact mill via a return line for further grinding.

[0018] In addition, the system may further comprise a jet mill (a second grinding mill) in fluid flow communication and downstream relative to the air classifier. A second classifier output line provides fluid flow communication between the air classifier and a jet mill. The air classifier is configured to separate GGP discharged from the impact mill to return particles, for example greater than 30 pm to the impact mill and output GGP particles having a particle size of 20 pm and less to the first silo, wherein at least 90% of the particles of the GGP sent to the first silo have a particle size of equal to or less than 20 pm and a mean particle of size of 5 pm, and output GGP particles between 20 pm (first particle size threshold) and 30 pm (second particle size threshold) to the jet mill via the second classifier output line.

[0019] In addition, the jet mill is configured to further grind the GGP and separate the particles according to one or more selected particle sizes and output GGP to a second silo in fluid flow communication with the jet mill and wherein at least 90% of the particles of the GGP sent to the second silo have a particle size of equal 20 pm and output GGP to one or more third silos and the GGP output to the third silos and at least 90% of the particles of the GGP sent to the one or more third silos have a particle size less than 20 pm.

[0020] The system may also include sensors, detectors and controllers to monitor the health of and operating condition of the system and system components. Accordingly, the system may include one or more inline particle analyzers operatively connected between the impact mill and the air classifier to detect a particle size of GGP output from the impact mill, air classifier, and / or jet mill and the one or more inline particle analyzers are programmed to generate first data signals indicative of a particle size distribution of the GGP and / or a GGP mean particle size.

[0021] One or more controllers are provided in signal communication with the inline particle analyzer(s) to receive the first data signals indicative from the inline particleanalyzers, and the one or more controllers are programmed to generate second data signals in response to the first data signals indicating whether the GGP particle size distribution or GGP mean particle size exceed a predetermined threshold and / or these conditions are within a predetermined range or threshold. The second data signals may indicate a condition of one or more operating parameters associated with the impact mill or air classifier or recommendations regarding the one or more parameters. The term controller as used herein may refer to a component of a system that receives signals that indicate input data from one or more components of a system, processes the input data and / or based on said processing of the input data, transmits signals to one or more components of the system to cause the components of the system to perform one or more actions.

[0022] A method, according to aspects of the invention may comprise:-inputting a feedstock into a grinding mill;-grinding the feedstock in the grinding mill and generating powdered material;-discharging the powder material from the grinding mill to an air classifier based on a threshold particle size;-discharging powder material having a particle size that is about equal to or less than the threshold particle size from the air classifier for storage or use;-inputting or returning the powder material having a particle size that is greater than the threshold particle size from the air classifier to the grinding mill for further particle size reduction; and,-wherein the threshold particle size is 30 pm or less, 20 pm or less, 10 pm or less or 5 pm or less.

[0023] In an embodiment, the feedstock is a silica-based waste material such as recycled glass the ground powder material is ground glass pozzolanic (GGP)

[0024] In an embodiment, the threshold particle size is a first threshold, and the method may further comprise storing or using powdered material that is at or below the first particle size threshold, delivering powdered material that exceeds a second threshold, which is greater than he first particle size threshold, to the grinding mill and delivering the classifiedpowdered material that exceeds the first threshold and is below the second threshold to a jet mill for furthering grinding to a particle size that is about or less than the first threshold, and then storing this powdered material.

[0025] The method may further comprise monitoring a particle size output from the grinding mill, air classifier and / or jet mill and adjusting operating parameters of the system according to a determined particle size output from the impact mill and / or an air classifier. The operating parameters, for example, may include for example, particle size of the feedstock, width of the grinding gap, the wear, number, shape, size of the grinding element, wear and shape of the inner liner, condition of the air classifier and / or jet mill, and / or a gap width of between an inner liner and grinding elements of an impact mill.

[0026] As used herein, Particle Size Distribution (PSD) refers to measuring the range and proportions of different-sized particles within a material sample. In the context of ground glass pozzolan, PSD describes how particle sizes vary within the pozzolan and how these particles are distributed across different size ranges. PSD is crucial for determining the performance characteristics of pozzolan, including its reactivity and workability in concrete mixtures, since smaller particles typically react more quickly and efficiently.

[0027] The term particles size threshold is a predetermined or selected particle size, particle size distribution or mean particle size used in operation of the disclosed and claimed system and method.

[0028] As used herein, mean particle size is the average size of particles within a sample of ground glass pozzolan. It is typically expressed in microns (pm) and is calculated using various methods such as volume or number-weighted averages. In pozzolan, a smaller mean particle size generally leads to greater pozzolanic reactivity due to the increased surface area available for chemical reactions, thus improving the overall performance of the concrete mix in terms of strength and durability.

[0029] As used herein, the terms D90 or D50 designate a percentage of particles that are a determined particle size. For example, D90 < 20 pm means about 90% of the particles are 20 pm or less in diameter size; and D50 < 2-3 pm means that about or at least 50% of the particles are 2 to 3 pm or less in diameter size.

[0030] Notwithstanding that the numerical ranges and parameters setting forth the broad scope are approximations, the numerical values set forth in specific non-limiting examplesare reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements at the time of this writing. Furthermore, unless otherwise clear from the context, a numerical value presented herein has an implied precision given by the least significant digit. Thus, a value 1.1 implies a value from 1.05 to 1.15. The term “about” is used to indicate a broader range centered on the given value, and unless otherwise clear from the context implies a broader range around the least significant digit, such as “about 1.1” implies a range from 1.0 to 1.2. If the least significant digit is unclear, then the term “about” implies a factor of two, e.g., “about X” implies a value in the range from 0.5X to 2X, for example, about 100 implies a value in a range from 50 to 200. Moreover, all ranges disclosed herein need to be understood to encompass any and all sub-ranges subsumed therein. For example, a range of "less than 10" can include any and all sub-ranges between (and including) the minimum value of zero and the maximum value of 10, that is, any and all sub-ranges having a minimum value of equal to or greater than zero and a maximum value of equal to or less than 10, e.g., 1 to 4. Additionally, the term “orthogonal” is used to indicate an angle between two directions in a range of 90 degrees ± 10 degrees or in a range of 90 degrees ± 20 degrees. Additionally, the term “parallel” is used to indicate an angle between two directions in a range of 0 degrees ± 10 degrees or in a range of 0 degrees ± 20 degreesMany modifications and other embodiments will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the foregoing is not to be limited to the example embodiments, and that modifications and other embodiments are intended to be included within the scope of the appended claims.Description of the Drawings

[0031] FIG. l is a sectional view of an impact mill in accordance with aspects of the invention.

[0032] FIG. 2A is a top / front perspective view of a pair of grinding elements for the impact mill.

[0033] FIG. 2B is a top plan view of the grinding elements of FIG. 2A.

[0034] FIG. 3 A is a rear plan view of the grinding elements of FIG. 2A.

[0035] FIG. 3B is side plan view of the grinding elements of FIG. 2A.

[0036] FIG. 4 is a perspective view of a grinding element for the impact mill.

[0037] FIG. 5 is a side view of grinding element of FIG. 4.

[0038] FIG. 6 is a perspective view of a grinding element for the impact mill.

[0039] FIG. 7 is a side view of grinding element of FIG. 6.

[0040] FIG. 8 is a material distribution plate of a rotor of the impact mill.

[0041] FIG. 9 is a front perspective view of a pair of grinding elements in accordance with aspects of the invention.

[0042] FIG. 10 is a side view of the grinding elements of FIG. 10 mounted to a rotor shelf of the impact mill.

[0043] FIG. 11 is a sectional view of the grinding elements of FIG. 10.

[0044] FIG. 12 is an exploded view of the grinding elements of FIG. 9.

[0045] FIG. 13 is an elevational view of a section of the inner liner of the impact mill in accordance with aspects of the invention.

[0046] FIG. 14 is a bottom view of a section of the inner liner.

[0047] FIG. 15 is a sectional view illustrating an interconnection of sections of the inner liner.

[0048] FIG. 16 is a schematic representation of the system including an impact mill, air classifier and jet mill according to aspects of the invention.

[0049] FIG. 17 is a flow chart for a method according to aspects of an embodiment of the invention.

[0050] FIG. 18 is a flow chart with additional steps for the method.

[0051] FIG. 19 is a flow chart including steps of a method according to aspects of the invention.Detailed Description

[0052] A system and method are described for generating micronized powder materials from waste or recycled / recyclable materials. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances,well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.Impact Mill

[0053] Embodiments may include an impact mill which are known for use in the micronization of materials, for example the grinding and micronization of silica-based waste products. Impact mills of the type for this invention are described in U.S. Patent Nos.: 7,861,958; 7900,860; 8,132,751; 8,302,892; 8,302,893, all of which are incorporated herein by reference.

[0054] An impact mill 100, according to aspects of the invention, is shown in FIG. 1 and includes housing 10 in which a rotor 12 is mounted and the rotor 12 is operatively connected to a motor (not shown). Housing 10 is configured to provide a concentric tapered nest for a conical grinding inner liner (stator) 14. In a preferred embodiment, and as described in more detail below, the inner liner 14 includes a serrated surface to promote micronization of a feedstock introduced into the impact mill 100 via an opening 15 in a top of the housing 10. In addition, a plurality of grinding elements 18 are mounted to the rotor 12 in spaced relation to the inner liner 14 form a conical grinding gap G.

[0055] Housing 10 includes top section 10A, middle section 10B and bottom section 10C. The axial position of the top section 10A relative to the rotor 12 is adjustable by spacer inserts 21 disposed between the top section 10A and middle section 10B of the housing 10. In addition, the inner liner 14 may include a plurality of stacked truncated conical sections that are interconnected, or interlocked, so that can be removed or added depending on a desired volume of the grinding gap G. According to operating parameters, including the GGP particle distribution size output, the mill 100 may include more or less liner sections; or the mill 100 may include only a single liner section.

[0056] Rotor 12 includes a central hub 13 and a plurality of radiating (radially extending relative to the central hub 13) shelves, plates or rings 16 extending circumferentially about and supported on the hub 13. The diameter of each shelf 16 from the top shelf 16Ato the bottom shelf 16B forming a conical configuration corresponding to that of the inner liner 14. In an example embodiment that includes five shelves 16 with grinding elements, the first, top shelf has a diameter of about 1600 mm; the second shelf has a diameter of about 1657mm; the third shelf has a diameter of about 1715 mm; the fourth shelf has a diameter of about 1772 mm; and, the fifth, bottom shelf has a diameter of about 1830 mm. Aperson of ordinary skill in the art will appreciate different numbers of shelves and / or shelves having varying diameters be used for the impact mill 100 affect the extent of micronization by varying the volume or width of the grinding gap G.

[0057] A plurality of grinding elements 18 are mounted along the periphery of each shelf 16, and the grinding elements 18 are spaced from the inner liner 14 which is secured within the housing 10 using known mounting mechanisms. Inner liner 14 may be a single truncated cone part or the liner may comprise multiple interconnected side-by-side liner plates or stacked plates. In a preferred embodiment the inner liner 14 comprises a plurality of liner sections (e.g. eight sections) stacked one on top of the other including increasing diameters from a top liner section 14Ato a bottom liner section 14B.

[0058] As noted above, housing 10 supports and covers the conical inner liner 14. The inner liner 14 has the shape of a truncated cone and is mounted to the housing 10 and positioned relative to the rotor 12 such that a grinding gap G is formed between the inner liner 14 and grinding elements 18. Depending on various operating parameters, such as the type of feedstock, composition of the grinding elements 18 and inner liner 14, and desired particle size output, the width dimension of the grinding gap G may vary. By way of example, in an embodiment in which the impact mill 100 is used to generate a pozzolanic powder material from silica-based waste, to produce pozzolanic particle sizes of 20 pm or less with a mean particle size of about 5 pm, and grinding elements 18 and inner liner 14 may have a ceramic-composition and the grinding gap G may be set at about 0.05 mm to about 6 mm, or 0.05 mm to about 3.0 mm. Depending on a desired particle size distribution an output, the gap width may be about 0.05 mm to about 0.30 mm for particle sizes of equal to or less than 20 pm. Tighter or narrower gap widths increase specific impact frequency and shear, driving finer product at the same speed.For highly abrasive feedstocks, the gap may be run slightly larger (e.g., +0.05-0.10 mm) to maintain stability and wear life.

[0059] In an exemplary embodiment the grinding gap G is disposed at an angle of about 80° (±2°) relative to a horizontal plane H (FIG. 1), which may, for example, correspond to any one of the shelves 16 of rotor 12. To that end, the surface of the inner liner 14 andrespective faces of the grinding elements 18 are disposed at angles corresponding to the angle of the grinding gap G.

[0060] The dimensions of the inner liner 14 may vary depending on a selected width of the grinding gap G. For example, with respect to an embodiment having a grinding gap G of about 2 mm, and the rotor shelves having the above-referenced dimensions, and an inner liner 14 having up to eight liner sections, the inner liner 14 may have an upper inside diameter of 1602 mm and a lower inside diameter of 1832 mm.

[0061] The angle of the grinding gap, or the slope between the grinding elements and the inner liner, is a parameter that governs the material throughput, particle size distribution, and energy efficiency of the mill. Precise control of this angle optimizes the reduction of materials to the desired fineness, minimizes wear on the grinding elements, and ensures a consistent product output. For high-precision applications such as micronizing down to sub- 20 micron particle sizes, this angle must be set carefully, considering the feed material's specific properties, including hardness, moisture content, and bulk density. Accordingly, grinding gap angle A may vary according to various operating parameters, including a desired PSD.

[0062] The conical rotor 12 moves up and down within the mill housing using known mechanisms that provide for manual or automated systems. Raising or lowering the mill housing 10 changes the spacing between the grinding elements and the inner liner. When the mill housing 10 to which the inner liner 14 is attached is raised, the grinding gap G between the rotor and stator increases, allowing larger particles to pass through with less grinding. This is typically done when coarser material is required or to reduce energy consumption for easier grinding tasks. Lowering the mill housing 10 and inner liner 14 decreases the grinding gap G, which increases the grinding pressure on the material. This creates finer particles as the material is subjected to more intense forces between the rotor and stator. The grinding G gap can be adjusted manually or automatically, depending on the mill configuration. Typically, hydraulic or mechanical lifting mechanisms raise or lower the rotor with high precision. Systems might include sensors or controls that allow for real-time adjustments to ensure consistent particle size distribution based on feedback from the milling process.

[0063] Feedstock 28 (e.g., silica-based waste material such as glass) enters the impact mill 100 travels to the grinding gap G through centrally aligned entrance / opening 15 and by means of a horizontal path 30 defined by the upper housing section 10A and top distribution plate 22 of rotor 12. Feedstock 28 moves to the peripheral conical grinding gap G by means of centrifugal force and directional blocks 24 and cones 26. In one embodiment shown in FIG. 8, directional blocks 24 are radially positioned on the top plate 22 relative to a central axis or rotor axis A of the top plate 22. In addition, at least one directional cone 26 is mounted on top plate 22, and this embodiment the cone 26 is centered over the central axis A of the top plate, which is mounted to a top of the central hub 13 of the rotor 12.Additional directions cones 26 may be positioned at different locations on the top plate 22 as necessary or otherwise control a desired distribution of the feedstock 28. In this configuration feedstock 28 enters the impact mill 100, the rotation of rotor 12 and top plate 22, and hence the blocks 24 and cones 26 provide a uniform distribution of the feedstock 18 toward the grinding gap G. An person of ordinary skill in the art will appreciate directional objects may be arranged in a variety of configurations below the opening 15 for distribution of the feedstock 28 to the grinding gap G.

[0064] As indicated above, the conically shaped impact mill 100, in a preferred embodiment, utilizes a conical inner liner 14 formed of separate conical sections. In this embodiment, each conical inner liner section 14 is selected to match a particular feedstock or desired end product according to a desired particle distribution size and / or mean particle size. The embodiment shown in FIG. 1, a plurality conical liner sections 14, for example, inner line 14 may include up to eight (8) sections or more. An advantage of this embodiment of mill 100 is economic. The replacement of worn or damaged conical liner sections, without the requirement to replace the entire conical assembly, reduces maintenance costs.

[0065] In an embodiment, each section of liner 14 may be provided with alternate impact configurations which provides capability of either increasing or decreasing the number of impacts to which feedstock 18 is subjected. By way of example, inner liner 14 may have serrated surfaces with varying numbers of serrations. In addition, the adjustment of the shape and angle of the impact surfaces of the conical liner also permits alteration of the direction of the feedstock particles.

[0066] Interconnection of the conical inner liner sections 14 may be provided by any connecting means known in the art. One such preferred design utilizes key interlocks, as illustrated in FIG. 15. Therein, complementary shapes of sections 14 result in an interlocking assembly. Specifically, sections 26 and 27 are interlocking mating frustum cones. In an alternate embodiment of the present invention, the design of the conical grinding assembly, independent of whether it is a single unit or a series of mating interlocking subassemblies, is changed by altering the impact surfaces, e.g. serrations, of the stationary impact surfaces disposed on the inner surface of the conical inner liner 14.

[0067] In this embodiment, impact mill housing 10 is divided into a plurality of sections. The drawings illustrate a typical design, a plurality of three sections of the housing 10 including a top section 10A, a middle section 10B and a bottom section 10C with the inner secured in place at its lower end pf the top section 10A. This configuration allows for the external adjustment of the grinding gap G by adding or subtracting spacer blocks 21. More specifically, the spacer blocks 21 may be used to adjust an axial position of the housing 10, and consequently the inner liner 14, relative to the rotor 12 and grinding elements 18 to adjust a width of the grinding gap G.

[0068] The top section 10A of the housing 10 may include a downwardly aligned cylindrical collar 17, which may be displaced axially within the center housing section 10B. Cylindrical collar 17 forms an integral component of the top section 10A. An outwardly aligned flange 19 is provided at the upper end of the cylindrical collar 17. One or more spacer inserts / blocks 21 may be disposed between flange 19 and a further flange 23 which is disposed at the upper end of center section 10C. Thus, spacer blocks 14 define the axial setting between flanges 19 and 23, and, part, define the width of the grinding gap G. As such, this width is adjustable. Once the desired grinding gap G is set, the top section 10A is securely fastened to the center section 10B by means of a plurality of bolts 25. The upper section 10A and the inner liner 14 are disposed coaxially with a rotor axis A.

[0069] These serrated edges 27 are normally aligned so that they are coaxial with rotor axis A. That is, the projection of each serrated edge on a plane of the rotor axis is a straight line coincident with rotor axis. A means of increasing or decreasing comminution is to increase or decrease, respectively, time duration of feedstock 18 to traverse the grinding path G. Obviously, the longer the grinding path G, the longer the time to traversethat path between grinding elements on rotor 12 and the serrated edges 27 of inner liner 14, and the greater the degree of comminution. One means of increasing or decreasing path 10 is by changing the disposition of serrated edges 27 so that they become unaligned with the rotor axis A. The greater the slope of the line projected on a plane intersecting rotor axis A, the greater the time divergence with a path where the serrated edge is coincident with the rotor axis. That is, the greater the divergence in positive slope, in the direction of rotation, the longer the time to traverse path 10 and, in turn, the greater the degree of comminution, and vice versa. Reversing the direction of rotation for the same slope reduces the effective length of path 10 by the same degree as it is increased in the opposite direction and thus decreases comminution by the same degree.

[0070] Grinding elements 40, 50 and 60 are shown in more detail with respect to FIGs. 2- 7 which include generally U-shaped and / or block-type, rectilinear configurations. Element 50, shown in FIGS. 4 and 5, include a planar base plate 52 and opposing end plates 54.With respect to FIGS. 2 and 3 grinding element 40 may include a generally rectilinear base 42 along a side and a series of aligned or parallel veins and 44 and troughs 46 along an opposite side. Similarly with respect to FIGS. 6 and 7, grinding element 60 includes base a plurality of aligned veins 62 and troughs 64. The inventors have found that at least with respect to the micronization of silica-based feedstock into a pozzolanic powder having particle size of 20 pm or less embodiments of grinding elements 18 having more contact surface area generate consistently sized particles that are 20 pm or less. Accordingly, embodiments of FIGS 2, 3, 6 and 7, are preferred.

[0071] To that end, the dimensions of the grinding elements 18, 40, 50 and 60 may vary according to the feedstock and desired parameters of the powder material. For example, with respect to a silica-based feedstock, such as recycled glass micronized for the production of pozzolanic powder the, the grinding elements 40, 50 may have a top width dimension TW of about 1.25 inches, a bottom width dimension BW of 1.75 inches, a length dimensions L of about 2 inches and a height dimension(H) of about 1.5 inches.

[0072] In an exemplary embodiment, the grinding elements 18, 40, 50 and 60 are mounted in pairs on the respective shelves 16 of rotor 12. With respect to FIGS. 9-12, the grinding elements are of the type depicted in FIGS. 2 and 3. As shown, the pair of grinding elements 40A, 40B are configured to define a void or gap 43 therebetween for receiving aperipheral portion of shelf 16. More specifically, element 40B includes a flange 41 forming and upper detent 45 and lower detent 47, and the flange 41 or upper detent 45 relative to the base 42 of element 40A form the gap 43 for receiving shelf 16. Fasteners 48, such as a nut and bolt system, are used to position and secure the pair of elements 40A, 40B relative to the shelf 16. The inventors have found that this configuration, with base of the element 40A flush against a top end of the element 40B eliminates spacing between the elements which may capture feedstock and inhibit grinding of the feedstock to a desired particle size.

[0073] The above-described geometric shapes and dimensions are provided by way of example and are non-limiting. Geometric shapes or configurations may include pins, teeth, blades, castellated inserts, or ridged / chevron profiles. The edge conditions of the elements may vary and preferably may be sharp-edged or micro-chamfered leading edges (e.g., 0.05- 0.20 mm chamfer) to balance aggressiveness and wear. A surface finish of a grinding element may include radii of about 0.4-1.6 pm on impact faces to avoid premature fouling or glazing with fine powders.

[0074] The number of grinding elements may depend on the size of the impact mill, type of feedstock and / or desired particle size output. For example, the number of grinding elements may range from 24 to 240 elements, and preferably 48 to 160 elements of an impact mill having from 2 to 8 shelves and preferably 3 to 6 shelves.

[0075] The composition of the grinding elements may vary again according to the feedstock input of the impact mill 100 and the desired particle size output. For example, grinding elements 18, 40, 50 and 60 may be composed of an abrasion resistant steel, ceramic or preferably an abrasion resistant ceramic-metallic composition, or other abrasion resistant materials. In an embodiment, ceramic-metallic formulations, or cermet, are believed to be the preferred composition for the production of a powdered pozzolanic powder from a silica- based feedstock. For example, such a composition may comprise high-hardness ceramics like alumina (ABOs) and zirconia (ZrO?) combined with metallic binders such as nickel (Ni) or cobalt (Co), these composites deliver exceptional wear resistance and toughness. Importantly, being primarily silica-based, ceramics do not introduce foreign metallic contaminants into the glass, preserving its integrity.

[0076] A ceramic-metallic formulation for the grinding elements designed for grinding glass involves selecting materials that provide high wear resistance, toughness, andhardness. Preferably a ceramic-metallic (cermet) composition selected from:- WC-Co (e.g., 4-12 wt% Co binder), hardness > 1,400 HV- TiC- or TiCN-based cermet- ZTA (zirconia-toughened alumina) or high-purity AI2O3 inserts for low contamination- Si3N4 or SiC ceramics where thermal shock resistance is prioritized.

[0077] Below is an example of a formulation for a grinding element according to aspects of the invention:1) about 70% to about 90% of Alumina (AI2O3) as a base material and which provides excellent hardness and wear resistance. A high-purity alumina minimizes contamination in glass grinding applications.2) about 5% to about 30% additives such as:(i) about 10% to about 30% Zirconia, which increases toughness and impact resistance.(ii) about 5% to about 15% Carbide (SiC), which adds additional hardness and abrasion resistance;(iii) about 2% to about 10% of Titanium Carbide (TiC), which enhances toughness and thermal stability.3) about 5% to about 10% of one or more metallic binders including, for example, Nickel (Ni) or Cobalt (Co), which may improve toughness and wear resistance and aid in the sintering of ceramic components; and,4) processing aids such as deflocculants and binders (e.g., Polyvinyl Alcohol, PVA or starch) improve the flow properties of the mixture during processing. Other processing aids may include sintering aids (e.g., Magnesium Oxide, MgO) which facilitates densification during a sintering process for grinding elements.

[0078] Depending on the size and material composition of the grinding elements 18, their weight may range steel anywhere from about 7.0 oz. to about 30 oz. For example, a grinding element composed of a steel may be 7.6 oz; a grinding element composed of an abrasion resistant steel may weigh about 28 oz.; and a grinding element composed of the above-described ceramic-metallic composition may weight about 13 oz.Testing

[0079] Test trials were conducted using the above-described impact mill to produce GGP powdered material that met the specification standards of ASTM Cl 866. The ASTM Cl 866 Standard Specification for Ground Glass Pozzolan in Concrete covers ground-glass pozzolans for use in concrete where pozzolanic action is desired. This specification applies to ground glass from sources that consist of container glass, plate glass, or E-glass.Standards according to ASTM Cl 866 are provided below :

[0080] The terms “Type GS” and “Type GE” used in the above and below ASTM Cl 866 standards refer to a type of glass used in production of GGP for use as an SCM. Type GS is ground soda-lime-silica glass typically from container- and plate-glass with equivalent alkali content of 10 to 15%; and Type GE, which is typically from glass fiber, with an equivalent alkali content of 0 to 1%.

[0081] For the test trials / runs an impact mill according to the above-described embodiments was used to produce GGP having a particle size of 20 pm or less. The impact mill included an inner liner and grinding elements having the described ceramic-metallic formulations, and a grinding gap of about 2 mm to about 3 mm. The rotor speeds for the trial runs ranged from about 3700 rpms to about 4000 rpms. The geometric configuration of the grinding elements used for these tests were consistent with the grinding elements depicted in FIGS. 2 and 3.

[0082] In embodiments of the invention the rotor speed may depend on the diameter of the rotor. For example, for a rotor diameter D of 0.30 m, the rotor speed be about 3,200 rpms to about 12,700 rpms (tip speed: 50 m / s - 200 m / s); for D of about 0.5 m, the rotor speed may be about 1,900 rpms to about 7,600 rpms (tip speed: 50 m / s - 120 m / s); and, for D of about 0.8 m, the rotor speed may be 1,200 rpms to about 4,800 rpms (tip speed: 50 m / s -120 m / s). This operating parameter may correspond to a rotor tip speed “U” which may be expressed as:U ~ n - D • N where D is rotor diameter and N is rotational frequency (rev / s). In practice N is specified in rpm; ranges below are given as both rpm and equivalent tip speeds for typical rotor diameters. The tip speed U may range from about 30 m / s to about 200 m / s.

[0083] The feedstock included recycled, or waste glass having been cleaned and pulverized passed through a sieve mesh of 3 mesh to 18 mesh providing about 1 mm to about 7 mm range of feedstock component size, with a mean size of about 2 mm or 10 mesh. The term “mesh” when you used in reference to particle size means there are, for example, 3 holes or 18 holes per linear inch of a mesh, and the feedstock was retained atop a mesh screen. In this example, feedstock particle size passed through the 3-mesh sieve and retained on the 18-mesh size sieve. Accordingly, the particles size of feedstock ranged from about 1mm to about 7 mm.

[0084] Known material recovery facility processes for separating cleaning process were used and can be used for producing GGP using the above describes impact mill.

[0085] For each of the trial runs, 50 lbs. of feedstock including recycled or waste glass that had been processed for micronization was input to an impact mill to produce 50 lbs. of GGP. The rotor operated at approximately 3700 to 4000 rpms or greater to produce GGP wherein at least 90% of the material had a particle size of about 20 pm or less. In addition, for each trial sample the GGP was produced in a single pass and no recirculation was incorporated to further reduce particle size. For example, an air classifier was not used to separate and recirculate particles that exceeded a predetermined particle size, e.g. 45 pm. In addition, the width of the grinding gap ranged from 2 mm to 3 mm and the grinding operation had run times ranging from about 11.00 seconds to about 11.80 seconds.

[0086] At least three of the trial runs produced GGP material wherein at least 90% of the GGP had a particle size of 20 pm and less and a mean particle size of about 5 pm. A particle distribution curve for two of the trial runs is reproduced below in Table 3. More specifically, a particle distribution curve was generated using a CILAS 920 particle analyzer. In these trials the impact was run from about 11 to 12 seconds, with a grinding gap width of 2-3 mm.

[0087] With respect to the trial represented in the graph of Table 4, the GGP included a particle distribution of 98.47% having a particle size less than 20 pm (i.e., -20 pm) and a mean particle size of 4.8 pm.Table 4: Particle distribution curve generated with a CILAS 920 particle analyzer showing mean particle size of 4.8 pm.

[0088] With respect to the trial represented in the graph of Table 5, the GGP included a particle distribution of 98.47% having a particle size less than 20 pm and a mean particle size of 4.8 pm.Table 5: Particle distribution curve generated with a CILAS 920 particle analyzer showing mean particle size of 5.6 pm.

[0089] As used herein the term particle Size Distribution (PSD) refers to measuring the range and proportions of different-sized particles within a material sample. In the context of ground glass pozzolan, PSD describes how particle sizes vary within the pozzolan and how these particles are distributed across different size ranges. PSD is crucial for determining the performance characteristics of pozzolan, including its reactivity and workability in concrete mixtures, since smaller particles typically react more quickly and efficiently.Blaine Fineness Testing

[0090] Blaine Fineness tests were performed GGP samples produced according to the abovedescribed impact mill using a Blaine permeability test. This test involves measuring the specific surface area of the particles, which is the total surface area of all the particles in a given amount of product / sample, typically expressed as square centimeters per gram (cm2 / g) or square meters per kilogram (m2 / kg). The test is based on the permeability of air through a compacted bed of particles.

[0091] To calculate the Blaine Fineness in cm2 / g for the sieve data, the following steps were applied(i) Step 1 includes Cumulative Sieve Data which includes the cumulative percentages of particles remaining selected sieve which provide insights into the particle size distribution. To that end the Blaine Fineness calculation was based on the weighted sum of particle size classes.(ii) Step 2 includes the specific surface area or Blaine Fineness is approximated by:S = K x(l / Weighted Sum of Sieve Sizes) Where:S is the Blaine Fineness in cm2 / g, and K is a constant (commonly 5000).(iii) Step 3 includes a calculation of the Weighted Sieve Sum using the Cumulative Sieve data (See Table 5 below), which accounts for the percentage of particles at each size; and(iv) The constant (commonly) is then applied to Weighted Sieve Sum as determined in Step 3.

[0092] Blaine Fineness was calculated for two samples of GGP produced according to the above-described impact mill and operating parameters. The first sample included a particle distribution size of -20 pm distribution wherein at least 90% of the GGP particles were 20 pm or less as determined using a Cilas 920 particle analyzer or similar instrument. A second sample included a particle distribution size of -5 pm distribution wherein at least 90% of the GGP particles were 5 pm or less as determined using a Cilas 920 particle analyzer or similar instrument.

[0093] Cumulative Sieve Data was generated using sieve sizes ranging from 40 pm down to 0.2 pm, and is reproduced below in Table 6 showing particle size distribution for each sample which shows the percentage of particles according to sieve size:Table 6: Cumulative Sieve Data

[0094] The "weighted sieve sum" was calculated for each sieve size by multiplying each sieve size by the percentage of material retained on that sieve for both distributions.

[0095] Formula:Weighted Sum for each size = (Sieve Size) x (Percentage of Material Retained on Sieve)Example for -20 pm at 23 pm sieve size:

[0096] Again, the weighted sum was calculated for all sieve sizes and then all the weighted sums for a sample were totaled to arrive at the Total Weighted Sieve Sum. For example, for the -20pm sample was calculated to be:Total Weight Sieve Sum, -20 pm GGP of all sieve sizes = 749.88 pm.Total Weight Sieve Sum, -5 pm GGP of all sieve sizes = 284.49 pm

[0097] The Blaine Fineness for each same was then calculated according to the formula:

[0098] These values reflect the relative fineness of the two materials. The -5 pm GGP has a much higher fineness due to its finer particle distribution. In the case of cement, a higher Blaine Fineness value means that the cement particles are finer, which results in a larger surface area for a given mass of cement. A lower bulk density, on the other hand, indicates that the cement particles are less tightly packed, which can also contribute to a larger surface area per unit volume. The product of Blaine Fineness and Density can be an indicator of the quality and performance of the cement. Cement with a higher specific surface area (Blaine Fineness) may have better reactivity and be more suitable for certain applications, such as high-strength concrete, where the increased surface area can lead to better bonding and strength development.

[0099] In addition to the above a test sample including a -20 pm PSD was tested against a control cement mixture, for chemical and physical properties according to ASTM Cl 866. The control included cement in combination with standard aggregate materials. A sampleincluding GGP according to the subject invention including a particle size distribution of 20pm. Specifically, a sample replaced 20% of the cement powder by mass with GGP powder material produced from an impact mill according to aspects of the invention.

[0100] As shown the GGP produced using the above-described impact mill meet or exceed the standards set forth in ASTM Cl 866 as an SCM, including both chemical and physical requirements.

[0101] Additional testing was performed on OPC / GGP test samples including GGP having particle sizes of D90 < 20 pm, 10 pm and 5 pm and different weight percents relative to OPC (Ordinary Portland Cement). More specifically, ASTM tests were performed onsamples that include a mixture of OPC / GGP at weight percents of 10%, 15%, 20% and 25% by weight of GGP with a balance of OPC. In addition, these same tests were performed on a control sample of 100 % by weight of OPC including a conventional mixture of clinker cement and other additives that may include gypsum, slag, fly ash etc. The test results below are an average of the different particle sizes for a given weight percent. For example, a 20% GGP Replacement is the average results of 20, 10 and 5 pm particles at that given weight percent.

[0102] Testing to evaluate or determine compressive strength of a cement of test samples as conducted according to ASTM Cl 09 standard test methods.

[0103] The compressive strength development of OPC control versus GGP replacements shows accelerated and higher strength gains for ultra-fine GGP mixes. At 15-25% replacement, GGP consistently delivers higher strength than 100% OPC. Smaller particle sizes (-5 pm) accelerate early strength development by 3-5 days compared to coarser fractions.

[0104] ASTM Cl 567 is a standard testing method for evaluating the potential of alkalisilica reactivity (ASR) in concrete. ASR is the chemical reaction between reactive silica,found in some aggregates, and alkalis of the cement in the presence of moisture. The reaction can create expansive gel that generates internal pressure leading to cracking of concrete and premature deterioration .

[0105] The ASTM ASR expansion testing demonstrates that OPC alone exceeds the ASTM 0.10% expansion limit (-0.35%). However, GGP replacement at 15% and above reduces expansion below 0.10%, with 20-25% GGP delivering <0.05% expansion. This establishes GGP as highly effective in ASR mitigation. GGP of the subject invention provides excellent ASR control, with >20% replacement ensuring safe expansion levels well below ASTM limits.

[0106] Tests were conducted according to ASTM Cl 202 for rapid chloride permeability, which is an indicator of the sample’s electrical conductance, which serves as a measure of itsability to resist chloride ion penetration. This is used to evaluate the durability of concrete in environments exposed to deicing salts and saltwater.

[0107] Rapid Chloride Permeability Testing shows significant reduction in ion penetration with GGP. Control OPC registers -4300 Coulombs at 90 days, whereas 25% GGP replacement reduces permeability below 1000 Coulombs. This represents very low chloride penetrability and greatly enhanced durability.

[0108] Testing according to ASTM C 1012 was performed to determine the sulfate resistance of a cement sample.

[0109] Sulfate resistance testing indicates that OPC control suffers expansion >0.40% over 12 months. Conversely, GGP replacements (10-25%) limit expansion to <0.1%, with 20-25% GGP replacement delivering near-complete mitigation. Ultra-fine GGP of embodiments dramatically enhances sulfate resistance, reducing expansion by over 90%.System

[0110] FIG. 16 is a schematic representation of system 200 for producing a powdered material from waste or recycled silica-based material in accordance with aspects of the invention. More specifically, system 200 may be used to produce a GGP powdered material from a silica-based waste / recycled feedstock, such as glass. In general, system 200 comprises the above-described impact mill 100 preferably in combination with an air classifier 300 and jet mill 400 to produce a GGP powdered material at least about 90% of which has a particle size of 20 pm and a mean particle size of about 5 pm. The end product GGP is conveyed to storage silos 90-93.

[0111] In addition, system 200 includes one or more inline particle analyzers (IPA) 102- 107 in fluid flow communication with output lines associated with the impact mill 200, air classifier 300 and jet mill 400 to monitor particle size, mean particle size and PSD of the GGP produced by each respective component. To that end, the IPA(s) are in signal communication with one or more controllers 110-115 and preferably a main controller 120 to monitor particle size, PSD and / or mean particle size and generate signals associated with operation / performance / condition of components of the system 200. The controllers 110- 115, each associated with a respective IPA 102-107, and a main controller 120. Each controller 110-115, 120 is configured or programmed to generate signals indicative of particle size distribution associated with the output of the respective components 100, 300, and 400, and / or is programmed to analyze data input from the IPA to monitor operation, performance of the components 200, 300, 400 and otherwise consider operating parameters of the system 200. Controller 120 may be a main controller that generates a condition of a component and / or recommendation relative to a component(s) in response to data signals generated by one or more IPA’ s 110-115.

[0112] Again, with respect to FIG. 16 system 200 includes impact mill 100 in fluid flow communication with an air classifier 300. In an embodiment, the impact mill 200 and air classifier 300 are in fluid flow communication via an output line 83 and return line 84 for transmission of GGP between these components. In addition, the air classifier 200 is in fluid flow communication with a first silo 90 via a first classifier output line 85 for storage of GGP. In addition, the air classifier 300 is in fluid communication with jet mill 400 for further processing and distribution of GGP according to selected particle sizes utilizing a second classifier output or conveyance line 86. The jet mill 300 further grinds GGP and classifies the same according to particle size and output GGP according to selected particle size and / or PSD to a series of second silos 91, 92, 93, via output lines 87, 88, 89.

[0113] The air classifier 300 uses known principles for particle separation and conveyance. For example, the air classifier utilizes adjustable centrifugal force to separate particles of different sizes within a pneumatic circuit. The raw product is conveyed through a primary air inlet. Once in the classifier, aerodynamic drag forces pneumatically act upon the particles. The force varies depending on the diameter and density of the particles in the classifier. Spiraling particles are directed toward the classifier rotor, where one of twothings occur, depending on particle size: 1) drag force on smaller, more aerodynamically particles exceeds the centrifugal force exerted by the rotor, and they pass through the machine as fines; or 2) centrifugal force overcomes the drag force, causing larger, less aerodynamically particles to accelerate away from the rotor. A cyclonic chamber collects this coarse fraction and enables discharge through a rotary airlock fitted to the bottom of the machine.

[0114] The balance between the drag force and the centrifugal force determines the cutpoint. When the forces are equal, particles have a 50 / 50 chance of passing out of the system as fines. The cut-point is variable and can be controlled by adjusting the rotor speed. Collection efficiency is enhanced by using a secondary air inlet, an adjustable air stream that moves upward into the classification zone. This airstream increases the residence time of agglomerated and near-size particles, thus allowing them to be classified with the fine product stream. Jet mill 400, for example, may incorporate eight opposing jets to introduce compressed air vertically upward to impact and grind GGP via collision of particles. The jet mill 400 may be a spiral jet mill with internal particle classification within a grinding chamber. In an embodiment, jet mill 400 may include four to twelve jet nozzles, and preferably eight nozzles aligned to converge at a single focal point inside a milling chamber. Operating parameters for jet mill 400 may include airflow rate, grinding pressure, particle (GGP) feed rate, number of passes within the mill 400, etc. To achieve a high percentage of particle size below 5 pm, for example the air flow rate may range from about 300 ft3 / min to about 800 ft3 / min; and the grinding pressure may range from about 60 psi to about 120 psi. The feed rate of GGP from the air classifier 300 may about 50 kg / hour to about 200 kg / hour, and the lower end of this range for smaller particle size output. In addition, the classifier speed of the jet mill may range from about 3,000 rpms to about 7,000 rpms. To avoid overheating the mill 100 may operate at controlled temperatures, often ranging from 20°C to about 40°C.

[0115] The conveyance of the GGP from the impact mill 100 to the air classifier 300, jet mill 400 and the silos 90-93 is accomplished using a negative pneumatic conveyance system which is known to a person of ordinary skill in the art. To that end, a negative pneumatic conveyance system operates under the principle of creating a vacuum or negative pressure to transport finely ground materials, such as Ground Glass Pozzolan (GGP), through enclosedpipelines. This method is often employed when handling fine powders like GGP because it minimizes dust generation, prevents contamination, and reduces energy consumption compared to positive pressure systems.

[0116] Accordingly, system 200 may include components such as vacuum pumps or blowers in fluid communication with output lines (also referred to or known as conveyance lines) that generate suction or negative pressure that moves GGP from one point to another. These pumps are typically positioned near, for example before or at a storage silo. A vacuum pump may be connected to the top of a silo to ensure a continuous flow of material and to maintain a controlled atmosphere inside.

[0117] In addition, system 200 may include a series of air locks or rotary air lock valves, each of which may be installed between a mill discharge area or outlet and output line. An air lock allows GGP to enter the conveying system while maintaining the negative pressure inside the pipeline, and meters the GGP flow into the system, preventing air from leaking into the line while moving material into the system efficiently. A rotary airlock valve may also be installed before a silo to allow GGP to enter while maintaining negative pressure in the conveying line. In some cases, a diverter valve is used to direct GGP to different silos or locations, depending on operational needs. In addition, a silo may be equipped with a vent filter to maintain proper airflow and ensure safety, the silo is equipped with a vent filter. This filter allows air to escape as GGP fills the silo while preventing dust from being released into the environment.

[0118] As represented in FIG. 16, feedstock 28 is input into impact mill 100 to initiate the production of the GGP, for example, to be used as an SCM. Feedstock 28 may be recycled glass having been cleaned, hydrated and pulverized. To that end, in an embodiment feedstock 28 may be passed through a sieve of 3 mesh to 18 mesh providing about 1 mm to about 7 mm range of feedstock component size, with a mean size of about 2 mm or 10 mesh.

[0119] As described above, depending on selected operating parameters of the impact mill 100, which may include a desired GGP particle size output, the rotor 12 of the impact mill 100 may be rotating at a rate of 3700 to 4000 rpms, for example. GGP produced in the impact mill 100 from feedstock 28 is transmitted to air classifier 300 which separates the GGP according to particle size, shape and density via mill output line 83. In a preferred embodiment, the air classifier 300 may be configured to separate particles that are largerthan 30 pm (a threshold particle size or first threshold particle size) for return, via return line 84, to impact mill 100 for further grinding. Particles that are 20 pm to 30 pm or less (a second threshold particle size) are conveyed to a jet mill 400 for further processing and distribution according to particle size. GGP produced from the impact mill 100 may be discharged into a hopper or surge bin (not shown) , which acts as a buffer, ensuring a constant feed of material into the pneumatic conveying system. It prevents blockages and ensures steady flow to the air classifier 300.

[0120] The air classifier 300 may be configured to further separate the GGP according to selected particle sizes. For example, in the embodiment of FIG. 16 first classifier output line 85 is provided to transmit a GGP particle stream to a first silo 90. In this embodiment, the air classifier 300 is configured separate and transmit GGP having a particle size of about 20 pm or less to the silo 90. Second output line 86 provides fluid flow communication from the air classifier 300 to jet mill for further particle size reduction of GGP by the jet mill 400. In this example, the air classifier 300 and second output line 86 transmits a GGP material stream including particle sizes from about 20 pm to about 30 pm to the jet mill 400.

[0121] In this exemplary embodiment shown in FIG. 16, a plurality of output lines 87, 88, 89 provide fluid flow communication from the jet mill to second silos 91, 91, 92 respectively, for a final GGP production according to particle size. For example, output line 87 transmits a GGP material stream of particles having a particle size of about 20 pm to silo 90, output line 88 transmits a GGP material stream of particles having a particle size of about 10 pm to silo 91 and output line transmits a GGP material stream of particles having a particle size of about 5 pm to silo 92.

[0122] As illustrated in FIG. 16, system 200 includes a plurality of inline particle analyzers 102-107 that are positioned downstream relative to the impact mill 100, air classifier 200 and jet mill 400 to generate data regarding GGP mean particle size and / or PSD and related data to monitor the system 200 and its components. To that end, the in-line particle analyzers provide condition-based monitoring to monitor the health / condition of system 200 and system components or system operating parameters to maintain a selected GGP particle size output.

[0123] An example of a particle analyzer that may be incorporated into system 200 is a Cilas 920 particle analyzer. For each particle analyzer 102-107, there may be controller 110- 113, and a display to generate data indicative of a GGP mean particle size and / or PSD.

[0124] Particle size of GGP of the impact mill 100, air classifier 300 and / or jet mill 400 is monitored to evaluate the health / condition of system components and relevant operating parameters. For example, operating parameters relevant to particle size output include the mill speed (rpms of the rotor), particle size of the feedstock, feed rate of feedstock into the impact mill, a width dimension of the grinding gap, resident grinding time for a set amount of feedstock, e.g. 50 lbs of feedstock may be associated with a resident grinding time of 11.25 seconds to produce a GGP with a mean particle size of less than 20 p.

[0125] By way of example, if the mean particle size of particles 20 microns or less shows an increase of more than 5 microns, this could indicate that the grinding elements are wearing down, resulting in a less effective grinding action. It may also suggest that the feed material characteristics have changed, leading to an altered response in the milling process.

[0126] A decrease in the percentage of particles measuring 20 microns or less might indicate several issues. Primarily, it could signal that the grinding process is becoming less efficient, potentially due to wear in the grinding elements or track sections. A change in PSD can also suggest that the mill is operating outside its optimal parameters, leading to changes in material flow or residence time. Component wear indicators may be addressed with specific readings to determine whether wear is occurring in the grinding elements or track sections. For instance, 1) - Increased Variability in PSD: A significant change in the uniformity of the particle size distribution might indicate localized wear on the grinding elements or track sections, causing inconsistent grinding; and, 2) Increased Coarse Particles: A rise in the proportion of larger particles in the PSD can also suggest that the grinding elements are losing their effectiveness, leading to insufficient breakdown of the material.

[0127] Another operating parameter for the system includes a width dimension of the grinding gap G, for grinding gap changes: Monitoring the mean particle size and PSD can provide indirect indications of changes in the grinding gap. If the mean particle size increases significantly or if there's a notable change in the distribution, it could imply that the grinding gap has widened due to wear.

[0128] Other operating parameters to consider is to meet the selected output parameters according to mean particle size and / or particle size distribution feed stock feed rate, mill speed (rpms), or the use of grinding aids to optimize performance. Regularly correlating inline analyzer readings with maintenance schedules is essential for timely intervention.

[0129] In summary, monitoring the inline particle analyzer readings provides crucial insights into the operational health of the milling process. While certain trends can indicate wear or operational issues, ongoing correlation with maintenance data and mill performance metrics is essential for a comprehensive understanding of the system's condition and to ensure optimal operation.Exemplary Non-limiting Parameters

[0130] An example of parameter settings to achieve a desired particle size output or size distribution for a particle size output of D50 « 20-60 pm; D90 « 80-180 pm:- Grinding gap width: 0.20-0.60 mm;- Tip speed: 60-95 m / s;- Grinding elements: 3-5 shelves, 12-20 grinding elements per row (toothed or pin);- Grinding element composition: ZTA or WC-Co;- Feedstock particle size: D90 = 0.5-2 mm;

[0131] An example of parameter settings to achieve a desired particle size output or size distribution for a particle size D50 « 5-20 pm; D90 ~ 30-80 pm):- Grinding gap width: 0.05-0.25 mm;- Tip speed: 85-115 m / s;-Grinding elements: 4-6 shelves, 16-24 grinding elements per row (micro-tooth or fine pins);- Grinding element composition: ZTA or Si3N4; and,- Feedstock particle size: D90 = 0.3-1.0 mm with moisture tightly controlled

[0132] The particle size of feedstock may vary according to feedstock type, e g. recycled glass, and may depend on the desired particle size output. Generally, the feedstock particle size may be about D90 = 0.5-5 mm. In an example embodiment for achieving GGP particle size of D50 < 60 pm the feedstock may have a particle size of D90 = 0.5-2 mm. In another embodiment for achieving a GGP particle size of D50 < 20 pm the feedstock may be D90 =0.3—1.0 mm. Very hard or tough feed (e.g., Mohs > 6) may require a D90 < 1 mm. Moisture of the feedstock is preferably < 1.5 wt% (non-hygroscopic minerals) or adjusted for material behavior; excess moisture raises agglomeration risk and output particle size.Method

[0133] With respect to FIGS. 17 and 18, flow charts are presented including steps of an embodiment for a method of producing a powdered material. In an embodiment, the method may be used to generate GGP from a silica-based feedstock such as recycled glass. As described above with respect to the system, the method may be used to generate GGP to have a particle size of D90 < 45 pm, 30 pm, 20 pm, 10 pm or 5 pm. In an embodiment, the powdered material may have particle size of D50 < 5 pm, or 2-3 pm.

[0134] In the first step 500 feedstock is input into a grinding mill (e.g. an impact mill), and in a second step 502 the grinding mill grinds the feedstock into fine or ultra-fine powder material. The feedstock may be a silica-based waste material such as recycled glass for production of GGP. To that end, the GGP produced and stored for use may be used as an SCM.

[0135] After the grinding step (502), the powdered material is discharged (504) to an air classifier for separation (506) of the powdered material according to a particle size threshold. In step 508, powdered material that is equal to or less than the threshold is discharged from the air classifier for storage and / or use. In step 510 powdered material that exceeds the threshold particle size is returned to the grinding mill for further size reduction.

[0136] In an embodiment, the grinding mill is a first grinding mill (e.g. the impact mill), and the particle size threshold is a first threshold. With respect to FIG. 18, the method includes a second particle size threshold. In step 512, the powdered material discharged from the air classifier that has a particle size greater than the first particle size threshold and less than the second particle size threshold is discharged to a second grinding mill (e.g. a jet mill) for further particle size reduction. In step 514, powdered material that is subjected to the second grinding mill and meets the first particle size threshold is discharged for storage / use.

[0137] As further described relative to the system 200, inline particle analyzers may be used to monitor and control operating conditions associated with system 200. For example,inline particle analyzers 102-107 are positioned relative to output / discharge locations of grinding mills 100, 400 and the air classifier 300. Accordingly, in steps 516 and 518, particle size is monitored at output locations relative to the grinding and size classification components, and signals are generated indicating a particle size (particle size data) of the powdered material at these locations.

[0138] As shown in FIG. 16, the IPAs 102-107 are in signal communication with one or more controllers 110-115 and / or a main controller 120 which are configured or programmed to generate signals indicative of an operating condition or component of the system 200 based on particle size data generated by one or more of the IPAs 102-17. Alternatively, the particle size data may be determined manually by removing powder material samples from lines for analyzing particle size production. In embodiments, particle size threshold data may be provided and is preferably associated with one or more particle discharge or output locations in the system.

[0139] In an embodiment, at step 702 parameters are selected, determined and / or entered regarding a milling operation. Operating parameters may include for example: 1) feedstock type (e.g. glass), particle size of feedstock; 2) grinding elements shapes, size, composition, and number of grinding elements; 3) dimension of grinding gap; 4) grinding gap G dimension; 5) rotor speed and / or tip speed; and 6) desired or threshold particle size or ranges thereof output at selected locations (impact mill output, air classifier outputs, jet mill output). In this example, parameters 1) and 2) may dictate data relative to the remaining parameters. That is, for example, if a glass-type feedstock of a particular particle size is used to produce a desired GGP particle size the other parameters will be determined based on this input and desired output.

[0140] Based on these operating parameters, the controller determines or refers to data indicating threshold particle size or threshold particle size range at various output locations in the system.

[0141] With respect to step 704, an embodiment may comprise providing particle size threshold data relative to one or more particle output or discharge locations. Such output or discharge locations may include, for example, locations along one or more of the output lines 83-89 of the system 200. The threshold data may include one or more particle sizes or a range of sizes.

[0142] At step 706, particle size data relative to one or more of the particle or discharge locations is generated for example by one or more of the IPAs 102-107. In that regard, a signal may be generated by an IPAthat is indicative of a particle size at one or more discharge or output locations. Alternatively, the step may comprise entering a detected particle size.

[0143] In step 708, the detected particle size data is then compared to the particle size threshold data to determine or evaluate a condition of one or more components of the system or evaluate one or more of operating parameters of the system. At step 708, if particle size data is not withing a range of particle sizes of the associated particles size threshold a signal is generated or transmitted indicating a recommendation relative to one or more operating parameters of the system. For example, particle size data that exceeds threshold data relative to a detected particle size at output line 83 may be indicative of a fault in the grinding gap G dimension. Accordingly, a recommendation may be made to narrow the grinding gap G to achieve the desired particle size output.

[0144] Many modifications and other embodiments will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the foregoing is not to be limited to the example embodiments, and that modifications and other embodiments are intended to be included within the scope of the appended claims. While embodiments of the invention are describing relative to the production of GGP from recycled glass, the invention is not so limited but may be incorporated in systems and methods for generating powder materials based on other waste or recycled biomass and / or rubber materials.

Claims

Claims:

1. A system for generating ground glass pozzolanic powder material, or GGP, from a feedstock, comprising: an impact mill comprising a rotor mounted within a housing and the rotor includes a central hub and a plurality of radially projecting shelves axially spaced relative to the rotor and central hub, wherein the shelves are dimensioned to define a conical shape, and the rotor is operatively connected to a motor to rotate about a common rotational axis of the rotor and hub; a conically shaped inner liner mounted to the housing and the inner liner having a serrated surface facing the rotor, and the inner liner is composed of a ceramic-metallic material; a plurality of grinding elements and each grinding element is mounted along a periphery of a respective rotor shelf and each grinding element has a grinding surface facing the inner liner and spaced from the inner liner, and each grinding element is composed of ceramic-metallic material; wherein the inner liner and grinding elements define a conically shaped grinding gap therebetween within the housing and the grinding gap is in fluid flow communication with an opening through a top of the rotor housing and through which a feedstock is input; an air classifier in fluid communication with the impact mill and grinding gap via an output of the impact mill to receive ground glass pozzolanic material (GGP) generated in the mill by grinding of the feedstock, and the air classifier is configured to separate the GGP material according to a threshold particle size, wherein GGP particles that are equal to or less than the threshold particle size are output relative to the air classifier to a first silo via a first classifier output and particles of the GGP that are greater than the threshold particle size are returned to the impact mill via a return line or are output to a another silo; wherein at least 90% of the pozzolanic particles of the GGP sent to the first silo have a particle size of less than 45 pm.

2. The system of claim 1 wherein at least 90% of the particles of the GGP sent to the first silo have a particle size of about or less than 20 pm and a mean particle of size of 5 pm or less.

3. The system of claim 1 wherein at least 90% of the particles of the GGP sent to the first silo have a particle size about or less than 10 pm and a mean particle of size of about 2 to 3 pm or less.

4. The system of claim 1 wherein at least 90% of the particles of the GGP sent to the first silo have a particle size about or less than 5 pm and a mean particle of size of about 2 to 3 pm or less.

5. The system of claim 1 wherein the inner liner has a serrated configuration and is composed of a ceramic-metallic composition.

6. The system of claim 1 wherein the feedstock is a silica-based material.

7. The system of claim 1 wherein the grinding gap has a width dimension of about 0.05 mm to about 3.0 mm, or a width dimension of about 0.1 mm to about 1.0 mm, or a width dimension of about 0.05 mm to about 0.30 mm.

8. The system of claim 1 further comprising: a second air classifier output line in fluid flow communication with the air classifier and a jet mill; and, wherein the air classifier is configured to separate GGP from the impact mill to return particles greater than 30 pm to the impact mill and output GGP particles having a particle size of 20 pm and less to the first silo, wherein at least 90% of the particles of the GGP sent to the first silo have a particle size of equal to or less than 20 pm and a mean particle of size of 5 pm, and output GGP particles between 20 pm and 30 pm to the jet mill via the second classifier output line, and wherein the jet mill is configured to further grind the GGP and separate the particles according to one or more selected particle sizes and output GGP to a second silo in fluid flow communication with the jet mill and wherein at least 90% of the particles of the GGP sent to the second silo have a particle size of equal 20 pm and a mean particle of size of 5 pm, and output GGP to one or more third silos and the GGP output to the third silos and at least 90% of the particles of the GGP sent to the one or more third silos have a particle size less than 20 pm.

9. The system of claim 1, wherein the ceramic-metallic composition of the inner liner and grinding elements comprises: about 70% to about 90% of Alumina (AI2O3); about 5% to about 30% additives such as:(i) about 10% to about 30% Zirconia,(ii) about 5% to about 15% Carbide (SiC),(iii) about 2% to about 10% of Titanium Carbide (TiC); and, about 5% to about 10% of one or more metallic binders including, but not limited to, Nickel (Ni) or Cobalt (Co).

10. The system of claim 1, further comprising: one or more first inline particle analyzers operatively connected between the impact mill and the air classifier to detect a particle distribution size of GGP output from the impact mill and the one or more inline particle analyzers are programmed to generate first data signals indicative of a particle size distribution of the GGP and / or a GGP mean particle size; one or more second inline particle analyzers operatively connected to an output line of the air classifer to detect a particle size distribution of GGP output from the air classifier and the one or more inline particle analyzers are programmed to generate first data signals indicative of a particle size distribution of the GGP and / or a GGP mean particle size; and, one or more controllers in signal communication with the first and second inline particle analyzer(s) to receive the first data signals indicative from the inline particle analyzers, and the one or more controllers are programmed to generate second data signals in response to the first data signals indicating the GGP particle size distribution or GGP mean particle size exceed a predetermined threshold, and the second data signals indicate a condition of one or more operating parameters associated with the impact mill or air classifier or recommendation regarding one or more operating parameters of the system or components of the system.

11. The system of claim 10 wherein the one or more operating parameters comprise; a width of the grinding gap of the impact mill and the recommendations to maintain or adjust the width of the grinding gap;a rotor speed or tip speed; surface dimensions of the inner liner and the grinding elements and recommendations to maintain the inner liner and grinding elements or replacement of one or more of the same; or, a range of particle size of the feedstock and recommendations to maintain the feedstock or change in the particle size of the feedstock.

12. The system of claim 11 further comprising: one or more inline particle analyzers operatively connected between the air classifier and the first silo, and / or between the jet mill and the one or more second silos.

13. A method for producing a ground glass pozzolanic material, or GGP, comprising. inputting into a grinding mill a silica-based feedstock; grinding the feedstock in the impact to GGP; discharging the GGP from the grinding mill to an air classifier for separating the GGP based on a threshold particle size; discharging GGP having a particle size that is about equal to or less than the threshold particle size from the air classifier for storage or use; returning or inputting the GGP having a particle size that is greater than the threshold particle size from the air classifier to the grinding mill for further particle size reduction; and, wherein the threshold particle size is about 20 pm or less.

14. The method of claim 13 wherein at least about 90% of GGP discharged to storage has a particle size of about 20 pm or less.

15. The method of claim 14, wherein the grinding mill is a first grinding mill, and the threshold particle size is a first threshold and the method further comprises: discharging GGP having a particle size that is greater than the first threshold and that is about or less than a second threshold particle size, which is greater than the first particle sizethreshold, to a second grinding mill for size reduction so the GGP is reduced in size based on the first threshold; and, and after reduction of the GGP by the second grinding mill for reduction to about or less than the first threshold, discharging the GGP for storage or use.

16. The method of claim 15 wherein the first grinding mill is an impact mill and the second griding mill is a jet mill.

17. The method of claim 13 wherein the impact mill comprises: a rotor mounted within a housing and the rotor includes a central hub and a plurality of radially projecting shelves axially spaced relative to the rotor and central hub, wherein the shelves are dimensioned to define a conical shape, and the rotor is operatively connected to a motor to rotate about a common rotational axis of the rotor and hub; a conically shaped inner liner mounted to the housing and the inner liner having a serrated surface facing the rotor, and the inner liner is composed of a ceramic-metallic material; a plurality of grinding elements and each grinding element is mounted along a periphery of a respective rotor shelf and each grinding element has a grinding surface facing the inner liner and spaced from the inner liner, and each grinding element is composed of ceramic-metallic material; wherein the inner liner and grinding elements define a conically shaped grinding gap therebetween within the housing and the grinding gap is in fluid flow communication with an opening through a top of the rotor housing and through which a feedstock is input;18. A supplemental cementitious material comprising ground glass pozzolanic (GGP) particles produced from grinding recycled silica-based waste materials wherein at least or about 90% of GGP particles have a particle size of about 20 pm or less.

19. The supplemental cementitious of claim 18 wherein at least 90% of the pozzolanic particles have a particle size of about 10 pm or less.

20. The supplemental cementitious of claim 18 wherein at least 90% of the pozzolanic particles have a particle size of about 5 pm or less.21 . A cement mixture comprising Ordinary Portland Cement (OPC) and from about 10% by weight to about 25% by weight of a pozzolanic powder material that comprises pozzolanic particles wherein about or at least 90% of the pozzolanic particles have a particle size of 20 pm or less.

22. The cement mixture of claim 21 wherein about or at least 90% of the pozzolanic particles have a particle size of 10 pm or less.

23. The cement mixture of claim 21 wherein about or at least 90% of the pozzolanic particles have a particle size of 10 pm or less.

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