Silicates and / or salts and methods of production and use thereof

Abstract

Disclosed herein are silicates and / or salts, methods of production and uses thereof. For example, methods of producing amorphous silicates and / or salts from materials comprising silicates are disclosed. As another example, the use of silicates and / or salts in the formation of cementitious materials is also disclosed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Serial No. 63 / 484,450, filed on February 10, 2023, entitled “Silicates and Methods of Production and Uses Thereof,” and U.S. Provisional Application Serial No. 63 / 484,474, filed on February 10, 2023, entitled “Silicates and Methods of Production and Uses Thereof,” and U.S. Provisional Application Serial No. 63 / 506,976, filed on June 8, 2023, entitled “Silicates and Methods of Production and Uses Thereof,” each of which is hereby incorporated by reference in its entirety.

[0003] Government sponsorship

[0004] This invention was made with Government support under DE-AR0001395 awarded by the U.S. Department of Energy. The Government has certain rights in this invention. Technical Field

[0005] Silicates and / or salts, methods for their production, and uses are generally described. Summary of the Invention

[0006] Disclosed herein are silicates and / or salts and methods for producing and using the same. For example, methods for producing amorphous silicates and / or salts from materials comprising silicates are disclosed (e.g., by merging the material comprising silicates with ammonium fluoride and / or ammonium bifluoride). In some cases, the method does not produce and / or accumulates a significant net amount of hydrogen fluoride, and / or the method regenerates ammonium fluoride and / or ammonium bifluoride. In some embodiments, the silicates and / or salts are suitable for use in gelling materials. In certain embodiments, the material comprising silicates also comprises lithium, and the method produces amorphous silicates and salts (e.g., lithium salts such as lithium fluoride, lithium carbonate, lithium hydroxide and / or lithium chloride, and / or aluminum salts such as aluminum fluoride, ammonium hexafluoroaluminate and / or alkali metal (e.g., sodium) hexafluoroaluminate (cryolith)) and / or aluminum oxide and / or aluminum hydroxide. In some cases, the subject matter of the present disclosure relates to related products, alternative solutions to specific problems, and / or a plurality of different uses of one or more systems and / or articles.

[0007] Certain aspects relate to amorphous silicates.In some embodiments, the amorphous silicate comprises greater than or equal to 10 ppm and less than or equal to 20 wt% fluoride.

[0008] Certain aspects relate to methods of producing silicates (e.g., amorphous silicates) and / or salts. In certain embodiments, the methods comprise combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination at a maximum temperature of greater than or equal to 10° C. and less than or equal to 125° C.; and producing an amorphous silicate and / or salt; wherein the method does not produce and / or accumulate a significant net amount of hydrogen fluoride.

[0009] In some embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination at a maximum temperature greater than or equal to 160°C and less than or equal to 250°C; and producing an amorphous silicate and / or salt; wherein the method does not produce and / or accumulate a significant net amount of hydrogen fluoride.

[0010] In certain embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination; and producing an amorphous silicate and / or salt; wherein the temperature of the material comprising the silicate is at a maximum temperature greater than or equal to 10°C and less than or equal to 125°C when the material comprising the silicate contacts the ammonium fluoride and / or ammonium bifluoride.

[0011] In some embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination; and producing an amorphous silicate and / or salt; wherein the temperature of the material comprising the silicate is at a maximum temperature greater than or equal to 160°C and less than or equal to 250°C when the material comprising the silicate contacts the ammonium fluoride and / or ammonium bifluoride.

[0012] In certain embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate, wherein the material comprising the silicate further comprises lithium; and producing a salt and an amorphous silicate; wherein the salt comprises a higher weight percentage of lithium than the material comprising the silicate; and wherein the amorphous silicate comprises a lower weight percentage of lithium than the material comprising the silicate.

[0013] Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments of the present disclosure when considered in conjunction with the accompanying drawings. In the event that this specification and the documents incorporated by reference include conflicting and / or inconsistent disclosures, this specification shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying drawings, which are schematic and not intended to be drawn to scale unless otherwise indicated. In the accompanying drawings, each identical or nearly identical component shown is generally illustrated by a single numeral. For the purpose of clarity, where no illustration is needed to enable one of ordinary skill in the art to understand the present disclosure, not every component is labeled in each drawing, nor is every component of each embodiment of the present disclosure shown.

[0015] Figure 1 Possible pathways for hardening cement (calcium silicate hydrate, CSH) according to some embodiments are shown.

[0016] Figure 2 A process for combining ammonium fluoride and / or ammonium bifluoride with a material containing silicates to produce a product is shown, according to some embodiments.

[0017] Figure 3A A three-step process for generating amorphous SiO 2 from crystalline SiO 2 is shown, according to some embodiments.

[0018] Figure 3B A process for processing lithium aluminosilicates, such as spodumene, is shown according to some embodiments.

[0019] Figure 4A A process for producing various Li salts according to some embodiments is shown.

[0020] Figure 4B A process for separating lithium as Li2CO3 by carbonating a Li-rich solution after recovering fluorine is shown according to some embodiments.

[0021] Figure 4C A process for processing lepidolite is shown according to some embodiments.

[0022] Figure 5 A process for silicate reduction, optionally including a process for lithium recovery and / or a process for aluminum recovery, is shown according to some embodiments.

[0023] Figure 6 A process for producing silicates and / or salts according to some embodiments is shown.

[0024] Figure 7A A process for converting non-pozzolanic silica to pozzolanic silica using ammonium bifluoride is shown, according to some embodiments.

[0025] Figure 7B Shown is a method for using a Figure 7ASchematic representation of the process for generating pozzolanic silica using the catalytic process depicted in FIG.

[0026] Figure 7C Shown is the relationship between coal combustion product (CCP) supply and use over time, reproduced from the American Coal Ash Association Production Use and Report (1991 to 2020).

[0027] Figure 8A It shows that the crystallized quartz sand is subjected to Figure 7A Scanning electron microscopy (SEM) images before (top) and after (bottom) the process described in .

[0028] Figure 8B It shows that the crystallized quartz sand is subjected to Figure 7A X-ray diffraction analysis (XRD) before (top) and after (bottom) the process described in . The broad peak at 20° to 25° is indicative of amorphous silica.

[0029] Figure 9 Shown is the process for technical grade (99.5% 400 mesh) silica, SEM images of the silica (before and after the process) and photographs of the SiO2-depleted residue. SEM analysis of the SiO2-depleted residue showed a composition dominated by Fe and O.

[0030] Figure 10 Shown is a SEM-EDS image of the SiO2-depleted residue after treating kaolinite with a silicate subtraction process, consistent with the XRD identification of the crystalline phase as (NH4)3AlF6, according to some embodiments.

[0031] Figure 11 Shown are XRDs of kaolinite (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate-removal process according to some embodiments. XRD indicates complete conversion of kaolinite to (NH4)3AlF6 and SiO2.

[0032] Figure 12 An SEM-EDS image of the SiO2-depleted residue after treating montmorillonite with a silicate-removal process according to some embodiments is shown. No Si signal was observed, indicating almost complete removal of Si, which is consistent with the SiO2 yield.

[0033] Figure 13 Shown are XRDs of montmorillonite (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate-removal process according to some embodiments. XRD of the insoluble fraction indicates that (NH4)3AlF6 is the main species with a small fraction of remaining montmorillonite.

[0034] Figure 14Shown is a SEM-EDS image of a SiO2-depleted residue after treating olivine with a silicate subtraction process, according to some embodiments.

[0035] Figure 15 Shown are XRDs of olivine (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate-removal process according to some embodiments. XRD indicates a small fraction of olivine remaining in the insoluble fraction.

[0036] Figure 16 Shown is a SEM-EDS image of a SiO2-depleted residue after treating wollastonite with a silicate-removal process according to some embodiments. No Si signal was observed in the SEM-EDS image of the insoluble fraction.

[0037] Figure 17 Shown are XRDs of wollastonite (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate-removal process, according to some embodiments. The XRD indicates complete dissolution of Si from the wollastonite.

[0038] Figure 18 Shown are XRD images of basalt (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate-removal process according to some embodiments. The red coloration of the insoluble residue is consistent with the Fe observed in the EDS pattern.

[0039] Figure 19 An SEM-EDS image of a SiO2-depleted residue after treating basalt with a silicate-removal process according to some embodiments is shown. Trace amounts of Si can be observed in the insoluble residue, and Na, Mg, Ca, Fe, and F are also present.

[0040] Figure 20 Shown are XRDs of ponded ash (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate removal process according to some embodiments. The XRD pattern is assigned to (NH4)3AlF6, with no other significant signals present.

[0041] Figure 21 Shown is a SEM-EDS image of the SiO2-depleted residue after treating pond dust with a silicate reduction process according to some embodiments. No signal for Si is observed, but both Mg and Ca signals are present.

[0042] Figure 22Shown are XRD images of bottom ash (top), alkalized filtrate (middle), and SiO2-depleted residue (bottom) after treatment with a silicate removal process according to some embodiments. Traces of unidentified compounds were observed in the soluble residue. The highest intensity signal is attributed to (NH4)3AlF6.

[0043] Figure 23 Shown is a SEM-EDS image of SiO2-depleted residue after treating bottom ash with a silicate reduction process according to some embodiments. Trace amounts of Si can be observed in the insoluble residue.

[0044] Figure 24 A system for catalyzing silica removal according to some embodiments is shown.

[0045] Figure 25 The XRD spectrum of the produced silica is shown with Si powder as an internal standard. The broad peak with a maximum in the range of 20 to 25 is characteristic of amorphous silica.

[0046] Figure 26 A system for detecting HF is shown. The system comprises a solution (500 mL, T 浴 =125°C). No HF was detected by fluoride indicator paper suspended above a boiling NH4F solution for approximately 5 hours, during which the solution volume decreased by approximately 150 mL. The presence of fluoride ions will cause a yellow stain on the test paper. The absence of yellow stain indicates that no significant amount of HF was emitted from the solution.

[0047] Figure 27 Shown is the NH4F / NH4HF2 solution heated to boiling in an oil bath at 125°C over the course of 4 hours. 19 FNMR spectrum, referenced to CH2FCN internal standard (-251 ppm). Expected position of aqueous HF relative to internal standard is -204 ppm.

[0048] Figure 28 The particle size distribution of pozzolanic silica obtained for fast NH3 titration and slow NH3 fumigation is shown.

[0049] Figure 29 Shown are SEM images of silicates produced with different NH4OH titration times.

[0050] Figure 30 The particle size distribution of pozzolanic silica produced with different NH4OH titration rates is plotted.

[0051] Figure 31Shown are SEM images of the silica starting material and the precipitated silica collected from the filtrate after ammonium bifluoride treatment.

[0052] Figure 32 A process for converting non-pozzolanic (crystalline) silica to pozzolanic (amorphous) silica using ammonium bifluoride is shown, according to some embodiments.

[0053] Figure 33 The photo, XRD and SEM-EDS of the silica product obtained from quartz sand are shown. The results show that the silica product obtained is similar to silica fume in structure.

[0054] Figure 34 Shown are DOR* calorimetry results for a silica product obtained from quartz sand (left) and a photograph of a vial of pozzolanic cement made from a silica product obtained from quartz sand after curing at 50°C for 48 hours (right).

[0055] Figure 35 The results of DOR*TGA (thermogravimetric analysis) measurements are shown, indicating that about 184 g of Ca(OH)2 are consumed per 100 g of pozzolan cement produced from silica product obtained from quartz sand.

[0056] Figure 36 Calorimetry and TGA data are presented that indicate that the silica product obtained from quartz sand has a reactivity comparable to that of fumed silica.

[0057] Figure 37 The reactivity of synthesized pozzolanic silica ("SynPozz") relative to other pozzolans using the Pozzolanic Reactivity Testing (PRT) is shown, showing that synthesized pozzolanic silica ("SynPozz") has the highest reactivity. Densified silica and undensified silica refer to fumed silica with different tap densities and aggregate particle sizes.

[0058] Figure 38 BET analysis of the resulting pozzolanic silica ("SynPozz") relative to other pozzolans is shown, indicating that the resulting pozzolanic silica ("SynPozz") has a higher surface area than the undensified silica fume. This is measured according to ASTM C1069-09 (BET surface area of ​​alumina and quartz). Densified silica and undensified silica refer to fumed silica with different tap densities and aggregate particle sizes.

[0059] Figure 39Calcium hydroxide ("CH") consumed during a standard pozzolan reactivity test (g / 100 g SCM), a measure of reactivity, is plotted against market price (US$ / ton).

[0060] Figure 40 Shown is an SEM image of the spodumene starting reagent.

[0061] Figure 41 Scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis showing the spodumene starting material to have 90% spodumene and 10% silica is shown.

[0062] Figure 42 Shown is an XRD analysis of the spodumene starting material phase indicating 90% LiSi2AlO6 and 10% SiO2. The phase (by XRD Rietveld analysis) is SiO2:LiAl(SiO3)2, 10:90.

[0063] Figure 43 Draw as from 7 Lithium extraction (%) from spodumene followed by Li-NMR versus time (hours).

[0064] Figure 44 The reaction mixture during leaching of spodumene in 3M NH4HF2 is shown over time. 7 Li NMR, which showed that lithium was readily soluble.

[0065] Figure 45 Lithium concentration (M) during leaching of spodumene in 3M NH4HF2 is plotted against reaction time (hours).

[0066] Figure 46 X-ray diffraction (XRD) and SEM-EDS of LiF separated from spodumene are shown. The silica impurity comes from residual precipitate from the previous step.

[0067] Figure 47 Plotting the normalized 7 Li signal (arbitrary units) versus time (hours), indicating that Li can be leached from lepidolite + .

[0068] Figure 48 Shown are 5.00 g of lepidolite before treatment with ammonium bifluoride (pre-leaching) (left) and 2.546 g of lepidolite after treatment with ammonium bifluoride (post-leaching) (right).

[0069] Figure 49Shown is an XRD overlay of lepidolite before treatment with ammonium bifluoride (pre-leaching) and after treatment with ammonium bifluoride (post-leaching). XRD indicates that the solid fraction remaining after lepidolite leaching consists of potassium hexafluoroaluminate (K3AlF6) and ammonium hexafluoroaluminate salt ((NH4)3AlF6).

[0070] Figure 50 XRD attributable to (NH4)2SiF6 is shown with the presence of amorphous SiO2 peaks from lepidolite leaching.

[0071] Figure 51 SEM-EDS images of lepidolite before treatment with ammonium bifluoride (pre-leaching) (left) and after treatment with ammonium bifluoride (post-leaching) (right) are shown. EDS detected elements of the lepidolite before leaching: Na, K, Al, Si, and O. EDS detected elements of the lepidolite after leaching: Na, K, Al, O, F, and N. SEM-EDS indicates that the solid fraction remaining after lepidolite leaching is composed of various hexafluoroaluminates.

[0072] Figure 52 Shows the effect of ammonium bifluoride treatment on the unhydrolyzed SiF6 2- Photograph of pozzolanic SiO2 separated from the soluble fraction in the absence of contamination. DETAILED DESCRIPTION

[0073] Disclosed herein are silicates and / or salts and their production methods and uses. For example, a method for producing amorphous silicates and / or salts by a material comprising silicates is disclosed (for example, by merging the material comprising silicates with ammonium fluoride and / or ammonium bifluoride). In some cases, the method does not produce and / or does not accumulate a significant net amount of hydrogen fluoride, and / or the method regenerates ammonium fluoride and / or ammonium bifluoride. In some embodiments, the silicates and / or salts are suitable for gelling materials. In certain embodiments, the material comprising silicates also comprises lithium, and the method produces amorphous silicates and salts (for example, lithium salts such as lithium fluoride, lithium carbonate, lithium hydroxide and / or lithium chloride, and / or aluminum salts such as aluminum fluoride, ammonium hexafluoroaluminate and / or sodium hexafluoroaluminate (cryolite)) and / or aluminum oxide and / or aluminum hydroxide.

[0074] Certain aspects relate to silicates.

[0075] The silicate may comprise silicon and oxygen-containing anions. In some cases, the silicate comprises silicon and oxygen-containing anions and no other anions. For example, in some cases, the silicate comprises silicon dioxide.

[0076] In some embodiments, the silicate comprises an amorphous silicate. When the silicate is non-crystalline, it is amorphous. In some cases, the amorphous silicate has a full width at half maximum (FWHM) of an X-ray diffraction peak derived from silicon dioxide (2θ = 20 degrees to 25 degrees) with a 2θ value greater than or equal to 8.0 ± 2.5 degrees.

[0077] According to certain embodiments, the silicate comprises a pozzolanic silicate.In some embodiments, a material is pozzolanic if, in finely divided form and in the presence of moisture, it will chemically react with calcium hydroxide to form a compound having gelling properties.

[0078] In some embodiments, the silicate (e.g., an amorphous silicate) comprises fluoride. For example, in certain embodiments, the silicate (e.g., an amorphous silicate) comprises greater than or equal to 10 ppm, greater than or equal to 20 ppm, greater than or equal to 30 ppm, greater than or equal to 40 ppm, greater than or equal to 50 ppm, greater than or equal to 75 ppm, greater than or equal to 100 ppm, greater than or equal to 125 ppm, greater than or equal to 150 ppm, greater than or equal to 175 ppm, or greater than or equal to 200 ppm of fluoride. In some embodiments, the silicate (e.g., an amorphous silicate) comprises less than or equal to 20% by weight, less than or equal to 15% by weight, less than or equal to 10% by weight, less than or equal to 5% by weight, less than or equal to 1% by weight, less than or equal to 0.5% by weight, less than or equal to 1000 ppm, less than or equal to 750 ppm, less than or equal to 500 ppm, or less than or equal to 250 ppm of fluoride. Combinations of these ranges are also possible (e.g., greater than or equal to 10 ppm and less than or equal to 20 wt % fluoride, or greater than or equal to 10 ppm and less than or equal to 250 ppm fluoride). As used herein, unless otherwise indicated, "ppm" means parts per million by weight.

[0079] In certain embodiments, the silicate (e.g., an amorphous silicate) has a suitable particle size distribution. For example, in some embodiments, the silicate (e.g., an amorphous silicate) has a suitable particle size distribution for use in a cementitious material. For example, according to some embodiments, the silicate (e.g., an amorphous silicate) has a particle size distribution greater than or equal to 0.01 micron, greater than or equal to 0.05 micron, greater than or equal to 0.1 micron, greater than or equal to 0.3 micron, greater than or equal to 0.5 micron, greater than or equal to 1 micron, greater than or equal to 2 microns, greater than or equal to 3 microns, greater than or equal to 5 microns, greater than or equal to 7 microns, or greater than or equal to 10 microns. According to certain embodiments, the silicate (e.g., an amorphous silicate) has a particle size distribution less than or equal to 20 microns, less than or equal to 18 microns, less than or equal to 15 microns, less than or equal to 10 microns, less than or equal to 8 microns, less than or equal to 5 microns, less than or equal to 3 microns, or less than or equal to 2 microns. Combinations of these ranges are also possible (eg, greater than or equal to 0.01 micrometers and less than or equal to 20 micrometers, or greater than or equal to 0.5 micrometers and less than or equal to 20 micrometers).Particle size and particle size distribution can be determined using a laser diffraction particle size analyzer.

[0080] According to some embodiments, the silicate (e.g., an amorphous silicate) has a suitable tap density. For example, in certain embodiments, the silicate (e.g., an amorphous silicate) has a suitable tap density for use in a cementitious material. For example, in some cases, the tap density of the silicate (e.g., an amorphous silicate) is greater than or equal to 0.1 g / cm 3 , greater than or equal to 0.2g / cm 3 , greater than or equal to 0.3g / cm 3 , greater than or equal to 0.4g / cm 3 , greater than or equal to 0.5g / cm 3 , greater than or equal to 0.7g / cm 3 , or greater than or equal to 1.0g / cm 3 In some cases, the silicate (e.g., an amorphous silicate) has a tap density less than or equal to 2.0 g / cm 3 , less than or equal to 1.9g / cm 3 , less than or equal to 1.8g / cm 3 , less than or equal to 1.7g / cm 3 , less than or equal to 1.6g / cm 3 , or less than or equal to 1.5g / cm 3 Combinations of these ranges are also possible (e.g., greater than or equal to 0.1 g / cm 3 and less than or equal to 2.0g / cm 3, greater than or equal to 0.2g / cm 3 and less than or equal to 1.9g / cm 3 , greater than or equal to 0.3g / cm 3 and less than or equal to 1.8g / cm 3 , greater than or equal to 0.5g / cm 3 and less than or equal to 1.8g / cm 3 , or greater than or equal to 1.0g / cm 3 and less than or equal to 1.8g / cm 3 ).

[0081] According to some embodiments, the silicate (e.g., an amorphous silicate) has a suitable specific surface area (SSA). For example, in certain embodiments, the silicate (e.g., an amorphous silicate) has a suitable specific surface area (SSA) for use in a cementitious material. For example, in certain embodiments, the SSA of the silicate (e.g., an amorphous silicate) is greater than or equal to 1 m 2 / g, greater than or equal to 2m 2 / g, greater than or equal to 5m 2 / g, greater than or equal to 10m 2 / g, greater than or equal to 15m 2 / g, greater than or equal to 20m 2 / g, greater than or equal to 25m 2 / g, greater than or equal to 30m 2 / g, greater than or equal to 35m 2 / g, greater than or equal to 40m 2 / g, greater than or equal to 50m 2 / g, greater than or equal to 60m 2 / g, greater than or equal to 75m 2 / g, or greater than or equal to 100m 2 According to some embodiments, the SSA of the silicate (e.g., amorphous silicate) is less than or equal to 2000 m 2 / g, less than or equal to 1900m 2 / g, less than or equal to 1800m 2 / g, less than or equal to 1700m 2 / g, less than or equal to 1600m 2 / g, less than or equal to 1500m 2 / g, less than or equal to 1400m 2 / g, less than or equal to 1300m 2 / g, less than or equal to 1200m 2 / g, less than or equal to 1100m 2 / g, less than or equal to 1000m 2 / g, less than or equal to 900m 2 / g, less than or equal to 800m 2 / g, less than or equal to 700m 2 / g, less than or equal to 600m 2 / g, less than or equal to 500m 2 / g, less than or equal to 400m 2 / g, less than or equal to 300m 2 / g, less than or equal to 200m 2 / g, less than or equal to 100m 2 / g, less than or equal to 90m 2 / g, less than or equal to 80m 2 / g, less than or equal to 70m 2 / g, less than or equal to 60m 2 / g, or less than or equal to 50m 2 / g. Combinations of these ranges are also possible (e.g., greater than or equal to 1 m 2 / g and less than or equal to 2000m 2 / g, greater than or equal to 1m 2 / g and less than or equal to 1000m 2 / g, greater than or equal to 1m 2 / g and less than or equal to 100m 2 / g, greater than or equal to 2m 2 / g and less than or equal to 50m 2 / g, greater than or equal to 5m 2 / g and less than or equal to 20m 2 / g, greater than or equal to 35m 2 / g and less than or equal to 100m 2 / g, or greater than or equal to 40m 2 / g and less than or equal to 100m 2 SSA can be measured according to the Brunauer-Emmett-Teller (BET) method.

[0082] In certain embodiments, the silicate (e.g., an amorphous silicate) comprises a metal (e.g., an amount of metal—total metal and / or individual metal—suitable for use in a cementitious material). For example, in some cases, the silicate (e.g., an amorphous silicate) comprises greater than or equal to 1000 ppm, greater than or equal to 2000 ppm, greater than or equal to 3000 ppm, greater than or equal to 4000 ppm, greater than or equal to 5000 ppm, greater than or equal to 6000 ppm, greater than or equal to 7000 ppm, greater than or equal to 8000 ppm, or greater than or equal to 9000 ppm of metal (e.g., total metal and / or individual metal). According to some embodiments, the silicate (e.g., an amorphous silicate) comprises less than or equal to 10,000 ppm, less than or equal to 9000 ppm, less than or equal to 8000 ppm, less than or equal to 7000 ppm, less than or equal to 6000 ppm, less than or equal to 5000 ppm, less than or equal to 4000 ppm, less than or equal to 3000 ppm, or less than or equal to 2000 ppm of metals (e.g., total metals and / or individual metals). Combinations of these ranges are also possible (e.g., greater than or equal to 1000 ppm and less than or equal to 10,000 ppm of metal).

[0083] In some embodiments, the silicate (e.g., an amorphous silicate) has a suitable degree of reactivity (DOR*). For example, in some cases, the silicate (e.g., an amorphous silicate) has a suitable degree of reactivity (DOR*) for use in a cementitious material. In some cases, the degree of reactivity (DOR*) of a material (e.g., a silicate) is the theoretical maximum mass fraction of the material (e.g., a silicate) that can react with calcium hydroxide to form cementitious calcium silicate. For example, in some cases, the DOR* of the silicate (e.g., an amorphous silicate) is greater than or equal to 30%, greater than or equal to 35%, greater than or equal to 40%, greater than or equal to 45%, greater than or equal to 50%, greater than or equal to 55%, greater than or equal to 60%, greater than or equal to 65%, greater than or equal to 70%, greater than or equal to 80%, or greater than or equal to 90%. In some cases, the DOR* of the silicate (e.g., an amorphous silicate) is less than or equal to 100%, less than or equal to 95%, less than or equal to 90%, less than or equal to 85%, less than or equal to 80%, less than or equal to 70%, less than or equal to 65%, less than or equal to 60%, or less than or equal to 50%. Combinations of these ranges are also possible (e.g., greater than or equal to 30% and less than or equal to 100%). DOR* can be measured as described in Weiss (Bharadwaj, K., Isgor, O.B. & Weiss, W.J.A. Simplified Approach to Determine Pozzolanic Reactivity of Commercial Supplementary Cementitious Materials. Towards the Development of Performance-Based Concrete Mixtures Made with Modern Cementitious Materials Using Thermodynamic Modeling 20 (2022)).

[0084] In certain embodiments, the silicate has a degree of reactivity (DOR*) that is higher than the degree of reactivity (DOR*) of the material comprising the silicate (e.g., a crystalline silicate). For example, in some cases, the degree of reactivity (DOR*) of the silicate is at least 10%, at least 20%, at least 30%, at least 40%, or at least 50% higher and / or less than or equal to 100%, less than or equal to 90%, less than or equal to 80%, less than or equal to 70%, or less than or equal to 60% higher (e.g., at least 10% higher and less than or equal to 100%) than the degree of reactivity (DOR*) of the material comprising the silicate (e.g., a crystalline silicate). For example, if the degree of reactivity (DOR*) of the material comprising the silicate (e.g., a crystalline silicate) is 10% and the degree of reactivity (DOR*) of the silicate (e.g., an amorphous silicate) is 50%, then the silicate will have a degree of reactivity (DOR*) that is 40% higher than the degree of reactivity (DOR*) of the material comprising the silicate (e.g., a crystalline silicate).

[0085] According to some embodiments, the silicate (e.g., an amorphous silicate) comprises any combination of the properties disclosed herein. For example, in some cases, the silicate (e.g., an amorphous silicate) comprises fluoride (e.g., any amount disclosed herein) (e.g., greater than or equal to 10 ppm and less than or equal to 20 wt% fluoride, or greater than or equal to 10 ppm and less than or equal to 250 ppm fluoride) and a tap density disclosed herein (e.g., greater than or equal to 0.1 g / cm 3 and less than or equal to 2.0g / cm 3 , greater than or equal to 0.2g / cm 3 and less than or equal to 1.9g / cm 3 , greater than or equal to 0.3g / cm 3 and less than or equal to 1.8g / cm 3 , greater than or equal to 0.5g / cm 3 and less than or equal to 1.8g / cm 3 , or greater than or equal to 1.0g / cm 3 and less than or equal to 1.8g / cm 3 ), and optionally a specific surface area as disclosed herein (e.g., greater than or equal to 1 m 2 / g and less than or equal to 2000m 2 / g, greater than or equal to 1m 2 / g and less than or equal to 1000m 2 / g, greater than or equal to 1m 2 / g and less than or equal to 100m 2 / g, greater than or equal to 2m 2 / g and less than or equal to 50m 2 / g, greater than or equal to 5m2 / g and less than or equal to 20m 2 / g, greater than or equal to 35m 2 / g and less than or equal to 100m 2 / g, or greater than or equal to 40m 2 / g and less than or equal to 100m 2 / g), and / or contains metals (e.g., greater than or equal to 1000 ppm and less than or equal to 10,000 ppm total metals).

[0086] In some cases, the silicate (e.g., an amorphous silicate) is produced by any of the methods disclosed herein. For example, in some cases, the silicate (e.g., an amorphous silicate) is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate. According to some embodiments, the silicate (e.g., an amorphous silicate) is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination at a maximum temperature of greater than or equal to 10° C. and less than or equal to 125° C. and a maximum pressure of greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, or a maximum pressure of greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres. According to certain embodiments, a silicate (e.g., an amorphous silicate) is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination at a maximum temperature greater than, or equal to, 160° C. and less than, or equal to, 250° C. and a maximum pressure greater than, or equal to, 0.1 atmosphere and less than, or equal to, 100 atmospheres, or a maximum pressure greater than, or equal to, 1 atmosphere and less than, or equal to, 100 atmospheres.

[0087] Certain aspects relate to cementitious materials. Examples of cementitious materials include building and structural materials, cement, mortar, concrete, supplementary cementitious additives, pozzolans, and / or pozzolanic cements. In certain embodiments, the pozzolans comprise siliceous materials, or siliceous and aluminous materials, which themselves have little cementitious value but which, at ambient temperature, react in finely divided form with calcium hydroxide in the presence of moisture to form a compound having cementitious properties.

[0088] In some embodiments, the cementitious material (eg, cement) comprises any amorphous silicate disclosed herein. In some embodiments, the silicate (eg, amorphous silicate) is suitable for use in the cementitious material.

[0089] In certain embodiments, the cementitious material (e.g., cement) has a suitable water demand (e.g., the mass ratio of water required to achieve a normal consistency of the water-cement mixture as determined by the Vicat needle penetration test (ASTM C191-21) and / or a "normal flow" as defined by the flow meter test (ASTM C230). For example, in some cases, the water demand of the cementitious material (e.g., cement) is less than or equal to 0.6, less than or equal to 0.55, less than or equal to 0.5, or less than or equal to 0.4. In some cases, the water demand of the cementitious material (e.g., cement) is greater than 0, greater than or equal to 0.1, greater than or equal to 0.2, or greater than or equal to 0.3. Combinations of these ranges are also possible (e.g., greater than 0 and less than or equal to 0.6, greater than or equal to 0.1 and less than or equal to 0.6, or greater than or equal to 0.3 and less than or equal to 0.5).

[0090] According to some embodiments, the cementitious material meets or exceeds the chemical and / or physical standards of ASTM C1157 (2010) (e.g., composition, fineness, autoclave length change, time to set (Vicat test), air content of mortar volume, compressive strength (1 day, 3 days, 7 days, 28 days), heat of hydration, mortar bar expansion, and / or sulfate expansion).

[0091] In some cases, a cementitious material (eg, concrete) is produced by any of the methods disclosed herein. Figure 1 Some possible methods of producing cement (eg, hardened cement) (eg, calcium silicate hydrate, CSH) according to some embodiments are shown.

[0092] Certain aspects relate to methods. In some embodiments, the method is a method of producing silicates (e.g., amorphous silicates) and / or salts (e.g., lithium salts such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride, and / or aluminum salts such as aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite)).

[0093] In some embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate. Figure 2 In the method, the method includes combining ammonium fluoride and / or ammonium bifluoride 101 with a material 102 comprising a silicate.

[0094] In certain embodiments, the method comprises combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination and / or in an anhydrous combination (e.g., an ammonium fluoride and / or ammonium bifluoride melt). In some cases, combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination provides one or more benefits, such as less decomposition of ammonium fluoride and / or ammonium bifluoride (e.g., compared to an anhydrous combination), less leaching of ammonium hexafluorosilicate (e.g., compared to an anhydrous combination), lower energy usage (e.g., compared to an anhydrous combination), easier to operate as a continuous process (e.g., compared to an anhydrous combination), and / or easier to operate on a large scale (e.g., compared to an anhydrous combination).

[0095] The method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination) can be at a suitable maximum temperature. For example, in some cases, the maximum temperature is greater than or equal to 10°C, greater than or equal to 20°C, greater than or equal to 30°C, greater than or equal to 40°C, greater than or equal to 50°C, greater than or equal to 60°C, greater than or equal to 70°C, greater than or equal to 80°C, or greater than or equal to 90°C. In some cases, the maximum temperature is less than or equal to 125°C, less than or equal to 120°C, less than or equal to 115°C, less than or equal to 110°C, less than or equal to 105°C, less than or equal to 100°C, less than or equal to 95°C, or less than or equal to 90°C. Combinations of these ranges are also possible (e.g., greater than or equal to 10° C. and less than or equal to 125° C., greater than or equal to 20° C. and less than or equal to 100° C., greater than or equal to 50° C. and less than or equal to 125° C., or greater than or equal to 50° C. and less than or equal to 100° C.). According to some embodiments, the maximum temperature is the maximum temperature of the material comprising the silicate when the material comprising the silicate contacts ammonium fluoride and / or ammonium bifluoride.

[0096] The method and / or steps thereof (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination) can be at a suitable maximum pressure. For example, in some cases, the maximum pressure is greater than or equal to 0.1 atmosphere, greater than or equal to 0.5 atmosphere, greater than or equal to 1 atmosphere, greater than or equal to 2 atmospheres, greater than or equal to 3 atmospheres, greater than or equal to 5 atmospheres, greater than or equal to 10 atmospheres, greater than or equal to 20 atmospheres, greater than or equal to 30 atmospheres, or greater than or equal to 40 atmospheres. In some cases, the maximum pressure is less than or equal to 100 atmospheres, less than or equal to 90 atmospheres, less than or equal to 80 atmospheres, less than or equal to 70 atmospheres, less than or equal to 60 atmospheres, less than or equal to 50 atmospheres, less than or equal to 40 atmospheres, less than or equal to 30 atmospheres, less than or equal to 20 atmospheres, less than or equal to 10 atmospheres, less than or equal to 5 atmospheres, less than or equal to 3 atmospheres, or less than or equal to 2 atmospheres. Combinations of these ranges are also possible (e.g., greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres, or greater than or equal to 1 atmosphere and less than or equal to 2 atmospheres). In some embodiments, the maximum pressure is 1 atmosphere. According to some embodiments, the maximum pressure is the maximum pressure of the environment in which the silicate-containing material is contained when the silicate-containing material contacts ammonium fluoride and / or ammonium bifluoride.

[0097] Combinations of these maximum temperature ranges and these maximum pressure ranges are also possible. For example, according to certain embodiments, the method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination) are at a maximum temperature greater than or equal to 10°C and less than or equal to 125°C and a maximum pressure greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, or a maximum pressure greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres. As another example, according to some embodiments, the method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination) are at a maximum temperature greater than or equal to 10°C and less than or equal to 125°C and a maximum pressure greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, or a maximum pressure greater than or equal to 1 atmosphere and less than or equal to 2 atmospheres.

[0098] The method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with the material comprising silicate in an anhydrous combination) can be at a suitable maximum temperature. For example, in some cases, the maximum temperature is greater than or equal to 160°C, greater than or equal to 170°C, greater than or equal to 180°C, greater than or equal to 190°C, greater than or equal to 200°C, or greater than or equal to 210°C. According to certain embodiments, the maximum temperature is less than or equal to 250°C, less than or equal to 240°C, less than or equal to 230°C, less than or equal to 220°C, less than or equal to 210°C, less than or equal to 200°C, or less than or equal to 190°C. Combinations of these ranges are also possible (e.g., greater than or equal to 160°C and less than or equal to 250°C). According to some embodiments, the maximum temperature is the maximum temperature of the material comprising silicate when the material comprising silicate contacts the ammonium fluoride and / or ammonium bifluoride.

[0099] The method and / or steps thereof (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with the material comprising silicate in an anhydrous combination) can be at a suitable maximum pressure. For example, in some cases, the maximum pressure is greater than or equal to 0.1 atmosphere, greater than or equal to 0.5 atmosphere, greater than or equal to 1 atmosphere, greater than or equal to 2 atmospheres, greater than or equal to 3 atmospheres, greater than or equal to 5 atmospheres, greater than or equal to 10 atmospheres, greater than or equal to 20 atmospheres, greater than or equal to 30 atmospheres, or greater than or equal to 40 atmospheres. In some cases, the maximum pressure is less than or equal to 100 atmospheres, less than or equal to 90 atmospheres, less than or equal to 80 atmospheres, less than or equal to 70 atmospheres, less than or equal to 60 atmospheres, less than or equal to 50 atmospheres, less than or equal to 40 atmospheres, less than or equal to 30 atmospheres, less than or equal to 20 atmospheres, less than or equal to 10 atmospheres, less than or equal to 5 atmospheres, less than or equal to 3 atmospheres, or less than or equal to 2 atmospheres. Combinations of these ranges are also possible (e.g., greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres, or greater than or equal to 1 atmosphere and less than or equal to 2 atmospheres). In some embodiments, the maximum pressure is 1 atmosphere. According to some embodiments, the maximum pressure is the maximum pressure of the material comprising the silicate when the material comprising the silicate contacts ammonium fluoride and / or ammonium bifluoride.

[0100] Combinations of these maximum temperature ranges and these maximum pressure ranges are also possible. For example, according to certain embodiments, the method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination) are at a maximum temperature of greater than or equal to 160°C and less than or equal to 250°C and a maximum pressure of greater than or equal to 0.1 atmosphere and less than or equal to 100 atmospheres, or a maximum pressure of greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres. As another example, according to some embodiments, the method and / or its steps (e.g., the step of combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination) are at a maximum temperature of greater than or equal to 160°C and less than or equal to 250°C and a maximum pressure of greater than or equal to 0.1 atmosphere and less than or equal to 2 atmospheres, or a maximum pressure of greater than or equal to 1 atmosphere and less than or equal to 2 atmospheres.

[0101] In some cases, the method includes reacting and / or dissolving only partially the silicate-containing material with ammonium fluoride and / or ammonium bifluoride. For example, in some cases, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more of the silicate-containing material is reacted and / or dissolved with ammonium fluoride and / or ammonium bifluoride. In some embodiments, less than 100% or less, 99% or less, 95% or less, 90% or less, 80% or less, 70% or less, 60% or less, or 50% or less of the silicate-containing material is reacted and / or dissolved with ammonium fluoride and / or ammonium bifluoride. Combinations of these ranges are also possible (e.g., greater than or equal to 10 wt % and less than 100 wt % or greater than or equal to 10 wt % and less than or equal to 99 wt %). In certain embodiments, the method comprises completely reacting and / or dissolving the silicate-containing material with ammonium fluoride and / or ammonium bifluoride.

[0102] In certain embodiments, the method produces and / or accumulates little hydrogen fluoride (HF). For example, in some cases, the method produces and / or accumulates less than or equal to 30 ppm, less than or equal to 25 ppm, less than or equal to 20 ppm, less than or equal to 15 ppm, less than or equal to 10 ppm, less than or equal to 5 ppm, less than or equal to 3 ppm, or less than or equal to 1 ppm of HF (e.g., within 30 minutes of combining ammonium fluoride and / or ammonium bifluoride with the material comprising silicate).

[0103] In some embodiments, the method does not produce and / or accumulate a significant net amount of hydrogen fluoride (HF). For example, in some cases, the combination (e.g., aqueous combination and / or anhydrous combination) of the silicate-containing material and ammonium fluoride and / or ammonium bifluoride does not have substantially no HF that can be detected by fluorine nuclear magnetic resonance ( 19 The amount of free HF detected by F NMR spectroscopy (e.g., no free HF was present at a signal-to-noise ratio (SNR) of 3.0) 19 F signal) and / or is substantially free of HF within the vicinity of the process (e.g., within 0.1 meter) in an amount observable by moistened fluoride ion detector paper having a sensitivity limit of 20 mg / L (e.g., no yellow coloration indicative of the presence of fluoride by macroscopically observable fluoride ion detector paper).

[0104] According to some embodiments, described method includes making ammonium fluoride and / or ammonium bifluoride regeneration.For example, in some cases, described method includes making greater than or equal to 10 weight %, greater than or equal to 20 weight %, greater than or equal to 30 weight %, greater than or equal to 40 weight %, greater than or equal to 50 weight %, greater than or equal to 60 weight %, greater than or equal to 70 weight %, greater than or equal to 80 weight % or greater than or equal to 90 weight % ammonium fluoride and / or ammonium bifluoride regeneration.In some cases, described method includes making less than or equal to 100 weight %, less than or equal to 99 weight %, less than or equal to 95 weight %, less than or equal to 90 weight %, less than or equal to 80 weight %, less than or equal to 70 weight %, less than or equal to 60 weight %, less than or equal to 50 weight %, less than or equal to 40 weight % or less than or equal to 30 weight % ammonium fluoride and / or ammonium bifluoride regeneration.The combination of these ranges is also possible (for example, greater than or equal to 10 weight % and less than or equal to 100 weight %).

[0105] In some cases, the material comprising silicate comprises crystalline silicate. In some cases, the material comprising silicate also comprises lithium and / or aluminum. According to some embodiments, the material comprising silicate comprises olivine and / or olivine type material, montmorillonite and / or montmorillonite type material, kaolinite and / or kaolinite type material, halloysite and / or halloysite type material, kyanite and / or kyanite type material, sillimanite and / or sillimanite type material, spodumene and / or spodumene type material, petalite and / or petalite type material, eucryptite and / or eucryptite type material, quartz and / or quartz type material, mullite and / or mullite type material, zircon and / or zircon type material, wollastonite and / or wollastonite type material, basalt and / or basalt type material, lepidolite and / or lepidolite type material, lithium apatite and / or lithium apatite type material, lithium iron phosphate and / or lithium phosphate Iron ore type materials, walterite and / or walterite type materials, ramsonite and / or ramsonite type materials, illite and / or illite type materials, smectite and / or smectite type materials, jadarite and / or jadarite type materials, chlorite and / or chlorite type materials, montebrasite and / or montebrasite type materials, tourmaline and / or tourmaline type materials, lepidolite and / or lepidolite type materials, rare earth element (REE) sands, laterite clays, desert sands, ash resulting from the combustion of fossil fuels (e.g., bottom ash, pond ash, fly ash), and / or residues resulting from industrial processes (e.g., mining tailings and / or bauxite residues). For example, according to certain embodiments, materials comprising silicates (e.g., materials comprising silicates and lithium and / or aluminum) include olivine, montmorillonite, kaolinite, halloysite, kyanite, sillimanite, spodumene, petalite, eucryptite, quartz, mullite, zircon, wollastonite, basalt, lepidolite, lepidolite, lepidolite, schizolinite, illite, smectite, jaddarite, chrysocolla, lepidolite, tourmaline, ferroalite, rare earth element (REE) sands, laterite clays, desert sands, ash produced from the combustion of fossil fuels (e.g., bottom ash, pond ash, fly ash), and / or residues produced from industrial processes (e.g., mining tailings and / or bauxite residues).

[0106] In some cases, the DOR* of a material comprising a silicate (e.g., a crystalline silicate) is greater than or equal to 0%, greater than or equal to 5%, greater than or equal to 10%, greater than or equal to 15%, or greater than or equal to 20%. In some cases, the DOR* of a material comprising a silicate (e.g., a crystalline silicate) is less than 30%, less than or equal to 25%, less than or equal to 20%, less than or equal to 15%, less than or equal to 10%, less than or equal to 5%, less than or equal to 3%, less than or equal to 1%, or 0%. Combinations of these ranges are also possible (e.g., greater than or equal to 0% and less than 30% or greater than or equal to 0% and less than or equal to 25%).

[0107] In certain embodiments, the methods include producing silicates (e.g., amorphous silicates) and / or salts (e.g., lithium salts such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride and / or aluminum salts such as aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite)). For example, in Figure 2 In some embodiments, the method includes producing a product 103. In some cases, the product 103 comprises a silicate (e.g., an amorphous silicate). In some cases, the product 103 comprises a salt (e.g., a lithium salt such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride and / or an aluminum salt such as aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite)). In some embodiments, the product 103 comprises a silicate (e.g., an amorphous silicate) and a salt (e.g., a lithium salt such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride and / or an aluminum salt such as aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite)).

[0108] Some examples of the method are Figure 3A 、 3B , 4A, 4B, 4C, 5 and 6. For example, Figure 3A A three-step process for generating amorphous SiO2 from crystalline silicon dioxide is shown according to some embodiments. Figure 3A In the first step, in some cases, ammonium bifluoride and ammonia are produced from ammonium fluoride. Figure 3A In a second step, in some cases, a silicate (e.g., crystalline silica) is combined with ammonium bifluoride to produce ammonium hexafluorosilicate, ammonia, and water. Figure 3A In the third step, according to some embodiments, ammonium hexafluorosilicate is combined with ammonia to precipitate amorphous silicate and ammonium fluoride.

[0109] As another example, Figure 3B A process for processing lithium aluminum silicates, such as spodumene, to produce pozzolanic SiO2 and / or lithium and / or aluminum salts is shown, according to some embodiments. Figure 3BIn step 1, in some cases, ammonium bifluoride and ammonia are generated from ammonium fluoride. Figure 3B In step 2, in some cases, spodumene is combined with ammonium bifluoride to produce Li2SiF6 and / or (NH4)2SiF6, as well as water, ammonia and (NH4)3AlF6. Figure 3B In step 3, according to some embodiments, the Li2SiF6 and / or (NH4)2SiF6 produced in step 2 are combined with NH4OH to produce amorphous silica, NH4F, water and / or LiF. Figure 3B In step 4, according to certain embodiments, LiF is combined with ammonium fluoride to produce LiHF2, ammonium bifluoride, and ammonia. Figure 3B In step 5, according to some embodiments, ammonia is combined with LiHF2 and / or ammonium bifluoride to produce ammonium fluoride and / or LiF. Figure 3B In step 6, according to certain embodiments, HF and ammonia are combined to form ammonium fluoride. Figure 3B In step 7, in some cases, (NH4)3AlF6 is combined with sulfuric acid to produce Al2(SO4)3, HF and (NH4)2SO4. Figure 3B In step 8, in some cases, NaOH is combined with Al2(SO4)3 and / or (NH4)2SO4 to produce Al(OH)3, NH3, water and / or Na2SO4.

[0110] In yet another example, Figure 4A A process for producing various Li salts and / or pozzolanic silica from spodumene according to some embodiments is shown. For example, in some cases, Figure 4A Step 1 of the process combines spodumene and ammonium bifluoride to produce Li2SiF6 and / or (NH4)2SiF6, as well as water, ammonia and (NH4)3AlF6. Figure 4A In step 2, in some cases, NH4OH is combined with Li2SiF6 and / or (NH4)2SiF6 to produce amorphous silica, water, ammonium fluoride and LiF (aq) .exist Figure 4A In step 3, according to various embodiments, LiF (s) 、Li2CO 3(s) and / or LiOH (s) Can be made of LiF (aq) , ammonium fluoride and optionally additional reagents.

[0111] In yet another example, Figure 4B A process for separating lithium into Li2CO3 by carbonating a Li-rich solution after recovering fluorine during the treatment of spodumene is shown, according to some embodiments. Figure 4BIn step 1, in some embodiments, ammonium bifluoride and ammonia are generated from ammonium fluoride. Figure 4B In step 2, in some cases, ammonium bifluoride is combined with spodumene to produce Li2SiF6 and / or (NH4)2SiF6, as well as water, ammonia and (NH4)3AlF6. Figure 4B In step 3, in some cases, NH4OH is combined with Li2SiF6 and / or (NH4)2SiF6 to produce amorphous silica, ammonium fluoride, water, and LiF (aq) .exist Figure 4B In step 5, according to some embodiments, ammonium fluoride and LiF (aq) Combined with heat to produce LiHF2, ammonium bifluoride and ammonia. Figure 4B In step 6, according to certain embodiments, ammonium bifluoride, sulfuric acid and LiF (aq) Combined to produce Li2SO4, HF and ammonium fluoride. Figure 4B In step 7, in some cases, Li2SO4 and Na2CO3 are combined to produce Li2CO3 and Na2SO4.

[0112] In yet another example, Figure 4C A process for processing lepidolite to produce pozzolanic SiO2 is shown, according to some embodiments. Figure 4C In step 1, in some embodiments, ammonium bifluoride and ammonia are produced from ammonium fluoride. Figure 4C In step 2, in certain embodiments, ammonium bifluoride is combined with lepidolite to produce (NH4, Li, K)2SiF6, (NH4, Li, K)3AlF6, ammonia, and water. Figure 4C In step 3, in some cases, (NH4,Li,K)2SiF6 is combined with NH4OH to produce amorphous silica, ammonium fluoride, water, and (Li,K)F. Figure 4C In step 4, according to some embodiments, ammonia and water are combined to produce NH4OH.

[0113] In yet another example, Figure 5 A silicate reduction process is shown according to some embodiments, optionally including a process for lithium recovery and / or an aluminum recovery process. Figure 5 In step 1, in some cases, ammonium bifluoride and ammonia are generated from ammonium fluoride. Figure 5 In step 2, in some cases, ammonium bifluoride is combined with lepidolite to produce (NH4,Li,K)2SiF6, (NH4,Li,K)3AlF6, ammonia, and water. Figure 5In step 3, according to some embodiments, (NH4,Li,K)2SiF6 is combined with NH4OH to produce amorphous silica, ammonium fluoride, water, and (Li,K)F. Figure 5 In step 4, according to certain embodiments, ammonia and water are combined to produce NH4OH. Figure 5 In step 5, according to some embodiments, ammonium fluoride and LiF (aq) Combined to produce ammonia, ammonium bifluoride and LiHF2. Figure 5 In step 6, in certain embodiments, ammonium hydroxide is combined with LiF and / or NH4HF2 to produce LiF, ammonium fluoride and / or water. Figure 5 In step 7, in some cases, HF is combined with ammonia to produce ammonium fluoride. Figure 5 In step 8, in certain embodiments, (NH4)3AlF6 is combined with sulfuric acid to produce Al2(SO4)3, HF, and (NH4)2SO4. Figure 5 In step 9, in some cases, NaOH is combined with Al2(SO4)3 and / or (NH4)2SO4 to produce Al(OH)3, Na2SO4, ammonia and / or water. Figure 5 In step 10, in some embodiments, Na2SO4 is combined with water to produce sulfuric acid and NaOH.

[0114] As another example, Figure 6 A process for producing silicates and / or salts according to some embodiments is shown. Figure 6 In step 1, in some cases, ammonium bifluoride and ammonia are generated from ammonium fluoride. Figure 6 In step 2, in some cases, ammonium bifluoride is combined with a lithium-containing aluminosilicate such as LiAl(SiO3) to produce, for example, (NH4,Li)2SiF6, (NH4)3AlF6 and water. Figure 6 In step 3, according to certain embodiments, NH4OH is combined with (NH4,Li)2SiF6 to produce silicon dioxide, LiF, ammonium fluoride, and water. Figure 6 In step 4, according to some embodiments, (NH4)3AlF6 is combined with sulfuric acid to produce (NH4)2SO4, HF and Al2(SO4)3. Figure 6 In step 4, according to certain embodiments, Al2(SO4)3 is combined with NaOH to produce Na2SO4 and Al(OH)3. Figure 6 In step 5, in some cases, silica, LiF, and sulfuric acid are combined to produce silica, Li2SO4, HF, and ammonium fluoride. Figure 6 In step 6, in some cases, NH4OH and HF are combined to produce ammonium fluoride and water. Figure 6In step 7, in some embodiments, Li2SO4 is combined with NaOH to produce LiOH and Na2SO4. Figure 6 In step 8, in certain embodiments, the acid and / or base is generated electrochemically.

[0115] It should be understood that in some embodiments, Figure 3A 、 3B , 4A, 4B, 4C, 5 and 6 are optional. It should be understood that in some cases, Figure 3A 、 3B , 4A, 4B, 4C, 5 and 6 can be performed in a non-sequential order. It should be understood that according to various embodiments, the compounds discussed above can be in a solid, liquid, aqueous and / or gaseous state.

[0116] In some embodiments, the method includes producing a silicate (e.g., an amorphous silicate), such as any silicate disclosed herein (e.g., an amorphous silicate). In some cases, the silicate (e.g., an amorphous silicate) comprises a lower weight percentage of lithium than the material comprising the silicate. For example, in some cases, the silicate (e.g., an amorphous silicate) comprises less than 1% by weight, more than 3% by weight, more than 5% by weight, more than 10% by weight, more than 15% by weight, more than 20% by weight, more than 30% by weight, more than 40% by weight, more than 50% by weight, more than 60% by weight, more than 70% by weight, more than 80% by weight, more than 90% by weight, or more than 95% by weight of lithium than the material comprising the silicate. In certain embodiments, the silicate (e.g., an amorphous silicate) contains less than or equal to 100% by weight, less than or equal to 99% by weight, less than or equal to 95% by weight, less than or equal to 90% by weight, less than or equal to 80% by weight, less than or equal to 70% by weight, less than or equal to 60% by weight, less than or equal to 50% by weight, less than or equal to 40% by weight, less than or equal to 30% by weight, less than or equal to 20% by weight, less than or equal to 10% by weight, or less than or equal to 5% by weight less lithium than the material comprising the silicate. Combinations of these ranges are also possible (e.g., greater than or equal to 1% by weight and less than or equal to 100% by weight or greater than or equal to 1% by weight and less than or equal to 95% by weight less lithium than the material comprising the silicate). For example, if the material comprising the silicate contains 20% by weight lithium and the silicate contains 5% by weight lithium, the silicate will contain 15% by weight less lithium than the material comprising the silicate.

[0117] In certain embodiments, the method includes producing salts. In some cases, the method includes producing salts other than silicates (e.g., amorphous silicates). In some cases, the method includes producing salts without producing silicates. In some embodiments, the salt comprises lithium and / or aluminum. In some cases, the salt comprises lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride. In some cases, the salt comprises lithium fluoride. According to some embodiments, the method includes producing salts used in electrolytes from lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride. In some embodiments, the electrolyte salt is LiPF6. In some embodiments, the method includes using salts in batteries such as lithium batteries (e.g., lithium ion batteries). According to certain embodiments, the method includes using LiPF6 in lithium batteries such as lithium ion batteries. According to some embodiments, the method includes producing a positive electrode comprising lithium carbonate, and / or lithium chloride, and / or lithium hydroxide. According to certain embodiments, the method includes producing a lithium battery comprising the positive electrode. In some cases, the salt comprises aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolith)).

[0118] In some cases, the salt (e.g., a lithium salt such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride) contains a higher weight percentage of lithium than the material containing silicate. For example, in some cases, the salt (e.g., a lithium salt such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride) contains greater than or equal to 1% by weight, greater than or equal to 3% by weight, greater than or equal to 5% by weight, greater than or equal to 10% by weight, greater than or equal to 15% by weight, greater than or equal to 20% by weight, greater than or equal to 30% by weight, greater than or equal to 40% by weight, greater than or equal to 50% by weight, greater than or equal to 60% by weight, greater than or equal to 70% by weight, greater than or equal to 80% by weight, greater than or equal to 90% by weight, or greater than or equal to 95% by weight of lithium than the material containing silicate. In certain embodiments, the (e.g., lithium salt, such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride) contains less than or equal to 100%, less than or equal to 99%, less than or equal to 95%, less than or equal to 90%, less than or equal to 80%, less than or equal to 70%, less than or equal to 60%, less than or equal to 50%, less than or equal to 40%, less than or equal to 30%, less than or equal to 20%, less than or equal to 10%, or less than or equal to 5% more lithium by weight than the material containing silicate. Combinations of these ranges are also possible (e.g., greater than or equal to 1% and less than or equal to 100% or greater than or equal to 1% and less than or equal to 95% more lithium than the material containing silicate). For example, if the material containing silicate contains 20% lithium by weight and the salt contains 50% lithium by weight, the salt will contain 30% more lithium by weight than the material containing silicate.

[0119] According to some embodiments, the method includes forming aluminum oxide and / or aluminum hydroxide. For example, in some cases, the method includes forming aluminum oxide and / or aluminum hydroxide in addition to silicates (e.g., amorphous silicates) and / or salts (e.g., lithium salts such as lithium fluoride, lithium carbonate, lithium hydroxide, and / or lithium chloride, and / or aluminum salts such as aluminum fluoride, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite)).

[0120] In some cases, the aluminum oxide and / or aluminum hydroxide has a low concentration of impurities, such as fluorine. For example, in certain embodiments, the aluminum oxide and / or aluminum hydroxide has less than or equal to 1 weight percent, less than or equal to 0.1 weight percent, less than or equal to 0.01 weight percent, less than or equal to 0.001 weight percent, or less than or equal to 0.0001 weight percent impurities, such as fluorine. In some cases, the aluminum oxide and / or aluminum hydroxide has greater than or equal to 0 weight percent impurities, such as fluorine. Combinations of these ranges are also possible (e.g., greater than or equal to 0 weight percent and less than or equal to 1 weight percent or greater than or equal to 0 weight percent and less than or equal to 0.0001 weight percent). In some cases, the aluminum oxide and / or aluminum hydroxide has 0 weight percent impurities, such as fluorine.

[0121] In some cases, the aluminum oxide and / or aluminum hydroxide has a high purity. For example, in some cases, the purity of the aluminum oxide and / or aluminum hydroxide is greater than or equal to 99% by weight, greater than or equal to 99.9% by weight, greater than or equal to 99.99% by weight, greater than or equal to 99.999% by weight, or greater than or equal to 99.9999% by weight. In some embodiments, the purity of the aluminum oxide and / or aluminum hydroxide is less than or equal to 100% by weight (e.g., less than 100% by weight). Combinations of these ranges are also possible (e.g., a purity of greater than or equal to 99% by weight and less than or equal to 100% by weight or greater than or equal to 99.9999% by weight and less than or equal to 100% by weight).

[0122] In some embodiments, the method includes producing a separator comprising aluminum oxide. In certain embodiments, the method includes producing a battery (eg, a lithium battery) comprising a separator comprising aluminum oxide.

[0123] In certain embodiments, the method includes producing a cementitious material (e.g., cement) comprising the produced amorphous silicate. In some embodiments, the method includes producing a cementitious material (e.g., cement) comprising aluminum oxide and / or aluminum hydroxide. According to some embodiments, the method includes producing a cementitious material (e.g., cement) comprising an amorphous silicate and aluminum oxide and / or aluminum hydroxide. In some cases, the ratio of aluminum to silicon is selected to achieve the desired composition of the hardened cementitious material, such as calcium aluminum silicate hydrate (CASH).

[0124] Certain embodiments relate to a collection of particles comprising a silicate (e.g., any silicate described elsewhere herein). In some embodiments, in a collection of particles, at least 90%, at least 95%, at least 98%, at least 99%, at least 99.9%, or at least 99.99% by weight of the total weight of the particles is comprised of particles having a maximum cross-sectional dimension greater than or equal to 0.01 micron, greater than or equal to 0.05 micron, greater than or equal to 0.1 micron, greater than or equal to 0.03 micron, greater than or equal to 0.05 micron, greater than or equal to 1 micron, greater than or equal to 2 microns, greater than or equal to 3 microns, greater than or equal to 5 microns, greater than or equal to 7 microns, or greater than or equal to 10 microns and / or less than or equal to 20 microns, less than or equal to 18 microns, less than or equal to 15 microns, less than or equal to 10 microns, less than or equal to 8 microns, less than or equal to 5 microns, less than or equal to 3 microns, or less than or equal to 2 microns. Such a collection can be used, for example, in a cementitious material.

[0125] The mineral spodumene, which has the basic chemical formula LiAlSi2O6, is the main mineral source of lithium. 10 Petalite and eucryptite, along with LiAlSiO4, are relevant mineral sources for lithium that are commonly found in hard rock deposits containing spodumene. Another mineral source of lithium is clay, including smectite and illite. Extracting lithium from such deposits typically requires multiple steps, including: i) grinding the hard rock and / or clay; ii) flotation to separate the lithium-rich ore; iii) converting the acid-resistant mineral phase (e.g., α-spodumene) to an acid-leachable phase (e.g., β-spodumene) via calcination; iv) sulfuric acid or sulfate roasting to extract the lithium as dissolved lithium sulfate; and v) precipitating or carbonating the dissolved lithium to obtain purified lithium salts, such as LiOH or Li2CO3. Such processes are commercially practiced but are expensive, energy-intensive, and produce undesirable waste.

[0126] In some embodiments, source materials comprising lithium and silica (including but not limited to lithium aluminosilicates, such as spodumene (including alpha and / or beta phases), petalite, eucryptite and / or lithium silicate clays, including but not limited to smectite and illite) are value-added by silicate subtraction to produce at least: 1) a lithium-enriched salt, and 2) a lithium-depleted silicate, compared to the starting material.

[0127] In one embodiment, the added value by silicate removal is carried out by a method disclosed herein, wherein an ammonium fluoride compound is used to dissolve and then precipitate solid silica in a cyclic process in which the ammonium fluoride is reused. When carrying out the cyclic process, in certain embodiments, the starting lithium-containing silicate is separated into at least a silica-rich fraction and a lithium-rich fraction. In some embodiments, lithium is separated into fluorides, which can be precipitated as solid fluorides comprising lithium fluoride. The solid lithium fluoride can be amorphous, disordered, nanocrystalline or crystalline. The lithium fluoride can include pure or impure lithium fluoride of a rock salt structure type. In some embodiments, lithium is separated into lithium carbonate, lithium chloride and / or lithium hydroxide.

[0128] The lithium fluoride can then be processed to produce LiPF6 (a key component for producing lithium batteries), which is widely used as a salt in liquid electrolytes used in lithium batteries. For example, LiPF6 can be prepared by the reaction of LiF with phosphorus pentafluoride PF5. Alternatively, the lithium fluoride can be processed to produce a precursor or compound used in a positive active or negative active lithium storage electrode for a battery, or a solid electrolyte that conducts lithium used in batteries and other devices. Lithium salts used as input materials for the preparation of such compounds include lithium sulfate (Li2SO4), lithium carbonate (Li2CO3) and lithium hydroxide (LiOH). As a non-limiting example, LiF can be converted to Li2SO4 by reacting with sulfuric acid H2SO4, producing HF as a by-product. The recovered fluorine can be reused in this process or for separate purposes. The Li2SO4 can then be processed to produce LiOH or Li2CO3, both of which are used as precursors for the preparation of lithium metal oxides. Examples of lithium metal oxides that can be produced are battery electrode compounds, including any of a wide range of positive electrode families including ordered and disordered rock salt structure type oxides such as LiCoO2, LiNiO2, nickel-manganese-cobalt "NMC" family of positive electrode oxides, and many other specific compositions. The positive electrode may contain polyanionic compounds such as phospho-olivine (including, for example, LiFePO4 and Li(Fe,Mn)PO4), and spinel (including, for example, LiMn2O4 or Li(Mn,Ni)2O4). The negative electrode active compound may include a spinel oxide such as Li4Ti5O12 (LTO). The lithium solid electrolyte may include garnet or compounds in the lithium superionic conductor (LiSICON) family, or chalcogenides such as lithium-phosphorus-sulfide "LPS" and lithium-germanium-phosphorus-sulfide "LGPS".

[0129] In some embodiments, the aluminum in the starting mineral forms ammonium aluminum fluoride, such as ammonium aluminum hexafluoride (NH4)3AlF6. In some embodiments, the aluminum-containing phase is separated from the silica-rich and / or lithium-rich fractions of the starting material. The aluminum-containing phase can then be decomposed to recover ammonia and fluoride, which can be reused in the catalytic process. In a specific embodiment, the ammonium aluminum hexafluoride is reacted with heated water and / or steam to increase the value of the aluminum to aluminum oxide and / or aluminum hydroxide. The reaction can be described in one form as:

[0130] (NH4)3AlF6+2H2O→Al2O3+3NH3+6HF

[0131] And as a non-limiting example, the reaction can be carried out by making (NH4)3AlF 6(s) The reaction is carried out by reacting with superheated steam. At ambient pressure, the temperature for such a reaction is preferably greater than about 300°C, and more preferably greater than about 350°C, but in some cases, other conditions for carrying out such a reaction may be used. In some embodiments, cooling of the generated ammonia and hydrofluoric acid is carried out to regenerate the ammonium bifluoride reagent according to the following reaction:

[0132]

[0133] In some embodiments, the catalytic silica removal process is used to separate the input mineral source into at least two reaction product streams. In preferred embodiments, at least a silica-rich stream, a lithium-rich stream, and an aluminum-rich stream are produced from the input mineral source. In other embodiments, one or more additional product streams enriched in other elements may be produced simultaneously. For example, value-added products produced simultaneously or sequentially from the same input material may include pure reactive amorphous silica, purified LiF salts, and purified alumina. The value-added residue from these three elements may itself be value-added due to the enrichment of other elements, which may include main group metals; energy-related metals such as Cu, Co, or Ni; rare-earth elements (REEs); precious metals; and platinum-group metals (PGMs). In some embodiments, the silica product stream is used to produce building and structural materials, including but not limited to cement, mortar, concrete, supplemental cementitious additives, pozzolans, or pozzolanic cements.

[0134] In some embodiments, the method includes the above processes, value-added materials resulting from conducting such processes, reactors designed to conduct such processes, and systems or subsystems that combine at least two, and preferably three or more, unit operations that perform the above steps. Such systems are shown in Figure 24 as follows.

[0135] The following examples are intended to illustrate certain embodiments of the invention but do not exemplify the full scope of the invention.

[0136] Example 1

[0137] This example describes a thermochemical catalytic process for converting crystalline non-volcanic silica (SiO2) that is not suitable for cement production (with low pozzolanic reactivity) into pozzolanic SiO2 that is suitable for cement production (amorphous with high pozzolanic reactivity). This process utilizes the thermal decomposition of ammonium fluoride (NH4F) at elevated temperatures (50 °C < T operation < 125 °C) to produce ammonium bifluoride (NH4HF2) and ammonia (NH3):

[0138] 1.6NH4F → 3NH4HF2 + 3NH3 <00所求翻译的原文中没有这段内容,因此无法翻译。00563>Ammonia is released from the ammonium bifluoride solution by heating. Subsequently, the dissolved NH4HF2 is used as a fluorinating agent to convert crystalline SiO2 into ammonium fluorosilicate ((NH4)2SiF6)) at 20 °C to 100 °C:

[0140] 2.SiO2 + 3NH4HF2 → (NH4)2(SiF6) + 2H2O + NH3

[0141] And subsequently, the ammonia (NH3) released in 1 and 2 is reintroduced to increase the pH and produce amorphous SiO2 and NH4F at approximately 20 °C:

[0142] 3.(NH4)2(SiF6) + 4NH3 + 2H2O → SiO2 + 6NH4F

[0143] The amorphous SiO2 is then filtered out of the dissolution medium, regenerating the initial reagent (NH4F) and closing the catalytic cycle. The regeneration is carried out at a temperature of approximately 100 °C.

[0144] As Figure 7A described, the process is run at an operating temperature of 50 °C to 125 °C. As Figure 7AAs shown, in step 1, ammonium bifluoride is combined with crystalline silica to produce (NH4)2SiF6, water, and ammonia. In step 2, ammonia, water, and (NH4)2SiF6 are combined to produce ammonium fluoride and amorphous silica. In step 3, the ammonium fluoride is heated to produce ammonium bifluoride and ammonia. When the system is operated at less than 125°C, the accumulation of hydrofluoric acid (HF) is avoided, allowing SiO2 to be dissolved and precipitated without the accumulation of HF.

[0145] Figure 7B The proposed 3-stage process is depicted in Figure 7B As shown, in some embodiments, the first stage of the 3-stage process includes combining a silicate (e.g., crystalline silica) with ammonium bifluoride to produce ammonium hexafluorosilicate, water, and ammonia. In some cases, as Figure 7B As shown, the second stage of the 3-stage process includes combining ammonium hexafluorosilicate with ammonia and water to produce amorphous silica and ammonium fluoride. In some cases, such as Figure 7B As shown, the optional third stage of the three-stage process involves combining ammonium fluoride and heat to produce ammonium bifluoride and ammonia, which can optionally be used in the first and second stages, respectively. Given the cost difference between highly amorphous silica ($100 to $300 / ton) and highly crystalline silica (approximately $10 / ton), this process could form the basis of a new technology for adding value to crystalline silica sources, which currently have limited value to the cement industry. This statement is further complicated by the fact that synthetic sources of pozzolanic silica, such as fly ash, are a dwindling resource, and that pozzolanic silica consumption is increasing annually with no signs of abating ( Figure 7C ).

[0146] 3. Data

[0147] Figure 8A and Figure 8B Shows that in undergoing Figure 7A SEM images and XRD of crystallized quartz sand before and after the process.

[0148] Example 2

[0149] Overview of the Silicate Removal Process

[0150] The silicate removal process described in this example utilizes ammonium fluoride in a catalytic cycle to dissolve and subsequently precipitate silicon dioxide. The process uses ammonium bifluoride (NH4HF2) as a fluorinating agent to convert silicon dioxide (SiO2) into ammonium hexafluorosilicate ((NH4)2SiF6), which is then alkalized with aqueous ammonia (NH3) to produce amorphous SiO2 and ammonium fluoride (NH4F). The solid SiO2 is separated from the NH4F solution by filtration, and the filtrate is then heated to decompose the NH4F into NH4HF2 and NH3, closing the catalytic loop. The catalytic cycle and mass balance are given below:

[0151] 1:SiO2+3NH4HF2→(NH4)2SiF6+2H2O+NH3

[0152] 2:(NH4)2SiF6+4NH3+2H2O→SiO2+6NH4F

[0153]

[0154] In some embodiments, the process operates at low temperatures (e.g., <100° C.) in aqueous solution and provides a means of removing silica from a variety of mineral or waste streams while enriching the remaining elements as non-siliceous residues. In a 1 L Teflon reaction vessel, 5 g of silica-rich feedstock, 25 g of NH4HF2, and 500 mL of H2O were reacted under magnetic stirring. Most of the silica in most feedstocks was completely leached after 48 hours, and the reaction time was strongly correlated with both the fineness of the sample (i.e., the degree of mechanical treatment) and the crystallinity of the feedstock. Precipitated silica is amorphous and fine ( to 10.0 μm), making it a potentially valuable by-product (approximately $100 / ton to $250 / ton) for use as pozzolan in the cement industry. Figure 9 The process flow for the entire process using technical grade silica (99.5%, 400 mesh) is depicted in FIG.

[0155] Application of this process to mineral processing can potentially be as a stand-alone process for simple aluminosilicate minerals / wastes (e.g., REE-rich sands, kaolinite, montmorillonite) or as a downstream process for more complex minerals / wastes (e.g., bottom ash, pond ash). The following is an analysis of the behavior of several minerals (kaolinite, montmorillonite, olivine, wollastonite, basalt) and wastes (bottom ash, pond ash) when exposed to strong fluorinating agents such as NH4HF2, an analysis of their compatibility with the silicate reduction process, and a discussion of the impact of this data on the feasibility of the process for a variety of minerals.

[0156] Reaction conditions and analytical procedures

[0157] All reactions were carried out in a 500 mL Teflon container with a screw cap and a magnetic stirring bar. All reactions were carried out in an oil bath at 25° C. and ambient pressure. The raw materials were manually mechanically crushed with a mortar and pestle and passed through a 1.0 mm sieve before use. 5.0 g of raw materials and 500 mL of H2O were charged into the container. All samples were stirred for 10 minutes and then 25 g of technical grade NH4HF2 (Fisher Scientific) was introduced. The sample was cooled immediately after the introduction of NH4HF2, and the pH of the solution was generally about 4 to 5. The reaction was stirred at room temperature for 48 hours and then filtered through a glass fiber filter to separate the insoluble material from the dissolved material. The filtrate was subsequently alkalized to a pH of 10 to 11 with concentrated NH4OH (Fisher Scientific), with an observable white solid precipitate. In the case of a high silica content source (99.5%, 400 mesh SiO2), typical SiO2 yields were >95%. In the case of lower silica content sources, the SiO2 yield varied, but no silica was observed remaining in the insoluble material after treatment.

[0158] The white solid was identified as amorphous silica, where the particle size depended on the rate and method of NH4OH addition. (aq) The alkalinization of the titration resulted in a narrow particle size distribution and an average particle size of about 0.5 μm. Whether the titration was performed slowly (about 1 hour) or quickly (10 seconds), the particle size and distribution were comparable. However, by titrating with NH 3(g) Alkalization of the fumigation produced larger particles with an average particle size of about 4.5 μm and a broader particle size distribution.

[0159] The insoluble residue varies depending on the mineral feedstock, and the siliceous precipitate is generally pure, except in high aluminum content samples where (NH4)3AlF6 is observed in the precipitate after alkalization. The feedstock, siliceous precipitate, and insoluble residue were all analyzed by SEM (morphological composition), EDS (elemental composition), and XRD (bulk composition).

[0160] Kaolinite

[0161] Kaolinite (Al2O3·2SiO2·2H2O, obtained from VWR) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 3.0 g, which represents a yield of about 129% relative to dry SiO2. Visually, most of the material dissolved, and the hue of the remaining insoluble material changed from off-white to bright white. The SEM-EDS image of the insoluble fraction showed large octahedral crystals intermixed with a smaller amorphous fraction, as well as significant signals for N, F, and Al overall ( Figure 10This is consistent with the XRD spectrum of the insoluble fraction, which is attributed to (NH4)3AlF6 ( Figure 11 , bottom), no other crystalline material is apparent in the spectrum, and there is no trace of residual kaolinite. Therefore, the insoluble fraction is not a residue of the starting material, but rather (NH4)3AlF6 precipitated from the reaction. The alkalized filtrate shows a broad peak characteristic of amorphous silica with traces of (NH4)3AlF6. Therefore, the catalytic process appears to dissolve and precipitate silica as expected. The presence of residual (NH4)3AlF6 in the silica is consistent with the large solubility difference between (NH4)2SiF6 and (NH4)3AlF6, and the yield is 29% greater than that expected for the pure SiO2 product. At room temperature, (NH4)3AlF6 does not seem to oxidize under conditions that would easily oxidize (NH4)2SiF6.

[0162] Montmorillonite

[0163] Montmorillonite ((Na,Ca) 0.33 (Al,Mg)2(Si4O 10 )(OH)2·nH2O, obtained from VWR) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 2.5 g, which represents a yield of about 75% relative to silica assuming a hydration degree of n=10. Visually, most of the material dissolved, and the remaining insoluble material darkened in tone. Similar to kaolinite, the SEM-EDS image of the insoluble fraction showed large octahedral crystals intermixed with a smaller amorphous fraction, as well as signals for N, O, F, Al, Si, Ca, Mg, and Fe ( Figure 12 This is consistent with the XRD spectrum of the insoluble fraction attributed to (NH4)3AlF6 and residual montmorillonite ( Figure 13 , bottom). Thus, both Si and Al appear to be removable using the ammonium bifluoride process, but increased reaction time and / or temperature will be required for complete removal of Al and Si. Ca and Mg are selectively concentrated in the insoluble residue, complicating catalysis and product separation. The alkalized filtrate exhibits a broad peak characteristic of amorphous silica with trace amounts of (NH4)3AlF6.

[0164] Peridot

[0165] Olivine ((Mg,Fe)SiO4), obtained from Southern Company) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 2.8 g, which represents a yield of about 123% relative to silica. Visually, most of the material dissolved, and the remaining insoluble material darkened in hue. The SEM-EDS image of the SiO2-depleted residue showed large crystalline blocks with diameters of about 20 μm to 50 μm intermixed with smaller blocks with diameters of about 1 μm to 5 μm. Small amounts of Fe and O and relatively large amounts of Mg and F ( Figure 14 ). The XRD spectrum shows that the residual olivine is not dissolved, but there is no Si signal in the SEM-EDS image. In the XRD spectrum, there is no peak that can be clearly attributed to MgF2 ( Figure 15 ), but overlap with olivine is a possible confounding factor. The presence of strong F and Mg signals in the SEM-EDS pattern seems to indicate the presence of MgF2, especially considering the absence of N signals, indicating no residual NH4F or NH4HF2. Overall, this demonstrates complete Si removal from olivine and the retention of Fe in the SiO2-depleted residue. Mg predictably forms MgF2, enriched in the SiO2 residue, and the rate of mineral dissolution is relatively slower than that of the pure aluminosilicates studied (e.g., kaolinite). The higher than expected yield of precipitate from the alkalized filtrate may be due to incomplete drying.

[0166] Wollastonite

[0167] Wollastonite (CaSiO4), obtained from 7 Springs Farm (426 Jerry Ln, Check, VA 24072) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 2.43 g, which represents a yield of about 94% relative to silica. Visually, no changes were observed during the reaction. The SEM-EDS image of the SiO2-depleted residue showed that the material was composed primarily of Ca and F, with no observable Si peaks ( Figure 16 The XRD spectrum supports the identification of the residue as CaF2, with peaks having a full width at half maximum indicating that the material is partially amorphous. The XRD spectrum of the alkalized filtrate showed that it consisted of amorphous SiO2 with no indication of fluorinated species ( Figure 17 ). SEM-EDS of amorphous SiO2 (not depicted) supports this assignment. In conclusion, Si is completely leached from wollastonite.

[0168] basalt

[0169] Basalt (obtained from SSLane, MA, Westfield, 01085) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 4.0 g (this yield may indicate that the precipitate was not completely dried). Visually, the reaction mixture changed from dark brown to light brown over the course of 48 hours. The SEM-EDS image of the SiO2-depleted residue showed that the material was a varying mixture of N, O, F, Mg, Ca, Na, Fe, and Si. The XRD spectrum showed that (NH4)3AlF6 was the major crystalline material in the residue, with trace amounts of (NH4)3AlF6 in the alkalized filtrate accompanied by amorphous SiO2 ( Figure 18 The presence of Fe in the SEM is supported by the red coloration in the SiO2 depleted residue, but no peaks in the XRD can be attributed to simple Fe species. Although both Ca and Mg are clearly present in the EDS pattern ( Figure 19 ), but no peaks can be clearly assigned to CaF2 or MgF2. In summary, Mg, Ca, Al and Fe are enriched in the insoluble residue, while Si and trace amounts of Al are separated into soluble fractions.

[0170] Pool dust

[0171] Pond ash (obtained from Southern Company, 30 Ivan Allen Jr. Blvd. NW, Atlanta, GA 30308) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was about 3.1 g. Visually, the reaction mixture changed from dark brown to light brown over the course of 48 hours. The SEM-EDS image of the SiO2-depleted residue showed that the material was a diverse mixture of N, O, F, Mg, Ca, Na, Fe, and Si. The XRD spectrum showed that (NH4)3AlF6 was the major crystalline material in the residue, with trace amounts of (NH4)3AlF6 in the alkalized filtrate accompanied by amorphous SiO2 ( Figure 20 The presence of Fe in the SEM is supported by the red coloration in the SiO2 depleted residue, but no peaks in the XRD can be attributed to simple Fe species. Although both Ca and Mg are clearly present in the EDS pattern ( Figure 21 ), but no peaks can be clearly assigned to CaF2 or MgF2. Overall, the final products of basalt and pond ash appear similar, with Mg, Ca, Al, and Fe enriched in the insoluble residue. Si and trace amounts of Al are selectively precipitated from the alkalized filtrate.

[0172] Bottom ash

[0173] Bottom ash (obtained from Southern Company, 30 Ivan Allen Jr. Blvd. NW, Atlanta, GA 30308) was subjected to the above procedure. The yield of precipitate from the alkalized filtrate was approximately 2.7 g. Visually, the reaction mixture changed from dark brown to light brown over the course of 48 hours. The SEM-EDS image of the SiO2-depleted residue indicated that the material was a diverse mixture of N, O, F, Mg, Ca, Na, Fe, and Si. The XRD spectrum indicated that (NH4)3AlF6 was the major crystalline species in the residue ( Figure 22 The presence of Fe in the SEM is supported by the red coloration in the SiO2-depleted residue, but no peaks in the XRD can be assigned to simple Fe species. Less Fe is observed than in basalt or pond ash. Although both Ca and Mg are clearly present in the EDS pattern ( Figure 23 ), but no peaks can be clearly assigned to CaF2 or MgF2. Overall, the final products of basalt, pond ash, and bottom ash appear similar, with Mg, Ca, Al, and Fe enriched in the insoluble residue. Si and trace amounts of Al are selectively precipitated from the alkalized filtrate.

[0174] Example 3

[0175] Amorphous silica was synthesized from SiO2 (400 mesh, 99.5%) and ammonium bifluoride:

[0176] 5.00 g of SiO2 (400 mesh, 99.5%) and 500 g of water were added to a PTFE round-bottom flask containing a PTFE stirring rod. The solution was stirred to form a suspension. The temperature was about 25°C. 25.00 g of NH4HF2 was slowly added to the suspension. After 24 hours, the now clarified solution was decanted through a glass fiber membrane and precipitated by rapidly basifying the solution with concentrated ammonium hydroxide to a final pH of 10 to 11. The precipitate was collected by filtration and washed with excess water. The collected solid was dried at 150°C overnight to obtain a white powder, which was further confirmed to be amorphous silica by XRD and SEM-EDS. Yield: about 4.8 g. Figure 25 The XRD spectrum of the produced silica is shown with Si powder as an internal standard. The broad peak with a maximum in the range of 20 to 25 is characteristic of amorphous silica.

[0177] HF detection:

[0178] Even boiling solutions of NH4F / NH4HF2 do not produce detectable free HF in or above the solution ( Figure 26 and 27 ).

[0179] Particle size:

[0180] like Figure 28 As shown, the desired particle size (approximately 5 μm) was achieved by fumigation with NH₃ gas. The particle size (blue) of silica precipitated from a fluorosilicate solution by dropwise addition of concentrated NH₄OH (14.8 M) over the course of approximately 30 minutes was 0.5 μm. The particle size from slow fumigation with NH₃ gas over the course of approximately 1 hour was approximately 4.25 μm. Particle size was determined using a laser diffraction particle size analyzer (Beckman LS13320).

[0181] like Figure 29 As shown, there are no major differences in morphology for the different precipitation rates. However, there are observable density differences in the slowly titrated samples.

[0182] like Figure 30 As shown, very slow titrations (>2 hours) resulted in particle sizes greater than about 500 nm.

[0183] Powdered silica (99.5%; 400 mesh) was partially dissolved by pure ammonium bifluoride to form a fluorosilicate solution (3 hours at room temperature). The fluorosilicate solution was precipitated with alkali to form silica (22% yield). The starting material was crystalline and coarse. Figure 31 As shown, the precipitated product is amorphous and fine. After the ammonium bifluoride treatment, the SiO2 precipitate is collected from the filtrate. The starting silica is mainly crystalline (quartz). The precipitated silica is mainly amorphous. Figure 8B Middle, the left tip is mostly quartz, and the right broad peak is glass.

[0184] At room temperature, with a longer reaction time and more NH4HF2 equivalents (approximately 18 hours, 15 equivalents), a yield of 82.6% was achieved. 5.00 g SiO2 (99.5%), 3 molar equivalents of NH4HF2 in approximately 50 mL of H2O. Stirring was carried out at room temperature for approximately 18 hours. The pH of the solution after treatment was 4 to 5 as measured by pH paper.

[0185] Figure 32 A process for converting non-pozzolanic (crystalline) silica to pozzolanic (amorphous) silica using ammonium bifluoride is shown, according to some embodiments.

[0186] Supplement: Reaction Considerations

[0187] Reaction SiO 2(s) with (NH4)(HF2) (aq) Reacts to generate (NH4)2(SiF6) (aq) .

[0188] 1:SiO2+3(NH4)(NF2)→(NH4)2(SiF6)+2H2O+NH3.

[0189] Reaction 2: (NH4)2(SiF6) (aq) With NH 3(aq) Reacts to form SiO 2(s) .

[0190] 2:(NH4)2(SiF6)+4NH3+2H2O→SiO2+6NH4F.

[0191] Reaction 3: NH 3(aq) With NH4F (aq) Reacts to form (NH4)(HF2).

[0192] 3:6NH4F+Δ→3(NH4)(HF2)+3NH3.

[0193] 1 to 3 are used to generate SiO 2(s) catalytic circuit.

[0194] The catalytic circuit starts with (NH4)(HF2) or NH4F. 3(g) The precipitation and removal of NH drives the circuit. 3(g) The reintroduction of maintains the loop. The catalytic process does not accumulate hydrofluoric acid (HF).

[0195] Desired main reaction: NH4F+Δ→NH3+NH4HF2-about 100℃

[0196] Undesirable side reaction I: NH4HF2+Δ→NH4F+HF-about 120℃ to 220℃

[0197] Undesirable side reaction II: NH4F+HA 强 →NH4A 强 +HF-about 25℃

[0198] HF prevention reaction: NH3+HF→NH4F+Δ-any temperature

[0199] In order to produce one equivalent of HF from NH4F, it is necessary to prevent HF from accumulating significantly in the system once one equivalent of NH3 has been generated. In addition, the decomposition of NH4HF2 occurs only at high temperatures exceeding the boiling point of the aqueous solution or with the introduction of a strong external acid. Ammonium bifluoride in boiling aqueous solution does not form HF in readily detectable amounts.

[0200] The tap density of the resulting filter cake silica collected as is was about 0.75 ± 0.10 g / cm 3 , and the resulting tap concentration of ground silica is about 0.35 ± 0.02 g / cm3 .

[0201] The density of the filter cake collected for the former state is determined, and the Archimedean method is used to determine the density of the material. About 1g filter cake (under minimum fragmentation and when not grinding) is added in the 10mL graduated cylinder. The little metal rod of known volume and quality is added to the top of the filter cake to keep the material from floating. Volume is adjusted to 10mL with water, and the volume of the filter cake of record known mass is subsequently. The filter cake of compacting is enough hydrophobic, and material can not absorb the water of significant amount during the time scale of measurement. This measurement is repeated to obtain the density of filter cake in triplicate.

[0202] For the tap density determination of ground silica, the filter cake was ground with a mortar and pestle to produce a fine powder that easily aerosolizes. A 10 mL graduated cylinder was filled to the 10 mL mark with ground silica and the mass was recorded. The cylinder was then tapped for 15 minutes to reduce the volume, which was then recorded. This procedure was repeated in triplicate to obtain the tap density.

[0203] Figure 33 The photo, XRD and SEM-EDS of the silica product obtained from quartz sand are shown. The results show that the silica product obtained is similar in structure to silica fume.

[0204] Figure 34 Shown are DOR* calorimetry results for a silica product obtained from quartz sand (left) and a photograph of a vial of pozzolanic cement made from the silica product obtained from quartz sand after curing at 50°C for 48 hours (right). The silica product releases approximately 524 J per gram of silica when reacting with excess Ca(OH)2. Amorphous silica was subjected to a Pozzolanic Reactivity Test (PRT). The PRT includes a calorimetric experiment to measure the heat of reaction and a thermogravimetric experiment to determine the amount of Ca(OH)2 remaining in the sample ( Figure 35 and Figure 36 ).

[0205] PRT analysis conditions are as follows. 0.921g of volcanic ash (500nm average particle size, generated by 400 mesh quartz sand) is added to 2.7763g of calcium hydroxide in a calorimetric bottle. Use a vortex mixer to mix the solid for 30 seconds. To these solids, add 3.316g of 0.5M KOH hydroxide solution (using a volumetric pipette calibrated with an alkaline solution to measure using a weight scale), and use a metal spatula to fully mix the resulting solution. These vials are capped and crimped, and immediately placed in the calorimeter. In a separate channel, a vial filled with 7.00g of sand is used as a reference. All measurements are carried out in duplicate. After thermal equilibrium reaches the 48-hour mark, the integral of the region is used to calculate the heat released. About 20mg of material is loaded into a Pt TGA pan and heated from 20°C to 850°C at a slope of 10°C / minute, and maintained at the final temperature for 30 minutes. These TGA measurements are carried out in triplicate.

[0206] The PRT results obtained thereby indicate that the silica produced according to certain embodiments has an extremely high reactivity, almost identical to that of silica fume. Thermogravimetric analysis (TGA) indicates that approximately 184 g of Ca(OH)2 is consumed per 100 g of the pozzolan cement formed.

[0207] The reactivity of the resulting pozzolanic silica ("SynPozz") was plotted relative to other pozzolans using the Pozzolanic Reactivity Test (PRT). Figure 37 The resulting pozzolanic silica ("SynPozz") has the highest reactivity. Figure 38 BET analysis of the resulting pozzolanic silica ("SynPozz") relative to other pozzolans is shown, indicating that the resulting pozzolanic silica ("SynPozz") has a higher surface area than undensified silica fume. This was measured using ASTM C1069-09 (Alumina and Quartz BET Surface Area). Figure 39 Calcium hydroxide ("CH") consumed (g / 100 g SCM) during a standard pozzolan reactivity test (which is a measure of reactivity) is plotted against market price (US$ / ton).

[0208] Example 4

[0209] Value-added of spodumene to LiF, Al2O3 and SiO2:

[0210] This example demonstrates that spodumene samples ( Figure 40 ) is increased. By X-ray diffraction ( Figure 41 and Figure 42) showed that the spodumene sample consisted of approximately 90% spodumene phase and approximately 10% crystalline silica phase. The average particle size (as determined by laser diffraction) was approximately 70 microns. The products of the process included LIF, Al2O3, and amorphous SiO2.

[0211] Experimental conditions: 500 g of water and 85 g of NH4HF2 were added to a PTFE round-bottom flask containing a PTFE stirring bar connected to a reflux condenser with cold water recirculation. The solution was stirred at approximately 100°C until the NH4HF2 dissolved. To this solution was added 10.00 g of the spodumene sample. The suspension was stirred continuously and allowed to react for 48 hours. Aliquots of the reaction were taken periodically and analyzed by 7 Li-NMR measurements of lithium concentrations on reaction aliquots ( Figure 43 、 Figure 44 and Figure 45 After 48 hours, the reaction mixture was cooled, and the insoluble fraction was collected by filtration and washed with water. XRD analysis showed that the insoluble product primarily consisted of (NH4)3AlF6. Yield: 9.50 g. (NH4)3AlF6 was then reacted sequentially with H2SO4 and NaOH at 60°C for approximately 48 hours each to produce Al(OH)3, which was characterized by SEM and EDS. This Al(OH)3 product can be converted to aluminum oxide (Al2O3) by heating to drive off the H2O.

[0212] To the remaining solution, approximately 150 g of NH₄OH was added and allowed to mix for 20 minutes, then cooled in an ice bath. The resulting precipitate was collected by filtration and washed with excess water. The collected solid was dried at 150°C overnight to obtain a white powder, which was further confirmed to be amorphous silica by XRD and SEM-EDS. Yield: approximately 7.7 g. The amorphous silica was subjected to BET surface area measurement. BET surface area measurements were performed according to ASTM C1069-09.

[0213] The volume of the remaining aqueous solution was then reduced by heating in an oil bath at about 80°C, and then about 100 g of NH4OH was added. The resulting white fine precipitate was collected by centrifuging the solution and washing the product with water. The collected solid was dried at 100°C overnight to obtain a white powder, which was identified by XRD and SEM-EDS ( Figure 46 ) was determined to be primarily LiF with trace amounts of amorphous silica.

[0214] For 5 g of spodumene, the yields obtained were 89.0% (measured by mass) for silica and 89.0% for (NH4)3AlF 6(s) 95.1% (measured by mass), and for LiHF 2(aq) or Li+ 89.6% (measured by Li-NMR).

[0215] Example 5

[0216] This example demonstrates the leaching of lepidolite to produce LiF, (M,NH4)3AlF6, and amorphous SiO2:

[0217] Experimental conditions: 250 g of water and 50 g of NH4HF2 were added to a PTFE screw-capped container including a PTFE stirring rod. The solution was stirred at approximately 85°C until the NH4HF2 dissolved. 5.00 g of the lepidolite sample was added to the solution. The suspension was stirred continuously and allowed to react for 120 hours. Figure 47 As indicated, reaction aliquots were taken periodically and analyzed by 7 Li-NMR measured the lithium concentration on the reaction aliquots, and the data indicated that the Li within the lepidolite sample was completely dissolved after 120 hours, corresponding to a dissolved Li concentration of 0.018M. 7 The Li-NMR sample was composed of 300 μL sample, 400 μL H2O and 50 μL D2O / CH2FCN. 19 F internal standard composition. After 120 hours, the reaction mixture was cooled, and the insoluble fraction was collected by filtration and washed with water ( Figure 48 ). XRD analysis showed that the insoluble product mainly contained (NH4)3AlF6 and trace amounts of (M,NH4)3AlF6 ( Figure 49 ; see formula below). The composition was further characterized by SEM and EDS, which showed angular crystals (about 20 μm) composed of Na, K, Al, O, F, and N (no Li could be detected by EDS).

[0218] KLi2AlSi4O 10 F(OH)+NH4HF 2(aq) →(NH4,Li,K)2SiF 6(aq) +(NH4,Li,K)3AlF 6(s) +NH 3(aq) +H2O (l)

[0219] To the remaining solution was added about 150 g of NH4OH and allowed to mix for 20 minutes and then cooled in an ice bath. The resulting precipitate was collected by filtration and washed with excess water. The collected solid was dried at 150 ° C overnight to obtain a white powder, which was characterized by XRD ( Figure 50 ) and SEM-EDS( Figure 51 ) was further determined to be amorphous silicon dioxide (see the following formula). Yield: about 6.0 g (wet) ( Figure 52). The silicon dioxide obtained was indistinguishable from the silicon dioxide obtained in Example 5.

[0220] (NH4,Li,K)2SiF 6(aq) +NH4OH (aq) →SiO 2(s) +NH4F (aq) +iF (aq) +KF (aq) +H2O (l)

[0221] Although several embodiments of the present invention have been described and illustrated herein, a person of ordinary skill in the art will readily envision various other means and / or structures for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each of such variations and / or modifications is considered to be within the scope of the present invention. More generally, a person skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the specific application in which the teachings of the present invention are used. A person skilled in the art will recognize or be able to determine many equivalents to the specific embodiments of the present invention described herein using only routine experimentation. Therefore, it should be understood that the foregoing embodiments are presented by way of example only, and within the scope of the appended claims and their equivalents, the present invention may be practiced in ways other than those specifically described and claimed. The present invention relates to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods is included within the scope of the present invention if such features, systems, articles, materials, and / or methods are not mutually inconsistent.

[0222] Unless explicitly stated to the contrary, as used herein in the specification and in the claims, nouns without quantifiers should be understood to mean "at least one."

[0223] As used herein in the specification and in the claims, the phrase "and / or" should be understood to mean "either or both" of the elements so connected, i.e., elements that are present in conjunction in some cases and separately in other cases. Unless expressly indicated to the contrary, other elements may optionally be present besides the elements specifically identified by the "and / or" clause, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, when used in combination with open language such as "comprising," a reference to "A and / or B" may, in one embodiment, refer to A without B (optionally including elements in addition to B); in another embodiment, to B without A (optionally including elements in addition to A); in yet another embodiment, to both A and B (optionally including other elements); and so on.

[0224] As used herein in the specification and in the claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating the items in a list, "or" or "and / or" should be interpreted as being inclusive, i.e., including at least one of a plurality of elements or a list of elements, but also including more than one, and optionally additionally unlisted items. Only when the opposite term is clearly indicated, such as "only one / kind" or "exactly one / kind", or when used in the claims, "consisting of..." will refer to including exactly one element in a number of elements or a list of elements. Generally, the term "or" as used herein should only be interpreted as indicating exclusive alternatives (i.e., "one or the other but not both") when preceded by an exclusive term (e.g., "any one", "one of", "only one of" or "exactly one of"). "Substantially consisting of..." should have its ordinary meaning used in the field of patent law when used in the claims.

[0225] As used herein in the specification and in the claims, the phrase "at least one" when referring to a list of one or more elements should be understood to mean at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each and every element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B”, or equivalently “at least one of A and / or B”) may, in one embodiment, refer to at least one A, optionally including more than one A, without B (and optionally including elements other than B); in another embodiment, may refer to at least one B, optionally including more than one B, without A (and optionally including elements other than A); in yet another embodiment, may refer to at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements); and so on.

[0226] In the claims and in the foregoing description, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "having," "consisting of," and the like are to be construed as open-ended, i.e., meaning including, but not limited to, including. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. An amorphous silicate comprising 10 ppm or more and 20 wt% or less of fluoride.

2. The amorphous silicate according to any one of the preceding claims, comprising greater than or equal to 10 ppm and less than or equal to 250 ppm of fluoride.

3. The amorphous silicate according to any one of the preceding claims, wherein the amorphous silicate has a particle size distribution greater than or equal to 0.01 microns and less than or equal to 20 microns.

4. The amorphous silicate according to any one of the preceding claims, wherein the amorphous silicate has a tap density greater than or equal to 0.1 g / cm 3 and less than or equal to 2.0g / cm 3 .

5. The amorphous silicate according to claim 4, wherein the tap density is greater than or equal to 0.3 g / cm 3 and less than or equal to 1.8g / cm 3 .

6. The amorphous silicate according to any one of the preceding claims, wherein the amorphous silicate has a specific surface area (SSA) greater than or equal to 1 m 2 / g and less than or equal to 2000m 2 / g.

7. The amorphous silicate according to claim 6, wherein the SSA is greater than 35 m 2 / g and less than or equal to 100m 2 / g.

8. Amorphous silicate according to any one of the preceding claims, wherein the degree of reactivity (DOR*) is greater than or equal to 30% and less than or equal to 100%.

9. The amorphous silicate of any one of the preceding claims, wherein the amorphous silicate comprises greater than or equal to 1000 ppm total metals and less than or equal to 10,000 ppm total metals.

10. A cementitious material comprising an amorphous silicate according to any one of the preceding claims.

11. The cementitious material according to any one of the preceding claims, wherein the water demand of the cementitious material is less than or equal to 0.

6. 12 . The cementitious material according to claim 11 , wherein the water demand is greater than or equal to 0.1 and less than or equal to 0.

6.

13. An amorphous silicate or cementitious material according to any one of the preceding claims, wherein the amorphous silicate is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate.

14. The amorphous silicate or cementitious material of claim 14, wherein the amorphous silicate is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination at a maximum temperature of greater than or equal to 10°C and less than or equal to 125°C and a maximum pressure of greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres.

15. The amorphous silicate or cementitious material of claim 14, wherein the amorphous silicate is produced by combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination at a maximum temperature of greater than or equal to 160°C and less than or equal to 250°C and a maximum pressure of greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres.

16. An amorphous silicate or cementitious material according to any one of the preceding claims, wherein the amorphous silicate is produced by a method according to any one of claims 17 to 46.

17. A method for producing amorphous silicates and / or salts, comprising: combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination at a maximum temperature greater than or equal to 10°C and less than or equal to 125°C; as well as Producing amorphous silicates and / or salts; wherein the process does not produce and / or accumulate a significant net amount of hydrogen fluoride.

18. A method for producing amorphous silicates and / or salts, comprising: combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination at a maximum temperature greater than or equal to 160° C. and less than or equal to 250° C.; as well as Producing amorphous silicates and / or salts; wherein the process does not produce and / or accumulate a significant net amount of hydrogen fluoride.

19. A method for producing amorphous silicates and / or salts, comprising: combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an aqueous combination; as well as Producing amorphous silicates and / or salts; wherein the temperature of the silicate-containing material is at a maximum temperature greater than or equal to 10°C and less than or equal to 125°C when the silicate-containing material contacts the ammonium fluoride and / or the ammonium bifluoride.

20. A method for producing amorphous silicates and / or salts, comprising: combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate in an anhydrous combination; as well as Producing amorphous silicates and / or salts; wherein the temperature of the silicate-containing material is at a maximum temperature greater than or equal to 160°C and less than or equal to 250°C when the silicate-containing material contacts the ammonium fluoride and / or the ammonium bifluoride.

21. The method of any one of the preceding claims, wherein the ammonium fluoride and / or ammonium bifluoride and the silicate-containing material are combined at a maximum pressure greater than or equal to 0.1 atmospheres and less than or equal to 100 atmospheres.

22. The method of any one of the preceding claims, wherein the ammonium fluoride and / or ammonium bifluoride and the silicate-containing material are combined at a maximum pressure greater than or equal to 1 atmosphere and less than or equal to 100 atmospheres.

23. A method according to any one of the preceding claims, wherein the method comprises producing an amorphous silicate.

24. A method according to any preceding claim, wherein the method comprises producing the salt.

25. A method comprising: combining ammonium fluoride and / or ammonium bifluoride with a material comprising a silicate, wherein the material comprising a silicate further comprises lithium; as well as produces salts and amorphous silicates; wherein the salt comprises a higher weight percentage of lithium than the silicate-containing material; and wherein the amorphous silicate comprises a lower weight percentage of lithium than the silicate-containing material.

26. The method of any one of the preceding claims, wherein the method further comprises producing a cementitious material comprising the produced amorphous silicate.

27. The method of any one of the preceding claims, wherein the silicate-containing material comprises a crystalline silicate.

28. The method according to any one of the preceding claims, wherein the silicate-containing material comprises olivine and / or olivine-type material, montmorillonite and / or montmorillonite-type material, kaolinite and / or kaolinite-type material, halloysite and / or halloysite-type material, kyanite and / or kyanite-type material, sillimanite and / or sillimanite-type material, spodumene and / or spodumene-type material, petalite and / or petalite-type material, eucryptite and / or eucryptite-type material, quartz and / or quartz-type material, mullite and / or mullite-type material, zircon and / or zircon-type material, wollastonite and / or wollastonite-type material, basalt and / or basalt-type material, lepidolite and / or lepidolite-type material, hexaphosphate and / or hexaphosphate-type material. or lithium phosphate aluminum type materials, lithium iron phosphate and / or lithium iron phosphate type materials, silicon lithium and / or silicon lithium type materials, magnesite and / or magnesite type materials, illite and / or illite type materials, smectite and / or smectite type materials, jaddarite and / or jaddarite type materials, lithium chlorite and / or lithium chlorite type materials, hydroxyaluminum phosphate and / or lithium hydroxyaluminum phosphate type materials, lithium tourmaline and / or lithium tourmaline type materials, iron lithium mica and / or iron lithium mica type materials, rare earth element (REE) sands, laterite clays, desert sands, ashes from the combustion of fossil fuels (e.g., bottom ash, pond ash, fly ash) and / or residues from industrial processes (e.g., mining tailings and / or bauxite residues).

29. The process of any one of the preceding claims, wherein the process further comprises regenerating the ammonium fluoride and / or ammonium bifluoride.

30. A method according to any preceding claim, wherein the silicate-containing material further comprises lithium and / or aluminium.

31. A process according to any one of the preceding claims, wherein the process comprises forming lithium fluoride, lithium carbonate, lithium hydroxide, lithium chloride, aluminum fluoride, ammonium hexafluoroaluminate, sodium hexafluoroaluminate (cryolite), aluminum oxide and / or aluminum hydroxide.

32. The method of claim 31 , wherein the method comprises producing LiPF6 from the lithium fluoride.

33. The method of claim 32, wherein the method comprises using LiPF6 in a lithium battery.

34. A method according to any one of claims 31 to 33, wherein the method further comprises producing a cementitious material comprising the aluminium oxide and / or aluminium hydroxide.

35. The method of claim 34, wherein the method further comprises producing a cementitious material comprising the amorphous silicate and aluminum oxide and / or aluminum hydroxide.

36. A method according to claim 35, wherein the ratio of aluminium to silicon is selected to achieve a desired composition of the hardened cementitious material, such as calcium aluminosilicate hydrate (CASH).

37. The process of any preceding claim, wherein the process does not produce and / or accumulate a significant net amount of hydrogen fluoride.

38. The method of any preceding claim, wherein the combining of ammonium fluoride and / or ammonium bifluoride with the silicate-containing material is an aqueous combination, and the maximum temperature is greater than or equal to 10°C and less than or equal to 125°C.

39. The method of any preceding claim, wherein the combining of ammonium fluoride and / or ammonium bifluoride with the silicate-containing material is an anhydrous combination, and the maximum temperature is greater than or equal to 160°C and less than or equal to 250°C.

40. The method of any preceding claim, wherein the maximum pressure is 1 atmosphere.

41. A method according to any one of the preceding claims, wherein the method comprises only partially reacting and / or partially dissolving the silicate-containing material with the ammonium fluoride and / or ammonium bifluoride.

42. The method of any preceding claim, wherein the amorphous silicate comprises the amorphous silicate of any one of claims 1 to 16.

43. The method of any one of the preceding claims, wherein the salt comprises lithium fluoride, lithium carbonate, lithium hydroxide, lithium chloride, aluminum fluoride, aluminum hydroxide, ammonium hexafluoroaluminate, and / or sodium hexafluoroaluminate (cryolite).

44. The method of any one of the preceding claims, wherein the method further comprises producing aluminum hydroxide and / or aluminum oxide.

45. The method of claim 44, wherein the method comprises producing alumina having a purity greater than or equal to 99% and less than or equal to 100%.

46. ​​The method of any one of claims 44 to 45, wherein the method further comprises producing a separator comprising the aluminum oxide.

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