Method for recycling lithium-aluminum-silicon-based glass waste

Abstract

This application provides a method for recycling lithium-aluminum-silicon glass waste, relating to the field of solid waste resource utilization. The method includes: mixing lithium-aluminum-silicon glass waste powder with additives, calcining to obtain a calcined material, wherein the additives include sodium and calcium salts, the sodium salt including at least one of sodium sulfate and sodium bisulfate, and the calcium salt including at least one of calcium sulfate and calcium bisulfate. The molar amount of calcium in the additives is more than 0.4 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste, and the molar amount of sodium is more than 0.9 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste. The calcined material is then mixed with a leaching agent for leaching. The lithium-containing leaching solution of this application contains few types and amounts of impurities, and high-purity lithium compounds can be prepared after simple impurity removal treatment. This enables efficient recovery and reuse of valuable elements in low-value lithium-aluminum-silicon glass waste, solving the environmental pollution problem caused by glass waste stockpiling and reducing space occupation.

Description

Technical Field

[0001] This application relates to the field of solid waste resource utilization, and in particular to a method for recycling lithium aluminum silicon glass waste. Background Technology

[0002] Lithium batteries are widely used in electronic equipment, aerospace, military communications and other fields. As a core raw material, lithium has received strong attention with the rapid development of the new energy industry. Lithium ore resources, salt lake lithium resources and waste battery lithium resources are the mainstream lithium extraction routes at present. At the same time, the development and utilization of new lithium resources is also a focus of related industries.

[0003] Li2O has a strong fluxing effect, which can effectively improve the thermal stability and physicochemical properties of glass. Lithium aluminum silicon glass, as a new type of glass, is widely used in fields such as electronics, aerospace, and high-speed rail. Accompanying this is the generation of a large amount of low-value lithium aluminum silicon glass waste. At present, there is little research and application of technologies for processing lithium aluminum silicon glass waste to recover valuable lithium elements. Expanding the application of lithium recycling and improving the utilization and recycling value of lithium-containing glass has broad market development prospects.

[0004] Several existing patents address the recycling and lithium extraction of lithium-aluminum-silicon glass waste:

[0005] CN202380010133.4 proposes a method for recycling waste lithium-aluminum-silicon microcrystalline glass: The waste lithium-aluminum-silicon microcrystalline glass is ball-milled (with citric acid and oxalic acid added during the process) to obtain glass powder; hydrofluoric acid is used as the leaching agent and leached for 4-6 hours at a certain solid-liquid ratio, during which silicon tetrafluoride gas is collected. After filtration, a calcium chloride hydrochloric acid solution is added to the filter residue (AlF3 precipitate, LiF precipitate, and ZrF4) to dissolve the lithium, aluminum, and zirconium. The residue is filtered again to obtain a conversion solution, which is then extracted and back-extracted to obtain zirconium sulfate; the pH of the converted solution is adjusted, and the residue is filtered to obtain aluminum hydroxide and a lithium-containing solution. Aluminum hydroxide reacts with soda ash and hydrofluoric acid to produce cryolite, zirconium sulfate reacts with silicon dioxide to form zirconium silicate, and the lithium-containing solution reacts with soda ash to form lithium carbonate. This process for treating waste glass powder involves mixed acid ball milling, long-term leaching with highly corrosive acid, conversion leaching of the leaching residue, extraction and separation of the leaching solution, and pH adjustment with alkali to separate aluminum. The mixed acid ball milling process not only causes wear and tear on the grinding balls but also introduces iron impurities into the system. Furthermore, the hydrofluoric acid leaching process generates highly toxic silicon tetrafluoride gas, requiring specialized gas collection and conversion equipment. The conversion solution undergoes secondary extraction and back-extraction to obtain the hazardous compound zirconium sulfate, which requires further conversion treatment. Adjusting the pH of the raffinate to remove aluminum is difficult, as it results in significant lithium entrainment losses. Finally, the entire process uses various organic and inorganic acids such as citric acid, oxalic acid, hydrofluoric acid, and hydrochloric acid, as well as various extraction reagents such as trioctylamine, tributyl phosphate, and sulfonated kerosene, resulting in high raw material and reagent costs, a complex process flow, and significant wastewater treatment challenges.

[0006] CN202310978528.5 proposes a method for the resource utilization of lithium-containing glass waste: After crushing, the lithium-containing glass waste is mixed with a leaching solution (containing Al-based alkaline solution) under ultrasonic radiation heating and stirring. After leaching, solid-liquid separation is performed. The product generated by the leaching reaction is a sodalite phase mainly composed of Na, Si, and Al. Lithium-containing compounds are obtained by precipitating lithium from the filtrate. Although this process is simple to operate, the leaching solution contains OH-. - Al(OH) 4- The leaching process involves complex compositions of alkali metal ions and acid radical ions, requiring high precision in solution preparation. The raw materials for solution preparation include water, NaOH, Al2(SO4)3, Al2O3, and Al(OH)3. Lithium concentration and crystallization are carried out in a leaching system containing a large amount of aluminum ions, making it difficult to guarantee the purity of lithium hydroxide. Furthermore, the overall lithium recovery rate is low, ranging from 20.3% to a maximum of only 93.1%, resulting in significant process fluctuations and hindering industrial application. Both the leaching solution and the leaching residue require further treatment before application, leading to low overall economic and social benefits.

[0007] Patent CN202310283975.9 proposes a comprehensive utilization method for lithium-containing glass waste. This method involves mixing the lithium-containing glass waste with lithium ceramic stone, a reconstructing agent, and a fluorine-fixing agent, then forming bricks, drying, calcining, crushing, and finally extracting lithium through water leaching. While this method can process lithium-containing glass waste in batches, it requires simultaneous processing with lithium ceramic stone, has high raw material requirements, and lacks versatility. Furthermore, the mass ratio of lithium-containing glass waste, lithium ceramic stone, reconstructing agent, and fluorine-fixing agent is 20-30:20-30:30-45:5-15, requiring large quantities of sulfate reconstructing agent and calcium salt fluorine-fixing agent. First, it significantly increases reagent costs and calcination capacity. Second, the large amount of slag generated during leaching forms new solid waste stockpiles, failing to address the goals of resource recovery and green recycling. Third, the reconstitution agent and solid fluoride agent are added according to the raw material mass ratio, resulting in a crude formulation method that is only suitable for lithium-containing glass waste and lithium ceramic stone raw materials with specific compositions. When the raw material composition changes, the dosage of the additives needs to be re-studied and adjusted. Fourth, the added reconstitution agent releases a large number of cations into the leaching process, adding an extra burden and pressure to the subsequent impurity removal of the leaching solution, making it impossible to achieve the true goal of short-process lithium extraction.

[0008] Furthermore, while conventional inorganic acid treatment can efficiently extract lithium from lithium-containing glass waste, it also results in the leaching of a large amount of aluminum. Using conventional pH-adjusted selective precipitation to separate aluminum and lithium, a significant amount of lithium is lost during this process, either as lithium hydroxide or entrained by colloidal aluminum hydroxide, and the process suffers from poor filtration, failing to achieve a simple and effective lithium-aluminum separation. To address this issue, patent CN202410536576.3 proposes a method for extracting lithium from lithium-containing aluminosilicate glass. This method involves adding a soluble M salt (M includes at least one of lithium, sodium, potassium, rubidium, cesium, silver, thallium, and ammonium ions, with a molar ratio of M to Al in the lithium-containing aluminosilicate glass of (0.3-1):1) during acid leaching, applying a pressure of 2-5 MPa, and performing high-temperature pressure leaching at 170-270°C. Achieving selective extraction of lithium and aluminum requires a high-temperature pressure acid leaching environment, demanding sophisticated equipment and numerous process parameters, requiring precise control of each parameter. Summary of the Invention

[0009] The purpose of this application is to provide a method for recycling lithium aluminum silicon glass waste to solve at least one of the technical problems mentioned in the background art.

[0010] To achieve the above objectives, this application adopts the following technical solution:

[0011] A method for recycling lithium aluminum silicon glass waste includes:

[0012] Lithium-aluminum-silicon glass waste powder is mixed with additives and calcined to obtain calcined material. The additives include sodium salts and calcium salts. The sodium salts include at least one of sodium sulfate and sodium bisulfate, and the calcium salts include at least one of calcium sulfate and calcium bisulfate. The molar amount of calcium in the additives is more than 0.4 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste, and the molar amount of sodium in the additives is more than 0.9 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste.

[0013] The roasted material is mixed with a leaching agent and then leached.

[0014] According to an embodiment of this application, the lithium content in the lithium-aluminum-silicon glass waste is 0.5 wt% or more.

[0015] According to an embodiment of this application, the particle size of the lithium aluminum silicon glass waste powder is smaller than the particle size corresponding to an 80-mesh sieve, preferably smaller than the particle size corresponding to a 100-mesh sieve, and more preferably smaller than the particle size corresponding to a 200-mesh sieve.

[0016] According to the embodiments of this application, the molar amount of calcium in the additive is more than 0.5 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 0.5-1.5 times, and more preferably 0.5-1.25 times;

[0017] And / or, the molar amount of sodium in the additive is more than 1.0 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 1.05-2.0 times, and more preferably 1.05-1.5 times;

[0018] And / or, the sum of the molar amounts of sodium and calcium in the additive is more than 1.4 times the molar amount of aluminum in the lithium aluminum silicon glass waste, preferably 1.5-3.0 times, more preferably 1.8-2.5 times.

[0019] According to the embodiments of this application, the roasting temperature is above 720°C, preferably 750-1050°C, more preferably 800-1000°C, and even more preferably 800-950°C;

[0020] And / or, the roasting time is 20 minutes or more, preferably 30-180 minutes, more preferably 30-60 minutes.

[0021] According to embodiments of this application, the pH of the leachate is 7±1.5, preferably 7±1, and more preferably 7±0.5.

[0022] According to an embodiment of this application, the leaching agent is an aqueous leaching agent, which includes one or more of water, wash water, leaching return liquid, and crystallization liquid.

[0023] According to the embodiments of this application, the liquid-to-solid ratio of the leaching agent to the calcined material is 2 mL / g or more, preferably 2-8 mL / g, and more preferably 2-6 mL / g;

[0024] And / or, the leaching temperature is above 20°C, preferably above 25°C, more preferably 25-95°C, and even more preferably 30-80°C;

[0025] And / or, the leaching time is 15 minutes or more, preferably 20 minutes or more, further preferably 30 minutes or more, and more preferably 30-60 minutes.

[0026] According to an embodiment of this application, the method further includes: performing solid-liquid separation after the leaching is completed to obtain a lithium-containing leachate and a leaching residue;

[0027] Preferably, the method further includes: returning part or all of the lithium-containing leachate to the leaching step.

[0028] According to embodiments of this application, the method further includes:

[0029] Lithium was precipitated from the leachate to obtain lithium compounds and a post-precipitation solution.

[0030] Preferably, the method further includes: crystallizing the lithium precipitation liquid to obtain sodium sulfate byproduct and a first crystallization liquid, and returning the sodium sulfate byproduct to the roasting step; preferably, the first crystallization liquid is returned to leaching;

[0031] And / or, the leaching residue is leached with a sulfuric acid solution to obtain a calcium- and aluminum-containing leachate. The pH is adjusted to remove aluminum, resulting in aluminum-containing slag. After aluminum removal, the slag is crystallized to obtain a calcium sulfate byproduct and a second crystallized liquid. The calcium sulfate byproduct is returned to the roasting step. Preferably, the second crystallized liquid is returned to the leaching process.

[0032] Compared with the prior art, the beneficial effects of this application include:

[0033] (1) The additives used in the roasting step of this application are simple and environmentally friendly, and do not involve the use of toxic, harmful, or corrosive reagents. Furthermore, no toxic, harmful, or corrosive substances are generated during the roasting process. Moreover, the additives used in the roasting step of this application are readily available and used in small quantities. They are precisely added based on glass waste. Compared with adding additives based on the quality of specific types of raw materials, this method not only avoids the poor treatment effect caused by the fluctuation of composition due to the source, batch, and pretreatment of waste raw materials, but also avoids the need for repeated investment of manpower and resources to specifically study and adjust the amount of additives. It can also make full use of various types of materials such as raw ores, tailings, intermediate products, and slag containing sodium and / or calcium salts, reduce or avoid the use of chemical or industrial grade additives, fully realize the full utilization of valuable resources while reducing additive costs, and quickly adjust the actual material ratio based on the composition of raw materials and additives, thus simply and effectively avoiding the impact of fluctuations in the composition of glass waste and additives on the roasting effect.

[0034] (2) The lithium leaching rate in lithium-aluminum-silicon glass waste is above 93%, with a maximum of 99.53%, and the lithium content in the slag is less than 0.1%, achieving efficient and short-process recovery of high-value lithium in lithium-aluminum-silicon glass waste; and effectively suppressing the leaching of aluminum, calcium and silicon in the leaching process, with the aluminum and silicon content in the leaching solution reaching undetectable levels, and the total calcium leaching rate of raw materials and additives controlled below 26%, with a minimum of 8.21%, achieving efficient separation of lithium from impurity elements such as aluminum, calcium and silicon, avoiding the subsequent impurity removal pressure and lithium loss risk caused by traditional acid and alkali treatment rich in silicon, aluminum and / or calcium impurities, especially the large amount of lithium entrainment loss and filtration difficulties caused by the formation of silicon and aluminum colloidal substances.

[0035] (3) This application uses neutral conditions without additives for leaching treatment. The leaching system and leaching conditions are simple and mild. No high temperature or pressure environment is required. No acid, alkali or other leaching aids are needed to assist or strengthen it. More than 90% of the lithium in the roasted material can be leached within 20 minutes. The leaching process is efficient and simple, with low production input and operating costs, high economic benefits, and does not involve irritating or corrosive working environments. It is energy-saving and environmentally friendly.

[0036] (4) After lithium extraction from the lithium-containing leaching solution obtained in this application, the sodium sulfate byproduct can be obtained by concentration and cooling crystallization. This byproduct can then be reused as an additive in the roasting process, thus achieving internal circulation of the roasting additive. The crystallized liquid can be returned to the leaching process for recycling. The leaching residue mainly contains aluminum, calcium, and silicon compounds. After further processing, the calcium salt can be recovered and returned as a roasting additive. The aluminum and silicon slag can be used in fields such as construction, glass, ceramics, and electronics, or further separated and extracted to obtain aluminum and silicon compounds.

[0037] (5) The lithium-containing leachate obtained by the method of this application has few types and contents of impurities. After simple impurity removal treatment, high-purity lithium compounds can be prepared, which can be used as raw materials for the production of lithium-ion battery materials. This enables efficient recovery and reuse of valuable elements in low-value lithium-containing aluminum-silicon glass waste, thereby solving the environmental pollution problem caused by glass waste pile-up and reducing space occupation. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0039] Figure 1 This is the XRD pattern of the calcined material in Example 3;

[0040] Figure 2 This is the XRD pattern of the leaching residue from Example 3;

[0041] Figure 3 This is the XRD pattern of the calcined material in Example 8;

[0042] Figure 4 The XRD pattern of the calcined material in Comparative Example 3 is shown.

[0043] Figure 5 This is the XRD pattern of the calcined material in Comparative Example 4. Detailed Implementation

[0044] As used in this article:

[0045] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0046] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0047] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0048] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0049] To better illustrate the technical solution provided in this application, the technical solution will be described in its entirety before the embodiments, as follows:

[0050] A method for recycling lithium aluminum silicon glass waste includes:

[0051] Lithium-aluminum-silicon glass waste powder is mixed with additives and then calcined to obtain calcined material;

[0052] The additives include sodium salts and calcium salts, wherein the sodium salts include at least one of sodium sulfate and sodium bisulfate, and the calcium salts include at least one of calcium sulfate and calcium bisulfate. The molar amount of calcium in the additives is more than 0.4 times the molar amount of aluminum in the lithium aluminum silicon glass waste, and the molar amount of sodium in the additives is more than 0.9 times the molar amount of aluminum in the lithium aluminum silicon glass waste.

[0053] The roasted material is mixed with the leaching agent and then leached.

[0054] Lithium-aluminum-silicon glass waste undergoes high-temperature treatment to acquire excellent thermal stability, chemical stability, and mechanical properties. Lithium, silicon, and aluminum generally consist of amorphous glass phases formed by the high-temperature melting of silica, alumina, and lithium oxide, as well as microcrystalline phases such as lithium disilicate, litharge, and β-quartz solid solutions. The types of phases and interphase transformation reactions between elements are complex. The inventors discovered that by using a combination of sulfate-containing sodium and calcium salts as calcination aids, under the combined action of the calcination aids, lithium in lithium-aluminum-silicon glass waste can be converted into water-soluble LiNaSO4 through calcination, while calcium, aluminum, and silicon are converted into phases such as anorthite, sodalite, quartz, and gypsum. Among these, anorthite, sodalite, and quartz are insoluble in water, while gypsum is slightly soluble in water. The calcined material can achieve efficient and selective leaching of lithium through simple water immersion. During the roasting process, sodium and calcium sulfate salts exhibit a mutually restraining and synergistic effect on the conversion reactions of LiNaSO4, anorthite, and sodalite. Adding sodium or calcium sulfate salts alone cannot achieve the aforementioned phase transformation in lithium-aluminum-silicon glass waste. Based on this, further research has identified a reasonable range for the dosage of sodium and calcium salts. Adding sodium and calcium sulfate salts within this range allows for the complete conversion of lithium in lithium-aluminum-silicon glass waste into water-soluble lithium salt LiNaSO4, achieving efficient and selective lithium leaching. Simultaneously, it converts non-lithium elements such as aluminum, silicon, and calcium into insoluble or low-water-soluble oxides or heteropolyacid salts, maximizing the suppression of non-lithium elements entering the liquid phase from the source and avoiding lithium loss and cumbersome impurity removal processes during subsequent leaching.

[0055] According to the embodiments of this application, the molar amount of sodium in the additive is more than 1.0 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 1.05-2.0 times, and more preferably 1.05-1.5 times;

[0056] For example, the molar amount of sodium in the additive can be any value that is 0.9 times, 1.0 times, 1.05 times, 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2.0 times, or more than 0.9 times the molar amount of aluminum in lithium aluminum silicon glass waste.

[0057] The molar amount of calcium in the additive is more than 0.5 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 0.5-1.5 times, and more preferably 0.5-1.25 times.

[0058] The molar amount of calcium in the additive can be any value greater than 0.4 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1.0 times, 1.05 times, 1.1 times, 1.2 times, 1.25 times, 1.3 times, 1.4 times, 1.5 times, or 0.4 times the molar amount of aluminum in lithium aluminum silicon glass waste.

[0059] According to the embodiments of this application, the sum of the molar amounts of sodium and calcium in the additive is more than 1.4 times the molar amount of aluminum in the lithium aluminum silicon glass waste, preferably more than 1.5 times, more preferably 1.5-3.0 times, and more preferably 1.8-2.5 times.

[0060] For example, the sum of the molar amounts of sodium and calcium in the additive can be any value that is 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2.0 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, 2.6 times, 2.7 times, 2.8 times, 2.9 times, 3.0 times, or more than 1.4 times the molar amount of aluminum in lithium aluminum silicon glass waste.

[0061] Further controlling the addition ratio of sodium and calcium in the additives, so that the sum of the molar amounts of sodium and calcium in the additives is controlled within a certain range, can take into account both the cost of the additives and the total amount of materials to be roasted, and does not constitute a specific limitation on the implementation of this patent application.

[0062] According to the embodiments of this application, the roasting temperature is above 720°C, preferably 750-1050°C, more preferably 800-1000°C, and even more preferably 800-950°C.

[0063] For example, the roasting temperature can be any value above 720℃, 730℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, or 720℃.

[0064] According to the embodiments of this application, the roasting time is 20 minutes or more, preferably 30-180 minutes, and more preferably 30-60 minutes.

[0065] For example, the roasting time can be any value of 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min, 140 min, 150 min, 160 min, 180 min, or more than 20 min.

[0066] If the calcination temperature is too low or the time is too short, the phase transformation will be difficult to proceed or will be difficult to proceed fully in the direction of phase transformation of the target substance. If the temperature is too high or the calcination time is too long, there will be drawbacks such as excessive energy consumption.

[0067] According to embodiments of this application, the pH of the leachate is 7±1.5, preferably 7±1, and more preferably 7±0.5;

[0068] For example, the pH of the leachate can be any value between 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, or 7 ± 1.5.

[0069] The leaching agent is an aqueous leaching agent, which includes one or more of water, wash water, leaching return liquid, and crystallization liquid, or other aqueous leaching agents generated during the production process that do not introduce difficult-to-treat impurities.

[0070] According to the embodiments of this application, the liquid-to-solid ratio of the leaching agent to the calcined material is 2 mL / g or more, preferably 2-8 mL / g, and more preferably 2-6 mL / g;

[0071] For example, the liquid-solid ratio of the leaching agent to the calcined material can be any value of 2 mL / g, 3 mL / g, 4 mL / g, 5 mL / g, 6 mL / g, 7 mL / g, 8 mL / g, or more than 2 mL / g.

[0072] The leaching temperature is above 20°C, preferably above 25°C, more preferably 25-95°C, and even more preferably 30-80°C.

[0073] The leaching temperature can be any value above 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃ or 20℃.

[0074] The leaching time is 15 minutes or more, preferably 20 minutes or more, more preferably 30 minutes or more, and even more preferably 30-60 minutes.

[0075] The leaching time can be any value of 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min or more than 15 min.

[0076] The calcined material obtained by calcining lithium-aluminum-silicon glass waste with the above-mentioned additives exhibits excellent selective lithium leaching performance. The leaching process requires no special treatment to achieve highly efficient selective lithium leaching. Furthermore, due to the superior solubility of LiNaSO4, selective lithium leaching can be achieved to varying degrees under both acidic and alkaline conditions. The further limitations on the leaching parameters mentioned above are mainly based on comprehensive considerations such as ease of leaching implementation, operating environment, energy saving and consumption reduction, and environmental safety, providing further optimized conditions, and do not constitute specific limitations on the implementation of this patent application.

[0077] According to an embodiment of this application, the method further includes: performing solid-liquid separation after the leaching is completed to obtain a lithium-containing leachate and a leaching residue;

[0078] In some embodiments, the method further includes: returning part or all of the lithium-containing leachate to the leaching step; since the lithium content in lithium-containing aluminum-silicon glass waste is low and the lithium concentration in the primary leachate is low, returning part or all of the leachate to the leaching stage can further increase the lithium content in the solution, and the recycling of the leachate can reduce the amount of external reagents used.

[0079] According to an embodiment of this application, the method further includes: precipitating lithium in the leaching solution to obtain a lithium compound and a post-precipitation solution;

[0080] The process further includes: crystallizing the lithium precipitation liquid to obtain sodium sulfate byproduct and a first crystallization liquid; returning the sodium sulfate byproduct to the roasting step; and returning the first crystallization liquid to the leaching step. The main component of the lithium precipitation liquid is sodium sulfate solution, which can be crystallized to obtain sodium sulfate byproduct, which can be used as an additive in the roasting step. The first crystallization liquid can be returned to the leaching step, thus realizing the internal circulation of roasting additives and leaching reagents.

[0081] According to embodiments of this application, the method further includes: leaching the leaching residue with a sulfuric acid solution to obtain a calcium- and aluminum-containing leaching solution and a silicon-containing leaching residue; adjusting the pH to remove aluminum to obtain a sulfate solution containing aluminum slag and calcium; crystallizing to obtain a calcium sulfate byproduct and a second post-crystallization liquid; and returning the calcium sulfate byproduct to the roasting step; preferably, the second post-crystallization liquid is returned to the leaching process. The leaching residue mainly contains compounds such as aluminum, calcium, and silicon. The above treatment can recover some of the calcium salts, which can be returned as an additive. The aluminum slag and silicon slag can be used in fields such as construction, glass, ceramics, and electronics, or further separated and extracted to obtain aluminum and silicon compounds.

[0082] According to the embodiments of this application, the lithium content in the lithium aluminum silicon glass waste is 0.5 wt% or more, preferably 1 wt% or more, more preferably 1.5 wt% or more, and even more preferably 2 wt% or more;

[0083] The aluminum content in the lithium aluminum silicon glass waste is 5 wt% or more, preferably 7 wt% or more, and more preferably 9 wt% or more;

[0084] The silicon content in the lithium aluminum silicon glass waste is 10 wt% or more, more preferably 15 wt% or more, more preferably 20 wt% or more, and even more preferably 30 wt% or more.

[0085] According to an embodiment of this application, the particle size of the lithium aluminum silicon glass waste powder is less than the particle size corresponding to an 80-mesh sieve, preferably less than the particle size corresponding to a 100-mesh sieve, and more preferably less than the particle size corresponding to a 200-mesh sieve.

[0086] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0087] In the following examples and comparative examples, the lithium aluminum silicon glass waste used in Examples 1-6 and Comparative Examples 1-10 contained 2.27 wt% lithium and 13.26 wt% aluminum; the lithium aluminum silicon glass waste used in Examples 7-10 contained 1.67 wt% lithium and 9.31 wt% aluminum; and the lithium aluminum silicon glass waste used in Examples 11-12 contained 1.93 wt% lithium and 10.90 wt% aluminum.

[0088] This invention uses atomic absorption and ICP to test the lithium and calcium content of materials. The lithium leaching rate and calcium leaching rate in Examples 1-12 and Comparative Examples 2-10 are calculated based on the lithium and calcium in the roasted material. Specifically, the lithium leaching rate in Examples 1-12 and Comparative Examples 2-10 is calculated as [1 - (wt% lithium in leaching residue × g mass of leaching residue) / (wt% lithium in roasted material × g mass of roasted material)] × %; the calcium leaching rate in Examples 1-12 and Comparative Examples 2-10 is calculated as [1 - (wt% calcium in leaching residue × g mass of leaching residue) / (wt% calcium in roasted material × g mass of roasted material)] × %.

[0089] The lithium leaching rate and calcium leaching rate in Comparative Example 1 are calculated based on lithium and calcium in lithium-aluminum-silicon glass waste. Specifically, the lithium leaching rate of Comparative Example 1 is calculated as [1 - (wt% lithium in leaching residue × g mass of leaching residue) / (wt% lithium in lithium-aluminum-silicon glass waste × g mass of lithium-aluminum-silicon glass waste)] × %; the calcium leaching rate of Comparative Example 1 is calculated as [1 - (wt% calcium in leaching residue × g mass of leaching residue) / (wt% calcium in lithium-aluminum-silicon glass waste × g mass of lithium-aluminum-silicon glass waste)] × %.

[0090] Example 1

[0091] Example 1 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0092] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 0.9 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.13 times the molar amount of aluminum in lithium aluminum silicon glass waste. Mix evenly to obtain a mixture.

[0093] (2) The mixture is calcined at 730°C for 120 minutes to obtain the calcined material.

[0094] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 20 min.

[0095] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0096] Example 2

[0097] Example 2 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0098] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1.05 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.88 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0099] (2) The mixture is calcined at 1000℃ for 30 minutes to obtain the calcined material.

[0100] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 3 mL / g, the leaching temperature is 25℃, and the leaching time is 40 min.

[0101] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0102] Example 3

[0103] Example 3 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0104] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that: the molar amount of sodium in sodium sulfate is 1.00 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.50 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0105] (2) The mixture is calcined at 900℃ for 180 minutes to obtain the calcined material.

[0106] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 5 mL / g, the leaching temperature is 45℃, and the leaching time is 60 min.

[0107] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0108] Example 4

[0109] Example 4 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0110] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that: the molar amount of sodium in sodium sulfate is 1.00 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.63 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0111] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0112] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0113] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0114] Example 5

[0115] Example 5 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0116] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that: the molar amount of sodium in sodium sulfate is 2.00 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.50 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0117] (2) The mixture is calcined at 950°C for 40 minutes to obtain the calcined material.

[0118] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 20℃, and the leaching time is 60 min.

[0119] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0120] Example 6

[0121] Example 6 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0122] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1.38 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.13 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0123] (2) The mixture is calcined at 750°C for 90 minutes to obtain the calcined material.

[0124] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 6 mL / g, the leaching temperature is 35℃, and the leaching time is 30 min.

[0125] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0126] Example 7

[0127] Example 7 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0128] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1.50 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.50 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0129] (2) The mixture is calcined at 750°C for 50 minutes to obtain the calcined material.

[0130] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 3 mL / g, the leaching temperature is 50℃, and the leaching time is 45 min.

[0131] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0132] Example 8

[0133] Example 8 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0134] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1.38 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.13 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0135] (2) The mixture is calcined at 850°C for 150 min to obtain the calcined material.

[0136] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 80℃, and the leaching time is 120 min.

[0137] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0138] Example 9

[0139] Example 9 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0140] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1.88 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.75 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0141] (2) The mixture is calcined at 900℃ for 60 minutes to obtain the calcined material.

[0142] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 2 mL / g, the leaching temperature is 60℃, and the leaching time is 90 min.

[0143] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0144] Example 10

[0145] Example 10 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0146] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 2.00 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.00 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0147] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0148] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0149] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0150] Example 11

[0151] Example 11 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0152] (1) Take lithium aluminum silicon glass waste powder, add sodium bisulfate and calcium bisulfate, and control the amount of sodium bisulfate and calcium bisulfate added so that: the molar amount of sodium in sodium bisulfate is 1.25 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium bisulfate is 0.4 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0153] (2) The mixture is calcined at 800℃ for 60 minutes to obtain the calcined material.

[0154] (3) After the calcined material cools down, the calcined material is mixed with the washing water of the lithium carbonate product from the production line and leached. The liquid-to-solid ratio of the leaching is 8 mL / g, the leaching temperature is 90℃, and the leaching time is 25 min.

[0155] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0156] (5) Add sodium carbonate to the lithium-containing leachate to precipitate lithium, and obtain crude lithium carbonate and lithium-precipitated liquid.

[0157] (6) Add sulfuric acid, which is 1.1 times the molar amount of carbonate in the lithium precipitation solution, and heat to remove carbon, to obtain the decarbonized solution.

[0158] (7) Cool the decarbonized liquid to 0°C to obtain sodium sulfate byproduct and crystallized liquid. The crystallized liquid is used for leaching of the next batch of roasted material.

[0159] Example 12

[0160] Example 12 provides a method for recycling lithium aluminum silicon glass waste, comprising:

[0161] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium hydrogen sulfate, wherein the sodium sulfate part is a by-product obtained in Example 11. Control the amount of sodium sulfate and calcium hydrogen sulfate added so that the following conditions are met: the molar amount of sodium is 1.25 times the molar amount of aluminum in the lithium aluminum silicon glass waste, and the molar amount of calcium is 0.75 times the molar amount of aluminum in the lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0162] (2) The mixture is calcined at 750°C for 75 minutes to obtain the calcined material.

[0163] (3) After the calcined material has cooled, the calcined material is mixed with the leaching agent and leached. The leaching agent includes the crystallized liquid from Example 11. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 40°C, and the leaching time is 60 min.

[0164] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0165] (5) The leaching residue was treated with 1 mol / L sulfuric acid and filtered to obtain a calcium and aluminum leaching solution.

[0166] (6) Adjust the pH to 5.0 with sodium hydroxide to obtain a solution containing aluminum slag and calcium salt.

[0167] (7) The calcium salt solution is concentrated and crystallized to obtain calcium sulfate residue, which is used for the next batch of roasting.

[0168] Comparative Example 1

[0169] In Comparative Example 1, the lithium aluminum silicon glass waste was not roasted but directly leached. The recycling method for the lithium aluminum silicon glass waste in Comparative Example 1 included:

[0170] (1) Take lithium aluminum silicon glass waste powder and mix it with water for leaching. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0171] (2) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0172] Comparative Example 2

[0173] In Comparative Example 2, sodium sulfate and calcium sulfate were not added during the roasting step; only lithium aluminum silicon glass waste powder was roasted. The recycling method for lithium aluminum silicon glass waste in Comparative Example 2 included:

[0174] (1) The lithium aluminum silicon glass waste powder was calcined at 800℃ for 45 minutes to obtain the calcined material.

[0175] (2) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0176] (3) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0177] Comparative Example 3

[0178] In Comparative Example 3, calcium sulfate was not added during the calcination step. The recycling method for lithium-aluminum-silicon glass waste in Comparative Example 3 included:

[0179] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate, and control the amount of sodium sulfate added so that the molar amount of sodium in sodium sulfate is 1 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0180] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0181] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0182] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0183] Comparative Example 4

[0184] In Comparative Example 4, sodium sulfate was not added during the calcination step. The recycling method for lithium-aluminum-silicon glass waste in Comparative Example 4 included:

[0185] (1) Take lithium aluminum silicon glass waste powder, add calcium sulfate, and control the amount of calcium sulfate added so that the molar amount of calcium in the calcium sulfate is 0.5 times the molar amount of aluminum in the lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0186] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0187] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0188] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0189] Comparative Example 5

[0190] The sodium ion content added in Comparative Example 5 was too low. The recycling methods for lithium-aluminum-silicon glass waste in Comparative Example 5 included:

[0191] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 0.6 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.4 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0192] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0193] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0194] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0195] Comparative Example 6

[0196] The sodium ion content added in Comparative Example 6 was too low. The recycling methods for lithium-aluminum-silicon glass waste in Comparative Example 6 included:

[0197] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 0.5 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.5 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0198] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0199] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0200] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0201] Comparative Example 7

[0202] The calcium ion content added in Comparative Example 7 was too low. The recycling methods for the lithium-aluminum-silicon glass waste in Comparative Example 7 included:

[0203] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 1 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 0.3 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0204] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0205] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0206] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0207] Comparative Example 8

[0208] The amounts of sodium sulfate and calcium sulfate added in Comparative Example 8 were determined based on the mass of lithium aluminum silicon glass waste. The recycling methods for the lithium aluminum silicon glass waste in Comparative Example 8 included:

[0209] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the mass of sodium sulfate accounts for 10 wt% of the mass of lithium aluminum silicon glass waste, and the mass of calcium sulfate accounts for 10 wt% of the mass of lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0210] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0211] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0212] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0213] Comparative Example 9

[0214] The amounts of sodium sulfate and calcium sulfate added in Comparative Example 9 were determined based on the mass of lithium aluminum silicon glass waste. The recycling methods for the lithium aluminum silicon glass waste in Comparative Example 9 included:

[0215] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the mass of sodium sulfate accounts for 50 wt% of the mass of lithium aluminum silicon glass waste, and the mass of calcium sulfate accounts for 50 wt% of the mass of lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0216] (2) The mixture is calcined at 800℃ for 45 minutes to obtain the calcined material.

[0217] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0218] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0219] Comparative Example 10

[0220] The calcination temperature in Comparative Example 10 was too low. The recycling method for lithium-aluminum-silicon glass waste in Comparative Example 10 included:

[0221] (1) Take lithium aluminum silicon glass waste powder, add sodium sulfate and calcium sulfate, and control the amount of sodium sulfate and calcium sulfate added so that the following conditions are met: the molar amount of sodium in sodium sulfate is 0.9 times the molar amount of aluminum in lithium aluminum silicon glass waste, and the molar amount of calcium in calcium sulfate is 1.13 times the molar amount of aluminum in lithium aluminum silicon glass waste; mix evenly to obtain a mixture.

[0222] (2) The mixture is calcined at 600℃ for 45 minutes to obtain the calcined material.

[0223] (3) After the calcined material has cooled, it is mixed with water and leached. The liquid-to-solid ratio of the leaching is 4 mL / g, the leaching temperature is 30℃, and the leaching time is 45 min.

[0224] (4) After leaching, solid-liquid separation is performed to obtain lithium-containing leachate and leaching residue.

[0225] In Examples 1-12, neither aluminum nor silicon was detected in the leachate, meaning that neither aluminum nor silicon was leached.

[0226] The test results of Examples 1-12 and Comparative Examples 1-10 are shown in Table 1.

[0227] Table 1. Test results of Examples 1-12 and Comparative Examples 1-10

[0228] Lithium leaching rate / % Calcium leaching rate / % Example 1 93.26 12.88 Example 2 96.15 8.21 Example 3 97.69 15.11 Example 4 98.55 19.25 Example 5 96.55 11.08 Example 6 98.61 25.41 Example 7 97.39 22.32 Example 8 99.53 24.77 Example 9 98.92 18.51 Example 10 95.17 23.16 Example 11 98.78 13.16 Example 12 99.36 12.31 Comparative Example 1 0.63 2.15 Comparative Example 2 0.7 29.02 Comparative Example 3 39.4 39.12 Comparative Example 4 0.32 21.69 Comparative Example 5 56.97 37.85 Comparative Example 6 46.96 36.53 Comparative Example 7 49.65 33.53 Comparative Example 8 36.24 27.87 Comparative Example 9 83.75 55.17 Comparative Example 10 80.90 38.89

[0229] As can be seen from Table 1, the lithium leaching rate of Examples 1-12 is significantly better than that of Comparative Examples 1-10.

[0230] Figure 1 This is the XRD pattern of the calcined material in Example 3. Figure 1 It can be seen that after calcination, most of the lithium forms soluble LiNaSO4, while a very small portion of the lithium forms a non-water-soluble spodumene structure.

[0231] Figure 2 This is the XRD pattern of the leaching residue from Example 3. Figure 2 It can be seen that the water-soluble LiNaSO4 phase disappears after immersion in water.

[0232] Figure 3 This is the XRD pattern of the calcined material in Example 8, from... Figure 3It can be seen that after calcination, almost all lithium exists in the form of soluble LiNaSO4. As shown in Table 1, the lithium leaching rate in Example 8 is as high as 99.53%.

[0233] Figure 4 This is the XRD pattern of the calcined material in Comparative Example 3, where only sodium sulfate was added during calcination. Figure 4 It can be seen that in Comparative Example 3, most of the lithium is converted into a non-water-soluble spodumene structure after calcination, and only a small portion of the lithium is converted into water-soluble LiNaSO4.

[0234] Figure 5 This is the XRD pattern of the calcined material in Comparative Example 4. Comparative Example 4 only added calcium sulfate, from... Figure 5 It can be seen that after calcination, lithium in Comparative Example 4 is converted into a spodumene structure and no LiNaSO4 phase is detected. Combined with Table 1, it can be seen that almost no lithium is leached out after water immersion in Comparative Example 4.

[0235] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0236] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for recycling lithium aluminum silicon-based glass waste, characterized by, include: Lithium-aluminum-silicon glass waste powder is mixed with additives and calcined to obtain calcined material. The additives include sodium salts and calcium salts. The sodium salts include at least one of sodium sulfate and sodium bisulfate, and the calcium salts include at least one of calcium sulfate and calcium bisulfate. The molar amount of calcium in the additives is more than 0.4 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste, and the molar amount of sodium in the additives is more than 0.9 times the molar amount of aluminum in the lithium-aluminum-silicon glass waste. The roasted material is mixed with a leaching agent and then leached.

2. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, characterized by, The lithium content in the lithium-aluminum-silicon glass waste is above 0.5 wt%.

3. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, characterized by, The particle size of the lithium aluminum silicon glass waste powder is smaller than that of an 80-mesh sieve, preferably smaller than that of a 100-mesh sieve, and more preferably smaller than that of a 200-mesh sieve.

4. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, characterized by, The molar amount of calcium in the additive is more than 0.5 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 0.5-1.5 times, and more preferably 0.5-1.25 times; And / or, the molar amount of sodium in the additive is more than 1.0 times the molar amount of aluminum in the lithium aluminum silicon glass waste, more preferably 1.05-2.0 times, and more preferably 1.05-1.5 times; And / or, the sum of the molar amounts of sodium and calcium in the additive is more than 1.4 times the molar amount of aluminum in the lithium aluminum silicon glass waste, preferably 1.5-3.0 times, more preferably 1.8-2.5 times.

5. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, characterized by, The roasting temperature is above 720°C, preferably 750-1050°C, more preferably 800-1000°C, and even more preferably 800-950°C; And / or, the roasting time is 20 minutes or more, preferably 30-180 minutes, more preferably 30-60 minutes.

6. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, wherein The pH of the leachate is 7±1.5, preferably 7±1, and more preferably 7±0.

5.

7. The lithium aluminum silicon-based glass scrap recycling method according to claim 1, characterized by, The leaching agent is an aqueous leaching agent, which includes one or more of water, washing water, leaching return liquid, and crystallization liquid.

8. The method for recycling lithium aluminum silicon-based glass scrap according to claim 1, wherein The liquid-to-solid ratio of the leaching agent to the calcined material is 2 mL / g or more, preferably 2-8 mL / g, and more preferably 2-6 mL / g; And / or, the leaching temperature is above 20°C, preferably above 25°C, more preferably 25-95°C, and even more preferably 30-80°C; And / or, the leaching time is 15 minutes or more, preferably 20 minutes or more, further preferably 30 minutes or more, and more preferably 30-60 minutes.

9. The lithium aluminum silicon-based glass scrap recycling method according to any one of claims 1 to 8, characterized by, The method further includes: performing solid-liquid separation after leaching to obtain lithium-containing leachate and leaching residue; Preferably, the method further includes: returning part or all of the lithium-containing leachate to the leaching step.

10. The lithium aluminum silicon-based glass scrap recycling method according to claim 9, wherein The method further includes: Lithium was precipitated from the leachate to obtain lithium compounds and a post-precipitation solution. Preferably, the method further includes: crystallizing the lithium precipitation liquid to obtain sodium sulfate byproduct and a first crystallization liquid, and returning the sodium sulfate byproduct to the roasting step; preferably, the first crystallization liquid is returned to leaching; And / or, the leaching residue is leached with a sulfuric acid solution to obtain a calcium- and aluminum-containing leachate. The pH is adjusted to remove aluminum, resulting in aluminum-containing slag. After aluminum removal, the slag is crystallized to obtain a calcium sulfate byproduct and a second crystallized liquid. The calcium sulfate byproduct is returned to the roasting step. Preferably, the second crystallized liquid is returned to the leaching process.

Images