Method for extracting metal lithium from lithium-containing glass powder

Abstract

The invention discloses a method for extracting metal lithium from lithium-containing glass powder. The method comprises the following steps: stirring and mixing the lithium-containing glass powder, hydrochloric acid and aluminum hydroxide, and reacting to obtain a solid-liquid mixed reaction product; wherein the mass ratio of the lithium-containing glass powder to the hydrochloric acid to the aluminum hydroxide is 1: (0.2-0.6): (0.2-0.5); carrying out solid-liquid separation on the reaction product to obtain filtrate and filter residues; and removing impurities from the filtrate to obtain a lithium-containing solution. According to the method, lithium in the glass powder is leached out through hydrochloric acid and aluminum hydroxide, then the leach liquor is subjected to impurity removal, efficient extraction of the metal lithium in the lithium-containing glass powder can be achieved, the recovery rate of the metal lithium is high, the technical economic feasibility is high, and compared with a traditional process for extracting the metal lithium from the glass powder, the method has the advantages that the cost is low; according to the invention, the glass powder does not need to be calcined at high temperature, the energy consumption is lower, no hazardous waste is generated in the production process, the production water can be self-recycled, and the environment-friendly benefit is excellent.

Description

Technical Field

[0001] The invention relates to the field of lithium resource recycling, and in particular to a method for extracting metallic lithium from lithium-containing glass powder. Background Art

[0002] Lithium metal has a wide range of applications, including nuclear industry, batteries, light alloys, medical treatment, glass, etc. Glass usually contains 0.5-3% lithium metal, and the introduction of lithium metal can increase the stability, strength, corrosion resistance and optical properties of mobile phone glass.

[0003] As a precious metal and new energy metal, lithium metal has high economic value. Therefore, the recycling of lithium metal in lithium-containing glass is particularly important. At present, there are few reports on the recycling of lithium metal in glass.

[0004] The patent document with publication number CN116445735A discloses a method for extracting metallic lithium from waste glass, which comprises grinding lithium-containing waste glass into glass powder, processing the glass powder with abrasive, and calcining in a high-temperature furnace, mixing the processed glass powder with acid solution, contacting the glass powder with hydrofluoric acid and perchloric acid for a first heat treatment, cooling, adding water to the cooled product for a second heat treatment, obtaining a glass dissolving solution, washing and filtering the prepared glass dissolving solution, extracting lithium carbonate, washing lithium carbonate with a circulating washing solution, and separating and precipitating to obtain metallic lithium. The document abandons the traditional process route of extracting lithium from seawater, which can improve the yield of lithium, but it also requires a calcination process during the processing, and it also requires the introduction of hydrofluoric acid and perchloric acid. Obviously, the technical solution inevitably has the disadvantages of high energy consumption, easy generation of hazardous waste, large environmental pollution, and low technical and economic feasibility. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for extracting metallic lithium from lithium-containing glass powder.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0007] A method for extracting metallic lithium from lithium-containing glass powder comprises the following steps:

[0008] (1) mixing and reacting lithium-containing glass powder with hydrochloric acid and aluminum hydroxide to obtain a solid-liquid mixed reaction product; wherein the mass ratio of the lithium-containing glass powder to the hydrochloric acid and aluminum hydroxide is 1:(0.2-0.6):(0.2-0.5); and the mass concentration of the hydrochloric acid is 31%-33%;

[0009] (2) separating the reaction product obtained in step (1) into solid and liquid to obtain a filtrate and a filter residue;

[0010] (3) removing impurities from the filtrate obtained in step (2) to obtain a lithium-containing solution.

[0011] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, in step (1), the reaction temperature is 70-105° C., and the reaction time is 60 min-120 min. The reaction temperature should not be too low, otherwise the reaction will be incomplete, and exceeding the reaction temperature will cause water evaporation.

[0012] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, in step (1), the reaction temperature is controlled by introducing steam.

[0013] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, in step (1), the particle size of the lithium-containing glass powder is not less than 100 mesh.

[0014] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, in step (2), the filter residue is added to step (1) and mixed with the lithium-containing glass powder, and then reused as raw material.

[0015] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, the operation of step (1) is carried out in an acid leaching tank, and the acid leaching tank is filled underground. The acid leaching tank is filled underground to achieve the best insulation effect, and steam can be directly added to heat the acid leaching solution, so as to achieve uniform heating, reduce heat loss, and ensure production safety and environmental protection.

[0016] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, in step (3), the impurity removal refers to first adding caustic soda and calcium chloride to the filtrate for preliminary impurity removal, and then performing fine impurity removal through an ultrafiltration membrane.

[0017] The above method for extracting metallic lithium from lithium-containing glass powder is preferably carried out for every 100m 3 In the filtrate, the amount of caustic soda added is 1-5t, the amount of calcium chloride added is 0.1-0.4t, the reaction temperature for adding caustic soda and calcium chloride for preliminary impurity removal is 30-60°C, and the reaction time is 10-30min.

[0018] In the above-mentioned method for extracting metallic lithium from lithium-containing glass powder, preferably, the ultrafiltration membrane comprises, from the water inlet end to the water outlet end, a 0.1-0.3 μm ultra-thin separation layer of polyamide material, a 35-45 μm porous intermediate support layer of polysulfone material, and a 110-130 μm polyester material reinforced non-woven fabric layer.

[0019] The ultrafiltration membrane is used for impurity removal. The ultrafiltration membrane can intercept macromolecular substances and impurities between 0.02-0.1 μm, and allow small molecular substances and soluble solids (inorganic salts) to pass through.

[0020] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, the concentrations of calcium, magnesium, aluminum and iron ions in the lithium-containing solution obtained by removing impurities do not exceed 0.59 ppm.

[0021] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, soda ash is added to the lithium-containing solution to carry out a lithium precipitation reaction, and after the reaction is completed, the solid and liquid are separated to obtain lithium carbonate solid and lithium precipitation mother liquor.

[0022] The above method for extracting metallic lithium from lithium-containing glass powder, preferably, during the lithium precipitation reaction, every 20m 3 When the mass concentration of the lithium-containing solution is 14-16 g / L, the amount of soda ash added is 2-4 t, and the temperature of the lithium precipitation reaction is 75-95°C.

[0023] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, the lithium content in the lithium precipitation mother liquor is not higher than 1.5 g / L, and the lithium precipitation mother liquor can be directly added to step (1) and reused as reaction water.

[0024] In the above method for extracting metallic lithium from lithium-containing glass powder, preferably, the lithium carbonate solid is subjected to flash drying, air flow crushing, and demagnetization processing to obtain an industrial-grade lithium carbonate product.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] (1) The present invention uses hydrochloric acid and aluminum hydroxide to leach lithium from glass powder, and then removes impurities from the leachate, thereby achieving efficient extraction of metallic lithium from lithium-containing glass powder, with a high recovery rate of metallic lithium and higher technical and economic feasibility. Compared with the traditional process of extracting metallic lithium from glass powder, the present invention does not require high-temperature calcination of the glass powder, has lower energy consumption, generates no hazardous waste in the production process, and the production water can be self-circulated and reused, with excellent environmental benefits.

[0027] (2) The present invention adds hydrochloric acid to the lithium-containing glass powder to dissolve the lithium ions. Since the glass powder is slightly soluble in water, an appropriate amount of aluminum hydroxide is added to reduce the solubility of the glass powder by utilizing the common ion effect without affecting the solubility of other water-soluble salts, which is beneficial to improving the efficiency of subsequent processes and the yield of the final product.

[0028] (3) The present invention utilizes the fact that the lattice of glass powder is more complete and stable than that of lithium ore to achieve the Li + , K + Al in aluminum hydroxide 3+ Exchange and reconstruct into new particles, Li + , K +It enters the water to form potassium chloride and lithium chloride aqueous solutions, which is beneficial to the leaching of metallic lithium.

[0029] (4) The present invention can achieve the best insulation effect by filling the acid leaching tank underground, and directly adding steam to heat the acid leaching liquid can achieve uniform heating, reduce heat loss, and ensure production safety and environmental protection.

[0030] (5) The present invention uses an ultrafiltration membrane to remove impurities from the lithium-containing solution, which can reduce the concentrations of calcium, magnesium, aluminum, and iron ions in the lithium-containing solution to below 0.59 ppm, thereby ensuring the purity of the subsequently prepared lithium carbonate.

[0031] (6) The process of the present invention is suitable for large-scale industrial application. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the preferred embodiments of the specification, but the protection scope of the present invention is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0034] Unless otherwise specified, all reagents and raw materials used in the present invention are commercially available products or products that can be prepared by known methods.

[0035] Embodiment 1:

[0036] In this embodiment, the lithium-containing glass powder to be processed is waste mobile phone glass powder, and its main components include 66% by mass of silicon dioxide, 18% of sodium oxide and 3% of lithium oxide.

[0037] The method for extracting metallic lithium from lithium-containing glass powder in this embodiment comprises the following steps:

[0038] (1) 40.6 tons of waste mobile phone glass was ground using a Raymond grinder to obtain about 40 tons of 120-mesh lithium-containing glass powder. The processing process generated about 600 kg of dust, which was collected by a bag filter and exhaust pipe and reused as raw material;

[0039] (2) According to the mass ratio of lithium-containing glass powder to hydrochloric acid with a mass concentration of 31% and aluminum hydroxide of 1:0.6:0.5, 40 tons of lithium-containing glass powder, 24 tons of hydrochloric acid, and 20 tons of aluminum hydroxide were added to 40 m 3 The water was stirred and mixed in the acid leaching tank (filled underground), and reacted at 90°C for 120 minutes (the reaction temperature was controlled by introducing steam), and about 123m3 The solid-liquid mixed reaction product, the dissolved lithium content in the reaction product was determined to be 7.6g / L, and the solid impurity lithium content in the reaction product was 0.1%, which showed that the yield of lithium ions in the acid leaching process was 99.9%; the processing process produced about 2m 3 The waste gas HCL is collected and treated through a spray tower and an exhaust pipe and then added to step (2) as hydrochloric acid for reuse;

[0040] (3) The approximately 123 m 3 The reaction product was separated into solid and liquid by plate and frame filter press and washed with water to obtain about 125m 3 Filtrate and about 12.5 tons of filter residue; the main component of the filtrate is lithium chloride, and the main component of the filter residue is sodium silicate, calcium, magnesium, aluminum and other metal impurities. The filter residue can be reused as raw materials;

[0041] (4) The approximately 125 m 3 2 tons of caustic soda flakes and 120 kg of calcium chloride were added to the filtrate in batches for preliminary impurity removal in a modulation kettle. The reaction temperature was controlled at 30 ° C and the reaction time was 30 min. About 110 m 3 The reaction product and about 12 tons of filter residue, the main component of the reaction product is lithium chloride, the main component of the filter residue is calcium hydroxide, magnesium hydroxide, iron hydroxide, etc., the filter residue can be sold as a by-product after treatment; then the reaction product is finely impurized using an ultrafiltration membrane device to obtain 90m 3 Lithium refined solution and 20m 3 The mass concentration of the wastewater and the lithium refined solution is 7.6 g / L, and the wastewater is directly added as production water to steps (2) and (3) for reuse; the concentrations of calcium, magnesium, aluminum and iron ions in the lithium-containing solution are all less than 0.59 ppm; wherein the ultrafiltration membrane is FTS-DLF-8040 produced by Shanghai Yuanmai Environmental Technology Co., Ltd., which includes, from the water inlet to the water outlet, a 0.2 μm polyamide material ultra-thin separation layer, a 40 μm polysulfone material porous intermediate support layer and a 120 μm polyester material reinforced non-woven fabric layer;

[0042] (5) The approximately 90 m 3 The concentration of 7.6g / L lithium refined liquid is concentrated by MVR concentration device to obtain about 45m 3 The concentration of 16g / L lithium refined solution and about 45m 3 The condensed water is directly added to steps (2) and (3) as production water for reuse;

[0043] (6) The approximately 45 m 37.2 tons of soda ash was added to the lithium refined solution with a concentration of 16 g / L and divided into two batches to carry out lithium precipitation reaction in a reactor. The reaction temperature was 90°C and the reaction time was 30 minutes to obtain about 50 m 3 Lithium carbonate solid-liquid mixture;

[0044] (7) filtering, washing, and solid-liquid separation of the lithium carbonate solid-liquid mixture obtained in step (6) by a centrifuge to obtain about 3.5 tons of lithium carbonate solid and about 30 m 3 The lithium precipitation mother liquor is directly added to step (2) as production water for reuse;

[0045] (8) The 3.5 tons of lithium carbonate obtained in step (7) is flash dried, air flow crushed, and demagnetized by a dryer, an air flow mill, and a demagnetization device to obtain about 3.0 tons of industrial-grade lithium carbonate products with a purity of 99.2%, and about 0.5 tons of water is evaporated and naturally discharged during the drying process.

[0046] After calculation, in this embodiment, the various main raw material consumptions of the lithium carbonate production device with an annual output of 5,000 tons are: sodium carbonate 2.4 t / t, aluminum hydroxide 6.7 t / t, water 187 t / t, electricity 9630 kW·h / t, steam 26.3 t / t, and industrial hydrochloric acid 8 t / t.

[0047] Embodiment 2:

[0048] In this embodiment, the lithium-containing glass powder to be processed is waste mobile phone glass powder, and its main components include 79% by mass of silicon dioxide, 15% of sodium oxide and 3% of lithium oxide.

[0049] The method for extracting metallic lithium from lithium-containing glass powder in this embodiment comprises the following steps:

[0050] (1) 40.6 tons of waste mobile phone glass was ground using a Raymond grinder to obtain about 40 tons of 120-mesh lithium-containing glass powder. The processing process generated about 600 kg of dust, which was collected by a bag filter and exhaust pipe and reused as raw material;

[0051] (2) According to the mass ratio of lithium-containing glass powder to hydrochloric acid with a mass fraction of 31% and aluminum hydroxide of 1:0.6:0.3, 40 tons of lithium-containing glass powder, 24 tons of hydrochloric acid, and 12 tons of aluminum hydroxide were added to 38 m 3 The water was stirred and mixed in the acid leaching tank (filled underground), and reacted at 80°C for 70 minutes (the reaction temperature was controlled by introducing steam) to obtain about 120m 3 The solid-liquid mixed reaction product was measured to have a lithium content of 7.0 g / L. By detecting the solid impurity lithium content in the reaction product, which was 0.18%, it was known that the lithium ion yield in the acid leaching process was 92.1%. The processing process produced about 2 m 3The waste gas and HCL are collected and treated through a spray tower and an exhaust pipe and then added as hydrochloric acid to step (2) for reuse;

[0052] (3) The approximately 120 m 3 The reaction product was separated into solid and liquid by plate and frame filter press and washed with water to obtain about 120m 3 Filtrate and 12 tons of filter residue; the main component of the filtrate is lithium chloride, and the main component of the filter residue is sodium silicate, calcium, magnesium, aluminum and other metal impurities. The filter residue can be reused as raw materials;

[0053] (4) The approximately 120 m 3 2 tons of caustic soda flakes and 120 kg of calcium chloride were added to the filtrate in batches for preliminary impurity removal in a modulation kettle. The reaction temperature was controlled at 40 ° C and the reaction time was 30 min. After filtration, about 110 m 3 The reaction product and about 12.8 tons of filter residue, the main component of the reaction product is lithium chloride, the main component of the filter residue is calcium hydroxide, magnesium hydroxide, iron hydroxide, etc., the filter residue can be sold as a by-product after treatment; then use an ultrafiltration membrane device to finely remove impurities to obtain about 90m 3 Lithium refined solution and 20m 3 The mass concentration of the wastewater and the lithium refined solution is 7.0 g / L, and the wastewater is directly added as production water to steps (2) and (3) for reuse; the concentrations of calcium, magnesium, aluminum and iron ions in the lithium-containing solution are all less than 0.59 ppm; wherein the ultrafiltration membrane is FTS-DLF-8040 produced by Shanghai Yuanmai Environmental Technology Co., Ltd., which includes, from the water inlet to the water outlet, a 0.2 μm polyamide material ultra-thin separation layer, a 40 μm polysulfone material porous intermediate support layer and a 120 μm polyester material reinforced non-woven fabric layer;

[0054] (5) The approximately 90 m 3 The concentration of 7.0g / L lithium refined liquid is concentrated by MVR concentration device to obtain about 43m 3 The concentration of 14.5g / L lithium refined solution and about 47m 3 The condensed water is directly added to steps (2) and (3) as production water for reuse;

[0055] (6) The approximately 43 m 3 The lithium refined solution with a concentration of 14.5g / L was added with 7 tons of soda ash and divided into two batches for lithium precipitation reaction in a reactor. The reaction temperature was 85℃ and the reaction time was 30min. About 48m 3 Lithium carbonate solid-liquid mixture;

[0056] (7) The approximately 48 m 3The solid-liquid mixture of lithium carbonate was filtered, washed, and separated into solid and liquid by a centrifuge to obtain about 3.3 tons of lithium carbonate solid and about 28m 3 The lithium precipitation mother liquor is directly added to step (2) as production water for reuse;

[0057] (8) The approximately 3.3 tons of lithium carbonate obtained in step (7) is flash dried, air flow crushed, and demagnetized by a dryer, an air flow mill, and a demagnetization device to obtain approximately 2.7 tons of industrial-grade lithium carbonate products with a purity of 99.2%. Approximately 0.6 tons of water evaporates and is naturally discharged during the drying process.

[0058] After calculation, in this embodiment, the various main raw material consumptions of the lithium carbonate production device with an annual output of 5,000 tons are: sodium carbonate 2.6 t / t, aluminum hydroxide 4.4 t / t, water 189 t / t, electricity 9605 kW·h / t, steam 25.8 t / t, and industrial hydrochloric acid 8.9 t / t.

[0059] Embodiment 3:

[0060] In this embodiment, the lithium-containing glass powder to be processed is waste mobile phone glass powder, and its main components include 70% by mass of silicon dioxide, 25% of sodium oxide and 3% of lithium oxide.

[0061] The method for extracting metallic lithium from lithium-containing glass powder in this embodiment comprises the following steps:

[0062] (1) 40.6 tons of waste mobile phone glass was ground using a Raymond grinder to obtain about 40 tons of 120-mesh lithium-containing glass powder. The processing process generated about 600 kg of dust, which was collected by a bag filter and exhaust pipe and reused as raw material;

[0063] (2) According to the mass ratio of lithium-containing glass powder to hydrochloric acid with a mass fraction of 31% and aluminum hydroxide of 1:0.6:0.4, 40 tons of lithium-containing glass powder, 24 tons of hydrochloric acid, and 16 tons of aluminum hydroxide were added to 39 m 3 The water was stirred and mixed in an acid leaching tank (filled underground), and reacted at 105°C for 65 minutes (the reaction temperature was controlled by introducing steam) to obtain 122m 3 The solid-liquid mixed reaction product was measured to have a lithium content of 7.3 g / L. The lithium content of the solid impurities in the reaction product was 0.15%, indicating that the lithium ion yield in the acid leaching process was 95.8%. The processing process produced about 2 m 3 The waste gas and HCL are collected and treated through a spray tower and an exhaust pipe and then added as hydrochloric acid to step (2) for reuse;

[0064] (3) The approximately 122 m 3 The reaction product was separated into solid and liquid by plate and frame filter press and washed with water to obtain about 122m3 Filtrate and 12.6 tons of filter residue; the main component of the filtrate is lithium chloride, and the main component of the filter residue is sodium silicate, calcium, magnesium, aluminum and other metal impurities. The filter residue can be reused as raw materials;

[0065] (4) The approximately 120 m 3 2 tons of caustic soda flakes and 120 kg of calcium chloride were added to the filtrate in batches for preliminary impurity removal in a modulation kettle. The reaction temperature was controlled at 40 ° C and the reaction time was 30 min. About 110 m 3 The reaction product and about 11 tons of filter residue, the main component of the reaction product is lithium chloride, the main components of the filter residue are calcium hydroxide, magnesium hydroxide, iron hydroxide, etc., the filter residue can be sold as a by-product after treatment; then use an ultrafiltration membrane device to finely remove impurities to obtain 90m 3 Lithium refined solution and 20m 3 The mass concentration of the wastewater and the lithium refined solution is 7.3 g / L, and the wastewater is directly added as production water to steps (2) and (3) for reuse; the concentrations of calcium, magnesium, aluminum and iron ions in the lithium-containing solution are all less than 0.59 ppm; wherein the ultrafiltration membrane is FTS-DLF-8040 produced by Shanghai Yuanmai Environmental Technology Co., Ltd., which includes, from the water inlet to the water outlet, a 0.2 μm polyamide material ultra-thin separation layer, a 40 μm polysulfone material porous intermediate support layer and a 120 μm polyester material reinforced non-woven fabric layer;

[0066] (5) The approximately 90 m 3 The concentration of 7.3g / L lithium refined liquid is concentrated by MVR concentration device to obtain about 45m 3 The concentration of 14.6g / L lithium refined solution and about 45m 3 The condensed water is directly added to steps (2) and (3) as production water for reuse;

[0067] (6) The approximately 45 m 3 6.8 tons of soda ash were added to the lithium refined solution with a concentration of 14.6 g / L and divided into two batches to carry out lithium precipitation reaction in a reactor at a reaction temperature of 80°C and a reaction time of 30 min to obtain about 49 m 3 Lithium carbonate solid-liquid mixture;

[0068] (7) The approximately 49 m 3 The solid-liquid mixture of lithium carbonate was filtered, washed, and separated into solid and liquid by a centrifuge to obtain about 3.2 tons of lithium carbonate solid and about 29m 3 The lithium precipitation mother liquor is directly added to step (2) as production water for reuse;

[0069] (8) The 3.2 tons of lithium carbonate obtained in step (7) is flash dried, air flow crushed, and demagnetized by a dryer, an air flow mill, and a demagnetization device to obtain about 2.8 tons of industrial-grade lithium carbonate products with a purity of 99.2%. About 0.4 tons of water evaporates and is naturally discharged during the drying process.

[0070] According to calculation, in this embodiment, the main raw material consumption of the lithium carbonate production device with an annual output of 5,000 tons is: sodium carbonate 2.4 t / t, aluminum hydroxide 5.7 t / t, water 189 t / t, electricity 9605 kW·h / t, steam 25.8 t / t, and industrial hydrochloric acid 8.6 t / t.

[0071] In summary, the present invention uses hydrochloric acid and aluminum hydroxide to leach lithium from glass powder, and then removes impurities from the leachate, so as to achieve efficient extraction of metallic lithium from lithium-containing glass powder, with a high recovery rate of metallic lithium and higher technical and economic feasibility. Compared with the traditional process of extracting metallic lithium from glass powder, the present invention does not require high-temperature calcination of the glass powder, has lower energy consumption, generates no hazardous waste in the production process, and the production water can be self-circulated and reused, with excellent environmental benefits, and is particularly suitable for large-scale industrial applications.

[0072] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for extracting metallic lithium from lithium-containing glass powder, characterized in that: The following steps are involved: (1) stirring and mixing lithium-containing glass powder with hydrochloric acid and aluminum hydroxide to react, thereby obtaining a solid-liquid mixed reaction product; wherein the mass ratio of the lithium-containing glass powder to the hydrochloric acid and aluminum hydroxide is 1:(0.2-0.6):(0.2-0.5); (2) separating the reaction product obtained in step (1) into solid and liquid to obtain a filtrate and a filter residue; (3) removing impurities from the filtrate obtained in step (2) to obtain a lithium-containing solution.

2. The method for extracting metallic lithium from lithium-containing glass powder as claimed in claim 1, characterized in that: In step (1), the reaction temperature is 70-105°C, and the reaction time is 60 min-120 min.

3. The method for extracting metallic lithium from lithium-containing glass powder according to claim 2, characterized in that: In step (1), the reaction temperature is controlled by introducing steam.

4. The method for extracting metallic lithium from lithium-containing glass powder according to claim 1, characterized in that: In step (1), the particle size of the lithium-containing glass powder is not less than 100 mesh.

5. The method for extracting metallic lithium from lithium-containing glass powder according to claim 1, characterized in that: In step (2), the filter residue is added to step (1) and mixed with the lithium-containing glass powder, and then recycled as a raw material.

6. The method for extracting metallic lithium from lithium-containing glass powder according to claim 1, characterized in that: The operation of step (1) is carried out in an acid leaching tank which is filled underground.

7. The method for extracting metallic lithium from lithium-containing glass powder according to any one of claims 1 to 6, characterized in that: In step (3), the impurity removal refers to first adding caustic soda and calcium chloride to the filtrate for preliminary impurity removal, and then performing fine impurity removal through an ultrafiltration membrane.

8. The method for extracting metallic lithium from lithium-containing glass powder according to claim 7, characterized in that: Every 100m 3 In the filtrate, the amount of caustic soda added is 1-5t, the amount of calcium chloride added is 0.1-0.4t, the reaction temperature for adding caustic soda and calcium chloride for preliminary impurity removal is 30-60°C, and the reaction time is 10-30min.

9. The method for extracting metallic lithium from lithium-containing glass powder according to claim 7, characterized in that: The ultrafiltration membrane comprises, from the water inlet end to the water outlet end, a 0.1-0.3 μm polyamide material ultrathin separation layer, a 35-45 μm polysulfone material porous intermediate support layer and a 110-130 μm polyester material reinforced non-woven fabric layer.

10. The method for extracting metallic lithium from lithium-containing glass powder according to claim 7, characterized in that: The concentrations of calcium, magnesium, aluminum and iron ions in the lithium-containing solution obtained by removing impurities do not exceed 0.59 ppm.

11. The method for extracting metallic lithium from lithium-containing glass powder according to any one of claims 1 to 6, characterized in that: Soda ash is added to the lithium-containing solution to carry out lithium precipitation reaction, and after the reaction is completed, solid-liquid separation is performed to obtain lithium carbonate solid and lithium precipitation mother liquor.

12. The method for extracting metallic lithium from lithium-containing glass powder according to claim 11, characterized in that: During the lithium precipitation reaction, every 20m 3 When the mass concentration of the lithium-containing solution is 14-16 g / L, the amount of soda ash added is 2-4 t, and the temperature of the lithium precipitation reaction is 75-95°C.

13. The method for extracting metallic lithium from lithium-containing glass powder according to claim 11, characterized in that: The lithium content in the lithium precipitation mother liquor is not higher than 1.5 g / L, and the lithium precipitation mother liquor can be directly added to step (1) for reuse as reaction water.

14. The method for extracting metallic lithium from lithium-containing glass powder according to claim 11, characterized in that: The lithium carbonate solid is flash dried, air flow crushed and demagnetized to obtain an industrial grade lithium carbonate product.