Method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder

Abstract

The invention relates to a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder, which comprises the following steps of: (1) carrying out alkaline leaching on the waste lithium-containing amorphous glass powder, and carrying out solid-liquid separation to obtain leaching residues and leaching liquid; (2) mixing a calcium source with the leaching solution obtained in the step (1), and carrying out aluminum precipitation to obtain an aluminum-precipitated solution; (3) extracting and separating lithium in the liquid after aluminum precipitation in the step (2) to obtain a lithium-rich solution and a silicon-rich mother solution; the lithium-rich solution in the step (3) is used for preparing a lithium product; the silicon-rich mother liquor in the step (3) is used for preparing a silicon product. According to the method, while the lithium compound is recovered, the silicic acid product is obtained by regulating and controlling the segmented precipitation process, the relatively high recovery rate of lithium is ensured, the processing cost of the lithium product is reduced in the whole process, the economic benefit is improved, and large-scale popularization and application in industry are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste recycling, and relates to a method for recycling waste lithium-containing amorphous glass powder, and in particular to a method for comprehensively recycling valuable components in waste lithium-containing amorphous glass powder. Background Art

[0002] Lithium-containing amorphous glass, a derivative form of LAS (Li2O-Al2O3-SiO2) microcrystalline glass, is widely used in electronics, aerospace and other fields due to its unique amorphous structure and chemical stability. This type of material contains approximately 0.1wt% to 5.5wt% Li2O, 20wt% to 30wt% Al2O3 and 60wt% to 70wt% silicon, and is an important secondary resource.

[0003] Currently, the main methods for recovering lithium-containing amorphous glass include acid leaching, alkali fusion, and high-temperature transformation. Acid leaching typically uses inorganic acids such as hydrochloric acid and sulfuric acid to directly dissolve the active components in the glass under mild conditions; alkali fusion utilizes strong bases such as sodium hydroxide to break down the glass network; and high-temperature transformation involves calcination to alter the phase structure and improve subsequent leaching efficiency. Each of these methods has its own advantages, but in industrial production, they generally face challenges such as low lithium recovery rates and difficulty separating aluminum from silicon.

[0004] CN116445735A discloses a method for extracting metallic lithium from waste glass. The method comprises grinding lithium-containing waste glass into glass powder, treating the glass powder with an abrasive, and calcining it in a high-temperature furnace. The processed glass powder is then mixed with an acid solution, exposed to hydrofluoric acid and perchloric acid for a first heat treatment, cooled, and the cooled product is subjected to a second heat treatment by adding water to obtain a glass dissolving solution. The prepared glass dissolving solution is washed and filtered, and lithium carbonate is extracted. The lithium carbonate is washed with a circulating washing solution, and the filtrate is neutralized with sodium hydroxide and then added with lithium carbonate to a constant volume to form a constant solution. The lithium content of the constant solution is measured, and the lithium content of the glass to be tested is determined based on the volume of the constant solution and the measured lithium content. The method employs a mixed acid system of hydrofluoric acid and perchloric acid at 65°C to 85°C to leach lithium-containing glass pretreated by calcination at 500°C to 750°C, achieving a lithium leaching rate of 99.4%. However, the hydrofluoric acid used in this method is highly corrosive and volatile, requiring extremely high corrosion resistance of the equipment. It also poses serious safety hazards and environmental pollution risks, limiting its industrial application.

[0005] Furthermore, when it comes to comprehensive resource utilization, existing technologies often focus on the recovery of lithium alone, while neglecting the synergistic recovery of associated valuable components like aluminum and silicon. Most processes utilize leach residue, primarily SiO2, as waste, failing to fully utilize glass waste. This treatment model not only wastes resources but also reduces the overall economic benefits of the process. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. While recovering lithium compounds, the method obtains silicic acid products by regulating the staged precipitation process and ensures a high lithium recovery rate. The processing cost of lithium products is reduced throughout the entire process, the economic benefits are improved, and it is conducive to large-scale promotion and application in industry.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder, the method comprising the following steps:

[0009] (1) alkali leaching of waste lithium-containing amorphous glass powder, solid-liquid separation, and obtaining leaching residue and leachate;

[0010] (2) mixing a calcium source with the leachate of step (1) to precipitate aluminum to obtain an aluminum-precipitated solution;

[0011] (3) extracting and separating lithium from the aluminum precipitation solution in step (2) to obtain a lithium-rich solution and a silicon-rich mother liquor;

[0012] The lithium-rich solution in step (3) is used to prepare lithium products;

[0013] The silicon-rich mother liquor in step (3) is used to prepare silicon products.

[0014] The method provided by the present invention recovers lithium compounds while obtaining a silicic acid product by regulating the staged precipitation process, and ensures a high recovery rate of lithium. This reduces the processing cost of lithium products throughout the entire process, improves economic benefits, and is conducive to large-scale industrial promotion and application. Among them, alkaline leaching can effectively avoid the large-scale dissolution of aluminum, reduce the pressure of aluminum removal and reduce the entrainment loss of lithium. The extraction separation realizes the selective separation of lithium and elements such as silicon and aluminum. The obtained silicon-rich mother liquor can be used to prepare by-products such as silicon dioxide, greatly increasing the added value of the product.

[0015] Preferably, the alkali leaching in step (1) is carried out using a sodium hydroxide solution with a concentration of 4 mol / L to 12 mol / L.

[0016] Preferably, the liquid-to-solid ratio of the alkali leaching in step (1) is 4:1 to 20:1, and the unit of the liquid-to-solid ratio is mL / g.

[0017] Preferably, the alkali leaching in step (1) is carried out at a temperature of 75° C. to 90° C. and for a time of 2 h to 6 h.

[0018] Preferably, the calcium source in step (2) includes any one of calcium hydroxide, calcium chloride or calcium bicarbonate, or a combination of at least two of them.

[0019] Preferably, the molar ratio of Ca in the calcium source in step (2) to Al in the leachate is 1.05:1 to 1.3:1.

[0020] Preferably, the extraction and separation in step (3) comprises: extracting the aluminum-precipitated liquid in step (2) using a lithium extractant, and stripping the extract with sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor.

[0021] Preferably, the lithium extractant comprises any one of an organophosphorus extractant, a crown ether extractant or an amide extractant, or a combination of at least two of them.

[0022] Preferably, the O / A ratio of the extraction is 1:1 to 3:1.

[0023] Preferably, the extraction temperature is 10°C to 50°C.

[0024] Preferably, the number of extraction stages is at least 3.

[0025] Preferably, the lithium-rich solution in step (3) is reacted with sodium carbonate and washed to obtain a lithium carbonate product.

[0026] Preferably, in step (3), a pH regulator is added to the silicon-rich mother liquor to carry out silicon precipitation reaction, solid-liquid separation, and crude silicic acid is obtained; the crude silicic acid is acid-washed to remove aluminum, washed with water, and pyrolyzed to obtain silicon dioxide.

[0027] Preferably, the pH adjuster includes any one of hydrochloric acid, sulfuric acid or nitric acid, or a combination of at least two of them.

[0028] Preferably, the pH value of the silicon precipitation reaction is 5-7.

[0029] Preferably, the temperature of the silicon precipitation reaction is 20°C to 60°C.

[0030] Preferably, the acid used for pickling and aluminum removal includes hydrochloric acid with a concentration of 2 mol / L to 6 mol / L.

[0031] Preferably, the number of water washings is at least 5 times.

[0032] Preferably, the pulping ratio of the water washing is 3:1 to 5:1.

[0033] Preferably, the pyrolysis temperature is 950°C to 1200°C.

[0034] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The method provided by the present invention recovers lithium compounds while obtaining a silicic acid product by regulating the staged precipitation process, and ensures a high recovery rate of lithium. This reduces the processing cost of lithium products throughout the entire process, improves economic benefits, and is conducive to large-scale industrial promotion and application. Among them, alkaline leaching can effectively avoid the large-scale dissolution of aluminum, reduce the pressure of aluminum removal and reduce the entrainment loss of lithium. The extraction separation realizes the selective separation of lithium and elements such as silicon and aluminum. The obtained silicon-rich mother liquor can be used to prepare by-products such as silicon dioxide, greatly increasing the added value of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a process flow chart of the method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder provided by the present invention. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0039] The present invention provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder, the method comprising the following steps:

[0040] (1) alkali leaching of waste lithium-containing amorphous glass powder, solid-liquid separation, and obtaining leaching residue and leachate;

[0041] (2) mixing a calcium source with the leachate of step (1) to precipitate aluminum to obtain an aluminum-precipitated solution;

[0042] (3) extracting and separating lithium from the aluminum precipitation solution in step (2) to obtain a lithium-rich solution and a silicon-rich mother liquor;

[0043] The lithium-rich solution in step (3) is used to prepare lithium products;

[0044] The silicon-rich mother liquor in step (3) is used to prepare silicon products.

[0045] The method provided by the present invention recovers lithium compounds while obtaining a silicic acid product by regulating the staged precipitation process, and ensures a high recovery rate of lithium. This reduces the processing cost of lithium products throughout the entire process, improves economic benefits, and is conducive to large-scale industrial promotion and application. Among them, alkaline leaching can effectively avoid the large-scale dissolution of aluminum, reduce the pressure of aluminum removal and reduce the entrainment loss of lithium. The extraction separation realizes the selective separation of lithium and elements such as silicon and aluminum. The obtained silicon-rich mother liquor can be used to prepare by-products such as silicon dioxide, greatly increasing the added value of the product.

[0046] In certain embodiments, the alkali leaching in step (1) is performed using a sodium hydroxide solution with a concentration of 4 mol / L to 12 mol / L, for example, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, 11 mol / L or 12 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0047] The present invention uses a sodium hydroxide solution with a concentration of 4 mol / L or more for alkali leaching, which can ensure that the leaching rate of lithium in the waste lithium-containing amorphous glass powder is more than 93%; as the concentration of the sodium hydroxide solution increases, the leaching rates of silicon and aluminum increase accordingly, but excessively high leaching rates of silicon and aluminum are not conducive to the subsequent selective separation of lithium, silicon and aluminum. Therefore, in the preferred embodiment provided by the present invention, the alkali leaching is carried out using a sodium hydroxide solution with a concentration of 4 mol / L to 12 mol / L.

[0048] In certain embodiments, the liquid-to-solid ratio of the alkali leaching in step (1) is 4:1 to 20:1, and the unit of the liquid-to-solid ratio is mL / g, for example, it can be 4:1, 5:1, 6:1, 8:1, 10:1, 12:1, 15:1, 16:1, 18:1 or 20:1, but is not limited to the listed values, and the remaining values ​​within the numerical range not listed are also applicable.

[0049] In certain embodiments, the alkali leaching in step (1) is carried out at a temperature of 75° C. to 90° C. and for a time of 2 h to 6 h.

[0050] The alkali leaching temperature is 75° C. to 90° C., for example, 75° C., 80° C., 85° C. or 90° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] The alkali leaching time is 2 hours to 6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] In certain embodiments, the calcium source in step (2) includes any one or a combination of at least two of calcium hydroxide, calcium chloride or calcium bicarbonate. Typical but non-limiting combinations include a combination of calcium hydroxide and calcium chloride, a combination of calcium chloride and calcium bicarbonate, a combination of calcium hydroxide and calcium bicarbonate, or a combination of calcium hydroxide, calcium chloride and calcium bicarbonate.

[0053] In certain embodiments, the molar ratio of Ca in the calcium source in step (2) to Al in the leachate is 1.05:1 to 1.3:1, for example, 1.05:1, 1.1:1, 1.15:1, 1.2:1, 1.25:1 or 1.3:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0054] The dosage of the calcium source described in the present invention can achieve an ideal aluminum removal rate; when the dosage of the calcium source is too low, the aluminum removal rate in the leachate is low; when the dosage of the calcium source is too high, the residual calcium affects the subsequent extraction and separation, affecting the purity of the lithium product.

[0055] In certain embodiments, the extraction and separation in step (3) includes: extracting the aluminum-precipitated liquid in step (2) using a lithium extractant, and stripping the extract with sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor.

[0056] In certain embodiments, the lithium extractant includes any one of an organophosphorus extractant, a crown ether extractant, or an amide extractant, or a combination of at least two thereof.

[0057] Optionally, the organophosphorus extractant includes di(2-ethylhexyl)phosphoric acid.

[0058] Optionally, the crown ether extractant includes dibenzo-18-crown-6.

[0059] Optionally, the amide extractant includes N,N-dioctylacetamide.

[0060] In certain embodiments, the O / A (Organic / Aqueous Ratio) of the extraction is 1:1 to 3:1, for example, 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0061] The O / A ratio of the present invention is the volume ratio of the organic phase to the aqueous phase. A too high O / A ratio affects production efficiency and increases costs. Therefore, in a preferred embodiment of the present invention, the O / A (Organic / Aqueous Ratio) ratio of the extraction is 1:1 to 3:1.

[0062] In some embodiments, the extraction temperature is 10°C to 50°C, for example, it can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0063] Optionally, the extraction method includes multi-stage countercurrent extraction.

[0064] In some embodiments, the number of extraction stages is at least 3, for example, 3, 4, 5 or 6, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0065] In certain embodiments, the lithium-rich solution in step (3) is reacted with sodium carbonate and washed to obtain a lithium carbonate product.

[0066] Optionally, the washing comprises at least 3 stages of countercurrent water washing.

[0067] In certain embodiments, a pH regulator is added to the silicon-rich mother liquor in step (3) to carry out silicon precipitation reaction, solid-liquid separation, and obtain crude silicic acid; the crude silicic acid is acid-washed to remove aluminum, washed with water, and pyrolyzed to obtain silicon dioxide.

[0068] In certain embodiments, the pH adjuster includes any one of hydrochloric acid, sulfuric acid, or nitric acid, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of hydrochloric acid and sulfuric acid, a combination of sulfuric acid and nitric acid, a combination of hydrochloric acid and nitric acid, or a combination of hydrochloric acid, sulfuric acid, and nitric acid.

[0069] In some embodiments, the pH value of the silicon precipitation reaction is 5 to 7, for example, 5, 5.5, 6, 6.5 or 7, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0070] By controlling the pH value of the silicon precipitation reaction, the aluminum remaining in the aluminum removal process (approximately 30ppm to 50ppm) can be precipitated into the crude silicic acid. At this time, combined with a suitable pickling method, the purity of the obtained silicon dioxide can be improved and the cost of pickling can be reduced.

[0071] In some embodiments, the temperature of the silicon precipitation reaction is 20°C to 60°C, for example, it can be 20°C, 30°C, 40°C, 50°C or 60°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0072] In some embodiments, the acid used for pickling and aluminum removal includes hydrochloric acid with a concentration of 2 mol / L to 6 mol / L, for example, it can be 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L or 6 mol / L, but is not limited to the listed values, and the remaining values ​​not listed within the numerical range are also applicable.

[0073] In certain embodiments, the number of water washings is at least 5 times, for example, 5 times, 6 times, 7 times, 8 times, 9 times, or 10 times, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0074] In certain embodiments, the pulping ratio of the water washing is 3:1 to 5:1, for example, 3:1, 4:1 or 5:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0075] The slurry ratio described in the present invention refers to the mass ratio of water to washed solids.

[0076] In some embodiments, the pyrolysis temperature is 950°C to 1200°C, for example, 950°C, 1000°C, 1050°C, 1100°C, 1150°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0077] In some embodiments, the particle size D50 of the waste lithium-containing amorphous glass powder is 5μm to 100μm, for example, it can be 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 80μm, 90μm or 100μm, but is not limited to the listed values, and the other unlisted values ​​within the numerical range are also applicable.

[0078] In order to clearly illustrate the technical solution of the present invention, the particle size D50 of the waste lithium-containing amorphous glass powder in the following embodiment is 60 μm, and its main components include 4 wt% Li2O, 26 wt% Al2O3, 63 wt% silicon and 3.4 wt% MgO; the above description of the waste lithium-containing amorphous glass powder is not regarded as a further limitation of the technical solution of the present invention.

[0079] Example 1

[0080] This embodiment provides a method for comprehensively recovering valuable components from waste lithium-containing amorphous glass powder. The process flow chart is as follows: Figure 1 As shown, the following steps are included:

[0081] (1) using a sodium hydroxide solution with a concentration of 5 mol / L to alkali-leach the waste lithium-containing amorphous glass powder, separating the solid and the liquid to obtain a leached residue and a leachate;

[0082] The liquid-to-solid ratio of the alkali leaching is 5:1, and the unit of the liquid-to-solid ratio is mL / g;

[0083] The alkali leaching temperature is 90°C and the time is 3h;

[0084] (2) mixing calcium chloride with the leachate of step (1), reacting for 1 hour to precipitate aluminum, and obtaining a post-precipitation aluminum solution and calcium-aluminum slag;

[0085] The molar ratio of Ca in the calcium chloride to Al in the leachate is 1.2:1;

[0086] (3) extracting the aluminum-precipitated solution in step (2) using a lithium extractant (di(2-ethylhexyl)phosphoric acid), and stripping the extract with 4N sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor;

[0087] The extraction was a three-stage countercurrent extraction with an O / A ratio of 2:1 and a temperature of 30°C;

[0088] (4) After the lithium-rich solution reacts with sodium carbonate, it is subjected to three-stage washing to obtain a lithium carbonate product;

[0089] Sulfuric acid is added to the silicon-rich mother liquor to adjust the pH value to 6 for silicon precipitation reaction, and the solution is separated by filtration to obtain crude silicic acid; the crude silicic acid is pickled with 2 mol / L hydrochloric acid to remove aluminum, washed with 5 levels of water (pulping ratio 4:1) and pyrolyzed at 950° C. to obtain a silicon dioxide product.

[0090] Example 2

[0091] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the concentration of the sodium hydroxide solution used in alkali leaching is 8 mol / L, the rest is the same as that in Example 1.

[0092] Example 3

[0093] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the molar ratio of Ca in calcium chloride to Al in the leachate is 1.05:1, the rest is the same as that in Example 1.

[0094] Example 4

[0095] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the O / A ratio of the extraction is 3:1, the rest is the same as that of Example 1.

[0096] Example 5

[0097] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the process for preparing silicon dioxide product from silicon-rich mother liquor is different from that in Example 1, the rest is the same as that in Example 1.

[0098] In this embodiment, sulfuric acid is added to the silicon-rich mother liquor to adjust the pH value to 7 for silicon precipitation reaction, which is filtered and separated to obtain crude silicic acid; the obtained crude silicic acid is pickled with 4 mol / L hydrochloric acid to remove aluminum, washed with 5 levels of water, and pyrolyzed at 950°C to obtain a silicon dioxide product.

[0099] Example 6

[0100] This embodiment provides a method for comprehensively recovering valuable components from waste lithium-containing amorphous glass powder, comprising the following steps:

[0101] (1) using a sodium hydroxide solution with a concentration of 4 mol / L to alkali-leach the waste lithium-containing amorphous glass powder, separating the solid and the liquid to obtain a leached residue and a leachate;

[0102] The liquid-to-solid ratio of the alkali leaching is 4:1, and the unit of the liquid-to-solid ratio is mL / g;

[0103] The alkali leaching temperature is 75°C and the time is 6 hours;

[0104] (2) mixing calcium chloride with the leachate of step (1), reacting for 1 hour to precipitate aluminum, and obtaining a post-precipitation aluminum solution and calcium-aluminum slag;

[0105] The molar ratio of Ca in the calcium chloride to Al in the leachate is 1.05:1;

[0106] (3) extracting the aluminum-precipitated solution in step (2) using a lithium extractant (di(2-ethylhexyl)phosphoric acid), and stripping the extract with 4N sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor;

[0107] The extraction was a three-stage countercurrent extraction with an O / A ratio of 1:1 and a temperature of 50°C;

[0108] (4) After the lithium-rich solution reacts with sodium carbonate, it is subjected to three-stage washing to obtain a lithium carbonate product;

[0109] Sulfuric acid is added to the silicon-rich mother liquor to adjust the pH value to 5 for silicon precipitation reaction, and the solution is separated by filtration to obtain crude silicic acid; the crude silicic acid is pickled with 2 mol / L hydrochloric acid to remove aluminum, washed with 5 levels of water (pulping ratio 3:1) and pyrolyzed at 950° C. to obtain a silicon dioxide product.

[0110] Example 7

[0111] This embodiment provides a method for comprehensively recovering valuable components from waste lithium-containing amorphous glass powder, comprising the following steps:

[0112] (1) using a sodium hydroxide solution with a concentration of 12 mol / L to alkali-leach waste lithium-containing amorphous glass powder, separating the solid and the liquid to obtain leached residue and leachate;

[0113] The liquid-to-solid ratio of the alkali leaching is 20:1, and the unit of the liquid-to-solid ratio is mL / g;

[0114] The alkali leaching temperature is 90°C and the time is 2h;

[0115] (2) mixing calcium chloride with the leachate of step (1), reacting for 1 hour to precipitate aluminum, and obtaining a post-precipitation aluminum solution and calcium-aluminum slag;

[0116] The molar ratio of Ca in the calcium chloride to Al in the leachate is 1.3:1;

[0117] (3) extracting the aluminum-precipitated solution in step (2) using a lithium extractant (di(2-ethylhexyl)phosphoric acid), and stripping the extract with 4N sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor;

[0118] The extraction was a three-stage countercurrent extraction with an O / A ratio of 3:1 and a temperature of 10°C;

[0119] (4) After the lithium-rich solution reacts with sodium carbonate, it is subjected to three-stage washing to obtain a lithium carbonate product;

[0120] Sulfuric acid is added to the silicon-rich mother liquor to adjust the pH value to 6 for silicon precipitation reaction, and filtered to separate to obtain crude silicic acid; the obtained crude silicic acid is pickled with 6 mol / L hydrochloric acid to remove aluminum, washed with 5 levels of water (pulping ratio 5:1) and pyrolyzed at 1200°C to obtain a silicon dioxide product.

[0121] Example 8

[0122] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the molar ratio of Ca in the calcium source to Al in the leachate is 1:1, the rest is the same as that in Example 1.

[0123] Example 9

[0124] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the molar ratio of Ca in the calcium source to Al in the leachate is 1.4:1, the rest is the same as that in Example 1.

[0125] Example 10

[0126] This embodiment provides a method for comprehensively recovering valuable components in waste lithium-containing amorphous glass powder. Except that the concentration of the acid used for pickling to remove aluminum is 1 mol / L, the rest is the same as that of Example 1.

[0127] Characterization

[0128] In the above embodiment, the lithium leaching rate, aluminum leaching rate and silicon leaching rate during alkaline leaching, the aluminum removal rate, lithium loss rate and silicon loss rate during aluminum precipitation, the lithium recovery rate, silicon recovery rate and main content of silicon dioxide in the whole process are shown in Table 1.

[0129] Table 1

[0130]

[0131] As can be seen from Table 1, the present invention uses a sodium hydroxide solution with a concentration of 4 mol / L or more for alkali leaching, which can ensure that the lithium leaching rate in the waste lithium-containing amorphous glass powder is more than 93%; as the concentration of the sodium hydroxide solution increases, the leaching rate of silicon and aluminum increases accordingly, but excessively high silicon and aluminum leaching rates are not conducive to the subsequent selective separation of lithium, silicon and aluminum. Therefore, in the preferred embodiment provided by the present invention, the alkali leaching is carried out using a sodium hydroxide solution with a concentration of 4 mol / L to 12 mol / L;

[0132] The amount of the calcium source used in the present invention can achieve an ideal aluminum removal rate; when the amount of the calcium source is too low, the aluminum leaching rate in the leachate is low; when the amount of the calcium source is too high, the residual calcium affects the subsequent extraction and separation, affecting the purity of the lithium product;

[0133] By controlling the pH value of the silicon precipitation reaction, the aluminum remaining in the aluminum removal process (approximately 30ppm to 50ppm) can be precipitated into the crude silicic acid. At this time, combined with a suitable pickling method, the purity of the obtained silicon dioxide can be improved and the cost of pickling can be reduced.

[0134] In summary, the method provided by the present invention recovers lithium compounds while obtaining a silicic acid product by regulating the staged precipitation process, and ensures a high recovery rate of lithium, thereby reducing the processing cost of lithium products in the entire process, improving economic benefits, and being conducive to large-scale promotion and application in industry; among them, alkaline leaching can effectively avoid the large-scale dissolution of aluminum, reduce the pressure of aluminum removal and reduce the entrainment loss of lithium; extraction separation realizes the selective separation of lithium and elements such as silicon and aluminum, and the obtained silicon-rich mother liquor can be used to prepare by-products such as silicon dioxide, greatly increasing the added value of the product.

[0135] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for comprehensively recovering valuable components from waste lithium-containing amorphous glass powder, characterized in that: The method comprises the following steps: (1) alkali leaching of waste lithium-containing amorphous glass powder, solid-liquid separation, and obtaining leaching residue and leachate; (2) mixing a calcium source with the leachate of step (1) to precipitate aluminum to obtain an aluminum-precipitated solution; (3) extracting and separating lithium from the aluminum precipitation solution in step (2) to obtain a lithium-rich solution and a silicon-rich mother liquor; The lithium-rich solution in step (3) is used to prepare lithium products; The silicon-rich mother liquor in step (3) is used to prepare silicon products.

2. The method according to claim 1, characterized in that The alkali leaching in step (1) is carried out using a sodium hydroxide solution with a concentration of 4 mol / L to 12 mol / L.

3. The method according to claim 1 or 2, characterized in that The liquid-to-solid ratio of the alkali leaching in step (1) is 4:1 to 20:1, and the unit of the liquid-to-solid ratio is mL / g; And / or, the alkali leaching in step (1) is carried out at a temperature of 75° C. to 90° C. and for a time of 2 h to 6 h.

4. The method according to claim 1, wherein The calcium source in step (2) comprises any one of calcium hydroxide, calcium chloride or calcium bicarbonate, or a combination of at least two thereof; And / or, the molar ratio of Ca in the calcium source in step (2) to Al in the leachate is 1.05:1 to 1.3:

1.

5. The method according to claim 1, wherein The extraction and separation in step (3) comprises: extracting the aluminum-precipitated liquid in step (2) with a lithium extractant, and stripping the extract with sulfuric acid to obtain a lithium-rich solution and a silicon-rich mother liquor.

6. The method according to claim 5, characterized in that The lithium extractant includes any one or a combination of at least two of an organophosphorus extractant, a crown ether extractant or an amide extractant; and / or, the O / A ratio of the extraction is 1:1 to 3:1; And / or, the extraction temperature is 10°C to 50°C; And / or, the number of extraction stages is at least 3.

7. The method according to claim 1, characterized in that The lithium-rich solution in step (3) reacts with sodium carbonate and is washed to obtain a lithium carbonate product.

8. The method according to claim 1, characterized in that In step (3), a pH regulator is added to the silicon-rich mother liquor to carry out silicon precipitation reaction, and solid-liquid separation is performed to obtain crude silicic acid; the crude silicic acid is acid-washed to remove aluminum, washed with water, and pyrolyzed to obtain silicon dioxide.

9. The method according to claim 8, characterized in that The pH adjuster includes any one of hydrochloric acid, sulfuric acid or nitric acid, or a combination of at least two thereof; And / or, the pH value of the silicon precipitation reaction is 5 to 7; And / or, the temperature of the silicon precipitation reaction is 20°C to 60°C.

10. The method according to claim 8 or 9, characterized in that The acid used for pickling and aluminum removal includes hydrochloric acid with a concentration of 2mol / L to 6mol / L; And / or, the number of times of washing is at least 5 times; and / or, the pulping ratio of the water washing is 3:1 to 5:1; And / or, the pyrolysis temperature is 950°C to 1200°C.

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