Method for extracting lithium from aluminum-lithium alloy waste

Abstract

The invention relates to a method for extracting lithium from aluminum-lithium alloy waste, which comprises the following steps: dissolving the aluminum-lithium alloy waste by using acid, and then evaporating the mixed solution obtained by dissolving to obtain a crystal to be treated; roasting the to-be-treated crystal, so that lithium and other metal elements in the to-be-treated crystal exist in different forms, and obtaining roasted powder; and the roasted powder is leached, and a leaching mixed solution is obtained. According to the method, all elements in the aluminum-lithium alloy waste are dissolved into ions through acid, aluminum salt, magnesium salt and the like in the crystals to be treated are converted into oxides through roasting, lithium can be leached into the solution through leaching, the purpose of lithium extraction is achieved, the method is easy to operate, the process is short, the lithium extraction rate is high, and the method is suitable for industrial production. The problem that the efficiency of extracting lithium from the aluminum-lithium alloy waste is low at present is solved.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum alloy waste recycling, and in particular to a method for extracting lithium from aluminum-lithium alloy waste. Background Art

[0002] Aluminum-lithium alloy refers to Al-Cu and Al-Mg alloys containing 0.7% to 2.7% lithium. Compared with foreign countries, my country's research on aluminum-lithium alloys started late, but has developed rapidly. Lithium-containing deformed aluminum alloys have been widely used. At the same time, due to the good mechanical properties of aluminum-lithium alloys, they have considerable application prospects in the aerospace field. As a result, more and more processing waste and scrapped parts are generated, so more and more attention is paid to how to effectively recycle and reuse aluminum-lithium alloy waste so that it can enter a virtuous cycle economy.

[0003] Lithium is known as "industrial MSG" and "energy metal". Lithium and its deep-processing products have a wide range of uses. The lithium content in aluminum-lithium alloy is low, but lithium is a rare light metal and is very expensive. Its value is much higher than the matrix aluminum in the alloy. At present, there are two directions for extracting lithium from aluminum-lithium alloy waste: one is the extraction of pure lithium, which extracts lithium from the waste to make it pure metal; the other is the compound method, in which the lithium extracted from the waste becomes a lithium compound. The extraction of pure lithium mainly includes vacuum distillation, three-layer liquid electrolysis, and graded solidification. The compound method is to melt the waste, then pass chlorine into the melt to mix it with the melt, and convert lithium into lithium chloride. The above methods have the problems of products being easily contaminated by aluminum and magnesium, low product purity, high energy consumption, and low lithium element separation efficiency. Therefore, how to provide a method for extracting lithium from aluminum-lithium alloy waste to solve the problems of low product purity and low lithium element separation efficiency in the process of extracting lithium from aluminum-lithium alloy waste is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a method for extracting lithium from aluminum-lithium alloy waste to solve the following technical problem: how to improve the separation efficiency of lithium elements from aluminum-lithium alloy waste.

[0005] In a first aspect, the present application provides a method for extracting lithium from aluminum-lithium alloy waste, the method comprising:

[0006] Using acid to dissolve aluminum-lithium alloy waste, and then evaporating the dissolved mixed solution to obtain crystals to be processed;

[0007] calcining the crystal to be processed so that lithium and other metal elements in the crystal to be processed exist in different forms, thereby obtaining a calcined powder;

[0008] The roasted powder is leached to obtain a leached mixed solution.

[0009] Optionally, the acid includes at least one of the following: hydrochloric acid and sulfuric acid.

[0010] Optionally, the molar concentration of the acid is 1 mol / L to 9 mol / L.

[0011] Optionally, the molar concentration of the acid is 6 mol / L.

[0012] Optionally, the calcination process parameters include: a calcination temperature of 500° C. to 850° C., and a calcination time of 3.0 h to 6.0 h.

[0013] Optionally, the leaching process parameters include: a leaching temperature of 85°C to 100°C, and a leaching time of 2.0h to 5.0h.

[0014] Optionally, the leaching is performed using a leaching agent, the leaching agent comprising water.

[0015] Optionally, the ratio V:M of the volume V of the leaching agent to the weight M of the roasted powder is (2.0-6.0):1, wherein the unit of V is L and the unit of M is kg.

[0016] Optionally, the method further includes:

[0017] Filtering the leached mixed solution to obtain a lithium leaching solution;

[0018] The lithium leaching solution is precipitated using carbonate to obtain a lithium carbonate product.

[0019] Optionally, the process parameters of the precipitation include: a precipitation temperature of 70° C. to 100° C., a precipitation time of 0.5 h to 3 h; and / or,

[0020] The weight of the carbonate is 100% to 120% of the theoretical weight required for complete precipitation of lithium ions.

[0021] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0022] The method for extracting lithium from aluminum-lithium alloy waste provided in the embodiment of the present application comprises: using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; roasting the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms to obtain a roasted powder; leaching the roasted powder to obtain a leached mixed solution. Using an acid to dissolve each metal element in the aluminum-lithium alloy waste into ions; evaporating the mixed solution obtained by the dissolution to obtain the crystal to be processed, and roasting to convert the aluminum salt, magnesium salt, etc. in the crystal to be processed into oxides, while lithium is not oxidized during the roasting process and is a free ion, so that the lithium and other metal elements in the crystal to be processed exist in different forms; leaching the roasted powder to achieve effective separation of lithium and other metal elements, thereby improving the separation efficiency of lithium elements from aluminum-lithium alloy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 A schematic flow chart of a method for extracting lithium from aluminum-lithium alloy waste provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0028] In this application, unless otherwise specified, directional words such as "upper" and "lower" used refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of this application, the terms "include", "comprise", etc. mean "including but not limited to".

[0029] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0030] As the application of aluminum-lithium alloys becomes more and more widespread, the amount of aluminum-lithium alloy waste is also increasing. The lithium content in aluminum-lithium alloys is low, but lithium, as a rare metal, is very expensive and has value for extraction. In aluminum-lithium alloy waste, the content of aluminum, magnesium, etc. is high, and it is difficult to directly extract lithium. In conventional separation methods, it is difficult to completely separate lithium from aluminum, magnesium, etc., resulting in low lithium element separation efficiency, low product purity and other problems. Therefore, in the first aspect, the present application provides a method for extracting lithium from aluminum-lithium alloy waste. Figure 1 A schematic diagram of a method for extracting lithium from aluminum-lithium alloy waste provided in an embodiment of the present application; see Figure 1 , the method comprising:

[0031] S1, using acid to dissolve aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain crystals to be processed;

[0032] In some embodiments, the acid comprises at least one of: hydrochloric acid, sulfuric acid.

[0033] In the embodiment of the present application, hydrochloric acid or sulfuric acid may be used to dissolve the aluminum-lithium alloy waste, so that the metal elements in the aluminum-lithium alloy waste exist in the form of free ions in the dissolved mixed solution.

[0034] In some embodiments, the molar concentration of the acid is 1 mol / L to 9 mol / L.

[0035] In some embodiments, the molar concentration of the acid is 6 mol / L.

[0036] In the embodiment of the present application, the aluminum-lithium alloy waste needs to be dissolved into a solution with acid; as the acid concentration increases, the amount of aluminum-lithium alloy waste that can be dissolved increases, and the appropriate amount of dissolution is conducive to the subsequent separation of lithium from other elements. The molar concentration of the acid can be 1mol / L~9mol / L, which is conducive to the subsequent separation of lithium and other metal elements, improves the efficiency of lithium extraction, and can also regulate the depth of dissolution to avoid excessive molar concentration of the acid, increase the amount of dissolved waste, and excessive aluminum content in the dissolved mixed solution, resulting in a decrease in the subsequent lithium extraction rate. Exemplarily, the molar concentration of the acid can be 1mol / L, 2mol / L, 3mol / L, 4mol / L, 5mol / L, 6mol / L, 7mol / L, 8mol / L, 9mol / L, etc.; further, the molar concentration of the acid can be 6mol / L. In addition, the above evaporation can be carried out on an electric furnace, a heating jacket or a hot plate, and the dissolved mixed solution is evaporated, so that the water and acid in the dissolved mixed solution can be completely evaporated, which can prevent the acid from corroding the roasting equipment in the subsequent roasting test.

[0037] S2, calcining the crystal to be processed so that lithium and other metal elements in the crystal to be processed exist in different forms to obtain calcined powder;

[0038] In some embodiments, the calcination process parameters include: a calcination temperature of 500° C. to 850° C., and a calcination time of 3.0 h to 6.0 h.

[0039] In the embodiment of the present application, the roasting temperature of the crystal to be treated can be 500℃~850℃. The appropriate roasting temperature can completely convert the aluminum salt, magnesium salt and the like in the crystal to be treated into oxides; if the roasting temperature is too high and higher than 850℃, it will increase energy consumption to a certain extent; if the roasting temperature is too low and lower than 500℃, it will cause the aluminum salt, magnesium salt and the like in the crystal to be treated to a certain extent. The aluminum salt, magnesium salt and the like in the crystal to be treated are difficult to be completely converted into oxides, and the purity of the lithium carbonate product is reduced with the lithium leaching in the subsequent leaching process. The roasting time of the crystal to be treated can be 3.0h~6.0h, and the above roasting temperature can completely convert the aluminum salt, magnesium salt and the like into oxides. Exemplarily, the above roasting temperature can be 500℃, 550℃, 600℃, 650℃, 700℃, 800℃, 850℃, etc.; the above roasting time can be 3.0h, 4.0h, 5.0h, 6.0h, etc.

[0040] S3, leaching the roasted powder to obtain a leaching mixture.

[0041] In some embodiments, the leaching process parameters include: a leaching temperature of 85° C. to 100° C., and a leaching time of 2.0 h to 5.0 h.

[0042] In the embodiment of the present application, the leaching temperature of the roasted powder can be 85°C to 100°C, and the leaching time can be 2.0h to 5.0h. The appropriate leaching temperature and leaching time can completely leach the lithium and ensure the leaching rate of lithium. For example, the leaching temperature can be 85°C, 90°C, 95°C, 100°C, etc.; the leaching time can be 2.0h, 3.0h, 4.0h, 5.0h, etc.

[0043] In some embodiments, the leaching is performed using a leaching agent, the leaching agent comprising water.

[0044] In an embodiment of the present application, the above-mentioned leaching can be carried out using a leaching agent, which may include water. During the roasting process, aluminum salts, magnesium salts, etc. will be converted into oxides, which are insoluble in water; while lithium is not oxidized during the roasting process and is a free ion. The roasted powder is leached with pure water. Since oxides are insoluble in water, while lithium ions are easily soluble in water, a leaching mixture can be obtained by water leaching, thereby achieving the purpose of separation, and the lithium extraction rate is relatively high.

[0045] In some embodiments, the ratio V:M of the volume V of the leaching agent to the weight M of the roasted powder is (2.0-6.0):1, wherein the unit of V is L and the unit of M is kg.

[0046] In the embodiment of the present application, the ratio V:M of the volume V of the leaching agent to the weight M of the roasted powder can be (2.0-6.0):1, which fully realizes the complete separation of lithium from aluminum, magnesium, etc. Exemplarily, the ratio V:M of the volume V of the above leaching agent to the weight M of the roasted powder can be 2.0:1, 3.0:1, 4.0:1, 5.0:1, 6.0:1, etc.

[0047] In some embodiments, the method further comprises:

[0048] S4, filtering the leached mixed solution to obtain a lithium leaching solution;

[0049] S5. Using carbonate to precipitate the lithium leaching solution to obtain a lithium carbonate product.

[0050] In some embodiments, the process parameters of the precipitation include: precipitation temperature of 70° C. to 100° C., precipitation time of 0.5 h to 3 h; and / or,

[0051] The weight of the carbonate is 100% to 120% of the theoretical weight required for complete precipitation of lithium ions.

[0052] In the embodiment of the present application, the leached mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using carbonate, and a lithium carbonate product can be obtained through a precipitation reaction, and the product purity is high, which solves the problem of low purity of lithium carbonate products in conventional separation methods. The precipitation temperature can be 70°C to 100°C, and the precipitation time can be 0.5h to 3h. The appropriate precipitation reaction temperature and precipitation time can make the precipitation reaction complete and ensure the lithium precipitation rate. The weight of the carbonate can be 100% to 120% of the theoretical weight required for complete precipitation of lithium ions, and the appropriate amount of carbonate added can completely precipitate lithium. Exemplarily, the above precipitation temperature can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc.; the precipitation time can be 0.5h, 1.5h, 2.0h, 2.5h, 3h, etc.; the weight of the carbonate can be 100%, 105%, 110%, 115%, 120%, etc. of the theoretical weight required for complete precipitation of lithium ions. The carbonate may be sodium carbonate or potassium carbonate. After step S5, the lithium carbonate product may be subjected to solid-liquid separation and drying.

[0053] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0054] The following examples and comparative examples are made of aluminum-lithium alloy waste recycled from a certain factory, and the properties of the raw materials are shown in Table 1.

[0055] Table 1 Aluminum-lithium alloy scrap

[0056] element Al Li Mg Cu Content (wt%) 91.6 2.32 5.78 0.0076

[0057] Example 1

[0058] A method for extracting lithium from aluminum-lithium alloy waste comprises the following steps: S11, dissolving the aluminum-lithium alloy waste with an acid, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until the mixture is completely dissolved; the mixed solution obtained by the dissolution is placed in an evaporating dish and evaporated on an electric furnace;

[0059] S21, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.0 h;

[0060] S31, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 2.5h; S41, filtering the leaching mixture to obtain a lithium leaching solution;

[0061] S51. Use carbonate to precipitate the lithium leaching solution to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0062] Example 2

[0063] A method for extracting lithium from aluminum-lithium alloy waste, comprising the following steps: S12, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until it is completely dissolved; the mixed solution obtained by the dissolution is placed in an evaporating dish and evaporated on an electric furnace;

[0064] S22, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 600° C. and the calcination time is 3.0 h;

[0065] S32, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 2.5h; S42, filtering the leaching mixture to obtain a lithium leaching solution;

[0066] S52, using carbonate to precipitate the lithium leaching solution, and then filtering and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0067] Example 3

[0068] A method for extracting lithium from aluminum-lithium alloy waste comprises the following steps: S13, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until the mixture is completely dissolved; placing the mixed solution obtained by the dissolution in an evaporating dish and evaporating it on an electric furnace;

[0069] S23, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.5 h;

[0070] S33, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 2.5h; S43, filtering the leaching mixture to obtain a lithium leaching solution;

[0071] S53, using carbonate to precipitate the lithium leaching solution, and then filtering and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0072] Example 4

[0073] A method for extracting lithium from aluminum-lithium alloy waste, comprising the following steps: S14, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until it is completely dissolved; the mixed solution obtained by the dissolution is placed in an evaporating dish and evaporated on an electric furnace;

[0074] S24, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.0 h;

[0075] S34, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 3.0h; S44, filtering the leaching mixture to obtain a lithium leaching solution;

[0076] S54, using carbonate to precipitate the lithium leaching solution, and then filtering and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0077] Example 5

[0078] A method for extracting lithium from aluminum-lithium alloy waste, comprising the following steps: S15, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until it is completely dissolved; the mixed solution obtained by the dissolution is placed in an evaporating dish and evaporated on an electric furnace;

[0079] S25, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.0 h;

[0080] S35, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 90°C, and the leaching time is 2.5h; S45, filtering the leaching mixture to obtain a lithium leaching solution;

[0081] S55, using carbonate to precipitate the lithium leaching solution, and then filtering and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0082] Example 6

[0083] A method for extracting lithium from aluminum-lithium alloy waste comprises the following steps: S16, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until the mixture is completely dissolved; the mixed solution obtained by the dissolution is placed in an evaporating dish and evaporated on an electric furnace;

[0084] S26, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.0 h;

[0085] S36, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 95°C, and the leaching time is 2.5h; S46, filtering the leaching mixture to obtain a lithium leaching solution;

[0086] S56. Precipitate the lithium leaching solution using carbonate, and then perform suction filtration and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 80° C., the precipitation time is 1 hour, and the amount of sodium carbonate used is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0087] Example 7

[0088] A method for extracting lithium from aluminum-lithium alloy waste comprises the following steps: S17, using an acid to dissolve the aluminum-lithium alloy waste, and then evaporating the mixed solution obtained by the dissolution to obtain a crystal to be processed; wherein the acid is 6 mol / L hydrochloric acid, and at room temperature, 45 g of the aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches for dissolution until the mixture is completely dissolved; placing the mixed solution obtained by the dissolution in an evaporating dish and evaporating it on an electric furnace;

[0089] S27, calcining the crystal to be processed so that the lithium and other metal elements in the crystal to be processed exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550° C. and the calcination time is 3.0 h;

[0090] S37, leaching the roasted powder to obtain a leaching mixture; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume of pure water V to the weight M of the roasted powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 2.5h; S47, filtering the leaching mixture to obtain a lithium leaching solution;

[0091] S57, using carbonate to precipitate the lithium leaching solution, and then filtering and drying in sequence to obtain a lithium carbonate product; wherein the carbonate is sodium carbonate, the precipitation temperature is 90° C., the precipitation time is 0.6 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0092] Comparative Example 1

[0093] The method for extracting lithium from aluminum-lithium alloy waste provided in Comparative Example 1 differs from Example 1 in terms of raw materials and steps in that:

[0094] The roasting temperature is 400°C; the leaching time is 1.0h;

[0095] Comparative Example 2

[0096] The method for extracting lithium from aluminum-lithium alloy waste provided in Comparative Example 2 differs from Example 1 in terms of raw materials and steps in that: the leaching temperature is 70°C; the precipitation temperature is 40°C, and the precipitation time is 0.3h.

[0097] Related experiments and effect data:

[0098] The experimental data and experimental results of Examples 1 to 7 and Comparative Examples 1 and 2 are shown in Table 2.

[0099] Table 2 Experimental data and experimental results

[0100]

[0101] As can be seen from Table 2, Examples 1 to 7 adopt the method for extracting lithium from aluminum-lithium alloy waste provided in the embodiments of the present application, and can all obtain a lithium leaching rate of ≥85%, and a lithium carbonate product purity of ≥99.2%. From the comparison between Example 1 and Comparative Example 1, it can be seen that the roasting temperature has a greater influence on the purity of lithium carbonate. When the roasting temperature is too low, the aluminum chloride is not completely oxidized, and the leachate still contains a large amount of aluminum chloride during the leaching process, and the separation purpose cannot be achieved; and the leaching time is too short, and it is difficult to leach lithium. From the comparison between Example 1 and Comparative Example 2, it can be seen that the leaching temperature affects the lithium leaching rate. If the leaching temperature is too low, the lithium leaching rate will be reduced; and if the precipitation reaction temperature is too low and the precipitation reaction time is too short, the lithium precipitation rate will also be reduced to a certain extent.

[0102] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0103] (1) Through the "acid dissolution-evaporation roasting-leaching-precipitation" technical route, lithium can be extracted from aluminum-lithium alloy waste and a lithium carbonate product with high product purity can be obtained. This method can solve the current problem of efficient utilization of aluminum-lithium alloy waste in China and achieve greater economic and social benefits;

[0104] (2) The elements in the aluminum-lithium alloy waste are dissolved into ions by acid, and aluminum salts, magnesium salts, etc. are converted into oxides by roasting. Then, lithium can be leached into water by leaching to achieve the purpose of lithium extraction. This method is simple to operate, has a short process, and has a high lithium extraction rate, which solves the problem of low lithium extraction efficiency in aluminum-lithium alloy waste.

[0105] (3) This method can obtain a lithium carbonate product through a precipitation reaction, and the product has a high purity, which solves the problem of low purity of the lithium carbonate product in conventional separation methods.

[0106] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for extracting lithium from aluminum-lithium alloy waste, characterized in that: The method comprises: Using acid to dissolve aluminum-lithium alloy waste, and then evaporating the dissolved mixed solution to obtain crystals to be processed; calcining the crystal to be processed so that lithium and other metal elements in the crystal to be processed exist in different forms, thereby obtaining a calcined powder; The roasted powder is leached to obtain a leached mixed solution.

2. The method according to claim 1, characterized in that The acid includes at least one of the following: hydrochloric acid and sulfuric acid.

3. The method according to claim 1 or 2, characterized in that: The molar concentration of the acid is 1 mol / L to 9 mol / L.

4. The method according to claim 3, characterized in that The molar concentration of the acid is 6 mol / L.

5. The method according to claim 1, characterized in that The calcination process parameters include: a calcination temperature of 500° C. to 850° C. and a calcination time of 3.0 h to 6.0 h.

6. The method according to claim 1, characterized in that The leaching process parameters include: leaching temperature of 85° C. to 100° C., and leaching time of 2.0 h to 5.0 h.

7. The method according to claim 1 or 6, characterized in that: The leaching is performed using a leaching agent, which includes water.

8. The method according to claim 7, characterized in that The ratio V:M of the volume V of the leaching agent to the weight M of the roasted powder is (2.0-6.0):1, wherein the unit of V is L and the unit of M is kg.

9. The method according to claim 1, characterized in that: The method further comprises: Filtering the leached mixed solution to obtain a lithium leaching solution; The lithium leaching solution is precipitated using carbonate to obtain a lithium carbonate product.

10. The method according to claim 9, characterized in that The process parameters of the precipitation include: precipitation temperature of 70°C to 100°C, precipitation time of 0.5h to 3h; and / or, The weight of the carbonate is 100% to 120% of the theoretical weight required for complete precipitation of lithium ions.

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