Method for extracting lithium from aluminum lithium alloy scrap

Abstract

Disclosed is a method for extracting lithium from aluminum lithium alloy scrap. The method comprises: using an acid to dissolve aluminum lithium alloy scrap, and then evaporating a mixed solution obtained by means of dissolution, so as to obtain a crystal to be processed; calcining said crystal, so that lithium and other metal elements in said crystal exist in different forms, so as to obtain calcined powder; and performing leaching on the calcined powder to obtain a leaching mixed solution.

Description

Method for extracting lithium from aluminum-lithium alloy waste Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411352650.2, filed September 26, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure 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

[0003] Aluminum-lithium alloy refers to Al-Cu, Al-Mg alloy containing 0.7% to 2.7% lithium. Compared with foreign countries, China started late in the research of aluminum-lithium alloy, but the development is very rapid. The application of deformed aluminum alloy containing lithium is already quite extensive. At the same time, due to the good mechanical properties of aluminum-lithium alloy, it has considerable application prospect in the field of aerospace. With the increasing number of processing waste and scrap parts, more and more attention is paid to how to effectively recycle and reuse aluminum-lithium alloy waste, so that it enters a loop of virtuous cycle economy.

[0004] Lithium is known as "industrial monosodium glutamate" and "energy metal", and 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, and its value is much higher than that of the base aluminum in the alloy. Currently, there are two directions for extracting lithium from aluminum-lithium alloy waste: one is the extraction of pure lithium, which extracts lithium from waste to become pure metal; the other is the compound method, which converts lithium in waste into lithium compounds for extraction. The extraction of pure lithium mainly includes vacuum distillation method, three-layer liquid electrolysis method and fractional solidification method. The compound method is to melt the waste, then pass chlorine gas into the melt, mix it with the melt, and convert lithium into lithium chloride. The above methods have problems such as product easily contaminated by aluminum and magnesium, low product purity, high energy consumption, and low lithium element separation efficiency. Therefore, how to solve the low purity of products and low separation efficiency of lithium elements in the process of extracting lithium from aluminum-lithium alloy waste is a technical problem that needs to be solved. SUMMARY

[0005] The problem of how to improve the separation efficiency of lithium elements extracted from aluminum-lithium alloy waste is solved by using one or more embodiments of the present disclosure.

[0006] The method for extracting lithium from aluminum-lithium alloy waste according to some embodiments of the present disclosure comprises: dissolving aluminum-lithium alloy waste using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolving to obtain a to-be-treated crystal, roasting the to-be-treated crystal to make lithium and other metal elements in the to-be-treated crystal exist in different forms to obtain a roasted powder, and leaching the roasted powder to obtain a leaching mixed solution. BRIEF DESCRIPTION OF DRAWINGS

[0007] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the related art, the accompanying drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0009] FIG. 1 shows a flowchart of a method for extracting lithium from aluminum-lithium alloy waste according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0010] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the protection scope of the present disclosure.

[0011] Various embodiments of the present disclosure can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present disclosure; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has 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, regardless of the range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) within the indicated range.

[0012] In the present disclosure, the orientation words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the present disclosure, the terms "include", "contain" and the like mean "include but not limited to".

[0013] Unless otherwise specifically stated, the various raw materials, reagents, instruments and equipment used in the present disclosure can be purchased on the market or can be prepared by existing methods.

[0014] With the increasing application of aluminum-lithium alloy, the amount of aluminum-lithium alloy waste is also increasing. The content of lithium in aluminum-lithium alloy is low, but lithium is a rare metal and very expensive, so it has the value of extraction. In aluminum-lithium alloy waste, the content of aluminum, magnesium and the like is high, and it is difficult to extract lithium directly. In the conventional separation method, it is difficult to completely separate lithium from aluminum, magnesium and the like, resulting in low separation efficiency of lithium element and low purity of product. Therefore, a method for extracting lithium from aluminum-lithium alloy waste is disclosed.

[0015] Figure 1 shows a flowchart of a method for extracting lithium from aluminum-lithium alloy waste according to some embodiments of the present disclosure. Referring to Figure 1, the method for extracting lithium from aluminum-lithium alloy waste includes:

[0016] S1, using acid to dissolve the aluminum-lithium alloy waste to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal;

[0017] S2, roasting the to-be-processed crystal to make lithium and other metal elements in the to-be-processed crystal exist in different forms, to obtain a roasted powder; and

[0018] S3, leaching the roasted powder to obtain a leaching mixed solution.

[0019] In some embodiments, when the aluminum-lithium alloy waste is dissolved using acid, the acid used includes at least one of hydrochloric acid and sulfuric acid.

[0020] In some embodiments of the present disclosure, when the aluminum-lithium alloy waste is dissolved using acid, hydrochloric acid and / or sulfuric acid can be used to dissolve the aluminum-lithium alloy waste to obtain a mixed solution, so that the metal elements in the aluminum-lithium alloy waste are dissolved in the obtained mixed solution and exist in the form of free ions.

[0021] In some embodiments, when the aluminum-lithium alloy waste is dissolved using acid, the molar concentration of the acid used is 1 mol / L to 9 mol / L.

[0022] In some embodiments, when the aluminum-lithium alloy waste is dissolved using acid, the molar concentration of the acid used is 6 mol / L.

[0023] In some embodiments of the present disclosure, the aluminum-lithium alloy waste needs to be dissolved into a mixed solution with acid; with the increase of the acid concentration, the dissolution amount of the aluminum-lithium alloy waste also increases, and a suitable dissolution amount is conducive to the subsequent separation of lithium and other elements. When the aluminum-lithium alloy waste is dissolved with acid, the molar concentration of the acid used can be 1 mol / L to 9 mol / L, which is conducive to the subsequent separation of lithium and other metal elements, improves the lithium extraction efficiency, and at the same time can control the depth of dissolution, avoid the molar concentration of the acid being too high, the amount of waste material being increased, and the aluminum content in the mixed solution obtained by dissolution being too high to reduce the subsequent lithium extraction rate.

[0024] For example, when the aluminum-lithium alloy waste is dissolved with acid, the molar concentration of the acid used can be 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, etc.; further, the molar concentration of the acid can be 6 mol / L.

[0025] In some embodiments of the present disclosure, when the mixed solution obtained by dissolution is evaporated, the mixed solution obtained by dissolution can be evaporated on an electric furnace, a heating jacket or an electric hot plate, which can evaporate the water and acid in the mixed solution obtained by dissolution completely and prevent the acid from corroding the calcination equipment in the subsequent calcination test.

[0026] In some embodiments, when the to-be-processed crystal is calcined, the process parameters of calcination can include a calcination temperature of 500°C to 850°C and a calcination time of 3.0 h to 6.0 h.

[0027] In some embodiments of the present disclosure, the calcination temperature for calcining the to-be-processed crystal can be 500°C to 850°C, and a suitable calcination temperature can make the aluminum salt, magnesium salt, etc. in the to-be-processed crystal more completely converted into oxides; if the calcination temperature is too high and higher than 850°C, the energy consumption will increase to some extent; if the calcination temperature is too low and lower than 500°C, the aluminum salt, magnesium salt, etc. in the to-be-processed crystal will be difficult to be more completely converted into oxides, which will make the aluminum salt, magnesium salt, etc. leach with lithium in the subsequent leaching process, and reduce the purity of lithium carbonate product.

[0028] In some embodiments of the present disclosure, the calcination time for calcining the to-be-processed crystal can be 3.0 h to 6.0 h, which, in combination with the above-mentioned calcination temperature, can make the aluminum salt, magnesium salt, etc. more completely converted into oxides.

[0029] For example, the calcination temperature for calcining the to-be-processed crystal can be 500°C, 550°C, 600°C, 650°C, 700°C, 800°C, 850°C, etc.; and the calcination time for calcining the to-be-processed crystal can be 3.0 h, 4.0 h, 5.0 h, 6.0 h, etc.

[0030] In some embodiments, when the roasted powder is subjected to leaching, the process parameters of the leaching include: the leaching temperature is 85-100℃, and the leaching time is 2.0-5.0h.

[0031] In some embodiments of the present disclosure, when the roasted powder is subjected to leaching, the leaching temperature of the roasted powder can be 85-100℃, and the leaching time can be 2.0-5.0h. The suitable leaching temperature and leaching time can ensure complete leaching of lithium and ensure the leaching rate of lithium.

[0032] For example, when the roasted powder is subjected to leaching, the leaching temperature can be 85℃, 90℃, 95℃, 100℃, etc. When the roasted powder is subjected to leaching, the leaching time can be 2.0h, 3.0h, 4.0h, 5.0h, etc.

[0033] In some embodiments, the leaching is performed using a leaching agent, and the leaching agent includes water.

[0034] In some embodiments of the present disclosure, when the roasted powder is subjected to leaching, the leaching can be performed using a leaching agent, and the leaching agent used can include water. During the roasting process of the to-be-processed crystals, aluminum salts, magnesium salts, etc. are converted into oxides, which are insoluble in water; and lithium is not oxidized during the roasting process and is a free ion. Therefore, during the leaching process of the roasted powder using water as the leaching agent, since the converted oxides of aluminum salts, magnesium salts, etc. are insoluble in water, and lithium ions are easily soluble in water, lithium ions can be enriched in the obtained leaching mixture through water leaching, so as to achieve the purpose of separation, and the lithium extraction rate is high.

[0035] In some embodiments, when the roasted powder is subjected to leaching, the ratio of the volume V of the leaching agent used to the weight M of the roasted powder can be V:M (2.0-6.0):1, wherein the unit of V is L, and the unit of M is kg.

[0036] In some embodiments of the present disclosure, when the roasted powder is subjected to leaching, the ratio of the volume V of the leaching agent used to the weight M of the roasted powder satisfies V:M (2.0-6.0):1, which can sufficiently separate lithium from aluminum, magnesium, etc.

[0037] For example, when the roasted powder is subjected to leaching, the ratio V:M of the volume V of the leaching agent used 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.

[0038] In some embodiments, the method for extracting lithium from aluminum-lithium alloy waste described above further includes:

[0039] S4, filtering the leaching mixed solution to obtain a lithium leaching solution; and

[0040] S5, precipitating the lithium leaching solution using a carbonate to obtain a lithium carbonate product.

[0041] That is, referring to FIG. 1, the method for extracting lithium from aluminum-lithium alloy waste according to some embodiments of the present disclosure includes:

[0042] S1, dissolving the aluminum-lithium alloy waste using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolving to obtain a to-be-processed crystal;

[0043] S2, roasting the to-be-processed crystal to make lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain a roasted powder;

[0044] S3, leaching the roasted powder to obtain a leaching mixed solution;

[0045] S4, filtering the leaching mixed solution to obtain a lithium leaching solution; and

[0046] S5, precipitating the lithium leaching solution using a carbonate to obtain a lithium carbonate product.

[0047] In some embodiments, when the lithium leaching solution is precipitated using the carbonate, the process parameters of the precipitation include: the precipitation temperature is 70-100°C, the precipitation time is 0.5-3h; and / or the weight of the carbonate is 100%-120% of the theoretical weight required for complete precipitation of lithium ions.

[0048] In some embodiments of the present disclosure, when the leaching mixed solution is filtered, the undissolved substances in the roasted powder can be filtered out, and the filtrate in which lithium ions are dissolved can be separated out to obtain the lithium leaching solution.

[0049] In some embodiments of the present disclosure, when the lithium leaching solution is precipitated using the carbonate, the lithium ions in the lithium leaching solution can be converted into lithium carbonate through a precipitation reaction to precipitate and separate out, and the precipitate is the lithium carbonate product, which has high purity and solves the problem of low purity of the lithium carbonate product in the conventional separation method.

[0050] In some embodiments of the present disclosure, when the lithium leaching solution is precipitated using the carbonate, the precipitation temperature can be 70-100°C, and the precipitation time can be 0.5-3h. The appropriate precipitation reaction temperature and precipitation time can make the precipitation reaction complete and ensure the lithium precipitation rate.

[0051] In some embodiments of the present disclosure, when the lithium leaching solution is precipitated using the carbonate, the weight of the carbonate can be 100%-120% of the theoretical weight required for complete precipitation of lithium ions. The appropriate amount of the carbonate added can make the lithium completely precipitate.

[0052] For example, when using carbonates to precipitate the lithium leaching solution, the precipitation temperature can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc.; when using carbonates to precipitate the lithium leaching solution, the precipitation time can be 0.5h, 1.5h, 2.0h, 2.5h, 3h, etc.; when using carbonates to precipitate the lithium leaching solution, the weight of the carbonates can be 100%, 105%, 110%, 115%, 120%, etc. of the theoretical weight required for complete precipitation of lithium ions. The carbonates can be sodium carbonate, potassium carbonate.

[0053] In some embodiments of the present disclosure, after step S5, the obtained lithium carbonate product can also be subjected to solid-liquid separation and drying.

[0054] The present disclosure will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present disclosure and are not used to limit the scope of the present disclosure. The experimental methods in the following examples, if no specific conditions are specified, are generally determined according to national standards. If there is no corresponding national standard, the international standard, the conventional condition, or the condition recommended by the manufacturer is used.

[0055] The following examples and comparative examples use aluminum-lithium alloy waste recovered from a certain factory, and the properties of the aluminum-lithium alloy waste are shown in Table 1.

[0056] Table 1 Aluminum-lithium alloy waste

[0057] Example 1

[0058] A method for extracting lithium from aluminum-lithium alloy waste includes the following steps: using an acid to dissolve the aluminum-lithium alloy waste to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste is added to 1 L of 6 mol / L hydrochloric acid in batches at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain a to-be-processed crystal; the to-be-processed crystal is calcined to make the lithium in the to-be-processed crystal and other metal elements exist in different forms, to obtain a calcined powder; wherein the calcination temperature is 550°C, and the calcination time is 3.0h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, and the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1; the leaching temperature is 85°C, and the leaching time is 2.5h; the leaching mixed solution is filtered to obtain a lithium leaching solution; carbonates are used to precipitate the lithium leaching solution to obtain a lithium carbonate product; wherein the carbonates are sodium carbonate, the precipitation temperature is 85°C, the precipitation time is 1h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0059] Example 2

[0060] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: dissolving the aluminum-lithium alloy waste material using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined so that lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 600°C and the calcination time is 3.0 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1, the leaching temperature is 85°C, and the leaching time is 2.5 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85°C, the precipitation time is 1 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0061] Example 3

[0062] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: dissolving the aluminum-lithium alloy waste material using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined so that lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 550°C and the calcination time is 3.5 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1, the leaching temperature is 85°C, and the leaching time is 2.5 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85°C, the precipitation time is 1 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0063] Example 4

[0064] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: using an acid to dissolve the aluminum-lithium alloy waste material to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined so that lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 550 DEG C and the calcination time is 3.0 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1, the leaching temperature is 85 DEG C, and the leaching time is 3.0 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85 DEG C, the precipitation time is 1 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0065] Example 5

[0066] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: using an acid to dissolve the aluminum-lithium alloy waste material to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined so that lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 550 DEG C and the calcination time is 3.0 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1, the leaching temperature is 90 DEG C, and the leaching time is 2.5 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 85 DEG C, the precipitation time is 1 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0067] Example 6

[0068] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: using an acid to dissolve the aluminum-lithium alloy waste material to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined to make lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 550 DEG C, and the calcination time is 3.0 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1; the leaching temperature is 95 DEG C, and the leaching time is 2.5 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 80 DEG C, the precipitation time is 1 h, and the amount of sodium carbonate is 110% of the theoretical amount required for complete precipitation of lithium ions.

[0069] Example 7

[0070] A method for extracting lithium from aluminum-lithium alloy waste material, comprising the following steps: using an acid to dissolve the aluminum-lithium alloy waste material to obtain a mixed solution, evaporating the mixed solution obtained by dissolution to obtain a to-be-processed crystal; wherein the acid is 6 mol / L hydrochloric acid, 45 g of aluminum-lithium alloy waste material is added in batches into 1 L of 6 mol / L hydrochloric acid at room temperature for dissolution until complete dissolution; the mixed solution obtained by dissolution is placed in an evaporating dish and evaporated on an electric furnace to obtain the to-be-processed crystal; the to-be-processed crystal is calcined to make lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain calcined powder; wherein the calcination temperature is 550 DEG C, and the calcination time is 3.0 h; the calcined powder is leached to obtain a leaching mixed solution; wherein the leaching agent used for leaching is pure water, the ratio V:M of the volume V of the pure water to the weight M of the calcined powder is 3.0:1; the leaching temperature is 85 DEG C, and the leaching time is 2.5 h; the leaching mixed solution is filtered to obtain a lithium leaching solution; the lithium leaching solution is precipitated using a carbonate, and then is sequentially subjected to suction filtration and drying to obtain lithium carbonate finished product; wherein the carbonate is sodium carbonate, the precipitation temperature is 90 DEG 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.

[0071] Comparative Example 1

[0072] Comparative Example 1 discloses a method for extracting lithium from aluminum-lithium alloy waste material, the raw material and steps of which are different from those of Example 1, wherein the calcination temperature is 400 DEG C, and the leaching time is 1.0 h.

[0073] Comparative Example 2

[0074] Comparative Example 2 discloses a method for extracting lithium from aluminum-lithium alloy waste, the raw materials and steps of which are different from Example 1 in that the leaching temperature is 70℃; the precipitation temperature is 40℃, and the precipitation time is 0.3h.

[0075] The experimental data and experimental results of Examples 1 to 7 and Comparative Examples 1 to 2 are shown in Table 2.

[0076] Table 2 Experimental data and experimental results

[0077] As can be seen from Table 2, the method for extracting lithium from aluminum-lithium alloy waste disclosed in Examples 1 to 7 can achieve a lithium leaching rate of ≥85% and a lithium carbonate product purity of ≥99.2%. As can be seen from the comparison between Example 1 and Comparative Example 1, the calcination temperature when the crystal to be treated is calcined has a greater impact on the purity of the lithium carbonate product. When the calcination temperature is too low, the aluminum chloride is not fully oxidized, and the leaching solution still contains a large amount of aluminum chloride during the leaching process, which fails to achieve the separation purpose. At the same time, due to the short leaching time when the calcined powder is leached, it is difficult to leach lithium. As can be seen from the comparison between Example 1 and Comparative Example 2, the leaching temperature when the calcined powder is leached also affects the lithium leaching rate. A too low leaching temperature will result in a decrease in the lithium leaching rate. At the same time, when the lithium leaching solution is precipitated using a carbonate, a too low precipitation reaction temperature and a too short precipitation reaction time will also reduce the lithium precipitation rate to some extent.

[0078] The one or more technical solutions in the embodiments of the present disclosure have at least the following technical effects or advantages:

[0079] The technical route of “acid dissolution-evaporation calcination-leaching-precipitation” can achieve the extraction of lithium from aluminum-lithium alloy waste, and can obtain a lithium carbonate product with high purity. This method can solve the problem of how to achieve efficient utilization of aluminum-lithium alloy waste, improve the separation efficiency of lithium elements from aluminum-lithium alloy waste, and achieve greater economic and social benefits.

[0080] By dissolving the elements in the aluminum-lithium alloy waste into ions through acid, converting aluminum salts and magnesium salts into oxides through calcination, and leaching lithium into leaching agents such as water through leaching, the purpose of extracting lithium is achieved. This method is simple to operate, has a short process, and has a high lithium extraction rate, solving the problem of low lithium extraction efficiency from aluminum-lithium alloy waste.

[0081] The precipitation reaction can obtain a lithium carbonate product with high purity, solving the problem of low purity of lithium carbonate products in conventional separation methods.

[0082] The method for extracting lithium from aluminum-lithium alloy waste material according to some embodiments of the present disclosure has the following advantages compared with the related art:

[0083] The method for extracting lithium from aluminum-lithium alloy waste material according to some embodiments of the present disclosure includes: dissolving the aluminum-lithium alloy waste material using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolving to obtain a to-be-processed crystal, roasting the to-be-processed crystal to make lithium and other metal elements in the to-be-processed crystal exist in different forms, and obtaining a roasted powder; and leaching the roasted powder to obtain a leaching mixed solution. The acid is used to dissolve each metal element in the aluminum-lithium alloy waste material into ions; the to-be-processed crystal obtained by evaporating the mixed solution obtained by dissolving is roasted to convert aluminum salt, magnesium salt, etc. in the to-be-processed crystal into oxides, while lithium is not oxidized in the roasting process and is a free ion, so that lithium and other metal elements in the to-be-processed crystal can exist in different forms; and the roasted powder is leached to effectively separate lithium and other metal elements, so that the separation efficiency of lithium elements from the aluminum-lithium alloy waste material can be improved.

[0084] The above only describes specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. 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 disclosure. Therefore, the present disclosure will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for extracting lithium from aluminum-lithium alloy waste, comprising: dissolving aluminum-lithium alloy waste using an acid to obtain a mixed solution, evaporating the mixed solution obtained by dissolving to obtain a to-be-processed crystal; roasting the to-be-processed crystal to make lithium and other metal elements in the to-be-processed crystal exist in different forms to obtain a roasted powder; and, leaching the roasted powder to obtain a leaching mixed solution.

2. The method of claim 1, wherein, The acid comprises at least one of hydrochloric acid and sulfuric acid.

3. The method of claim 1 or 2, wherein, The molar concentration of the acid is 1 mol / L to 9 mol / L.

4. The method of claim 3, wherein, The molar concentration of the acid is 6 mol / L.

5. The method of claim 1, wherein, The process parameters of the roasting include a roasting temperature of 500 ℃ to 850 ℃ and a roasting time of 3.0 h to 6.0 h.

6. The method of claim 1, wherein, The process parameters of the leaching include a leaching temperature of 85 ℃ to 100 ℃ and a leaching time of 2.0 h to 5.0 h.

7. The method according to any one of claims 1 to 6, wherein, The leaching is performed using a leaching agent, and the leaching agent comprises water.

8. The method of claim 7, wherein, The ratio of the volume V of the leaching agent to the weight M of the roasted powder satisfies V: M = (2.0-6.0): 1, wherein the unit of V is L and the unit of M is kg. 9.The method of claim 1, further comprising: filtering the leaching mixed solution to obtain a lithium leaching solution; and, precipitating the lithium leaching solution using a carbonate to obtain a lithium carbonate product.

10. The method of claim 9, wherein, The process parameters of the precipitation include a precipitation temperature of 70 ℃ to 100 ℃ and a precipitation time of 0.5 h to 3 h; 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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