Method for preferentially extracting lithium from waste lithium-containing material

Abstract

The invention provides a method for preferentially extracting lithium from a waste lithium-containing material, and relates to the field of battery recovery. Mixing the waste lithium-containing material with a lead-containing compound, and roasting to obtain roasted sand; carrying out water leaching on the roasted product, and carrying out solid-liquid separation to obtain lithium-rich water leaching liquid and water leaching residues; the water leaching residues are subjected to acid leaching and liquid-solid separation, and acid leaching residues and acid leaching liquid are obtained; the waste lithium-containing material comprises black powder and / or positive electrode powder; the lead-containing compound comprises lead sulfate and / or lead sulfide. A lead-containing compound is added into a waste lithium-containing material for roasting-water leaching, the leaching rate of lithium can be 99% or above, nickel / cobalt / manganese near-zero leaching can be achieved, the production cost of lithium extraction is reduced, and efficient extraction of lithium is achieved; the leaching rate of nickel / cobalt / manganese is 99% or above only by performing simple acid leaching on the water leaching residues, and lead is nearly zero leaching and exists in the acid leaching residues in the form of lead sulfate.

Description

Technical Field

[0001] The present application relates to the field of battery recycling, and in particular to a method for preferentially extracting lithium from waste lithium-containing materials. Background Art

[0002] There are many methods for treating black powder from waste lithium batteries. These methods are primarily categorized as pre-extraction and post-extraction processes, depending on the order in which lithium is extracted. While post-extraction processes are adopted by many companies due to their proven and reliable process, pre-extraction processes are favored by many researchers due to their shorter process steps and lower production costs. Consequently, a series of process technologies have been developed, such as sulfuric acid roasting, carbothermal reduction, and sulfate roasting. While these technologies can achieve selective lithium extraction, they also present challenges such as high reagent dosages and high post-processing costs. For example, sulfuric acid roasting consumes large amounts of sulfuric acid, leading to equipment corrosion and the generation of large amounts of toxic SO2 gas. Sodium sulfate roasting, on the other hand, results in a lithium-containing solution containing a large amount of sodium sulfate in the water leaching process, and requires evaporation and crystallization for recycling, reducing the yield of lithium carbonate and increasing production costs.

[0003] Based on this, there is an urgent need to provide a method for preferentially extracting lithium from positive electrode active materials in waste lithium batteries to solve the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a method for preferentially extracting lithium from waste lithium-containing materials to solve the above problems.

[0005] To achieve the above objectives, the present application provides a recovery method for preferentially extracting lithium from waste lithium-containing materials, comprising: mixing the waste lithium-containing material with the lead-containing compound and roasting them to obtain roasted sand; The calcined sand is subjected to water leaching and solid-liquid separation to obtain lithium-rich water leaching solution and water leaching residue; acid leaching the water leaching residue and performing liquid-solid separation to obtain acid leaching residue and acid leaching liquid; The waste lithium-containing materials include black powder and / or positive electrode powder; The lead-containing compound includes lead sulfate and / or lead sulfide.

[0006] The method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The mass ratio of the lead-containing compound to the waste lithium-containing material is 0.5-1.5:1; B. When the lead-containing compound comprises lead sulfide, the calcination should be carried out in an oxygen-containing atmosphere. Optionally, the calcination temperature is 300° C. to 900° C. and the calcination time is 1 hour to 6 hours.

[0007] Optionally, the particle size of the roasted sand is greater than or equal to 200 mesh.

[0008] Optionally, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The liquid-to-solid ratio of the water immersion is 2mL-10mL:1g; B. The pH value of the water immersion is 6-8. Optionally, the water immersion temperature is room temperature and the time is 0.5-3 hours.

[0009] Optionally, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The liquid-to-solid ratio of the acid leaching is 3 mL-7 mL: 1 g; B. The pH value of the acid leaching is ≤2.

[0010] Optionally, the acid leaching temperature is 30° C.-90° C., and the time is 1 h-6 h.

[0011] Optionally, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The acid in the acid leaching is 1.05 to 2 times the theoretical amount of metal in the water leaching residue; B. The acid includes sulfuric acid.

[0012] Optionally, the acid leaching residue is returned for roasting.

[0013] Compared with the prior art, the advantages of this application include: The present application provides a method for preferentially extracting lithium from waste lithium-containing materials. By adding lead sulfate / lead sulfide to the waste lithium-containing materials for roasting and water leaching, a lithium leaching rate of more than 99% and near-zero leaching of nickel / cobalt / manganese can be achieved, thereby reducing the production cost of lithium extraction and achieving efficient lithium extraction. The water-leached residue only needs to be subjected to simple acid leaching to achieve a leaching rate of more than 99% for nickel / cobalt / manganese, and near-zero leaching of lead, which exists in the form of lead sulfate in the acid leaching residue. Lead sulfate / lead sulfide is used as a roasting additive, and through the main process of "roasting-water leaching-acid leaching", no evaporation and crystallization process is required, further reducing production costs. This method can achieve the purpose of low-cost and short-process recovery and disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0015] Figure 1 is the Gibbs free energy curve of the reaction between nickel / cobalt / manganese / lithium oxide and lead sulfate; Figure 2is the Gibbs free energy curve of the reaction between nickel / cobalt / manganese / lithium oxide and lead sulfide; Figure 3 This is a flow chart of a recovery method for preferentially extracting lithium from waste lithium-containing materials provided in Example 1. DETAILED DESCRIPTION

[0016] As used herein: "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0017] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0018] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0019] In these examples, parts and percentages are by mass unless otherwise indicated.

[0020] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. For example, if we say that the parts by mass of component A are a parts and the parts by mass of component B are b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.

[0021] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0022] The present application provides a recovery method for preferentially extracting lithium from waste lithium-containing materials, comprising: mixing the waste lithium-containing material with the lead-containing compound and roasting them to obtain roasted sand; It should be noted that the sources of lead-containing compounds include but are not limited to secondary resources such as waste lead-acid batteries, lithopone production slag, zinc smelting waste slag, electrolytic manganese anode mud, and purchased crude or analytically pure raw materials, as well as acid leaching residue obtained according to the scheme of this application; The calcined sand is subjected to water leaching and solid-liquid separation to obtain lithium-rich water leaching solution and water leaching residue; It should be noted that the lithium-containing materials in the black powder or positive electrode powder in the waste lithium-containing materials are basically layered structures, specifically hexagonal crystal structures. It can be understood that nickel / cobalt / manganese oxide and lithium oxide form a two-dimensional plane. The reaction during the roasting process of black powder and lead sulfate is mainly the reaction of the positive electrode active materials nickel / cobalt / manganese / lithium oxide with lead sulfate. The reaction equation and Gibbs free energy are as follows: (a)NiO + PbSO4 = NiSO4 + PbO; (b) CoO + PbSO4 = CoSO4 + PbO; (c)MnO + PbSO4 = MnSO4 + PbO; (d)Li2O + PbSO4= Li2SO4+ PbO; The standard Gibbs free energy curve of the above reaction is as follows Figure 1 As shown, it can be seen that the Gibbs free energy of the standard reaction between lead sulfate and lithium oxide is less than 0, the reaction proceeds spontaneously, and lithium is transformed into water-soluble lithium sulfate. The Gibbs free energy of the reaction between nickel / cobalt / manganese and other oxides and lead sulfate is greater than 0, and they do not participate in the reaction and basically exist in the form of water-insoluble oxides. Lithium can be separated from nickel / cobalt / manganese by water immersion, and lithium can be preferentially extracted. The reaction that occurs during the roasting process of black powder and lead sulfide is mainly the reaction between the positive electrode active materials nickel / cobalt / manganese / lithium oxide and lead sulfide. The reaction equation and Gibbs free energy are as follows: (e)Li2O + PbS + 2O2(g) = PbO + Li2SO4; (f)MnO + PbS + 2O2(g) = PbO + MnSO4; (g)CoO + PbS + 2O2(g) = PbO + CoSO4; (h)NiO + PbS + 2O2(g) = PbO + NiSO4; The standard Gibbs free energy curve of the above reaction is as follows Figure 2 As shown, it can be seen that the standard reaction Gibbs free energy of lead sulfide with lithium oxide / nickel oxide / cobalt oxide / manganese oxide is less than 0, and the reaction proceeds spontaneously. However, the Gibbs free energy of the reaction of lead sulfide with lithium oxide is generally lower than that of nickel oxide / cobalt oxide / manganese oxide with lithium oxide. This means that even if lead sulfide can react with lithium oxide / nickel oxide / cobalt oxide / manganese oxide, the nickel sulfate / cobalt / manganese sulfate generated in the final process can continue to react with lithium oxide to form lithium sulfate (easily soluble in water) and nickel / cobalt / manganese oxide (insoluble in water). Lithium can be separated from nickel / cobalt / manganese oxide by water leaching, achieving the preferential extraction of lithium. acid leaching the water leaching residue and performing liquid-solid separation to obtain acid leaching residue and acid leaching liquid; It should be noted that the main chemical reactions that occur during the acid leaching process are as follows: NiO+H2SO4=NiSO4+H2O; CoO+H2SO4=CoSO4+H2O; MnO+H2SO4=MnSO4+H2O; PbO+H2SO4=PbSO4↓+H2O; During the acid leaching process, nickel, cobalt and manganese all enter the acid leaching solution in the form of soluble sulfates, while lead exists in the acid leaching residue in the form of insoluble lead sulfate, thereby achieving the separation of lead from nickel, cobalt and manganese. The acid leaching residue does not need to be dried and can be directly returned to the roasting stage to react with the lithium in the black powder again to achieve the recycling of lead sulfate. Compared with other sulfates, if nickel sulfate / cobalt sulfate is used, after roasting and water leaching, the added nickel, cobalt and other metals enter the water leaching residue in the form of metal oxides. After acid leaching, a mixed acid leaching solution of nickel, cobalt and manganese sulfate is obtained. If you want to make nickel sulfate / cobalt sulfate To recycle cobalt acid, the acid leaching solution must go through the main processes of "impurity removal - extraction and impurity removal - extraction separation - evaporation and crystallization" before it can be obtained. If it is not recycled, a large amount of nickel sulfate / cobalt sulfate must be purchased, which is costly. If sodium sulfate is used, after roasting and water leaching, sodium will enter the water leaching solution together with lithium, often resulting in a high sodium-lithium ratio of more than 10:1. When preparing lithium carbonate, sodium carbonate will be added to precipitate lithium, resulting in a serious excess of sodium in the system, and even saturation of sodium sulfate solubility and spontaneous crystallization, which seriously affects production and causes lithium loss due to entrainment with sodium sulfate. The waste lithium-containing materials include black powder and / or positive electrode powder; It should be noted that black powder is obtained by discharging, disassembling, crushing and separating the battery pack. The positive electrode powder mainly comes from unqualified products produced in the production process of positive electrode materials, mainly positive electrode active materials. Battery pack types include but are not limited to nickel-cobalt-manganese ternary lithium batteries, nickel-cobalt-aluminum ternary lithium batteries, nickel / cobalt / manganese single or dual lithium batteries, etc. The lead-containing compound includes lead sulfate and / or lead sulfide.

[0023] It should be noted that sources of lead sulfide include, but are not limited to, galena or analytically pure raw materials; It should also be noted that the introduced lead sulfide will generate a large amount of heat during the oxidation process, reducing the supply of heat source required for the reaction process and further reducing costs. If lead sulfate and lead sulfide are introduced at the same time, a mutual reaction will occur to produce sulfur dioxide and metallic lead. The sulfur dioxide reacts with the lithium oxide in the black powder to produce lithium sulfate, while nickel / cobalt / manganese still exist in the form of oxides or metals. The method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The mass ratio of the lead-containing compound to the waste lithium-containing material is 0.5-1.5:1; Optionally, the mass ratio of the lead-containing compound to the waste lithium-containing material can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1 or any value between 0.5 and 1.5:1; B. When the lead-containing compound comprises lead sulfide, the calcination needs to be carried out in an oxygen-containing atmosphere.

[0024] In some embodiments, the calcination temperature is 300° C.-900° C., and the calcination time is 1 h-6 h.

[0025] It should be noted that within this temperature range, the destruction of the black powder layered structure and the full transformation of lithium can be achieved, which is beneficial to the selective extraction of lithium in the subsequent water leaching process.

[0026] In some embodiments, the particle size of the roasted sand is greater than or equal to 200 mesh.

[0027] It should be noted that at this particle size, the roasted sand is in full contact with water, and the lithium leaching effect will not be reduced due to the coating.

[0028] In some embodiments, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The liquid-to-solid ratio of the water immersion is 2mL-10mL:1g; Optionally, the liquid-to-solid ratio of the water immersion may be 2 mL:1 g, 3 mL:1 g, 4 mL:1 g, 5 mL:1 g, 6 mL:1 g, 7 mL:1 g, 8 mL:1 g, 9 mL:1 g, 10 mL:1 g, or any value between 2 mL and 10 mL:1 g; B. The pH value of the water soak is 6-8.

[0029] Optionally, the pH value of the water soak can be 6, 6.5, 7, 7.5, 8 or any value between 6 and 8.

[0030] It should be noted that the pH during the leaching process should not be too low, otherwise nickel, cobalt, and manganese will enter the leaching solution together with lithium, affecting the selective leaching effect of lithium. In some embodiments, the leaching temperature is room temperature and the time is 0.5-3 hours.

[0031] Optionally, the immersion time can be 0.5h, 1h, 2h, 3h or any value between 0.5h and 3h.

[0032] In some embodiments, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The liquid-to-solid ratio of the acid leaching is 3 mL-7 mL: 1 g; Optionally, the liquid-to-solid ratio of the acid leaching may be 3 mL:1 g, 4 mL:1 g, 5 mL:1 g, 6 mL:1 g, 7 mL:1 g, or any value between 3 mL and 7 mL:1 g; B. The pH value of the acid leaching is ≤2.

[0033] It should be noted that under this condition, efficient leaching of nickel, cobalt and manganese can be achieved, and lead will exist in the acid leaching residue in the form of lead sulfate, realizing effective separation of lead from nickel, cobalt and manganese.

[0034] In some embodiments, the acid leaching temperature is 30° C.-90° C., and the time is 1 h-6 h.

[0035] Optionally, the acid leaching temperature can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or any value between 30°C and 90°C, and the time can be 1h, 2h, 3h, 4h, 5h, 6h or any value between 1h and 6h.

[0036] In some embodiments, the method for preferentially extracting lithium from waste lithium-containing materials satisfies at least one of the following conditions: A. The acid in the acid leaching is 1.05 to 2 times the theoretical amount of metal in the water leaching residue; Optionally, the acid in the acid leaching may be 1.05 times, 1.1 times, 1.5 times, 2 times, or any value between 1.05 times and 2 times the theoretical amount of metal in the water leaching residue; B. The acid includes sulfuric acid.

[0037] In some embodiments, the acid leaching residue is returned for the roasting.

[0038] It should be noted that the acid leaching residue obtained in this application contains a large amount of lead sulfate, which can be recycled for roasting to achieve the recycling of lead.

[0039] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0040] Example 1 This embodiment provides a recovery method for preferentially extracting lithium from waste lithium-containing materials, and the specific steps are as follows: S1: Lead sulfate and waste lithium battery black powder are mixed in a mass ratio of 0.8:1 and roasted at a temperature of 500°C for 2 hours to obtain calcine; S2: Finely grinding the calcined sand to a particle size greater than or equal to 200 mesh; S3: The finely ground calcine obtained in step S2 is subjected to water immersion (pH 7.2) at a liquid-to-solid ratio of 3 mL:1 g, at room temperature, for a time of 0.5. After liquid-solid separation, a lithium-rich water leaching solution and water leaching residue are obtained. The water leaching solution is deeply purified to obtain a qualified lithium-containing solution for preparing lithium carbonate to achieve lithium recovery; S4: The water leaching residue is acid-leached with sulfuric acid (pH value is 1.5). The acid in the acid leaching is 1.1 times the theoretical amount of metal in the water leaching residue. The liquid-solid ratio of the acid leaching is 4 mL:1 g. The temperature is 80 ° C. and the time is 2 h. The liquid-solid separation is performed to obtain the acid leaching residue and the acid leaching liquid. The acid leaching residue is returned to S1 step 1 for roasting with black powder, and the acid leaching liquid is used to recover nickel, cobalt and manganese.

[0041] The recovery method for preferentially extracting lithium from waste lithium-containing materials is as follows: Figure 3 shown.

[0042] Example 2 The difference from Example 1 is that the mass ratio of lead sulfate to waste lithium battery black powder is 0.5:1.

[0043] Example 3 The difference from Example 1 is that the mass ratio of lead sulfate to waste lithium battery black powder is 1.5:1.

[0044] Example 4 The difference from Example 1 is that lead sulfate is replaced by lead sulfide, and oxygen is introduced during roasting.

[0045] Comparative Example 1 The difference from Example 1 is that no lead sulfate is added.

[0046] Comparative Example 2 The difference from Example 1 is that lead sulfate is replaced by lead nitrate.

[0047] The results show that it is not just any lead salt that can achieve the effect of lead sulfate.

[0048] Comparative Example 3 The difference from Example 1 is that lead sulfate is replaced by barium sulfate.

[0049] The results show that not just any sulfate can achieve the same effect as lead sulfate / lead sulfide.

[0050] Comparative Example 4 The difference from Example 1 is that the calcination temperature is 200°C.

[0051] Comparative Example 5 The difference from Example 1 is that the calcination temperature is 1000°C.

[0052] Comparative Example 6 The difference from Example 1 is that the pH value of the water immersion is 4.

[0053] Comparative Example 7 The difference from Example 1 is that the pH value of the acid leaching is 3.

[0054] The lithium and nickel, cobalt and manganese recoveries of the above examples and comparative examples were tested, and the specific test results are shown in Table 1.

[0055] Table 1 Test results

[0056] analyze: As can be seen from Table 1, Examples 1 to 4 can all achieve efficient separation of lithium from nickel, cobalt and manganese, and do not affect the efficient leaching of nickel, cobalt and manganese in the subsequent lithium extraction slag; Comparative Examples 1 to 3 show that without adding lead sulfate or adding any lead salt and sulfate, the effect of using lead sulfate / lead sulfide cannot be achieved; in Comparative Example 4, the calcination temperature is too low, and the selectivity for lithium is poor. The main reason is that the temperature is too low and the structural destructiveness of the positive electrode active material is poor, making it difficult to achieve sufficient reaction with the additive; in Comparative Example 5, the calcination temperature is too high, which will cause overburning of the positive electrode active material, resulting in the nickel, cobalt and manganese oxide being reduced to a metallic state or an alloy state by graphite, thereby reducing the leaching rate of lithium / nickel / cobalt / manganese; in Comparative Example 6, the calcination temperature is too high, which will cause overburning of the positive electrode active material, resulting in the nickel, cobalt and manganese oxide being reduced to a metallic state or an alloy state by graphite, thereby reducing the leaching rate of lithium / nickel / cobalt / manganese; in Comparative Example 7, when the amount of acid is too low during the acid leaching process, the leaching rate of nickel, cobalt and manganese will be affected to a certain extent.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0058] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preferentially extracting lithium from waste lithium-containing materials, characterized in that: include: mixing the waste lithium-containing material with the lead-containing compound and roasting them to obtain roasted sand; The calcined sand is subjected to water leaching and solid-liquid separation to obtain lithium-rich water leaching solution and water leaching residue; acid leaching the water leaching residue and performing liquid-solid separation to obtain acid leaching residue and acid leaching liquid; The waste lithium-containing materials include black powder and / or positive electrode powder; The lead-containing compound includes lead sulfate and / or lead sulfide.

2. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: At least one of the following conditions is met: A. The mass ratio of the lead-containing compound to the waste lithium-containing material is 0.5-1.5:1; B. When the lead-containing compound comprises lead sulfide, the calcination needs to be carried out in an oxygen-containing atmosphere.

3. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: The calcination temperature is 300° C.-900° C., and the calcination time is 1 h-6 h.

4. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: The particle size of the calcined sand is greater than or equal to 200 meshes.

5. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: At least one of the following conditions is met: A. The liquid-to-solid ratio of the water immersion is 2mL-10mL:1g; B. The pH value of the water soak is 6-8.

6. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: The water immersion is carried out at room temperature for 0.5-3 hours.

7. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: At least one of the following conditions is met: A. The liquid-to-solid ratio of the acid leaching is 3 mL-7 mL: 1 g; B. The pH value of the acid leaching is ≤2.

8. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: The acid leaching temperature is 30° C.-90° C., and the time is 1 h-6 h.

9. The method for preferentially extracting lithium from waste lithium-containing materials according to claim 1, characterized in that: At least one of the following conditions is met: A. The acid in the acid leaching is 1.05 to 2 times the theoretical amount of metal in the water leaching residue; B. The acid includes sulfuric acid.

10. The method for preferentially extracting lithium from waste lithium-containing materials according to any one of claims 1 to 9, characterized in that: The acid leaching residue is returned for roasting.

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