A method for extracting lithium from a lithium-containing ore

Abstract

The present application relates to a kind of methods for extracting lithium from lithium-containing ore.The method for extracting lithium from lithium-containing ore includes the following steps: roasting lithium-containing ore powder, then fast cooling or quenching to room temperature;Solid organic acid is added to the cooled lithium-containing ore powder for mixing grinding;Water is added to the mixed powder after mixing, leaching reaction is carried out, and lithium-containing filtrate is obtained after solid-liquid separation, which is used for the extraction of lithium.The present application solves the problem that the existing inorganic acid is used to extract lithium from lithium ore, which has a great influence on the structure and performance of the ore powder, leading to difficult subsequent processing, and also solves the problems of difficult leaching, large amount of mixing and high cost in the extraction of lithium from lithium ore using organic acid.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium extraction, and in particular to a method for extracting lithium from lithium-containing ores. Background Art

[0002] As a strategic metal, lithium has a wide range of applications in lithium-ion batteries, ceramics, glass, oils and fats, primary aluminum production, polymers, and other fields. With the rapid development of new energy vehicles and the energy storage industry, the demand for lithium is increasing year by year. As a result, lithium resources face serious challenges in terms of sustainable supply. Natural lithium resources are generally divided into three categories: salt lake brines, rocks, and clays. Currently, the world's most mined lithium resources are salt lake brines and lithium-containing ores. Due to the declining grade and high extraction costs of rock-based lithium resources, and the low lithium content and high impurity content of salt lake resources, there is an urgent need to develop low-lithium clay resources to meet the growing demand for lithium and alleviate pressure on lithium supply. Therefore, research on lithium extraction from clay-based lithium-poor ores is of great significance.

[0003] Currently, the main methods for extracting lithium from ores include direct acid leaching, auxiliary roasting, chlorination, and sulfidation. Existing acid leaching processes typically use inorganic acids (such as sulfuric acid) as leaching agents, which have disadvantages such as high acid consumption, severe equipment corrosion, environmental pollution, and high costs. Auxiliary roasting methods involve adding one or more additives during the roasting process to increase the lithium extraction rate, but impurity ions make subsequent purification more difficult. In the chlorination or sulfidation methods, the sample is roasted in an HCl or SO2 atmosphere, and then the chlorinated or sulfated lithium clay sample is subjected to water leaching. In addition to the severe corrosion of the acidic gases on the equipment in the chlorination or sulfidation methods, impurity elements such as calcium and magnesium also enter the solution along with the lithium, making subsequent separation difficult. Weak acids can also be used as leaching agents, but lithium ions are difficult to leach in weak acids and require external activation agents for activation. For lithium extraction from ores with low lithium content, not only does the large amount of weak acid required, making solid waste or waste liquid treatment difficult, but the addition of external activators also makes solid waste or waste liquid treatment even more difficult. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for extracting lithium from lithium-containing ores, so as to solve the problem that the existing method of extracting lithium from lithium ores using inorganic acids has a great impact on the structure and properties of the ore powder, resulting in difficulties in subsequent processing. It can also solve the problems of leaching difficulties, large dosage and high cost in extracting lithium from lithium ores using organic acids.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for extracting lithium from a lithium-containing ore comprises the following steps:

[0007] S1. roasting the lithium-containing ore powder, and rapidly cooling or quenching it to room temperature, wherein rapid cooling refers to cooling at a cooling rate of not less than 2°C / s, and quenching refers to cooling at a cooling rate of not less than 10°C / s;

[0008] S2, adding solid organic acid to the calcined lithium-containing ore powder for mixing and grinding;

[0009] S3. Add water to the mixed powder after mixing and grinding to carry out leaching reaction, and obtain lithium-containing filtrate after solid-liquid separation. The lithium-containing filtrate is used for lithium extraction and organic acid recycling.

[0010] According to the above technical means, by roasting the clay-type associated lithium ore, rapid cooling or quenching is used to put the roasted powder into a metastable state in which some thermal stress cannot be released in time, so that the clay ore powder is effectively activated, creating the necessary conditions for subsequent treatment; solid organic acid is used to mix and grind the roasted ore powder, which effectively promotes the combination of ligands in the solid organic acid with lithium ions in the clay-type lithium ore and the replacement of hydrogen ions with lithium ions. Therefore, the mixing and grinding process effectively promotes the combination of organic acid and lithium ions in clay-type lithium ore, providing a very good prerequisite for lithium leaching, thereby effectively ensuring not only the lithium leaching rate, but also the lithium content in the lithium-containing filtrate. Moreover, since the solution saturation concentration of the selected organic acid at room temperature is relatively low, the organic acid in the lithium-containing filtrate can be subsequently recovered by condensation and the like, effectively reducing the difficulty of subsequent treatment.

[0011] Preferably, the solid organic acid is selected from solid oxalic acid and / or solid tartaric acid.

[0012] Since clay-type lithium ore has an interlayer structure, based on the interlayer domain size of clay minerals, the use of small-molecule solid organic acids and clay-type associated lithium ore for mixing and grinding is more conducive to the organic acid complexing lithium ions. Compared with large-molecule organic acids, small-molecule solid organic acids have a low degree of dissociation and a small relative molecular weight. They have stronger complexing stability with lithium ions per unit mass and are more conducive to lithium leaching. At the same time, the waste liquid treatment of small-molecule organic acids is easier than that of large-molecule organic acids, thereby effectively reducing the process conditions and costs.

[0013] Preferably, in S2, the mass ratio of lithium-containing mineral powder to solid organic acid is 10:1 to 1:2.

[0014] Experiments have shown that when the mass ratio of lithium-containing mineral powder to solid organic acid is lower than 10:1, the mixed system is not acidic enough, and thus a high leaching rate cannot be achieved. When the mass ratio of lithium-containing mineral powder to solid organic acid is higher than 1:2, the leaching rate does not increase much, and there is a problem of excessive acid consumption.

[0015] Preferably, in S3, the mass ratio of the mixed powder to water is 1:1 to 1:5. When lithium is immersed in a solution using water as a medium, if the mass ratio of the mixed powder to water is lower than 1:1, the boundary cannot be uniform during stirring, and if the mass ratio of the mixed powder to water is higher than 1:5, the acidity will be reduced, thereby affecting the leaching effect.

[0016] Preferably, in S1, the calcination temperature is between 300° C. and 700° C., the calcination time is between 5 min and 4 h, and rapid cooling or quenching is performed immediately after calcination.

[0017] Preferably, the calcination time is between 5 minutes and 3.5 hours.

[0018] The purpose of roasting is to activate the clay powder, and rapid cooling or quenching after roasting can further keep the roasted powder in a thermal stress state, thereby making it more active when mixed with solid organic acid.

[0019] Preferably, the leaching temperature is between 60° C. and 120° C., and the leaching time is between 5 minutes and 8 hours.

[0020] Preferably, the leaching time is 5 minutes to 3 hours.

[0021] Preferably, the mixing and grinding temperature is 30° C. to 100° C., and the mixing and grinding time is 10 min to 3 h.

[0022] Preferably, the lithium content in the lithium-containing mineral powder is between 0.1% and 0.6%, and the mesh size of the lithium-containing mineral powder is less than or equal to 180 meshes.

[0023] Preferably, the clay-type associated lithium ore or concentrate containing lithium chlorite.

[0024] Preferably, the leaching rate of the lithium-containing ore powder is above 88%, and the lithium content in the lithium-containing filtrate is above 46 mg / L.

[0025] Preferably, the method further includes: S4, washing the filter residue obtained after solid-liquid separation in S3, wherein the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; and combining the washed filtrate and the lithium-containing filtrate obtained in S3 for lithium extraction and organic acid reuse, thereby achieving recycling.

[0026] Beneficial effects of the present invention:

[0027] The method of extracting lithium from clay-type associated lithium ore of the present invention first activates the clay ore powder by roasting the clay-type associated lithium ore. Even when the mineral undergoes chemical changes, the physical form of the ore powder becomes loose and porous. At the same time, the roasted powder is immediately cooled or quenched to put it in a metastable state where some thermal stress has not been released in time, so that the clay ore powder is further effectively activated, creating necessary conditions for subsequent treatment. Secondly, a solid organic acid is used to mix and grind the roasted ore powder, which effectively promotes the combination of the ligand in the organic acid with the lithium ions in the clay-type lithium ore and the replacement of hydrogen ions with lithium ions. Therefore, the mixing and grinding process effectively promotes the combination of the organic acid with the lithium ions in the clay-type lithium ore. And because clay-type lithium ore has an interlayer structure, the size of the interlayer domain makes it more conducive to the selection of small and medium-molecule organic acids and clay-type associated lithium ore for mixing and grinding, which is more conducive to the complexation of lithium ions by organic acids, and provides a very good prerequisite for the leaching of lithium, thereby effectively ensuring not only the leaching rate of lithium, but also the lithium content in the lithium-containing filtrate; at the same time, because the mixing and grinding process effectively promotes the combination of organic acids and lithium ions in clay-type lithium ore, the amount of solid organic acid used is effectively reduced, and because the solution saturation concentration of the selected organic acid at room temperature is relatively low, the organic acid can be directly recovered by condensation and the like, which reduces the difficulty and cost of subsequent treatment, is suitable for industrial application, and has promotion and application value in the field of lithium extraction technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of the method for extracting lithium from clay-type associated lithium ore of the present invention;

[0029] Figure 2 This is the XRD test result diagram of clay-type associated lithium ore containing lithium chlorite;

[0030] Figure 3 This is an SEM image of clay-type associated lithium ore containing lithium chlorite. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0032] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0033] The clay-type lithium ore or concentrate containing lithium chlorite is a clay-type ore with very low lithium content. The XRD analysis results of the clay-type lithium ore containing lithium chlorite are as follows: Figure 2 As shown, from Figure 2 The analysis shows that its main components are quartz, kaolinite and calcium carbonate, and lithium exists in the form of lithium chlorite. The SEM analysis results of the clay-type associated lithium ore containing lithium chlorite are as follows: Figure 3 As shown, from Figure 3 The analysis shows that the mineral has a layered structure. The XRF analysis results of the clay-type associated lithium ore containing lithium chlorite are shown in Table 1. From the analysis in Table 1, it can be seen that quartz accounts for 59.18%, the content of calcium carbonate is about 6%, and the content of lithium oxide is 0.568%. It is obvious that it is a frame with extremely low lithium content. The proportion of other metal oxides is extremely low, and the total amount does not exceed 7%. The clay-type associated lithium ores in the following examples are all clay-type associated lithium ores containing lithium chlorite.

[0034] Table 1 XRF results of clay-type associated lithium ore containing lithium chlorite

[0035]

[0036] Example 1

[0037] like Figure 1 As shown, a method for extracting lithium from clay-type associated lithium ore comprises the following steps:

[0038] S1, crushing and screening the clay-type associated lithium ore, taking clay-type associated lithium ore powder less than 200 mesh for standby use;

[0039] S2, calcining the clay-type associated lithium ore powder obtained in S1 at 650°C for 2h, and then immediately cooling it to room temperature at a rate of 10°C / s;

[0040] S3, mixing the clay-type associated lithium ore powder obtained by cooling in S2 with oxalic acid in a mass ratio of 3:1 and ball-milling at 50° C. for 30 min to obtain a mixed powder;

[0041] S4, adding water to the mixed powder obtained in S3, wherein the mass ratio of the mixed powder to water is 1:2.5, and then performing a leaching reaction at a temperature of 120° C., and then performing filter press separation to obtain a lithium-containing filtrate and a filter residue;

[0042] S5. The filter residue obtained in S4 is washed with water, and the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling.

[0043] Example 2

[0044] like Figure 1 As shown, a method for extracting lithium from clay-type associated lithium ore comprises the following steps:

[0045] S1, crushing and screening the clay-type associated lithium ore, taking the clay-type associated lithium ore powder less than 200 mesh for standby use;

[0046] S2, calcining the clay-type associated lithium ore powder obtained in S1 at 600°C for 1.5 hours, and then immediately cooling it to room temperature at a rate of 5°C / s;

[0047] S3, mixing the clay-type associated lithium ore powder obtained by cooling in S2 with oxalic acid in a mass ratio of 4:1 and ball-milling at 50° C. for 40 min to obtain a mixed powder;

[0048] S4, adding water to the mixed powder obtained in S3, wherein the mass ratio of the mixed powder to water is 1:2.5, then performing a leaching reaction at a temperature of 100° C., and then performing filter press separation to obtain a lithium-containing filtrate and a filter residue;

[0049] S5. The filter residue obtained in S4 is washed with water, and the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling.

[0050] Example 3

[0051] like Figure 1 As shown, a method for extracting lithium from clay-type associated lithium ore comprises the following steps:

[0052] S1, crushing and screening the clay-type associated lithium ore, taking the clay-type associated lithium ore powder less than 200 mesh for standby use;

[0053] S2, calcining the clay-type associated lithium ore powder obtained in S1 at 500° C. for 2.5 h, and then immediately cooling it to room temperature at a rate of 5° C. / s;

[0054] S3, mixing the clay-type associated lithium ore powder obtained by cooling in S2 with tartaric acid in a mass ratio of 3:1 and ball-milling at 60° C. for 60 min to obtain a mixed powder;

[0055] S4, adding water to the mixed powder obtained in S3, wherein the mass ratio of the mixed powder to water is 1:3, then performing a leaching reaction at a temperature of 90° C., and then performing filter press separation to obtain a lithium-containing filtrate and a filter residue;

[0056] S5. The filter residue obtained in S4 is washed with water, and the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling.

[0057] Example 4

[0058] like Figure 1 As shown, a method for extracting lithium from clay-type associated lithium ore comprises the following steps:

[0059] S1, crushing and screening the clay-type associated lithium ore, taking clay-type associated lithium ore powder less than 200 mesh for standby use;

[0060] S2, calcining the clay-type associated lithium ore powder obtained in S1 at 600°C for 2.5 hours, and then immediately cooling it to room temperature at a rate of 3°C / s;

[0061] S3, mixing the clay-type associated lithium ore powder obtained by cooling in S2 with the solid acid mixture in a mass ratio of 6:1 and ball-milling at 70° C. for 60 min to obtain a mixed powder, wherein the solid acid mixture is a mixture of oxalic acid and tartaric acid in a mass ratio of 3:1;

[0062] S4, adding water to the mixed powder obtained in S3, wherein the mass ratio of the mixed powder to water is 1:2, and then performing a leaching reaction at a temperature of 120° C., and then performing filter press separation to obtain a lithium-containing filtrate and a filter residue;

[0063] S5. The filter residue obtained in S4 is washed with water, and the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling.

[0064] Example 5

[0065] like Figure 1 As shown, a method for extracting lithium from clay-type associated lithium ore comprises the following steps:

[0066] S1, crushing and screening the clay-type associated lithium ore, taking clay-type associated lithium ore powder less than 200 mesh for standby use;

[0067] S2, calcining the clay-type associated lithium ore powder obtained in S1 at 550°C for 2h, and then immediately cooling it to room temperature at a rate of 10°C / s;

[0068] S3, mixing the clay-type associated lithium ore powder obtained by cooling in S2 with oxalic acid in a mass ratio of 6:1 and ball-milling at 60° C. for 50 min to obtain a mixed powder;

[0069] S4, adding water to the mixed powder obtained in S3, wherein the mass ratio of the mixed powder to water is 1:1.5, then performing a leaching reaction at a temperature of 100° C., and then performing filter press separation to obtain a lithium-containing filtrate and a filter residue;

[0070] S5. The filter residue obtained in S4 is washed with water, and the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling.

[0071] Detection and Analysis

[0072] 1) Lithium leaching rate detection

[0073] The lithium-containing filtrates obtained in Examples 1 to 5 were placed in volumetric flasks for constant volume, and then the lithium-containing filtrates after constant volume were diluted to appropriate multiples for atomic absorption testing. The lithium leaching rates obtained in Examples 1 to 5 were 93.15%, 92.63%, 88.24%, 91.67% and 90.23%, respectively.

[0074] 2) Detection of lithium content in lithium-containing filtrate

[0075] The filter residues obtained in Examples 1 to 5 were subjected to ICP testing to infer the lithium content in the lithium-containing filtrate. The lithium contents in the lithium-containing filtrates obtained in Examples 1 to 5 were 2.474 mg / g, 2.461 mg / g, 2.344 mg / g, 2.435 mg / g and 2.397 mg / g, respectively.

[0076] 3) Detection of various contents in lithium-containing filtrate

[0077] The lithium-containing filtrates obtained in Examples 1 to 5 were subjected to ICP full element analysis, and the results are shown in Table 2 (only major elements are listed).

[0078] Table 2 ICP results of lithium-containing filtrate (mg / L)

[0079]

[0080] From the analysis in Table 1, it can be seen that the lithium content in the lithium-containing filtrates obtained in Examples 1 to 5 is all above 46 mg / L.

[0081] 4) Filter residue detection

[0082] The filter residues obtained in Examples 1 to 5 were subjected to XRF analysis, and the results are shown in Table 3.

[0083] Table 3 XRF results of filter residues obtained in Examples 1 to 5

[0084]

[0085]

[0086] As can be seen from Table 3, the filter residues obtained in Examples 1 to 5 no longer contain lithium-containing compounds, thereby proving that the method of extracting lithium from clay-type associated lithium ore of the present invention achieves efficient leaching of lithium.

[0087] In summary, the method of extracting lithium from clay-type associated lithium ore of the present invention first activates the clay ore powder by roasting the clay-type associated lithium ore. Even when the mineral undergoes chemical changes, the physical form of the ore powder becomes loose and porous. At the same time, rapid cooling or quenching is used to put the powder into a metastable state where some thermal stress is not released in time, so that the clay ore powder is further activated, creating necessary conditions for subsequent treatment. Secondly, solid organic acid is used to mix and grind the roasted ore powder, which effectively promotes the combination of ligands in the organic acid with lithium ions in the clay-type lithium ore and the replacement of hydrogen ions with lithium ions. Therefore, the mixing and grinding process effectively promotes the combination of organic acid and lithium ions in the clay-type lithium ore. Since the clay-type lithium ore is an interlayer structure, the selection of small and medium molecular organic acids and clay-type The mixed grinding of associated lithium ores is more conducive to the complexation of lithium ions by organic acids, providing very good prerequisites for the leaching of lithium, thereby effectively ensuring not only the leaching rate of lithium, but also the lithium content in the lithium-containing filtrate; at the same time, since the rapid cooling and quenching treatments improve the degree of activation of the ore powder, the mixed grinding process effectively promotes the combination of organic acids and lithium ions in clay-type lithium ores, thereby effectively reducing the amount of solid organic acid used, and the saturated concentration of the selected organic acid solution at room temperature is relatively low, and the organic acid can be directly recovered by condensation and other methods, reducing the difficulty and cost of subsequent waste liquid treatment, and compared with inorganic acids, solid organic acids are generally weak acids, which have less corrosion to equipment, thereby effectively reducing damage to equipment, suitable for industrial applications, and have promotion and application value in the field of lithium extraction technology.

[0088] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A method for extracting lithium from a lithium-containing ore, characterized in that: The following steps are involved: S1. calcining the lithium-containing mineral powder, and then rapidly cooling or quenching it to room temperature, wherein rapid cooling refers to cooling at a cooling rate of not less than 3°C / s, and quenching refers to cooling at a cooling rate of not less than 10°C / s; rapid cooling or quenching is used to place the calcined powder in a metastable state in which some thermal stress has not been released in time, thereby effectively activating the clay mineral powder; S2. Adding solid organic acid to the calcined lithium-containing ore powder and grinding the mixture to promote the combination of ligands in the solid organic acid and lithium ions in the clay-type lithium ore and the replacement of hydrogen ions with lithium ions; the mass ratio of the lithium-containing ore powder to the solid organic acid is 10:1 to 3:1; S3, adding water to the mixed powder after mixing and grinding to carry out leaching reaction, and obtaining a lithium-containing filtrate after solid-liquid separation, which is used for lithium extraction; S4, washing the filter residue obtained after solid-liquid separation in S3, so that the pH value of the obtained solid waste is between 6 and 8, thereby achieving harmless treatment of the filter residue; the washed filtrate and the lithium-containing filtrate obtained in S4 are combined for lithium extraction and condensation recovery of organic acid, thereby achieving recycling; The solid organic acid is selected from solid oxalic acid and / or solid tartaric acid; The lithium-containing ore is a clay-type associated lithium ore.

2. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: In S3, the mass ratio of the mixed powder to water is 1:1 to 1:

5.

3. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: In the step S1, the calcination temperature is between 300° C. and 700° C., and the calcination time is between 5 minutes and 4 hours.

4. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: The leaching temperature is between 60° C. and 120° C., and the leaching time is between 5 minutes and 8 hours.

5. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: The mixing temperature is 30° C. to 100° C., and the mixing time is 10 min to 3 h.

6. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: The lithium content of the lithium-containing mineral powder is between 0.1% and 0.6%, and the mesh size of the lithium-containing mineral powder is less than or equal to 180 meshes.

7. The method for extracting lithium from lithium-containing ore according to claim 1, characterized in that: The leaching rate of the lithium-containing ore powder is above 88%, and the lithium content in the lithium-containing filtrate is above 46 mg / L.

Images