A preparation process of lithium carbonate

Abstract

The present application provides a preparation process of lithium carbonate, which is applied to the technical field of lithium carbonate preparation. It includes: S1. Mix aluminosilicate with lithium hydroxide solution for reaction, filter, wash and dry the product to obtain a lithium-rich adsorbent; S2. Mix sodium chloride or sodium nitrate solution with the lithium-rich adsorbent and react at 150-200 °C. After the reaction, elute lithium ions, cool down, filter and wash to obtain a lithium-poor adsorbent; S3. Mix the lithium-poor adsorbent with a lithium-containing solution and react at 15-30 °C to obtain a lithium-rich adsorbent and a lithium-removed solution; S4. Mix the lithium-rich adsorbent in step three with sodium chloride or sodium nitrate solution and react at 150-200 °C, elute lithium ions, and add sodium carbonate to the solution to precipitate lithium carbonate. By using a silicate-type lithium ion adsorbent and a sodium ion solution as an exchanger to elute lithium ions, the cyclic use of the adsorbent is realized through a temperature-variable ion exchange process, reducing the production cost.

Description

Technical Field

[0001] This application relates to the technical field of lithium carbonate preparation, and specifically relates to a preparation process of lithium carbonate. Background Art

[0002] The demand for lithium resources in the lithium-ion battery industry is increasing day by day. Lithium carbonate is the main raw material for lithium-ion batteries and is usually obtained by processing solid spodumene, lepidolite, or lithium-containing brine. About 85% of China's lithium resources exist in the form of brine, and the ion sieve adsorption method is the main method for lithium extraction.

[0003] Currently, the main types of lithium ion adsorbents are manganese-based oxides, titanium-based oxides, and doped ion sieves, with relatively high costs.

[0004] Based on this, a new technical solution is needed. Summary of the Invention

[0005] In view of this, the embodiments of this specification provide a preparation process of lithium carbonate, which elutes lithium ions through sodium ions, realizes the recycling of the adsorbent through temperature-variable ion exchange, effectively separates magnesium ions and lithium ions, and reduces the separation cost.

[0006] The embodiments of this specification provide the following technical solutions: A preparation process of lithium carbonate, including: S1. Mix and react aluminum silicate with lithium hydroxide solution, filter, wash, and dry the product to obtain a lithium-rich adsorbent;

[0007] S2. Mix the sodium chloride or sodium nitrate solution with the lithium-rich adsorbent and react under the condition of 150 - 200 °C. After the reaction, elute the lithium ions, cool down, filter, and wash to obtain a lithium-poor adsorbent;

[0008] S3. Mix the lithium-poor adsorbent with a lithium-containing solution and react under the condition of 15 - 30 °C to obtain a lithium-rich adsorbent and a lithium-removed solution;

[0009] S4. Mix the lithium-rich adsorbent in step three with the sodium chloride or sodium nitrate solution and react under the condition of 150 - 200 °C, elute the lithium ions, and add sodium carbonate to the solution to precipitate lithium carbonate.

[0010] Optionally, the aluminum silicate in S1 is an amorphous material, and the molar ratio of Si / Al in the aluminum silicate is greater than 1.5.

[0011] Optionally, the concentration of the lithium hydroxide is 1 - 3 mol / L, and the mass ratio of the aluminum silicate to the lithium hydroxide solution is 1:2 - 4.

[0012] Optionally, the raw material of the aluminum silicate in S1 is slag, fly ash, or natural rock minerals.

[0013] Optionally, mix aluminosilicate and lithium hydroxide in a mass ratio of 2:5, heat and stir, with the heating temperature being 80 - 200°C and the reaction time being 3 - 48 h.

[0014] Optionally, the concentration of lithium ions in the lithium-containing solution in S3 is greater than 0.1%.

[0015] Optionally, the reaction time in S2 is 0.5 - 2 h, and after the reaction, it is cooled to room temperature by water cooling.

[0016] Optionally, the concentration of sodium chloride or sodium nitrate solution in S2 is 0.8 - 2 mol / L, and the ratio of the lithium-rich adsorbent to the sodium chloride or sodium nitrate solution is 1 kg:10 - 30 L.

[0017] Optionally, the mass of sodium carbonate in S4 is 3% - 5% of the mass of the lithium-rich adsorbent in S1.

[0018] Optionally, the sodium chloride or sodium nitrate solution obtained by filtering sodium carbonate in S4 can be added to S2 for recycling.

[0019] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

[0020] In this application, a silicate-type lithium ion adsorbent and a sodium ion solution are used as exchange agents to elute lithium ions, and the adsorbent is recycled through a temperature-variable ion exchange process, reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a flowchart in a preparation process of lithium carbonate in this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will describe the embodiments of this application in detail with reference to the drawings.

[0024] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0025] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0026] It should also be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application schematically. The diagrams only show the components related to the present application and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0027] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the examples can be practiced without these specific details.

[0028] Lithium carbonate is the main raw material for lithium-ion batteries and is usually obtained by processing solid spodumene, lepidolite, or lithium-containing brine. Currently, the main types of lithium-ion adsorbents are manganese-based oxides, titanium-based oxides, and doped ion sieves, with relatively high costs. Silicate-type lithium-ion sieves are currently not common because common silicate adsorbents usually have a zeolite structure and have a weak ion sieve effect on lithium ions with a relatively small radius. If a special silicate compound with selectivity for lithium ions can be obtained, the cost can be effectively reduced compared to the above-mentioned adsorbents.

[0029] Based on this, an embodiment of this specification proposes a preparation process for lithium carbonate.

[0030] Example 1

[0031] Mix the calcined kaolin (with 58.6% SiO2 content and 37.4% Al2O3 content) and white carbon black (with 98% SiO2 content) in a mass ratio of 5:2 so that the molar ratio of Si / Al is 2.2, and then mix it with a 1.5 mol / L lithium hydroxide solution in a mass ratio of 1:2.5. Stir and heat at 80 °C for 4 h, then cool to room temperature with tap water, filter and wash three times, with the water consumption each time being 1.5 times the mass of the filter cake. Dry the obtained product at 105 °C for more than 8 h to obtain a lithium-rich adsorbent.

[0032] Treat 100 g of the lithium-rich adsorbent and a 1.0 mol / L sodium chloride solution in a ratio of 1 g / 20 mL under stirring conditions at 200 °C for 30 min to obtain a lithium-poor adsorbent.

[0033] Treat the lithium-poor adsorbent and a lithium-ion solution containing 0.5 mol / L in a ratio of 1 g / 40 mL at 30 °C for 1 h, then return to the above sodium chloride solution and treat it under stirring conditions at 150 °C for 30 min and cool. Then add 3.7 g of sodium carbonate to the obtained exchange solution, stir, filter the precipitate and dry it to obtain lithium carbonate, with the mass of lithium carbonate being about 2.6 g.

[0034] Example 2

[0035] Mix kaolin (with 47.6% SiO2 content and 31.45% Al2O3 content) and white carbon black (with 98% SiO2 content) in a mass ratio of 5:3 (the molar ratio of Si / Al is about 2.2), and then mix it with a 2 mol / L lithium hydroxide solution in a mass ratio of 1:2. Stir and heat at 150 °C for 12 h, then cool to room temperature with tap water, filter and wash three times, with the water consumption each time being 1.5 times the mass of the filter cake. Dry the obtained product at 105 °C for more than 8 h to obtain a lithium-rich adsorbent.

[0036] Treat 100 g of the lithium-rich adsorbent and a 1.0 mol / L sodium nitrate solution in a ratio of 1 g / 20 mL under stirring conditions at 180 °C for 40 min to obtain a lithium-poor adsorbent.

[0037] Treat the lithium-poor adsorbent and a lithium-ion solution containing 0.6 mol / L in a ratio of 1 g / 30 mL at 30 °C for 1 h, then return to the above sodium nitrate solution and treat it under stirring conditions at 200 °C for 30 min and cool. Then add 3.4 g of sodium carbonate to the obtained exchange solution, stir, filter the precipitate and dry it to obtain lithium carbonate, with the mass of lithium carbonate being about 2.4 g.

[0038] Example 3

[0039] Bentonite (SiO₂ content 58.8%, Al₂O₃ content 19.9%, Si / Al molar ratio about 2.5) was mixed with a 3 mol / L lithium hydroxide solution at a mass ratio of 1:3. Stir and heat at 200 °C for 8 h, then cool to room temperature with tap water, filter and wash three times, with the water consumption each time being 1.5 times the mass of the filter cake. The obtained product was dried at 105 °C for more than 8 h to obtain a lithium-rich adsorbent.

[0040] 100 g of the lithium-rich adsorbent and a 1.0 mol / L sodium chloride solution were treated at a ratio of 1 g / 10 mL under stirring conditions at 200 °C for 30 min to obtain a lithium-depleted adsorbent.

[0041] The lithium-depleted adsorbent and a lithium-ion solution containing 1 mol / L were treated at a ratio of 1 g / 15 mL at 20 °C for 10 min, and then returned to the above sodium nitrate solution and treated under stirring conditions at 200 °C for 30 min and cooled. Then, 4.3 g of sodium carbonate was added to the obtained exchange solution, stirred, the precipitate was filtered and dried to obtain lithium carbonate, and the mass of lithium carbonate was about 3 g.

[0042] Example 4

[0043] High-aluminum fly ash (SiO₂ content 52%, Al₂O₃ content 38%) and diatomite (SiO₂ content 90%) were mixed at a mass ratio of 25:8 (Si / Al molar ratio about 1.8), and then mixed with a 1 mol / L lithium hydroxide solution at a mass ratio of 1:4. Stir and heat at 90 °C for 24 h, then cool to room temperature with tap water, filter and wash three times, with the water consumption each time being 1.5 times the mass of the filter cake. The obtained product was dried at 105 °C for more than 8 h to obtain a lithium-rich adsorbent.

[0044] 100 g of the lithium-rich adsorbent and a 1.5 mol / L sodium chloride solution were treated at a ratio of 1 g / 20 mL under stirring conditions at 200 °C for 30 min to obtain a lithium-depleted adsorbent.

[0045] The lithium-depleted adsorbent and a lithium-ion solution containing 0.1 mol / L were treated at a ratio of 1 g / 80 mL at 20 °C for 2 h, and then returned to the above sodium chloride solution and treated under stirring conditions at 200 °C for 30 min and cooled. Then, 3.6 g of sodium carbonate was added to the obtained exchange solution, stirred, the precipitate was filtered and dried to obtain lithium carbonate, and the mass of lithium carbonate was about 2.5 g.

[0046] Example 5

[0047] Mix fly ash (with 58% SiO₂ content, 17% Al₂O₃ content, and an Si / Al molar ratio of approximately 2.5) with a 1 mol / L lithium hydroxide solution at a mass ratio of 1:3.5. Stir and heat at 85 °C for 4 h, then cool to room temperature with tap water, filter and wash three times, with the water consumption each time being 1.5 times the mass of the filter cake. Dry the obtained product at 105 °C for more than 8 h to obtain a lithium-rich adsorbent.

[0048] Treat 100 g of the lithium-rich adsorbent and a 0.8 mol / L sodium chloride solution at a ratio of 1 g / 25 mL under stirring conditions at 180 °C for 30 min to obtain a lithium-depleted adsorbent.

[0049] Treat the lithium-depleted adsorbent and a lithium ion solution containing 0.1 mol / L at a ratio of 1 g / 80 mL at 25 °C for 2 h, then return it to the above sodium chloride solution and treat it under stirring conditions at 200 °C for 30 min and cool. Then add 4.1 g of sodium carbonate to the obtained exchange solution, stir, filter the precipitate and dry it to obtain lithium carbonate, and the mass of lithium carbonate is about 2.9 g.

[0050] In this specification, for the same or similar parts among the various embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, the description is relatively simple, and for the relevant parts, reference can be made to the partial description of the foregoing embodiments.

[0051] As described above, this is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A preparation process of lithium carbonate, characterized in that: Including S1, mixing aluminosilicate with lithium hydroxide solution for reaction, filtering, washing and drying the product to obtain a lithium-rich adsorbent; the aluminosilicate is an amorphous material, and the Si / Al molar ratio in the aluminosilicate is greater than 1.5; the concentration of the lithium hydroxide is 1 - 3 mol / L, and the mass ratio of the aluminosilicate to the lithium hydroxide solution is 1:2 - 4; S2, mixing a sodium chloride or sodium nitrate solution with the lithium-rich adsorbent and reacting at 150 - 200 °C, eluting lithium ions after the reaction, cooling, filtering and washing to obtain a lithium-poor adsorbent; S3, mixing the lithium-poor adsorbent with a lithium-containing solution and reacting at 15 - 30 °C to obtain a lithium-rich adsorbent and a lithium-removed solution; S4, mixing the lithium-rich adsorbent in step three with a sodium chloride or sodium nitrate solution and reacting at 150 - 200 °C, eluting lithium ions, and adding sodium carbonate to the solution to precipitate lithium carbonate; Adding the sodium chloride or sodium nitrate solution filtered from the sodium carbonate in S4 to S2 for recycling.

2. The preparation process of lithium carbonate according to claim 1, characterized in that: The raw material of the aluminosilicate in S1 is slag, fly ash or natural rock minerals.

3. The preparation process of lithium carbonate according to claim 1, wherein: Mixing aluminosilicate and lithium hydroxide in a mass ratio of 2:5, heating and stirring, the heating temperature is 80 - 200 °C, and the reaction time is 3 - 48 h.

4. The preparation process of lithium carbonate according to claim 1, characterized in that: The concentration of lithium ions in the lithium-containing solution in S3 is greater than 0.1%.

5. The preparation process of lithium carbonate according to claim 1, characterized in that: The reaction time in S2 is 0.5 - 2 h, and after the reaction, it is cooled to room temperature by water cooling.

6. The preparation process of lithium carbonate according to claim 1, characterized in that: The concentration of the sodium chloride or sodium nitrate solution in S2 is 0.8 - 2 mol / L, and the ratio of the lithium-rich adsorbent to the sodium chloride or sodium nitrate solution is 1 kg:10 - 30 L.

7. The preparation process of lithium carbonate according to claim 1, characterized in that: The mass of sodium carbonate in S4 is 3% - 5% of the mass of the lithium-rich adsorbent in S1.

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