Method for efficiently extracting lithium carbonate from clay type lithium ore by selective adsorption method

Abstract

The invention discloses a method for efficiently extracting lithium carbonate from clay type lithium ore by a selective adsorption method. The clay type lithium ore is crushed and finely ground, and powdery clay type lithium ore is obtained; roasting the powdery clay type lithium ore at high temperature to obtain a roasted product; a dilute acid solution is added into the roasted product for leaching and separation, a leaching solution and high-silicon slag are obtained, and the high-silicon slag serves as a cement production raw material; a NaOH solution is added into the leachate to adjust the pH value of the leachate, stirring adsorption and separation are conducted, and precipitates and supernate are obtained; the precipitate is roasted, the roasted product is subjected to water leaching and solid-liquid separation, a leaching solution and an insoluble substance are obtained, and the insoluble substance is used for producing a refractory material; carrying out adsorption treatment on the leachate through cation exchange resin; and concentrating the obtained aqueous solution, then adding Na2CO3 to carry out lithium precipitation reaction, and finally carrying out liquid-solid separation to obtain the product Li2CO3. According to the invention, comprehensive utilization of lithium, aluminum and silicon elements in the clay type lithium ore can be realized; and tailings can be reduced, the production time is saved, and the production cost is reduced.

Description

1. Technical field:

[0001] The invention relates to the technical field of comprehensive utilization of lithium-containing clay ores, and in particular to a method for efficiently extracting lithium carbonate from clay-type lithium ores by a selective adsorption method. 2. Background technology:

[0002] With the development of my country's economy, the field of lithium batteries has made continuous breakthroughs, and the market demand for lithium has grown rapidly. At present, lithium resources are divided into salt lake brine type, hard rock type and clay type. The developed lithium resources are salt lake type and hard rock type lithium resources; among them, salt lake type lithium resources have restricted the development of salt lake lithium industry to a certain extent due to problems such as high altitude and high magnesium-lithium ratio, while hard rock type lithium mine technology is relatively mature, but accounts for a small proportion.

[0003] When extracting lithium from clay lithium ore, due to the high aluminum content in clay lithium ore, in order to improve the quality of lithium and reduce the acid consumption of aluminum minerals during leaching, aluminum silicon separation operations need to be carried out before leaching. However, due to the fine particle size of aluminum silicon minerals and the complex intergrowth relationship, it is difficult to achieve good results in aluminum silicon separation.

[0004] At present, the lithium extraction process of minerals at home and abroad is mainly aimed at spodumene and lepidolite. There is less research on lithium extraction from lithium-containing clay minerals. The main lithium extraction processes for spodumene and lepidolite are: 1) Sulfuric acid production process: spodumene-high temperature roasting-cooling grinding to 0.152mm mixed with sufficient sulfuric acid (93-98%), sent to a 250℃ acidification rotary furnace for acidification roasting. 2) Sulfate mixed sintering production process: add potassium sulfate (or calcium sulfate or a mixture of the two), mix and sinter at a certain temperature, and then leach and separate the sintered clinker. 3) Sodium carbonate pressure leaching production process: first, process spodumene to obtain β-spodumene and grind it to 0.074mm, then add 3.5-7 times sodium carbonate according to the proportion of lithium oxide and mix well, pressurize and leach at 200℃ in the reactor, and pass carbon dioxide gas to generate soluble lithium bicarbonate. 4) Chlorination roasting production process: spodumene is mixed with limestone and calcium chloride in a ratio of 1:3:1, roasted at 1000℃, and lithium chloride is generated and sublimated, entering the kiln gas together with dust, and the lithium chloride solution is collected in the dust collector and washing tower. 5) Limestone roasting production process: First, the limestone is finely ground, and the ratio of spodumene to limestone is 1:3.05-3.15, and a certain amount of calcium oxide (40-42%) is added to form a qualified raw material slurry, which is then put into a rotary kiln for roasting to convert the lithium in the mineral into a water-soluble compound.

[0005] There are also many related patent literature reports on the extraction of lithium products from lithium-containing clay ores. For example: 1. The invention patent of CN103849761A discloses a method for extracting lithium from low-grade lithium-containing clay ores. The method is a process for low-grade lithium-containing clay ores in northern Henan Province, where sulfate and fluoride salts are mixed with the original ore for modified roasting at 800°C, and then the modified roasted raw materials are granulated and heap leached, and the lithium leaching rate reaches 91%. The process is carried out by adding a large amount of roasting aids to the original ore for high-temperature roasting, and the requirements for equipment and cost are relatively high. 2) The invention patent application of CN117488099A discloses a method for extracting lithium from clay lithium ore and producing aluminum-based lithium adsorbents as a by-product. In the technical solution disclosed in the method, in the process of lithium desorption, in order to make the desorption sufficient, a large amount of water is required, which increases the time and energy required for subsequent evaporation and concentration. At the same time, since aluminum hydroxide will carry some calcium and magnesium ions, the purity of the lithium carbonate generated later will be low and cannot meet high standards. 3) The invention patent application CN110042262A discloses a method for selectively leaching low-grade sedimentary lithium ore. The method is a metallurgical process for extracting lithium from sedimentary lithium ore in Guizhou, and lithium leaching solution and leaching tailings are obtained by selective leaching. However, the method has the following disadvantages: the method produces a large amount of tailings, the utilization rate of the original ore is low, and the economic value needs to be improved. 3. Summary of the invention:

[0006] The technical problem to be solved by the present invention is: based on the existing technology and existing problems of the method for extracting lithium products from lithium-containing clay ores, the present invention provides a method for efficiently extracting lithium carbonate from clay-type lithium ores by a selective adsorption method in order to realize the comprehensive utilization of lithium, aluminum, and silicon elements in lithium-containing clay ores. Through the technical scheme of the present invention, the comprehensive utilization of lithium, aluminum, and silicon elements in clay-type lithium ores can be realized; and the generation of tailings can be reduced, production time can be saved, production costs can be reduced, and multiple benefits can be achieved at one stroke.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is:

[0008] The present invention provides a method for efficiently extracting lithium carbonate from clay-type lithium ore by a selective adsorption method, the method comprising the following steps:

[0009] 1) crushing and finely grinding the clay-type lithium ore to obtain powdery clay-type lithium ore;

[0010] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting to obtain a roasted product;

[0011] 3) adding the obtained roasted product into a dilute acid solution for leaching, and separating the solid and liquid after leaching to obtain a leachate and high-silicon slag; the obtained high-silicon slag is used as a raw material for cement production;

[0012] 4) adding NaOH solution to the obtained leachate to adjust its pH value, and stirring and adsorbing; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0013] 5) calcining the precipitate obtained in step 4) to convert Li-Al LDHs into Al2O3 and LiCl;

[0014] 6) soaking the product generated in step 5) in water, and then performing solid-liquid separation to separate the leaching liquid and the insoluble matter, wherein the obtained insoluble matter is used to produce refractory materials (the main component of the insoluble matter is alumina);

[0015] 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin;

[0016] 8) The aqueous solution obtained in step 7) is concentrated, and then Na2CO3 is added to carry out lithium precipitation reaction, and finally liquid-solid separation is carried out to obtain the product Li2CO3.

[0017] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, the particle size of the powdery clay-type lithium ore obtained in step 1) is 50-200 mesh.

[0018] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, during the high-temperature roasting in step 2), the roasting temperature is controlled to be 600-900° C. and the roasting time is 1-4 hours.

[0019] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, the concentration of the dilute acid solution in step 3) is 1 to 8 mol / L.

[0020] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, during the leaching in step 3), the solid-liquid ratio is controlled to be 1:2-8 (g:mL); the leaching conditions are: leaching for 0.5-3h under 80-150°C water bath or oil bath conditions.

[0021] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the above-mentioned selective adsorption method, the mass percentage concentration of the NaOH solution in step 4) is 5-20%; its pH is adjusted to 4-8, and the stirring adsorption time is 0.5-4h.

[0022] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, during the roasting in step 5), the roasting temperature is controlled to be 300-700° C. and the roasting time is 30-120 min.

[0023] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the above-mentioned selective adsorption method, during the leaching in step 6), the solid-liquid ratio is controlled to be 3-1:1, the temperature is 20-60°C, and the time is 5-20min.

[0024] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by the selective adsorption method, the rate at which the leaching solution passes through the Li-type cation exchange resin in step 7) is 4 to 10 BV / h.

[0025] According to the method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption, the amount of Na2CO3 added in step 8) is Li + 0.5 to 0.6 times the amount of substance.

[0026] The positive beneficial effects of the present invention are:

[0027] 1. Through the technical solution of the present invention, the comprehensive utilization of lithium, aluminum and silicon elements in clay-type lithium ore can be achieved; for example: the main component of the filter residue after acid leaching is silicon dioxide, which can be used as a raw material for cement production, and can also be used to prepare concrete materials or further processed to produce silicone oil, silicone rubber, etc.; the main component of the filter residue after water leaching is aluminum oxide, which can be used as a raw material for producing refractory materials, and can also be used to produce abrasives and ceramics. The main product, lithium carbonate, can be used in the fields of battery materials, optical glass materials, ceramics and coatings. It can also reduce the generation of tailings, save production time, reduce production costs, and achieve multiple goals at one stroke.

[0028] 2. By using the technical solution of the present invention, the purity of the lithium carbonate product prepared reaches above 99.5%.

[0029] 3. In the operation method of the technical solution of the present invention, the pH of the discharged waste liquid is close to neutral, and the main component of the waste liquid is sodium chloride, which effectively reduces the impact on the environment and is beneficial to environmental protection.

[0030] 4. The technical solution of the present invention is used to efficiently extract lithium carbonate from clay-type lithium ore, and the production process is highly safe and reliable. 4. Description of the drawings:

[0031] Figure 1 A schematic flow chart of a method for efficiently extracting lithium carbonate from clay-type lithium ore by a selective adsorption method according to the present invention. V. Specific implementation methods:

[0032] The present invention is further described below in conjunction with embodiments, but the protection scope of the technical solution of the present invention is not limited thereto.

[0033] Embodiment 1:

[0034] The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption of the present invention has the following detailed steps:

[0035] 1) crushing and finely grinding the clay-type lithium ore, and passing the finely ground ore through a 100-mesh sieve to obtain a powdery clay-type lithium ore;

[0036] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting, the roasting temperature is 700° C., the roasting time is 2 h, and a roasting product is obtained after roasting;

[0037] 3) adding the obtained roasted product to a hydrochloric acid solution with a concentration of 4 mol / L for leaching, controlling the solid-liquid ratio to be 1:6 (g:mL), and leaching for 2 hours in a water bath at 90°C; after leaching, the solid and liquid are separated to obtain a leachate and high-silicon slag; the main component of the obtained high-silicon slag is silicon dioxide, which is used as a raw material for cement production;

[0038] 4) adding a 20% by mass concentration NaOH solution to the obtained leachate to adjust its pH to 8.0, and stirring and adsorbing for 30 minutes; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0039] 5) The precipitate obtained in step 4) is repeatedly washed with pure water, and then placed in a muffle furnace for calcination at a temperature of 500° C. for 30 min to convert Li-Al LDHs into Al2O3 and LiCl;

[0040] 6) taking out the product generated in step 5) and cooling it, adding pure water for water immersion after cooling, controlling the solid-liquid ratio to be 1:1, the temperature to be 20° C., and the time to be 10 min; after water immersion, performing solid-liquid separation to separate the leaching liquid and the insoluble matter (the main component of the insoluble matter is alumina), and the obtained insoluble matter can be used to produce refractory materials;

[0041] 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin at a rate of 10 BV / h;

[0042] 8) The aqueous solution obtained in step 7) is concentrated, and then Li + 0.5 times the amount of Na2CO3 is used for lithium precipitation reaction, and finally liquid-solid separation is carried out to separate the precipitate and the supernatant. The precipitate is repeatedly washed with pure water to obtain a Li2CO3 product with a purity of 99.62%.

[0043] During the treatment process of this embodiment, the leaching rate of lithium can reach 82.3%, the adsorption rate can reach 97.4%, and the desorption rate can reach 91.3%.

[0044] Embodiment 2:

[0045] 1) crushing and finely grinding the clay-type lithium ore, and passing the finely ground ore through a 100-mesh sieve to obtain a powdery clay-type lithium ore;

[0046] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting, the roasting temperature is 800° C., the roasting time is 2 h, and a roasting product is obtained after roasting;

[0047] 3) adding the obtained roasted product to a sulfuric acid solution with a concentration of 8 mol / L for leaching, controlling the solid-liquid ratio to 1:8 (g:mL), and leaching for 1 hour in a water bath at 130°C; after leaching, the solid and liquid are separated to obtain a leachate and high-silicon slag; the main component of the obtained high-silicon slag is silicon dioxide, which is used as a raw material for cement production;

[0048] 4) adding a 10% by mass concentration NaOH solution to the obtained leachate to adjust its pH to 6.0, and stirring and adsorbing for 30 minutes; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0049] 5) The precipitate obtained in step 4) is repeatedly washed with pure water, and then placed in a muffle furnace for calcination at a temperature of 600° C. for 30 min to convert Li-Al LDHs into Al2O3 and LiCl;

[0050] 6) taking out the product generated in step 5) and cooling it, adding pure water for water immersion after cooling, controlling the solid-liquid ratio to 2:1, the temperature to 30° C., and the time to 10 min; after water immersion, performing solid-liquid separation to separate the leaching liquid and the insoluble matter (the main component of the insoluble matter is alumina), and the obtained insoluble matter can be used to produce refractory materials;

[0051] 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin at a rate of 10 BV / h;

[0052] 8) The aqueous solution obtained in step 7) is concentrated, and then Li + 0.6 times the amount of Na2CO3 is used for lithium precipitation reaction, and finally liquid-solid separation is carried out to separate the precipitate and the supernatant. The precipitate is repeatedly washed with pure water to obtain a Li2CO3 product with a purity of 99.68%.

[0053] During the treatment process of this embodiment, the leaching rate of lithium can reach 89.4%, the adsorption rate can reach 81.7%, and the desorption rate can reach 90.5%.

[0054] Embodiment 3:

[0055] 1) crushing and finely grinding the clay-type lithium ore, and passing the finely ground ore through a 100-mesh sieve to obtain a powdery clay-type lithium ore;

[0056] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting, the roasting temperature is 600° C., the roasting time is 2 h, and a roasting product is obtained after roasting;

[0057] 3) adding the obtained roasted product to a hydrochloric acid solution with a concentration of 2 mol / L for leaching, controlling the solid-liquid ratio to be 1:4 (g:mL), and leaching for 1 hour in a water bath at 80°C; after leaching, the solid and liquid are separated to obtain a leachate and high-silicon slag; the main component of the obtained high-silicon slag is silicon dioxide, which is used as a raw material for cement production;

[0058] 4) adding a 15% by mass concentration NaOH solution to the obtained leachate to adjust its pH to 5.5, and stirring and adsorbing for 30 minutes; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0059] 5) The precipitate obtained in step 4) is repeatedly washed with pure water, and then placed in a muffle furnace for calcination at a temperature of 500° C. for 60 min to convert Li-Al LDHs into Al2O3 and LiCl;

[0060] 6) taking out the product generated in step 5) and cooling it, adding pure water for water immersion after cooling, controlling the solid-liquid ratio to be 1:1, the temperature to be 40° C., and the time to be 5 min; after water immersion, performing solid-liquid separation to separate the leaching liquid and the insoluble matter (the main component of the insoluble matter is alumina), and the obtained insoluble matter can be used to produce refractory materials;

[0061] 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin at a rate of 10 BV / h;

[0062] 8) The aqueous solution obtained in step 7) is concentrated, and then Li + 0.55 times the amount of Na2CO3 is used for lithium precipitation reaction, and finally liquid-solid separation is carried out to separate the precipitate and the supernatant. The precipitate is repeatedly washed with pure water to obtain a Li2CO3 product with a purity of 99.69%.

[0063] During the treatment process of this embodiment, the lithium leaching rate can reach 77.8%, the adsorption rate can reach 92.5%, and the desorption rate can reach 91.2%.

[0064] Embodiment 4:

[0065] 1) crushing and finely grinding the clay-type lithium ore, and passing the finely ground ore through a 100-mesh sieve to obtain a powdery clay-type lithium ore;

[0066] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting, the roasting temperature is 700° C., the roasting time is 2 h, and a roasting product is obtained after roasting;

[0067] 3) adding the obtained roasted product to a sulfuric acid solution with a concentration of 8 mol / L for leaching, controlling the solid-liquid ratio to be 1:5 (g:mL), and leaching for 2 hours under 140°C oil bath conditions; after leaching, the solid and liquid are separated to obtain a leachate and high-silicon slag; the main component of the obtained high-silicon slag is silicon dioxide, which is used as a raw material for cement production;

[0068] 4) adding a 10% by mass concentration NaOH solution to the obtained leachate to adjust its pH to 8.0, and stirring and adsorbing for 30 minutes; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0069] 5) The precipitate obtained in step 4) is repeatedly washed with pure water, and then placed in a muffle furnace for calcination at a temperature of 600° C. for 30 min to convert Li-Al LDHs into Al2O3 and LiCl;

[0070] 6) taking out the product generated in step 5) and cooling it, adding pure water for water immersion after cooling, controlling the solid-liquid ratio to be 1:1, the temperature to be 30° C., and the time to be 10 min; after water immersion, performing solid-liquid separation to separate the leaching liquid and the insoluble matter (the main component of the insoluble matter is alumina), and the obtained insoluble matter can be used to produce refractory materials;

[0071] 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin at a rate of 10 BV / h;

[0072] 8) The aqueous solution obtained in step 7) is concentrated, and then Li + 0.6 times the amount of Na2CO3 is used for lithium precipitation reaction, and finally liquid-solid separation is carried out to separate the precipitate and the supernatant. The precipitate is repeatedly washed with pure water to obtain a Li2CO3 product with a purity of 99.72%.

[0073] During the treatment process of this embodiment, the lithium leaching rate can reach 90.8%, the adsorption rate can reach 95.2%, and the desorption rate can reach 90.5%.

[0074] Comparative Example 1:

[0075] The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption of the present invention has the following detailed steps:

[0076] 1) crushing and finely grinding the clay-type lithium ore, and passing the finely ground ore through a 100-mesh sieve to obtain a powdery clay-type lithium ore;

[0077] 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting, the roasting temperature is 700° C., the roasting time is 2 h, and a roasting product is obtained after roasting;

[0078] 3) adding the obtained roasted product to a hydrochloric acid solution with a concentration of 4 mol / L for leaching, controlling the solid-liquid ratio to be 1:6 (g:mL), and leaching for 2 hours in a water bath at 70°C; after leaching, the solid and liquid are separated to obtain a leachate and high-silicon slag; the main component of the obtained high-silicon slag is silicon dioxide, which is used as a raw material for cement production;

[0079] 4) adding a 20% by mass concentration NaOH solution to the obtained leachate to adjust its pH to 8.0, and stirring and adsorbing for 30 minutes; then centrifuging to obtain Li-Al LDHs precipitate and supernatant;

[0080] 5) The precipitate obtained in step 4) is repeatedly washed with pure water, and then placed in a muffle furnace for calcination at a temperature of 500° C. for 30 min to convert Li-Al LDHs into Al2O3 and LiCl;

[0081] 6) taking out the product generated in step 5) and cooling it, adding pure water for water immersion after cooling, controlling the solid-liquid ratio to be 1:1, the temperature to be 20° C., and the time to be 10 min; after water immersion, performing solid-liquid separation to separate the leaching liquid and the insoluble matter (the main component of the insoluble matter is alumina), and the obtained insoluble matter can be used to produce refractory materials;

[0082] 7) The leaching solution obtained in step 6) is concentrated, and then Li + 0.6 times the amount of Na2CO3 was used for lithium precipitation reaction, and finally liquid-solid separation was carried out to separate the precipitate and the supernatant. The precipitate was repeatedly washed with pure water to obtain a Li2CO3 product with a purity of 97.92%.

[0083] During the treatment process of this embodiment, the leaching rate of lithium can reach 65.2%, the adsorption rate can reach 98.2%, and the desorption rate can reach 91.6%.

Claims

1. A method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption, characterized in that: The method comprises the following steps: 1) crushing and finely grinding the clay-type lithium ore to obtain powdery clay-type lithium ore; 2) placing the obtained powdered clay-type lithium ore in a muffle furnace for high-temperature roasting to obtain a roasted product; 3) adding the obtained roasted product into a dilute acid solution for leaching, and separating the solid and liquid after leaching to obtain a leachate and high-silicon slag; the obtained high-silicon slag is used as a raw material for cement production; 4) adding NaOH solution to the obtained leachate to adjust its pH value, and stirring and adsorbing; then centrifuging to obtain Li-Al LDHs precipitate and supernatant; 5) calcining the precipitate obtained in step 4) to convert Li-Al LDHs into Al2O3 and LiCl; 6) soaking the product produced in step 5) in water, and then performing solid-liquid separation to separate the leaching liquid and insoluble matter, wherein the obtained insoluble matter is used to produce refractory materials; 7) the leachate obtained by solid-liquid separation in step 5) is subjected to adsorption treatment by a Li-type cation exchange resin; 8) The aqueous solution obtained in step 7) is concentrated, and then Na2CO3 is added to carry out lithium precipitation reaction, and finally liquid-solid separation is carried out to obtain the product Li2CO3.

2. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: The particle size of the powdery clay-type lithium ore obtained in step 1) is 50 to 200 meshes.

3. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: During the high temperature calcination in step 2), the calcination temperature is controlled to be 600-900° C. and the calcination time is controlled to be 1-4 hours.

4. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: The concentration of the dilute acid solution in step 3) is 1-8 mol / L.

5. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: During the leaching in step 3), the solid-liquid ratio is controlled to be 1:2-8; the leaching conditions are: leaching in a water bath or oil bath at 80-150° C. for 0.5-3 h.

6. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: The mass percentage concentration of the NaOH solution in step 4) is 5-20%; its pH is adjusted to 4-8, and the stirring adsorption time is 0.5-4h.

7. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: During the calcination in step 5), the calcination temperature is controlled to be 300-700° C. and the calcination time is controlled to be 30-120 min.

8. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: During the leaching in step 6), the solid-liquid ratio is controlled to be 3-1:1, the temperature is 20-60° C., and the time is 5-20 min.

9. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: In step 7), the rate at which the leaching solution passes through the Li-type cation exchange resin is 4 to 10 BV / h.

10. The method for efficiently extracting lithium carbonate from clay-type lithium ore by selective adsorption according to claim 1, characterized in that: In step 8), the amount of Na2CO3 added is Li + 0.5 to 0.6 times the amount of substance.

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