A method for simultaneously extracting lithium and potassium from clay lithium ore

Abstract

This invention relates to a method for simultaneously extracting lithium and potassium from clay lithium ore. The method primarily involves thoroughly grinding and mixing crushed and ball-milled clay lithium ore powder with a specific chlorinating agent, followed by roasting. This process converts lithium and potassium in the clay ore into soluble salts, while aluminum, magnesium, and silicon are transferred into a complex silicate phase that is difficult to dissolve in water. The resulting roasted clinker is leached with deionized water, and after solid-liquid separation, a lithium- and potassium-rich leachate is obtained, thus achieving the goal of efficiently extracting lithium and potassium from clay lithium ore. This invention comprehensively utilizes clay lithium ore, a resource with relatively low grade but large reserves. The process design is reasonable, resource utilization is high, it is environmentally friendly, and it is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive resource utilization technology, and specifically relates to a method for simultaneously extracting lithium and potassium from lithium clay ore containing lithium and potassium through a roasting-water leaching process. Background Technology

[0002] Lithium clay deposits are typically associated minerals in sedimentary deposits such as bauxite and coal, and are abundant and widely distributed, making them a typical unconventional lithium resource. Various techniques have been explored to extract lithium from these lithium-bearing clay rock resources, including direct leaching, roasting acid leaching, additive roasting water leaching, and roasting ion exchange leaching. However, due to the low lithium content and complex composition of lithium-bearing clay rocks, the leachates obtained using these methods often contain a large number of impurity ions, such as Al. 3 + Mg 2+ These factors, such as the presence of Al(OH)3 and Mg(OH)2 generated during purification, make subsequent leaching solution purification difficult. The Al(OH)3 and Mg(OH)2 produced during purification have a strong adsorption capacity for lithium ions, severely impacting lithium recovery rates. Furthermore, currently reported treatment technologies primarily target clay lithium ores lacking independent lithium ore phases. In these clay lithium ores, lithium is mainly adsorbed between mineral structural layers such as montmorillonite and kaolinite, making it difficult to simultaneously recover other valuable metals like potassium during lithium extraction. Summary of the Invention

[0003] The purpose of this invention is to propose a method for simultaneously extracting lithium and potassium from clay lithium ore containing independent mineral phases (lithium chlorite and illite). The key is to thoroughly grind and mix the crushed and ball-milled clay lithium ore powder with a chlorinating agent, and then roast it. During the roasting process, the lithium chlorite and illite in the clay ore react with the chlorinating agent at the same time, transforming into a thermodynamically stable and water-insoluble complex silicate phase and a water-soluble lithium salt phase. The resulting roasted clinker is leached with deionized water, and after solid-liquid separation, a leachate rich in lithium and potassium but free of aluminum and magnesium ions is obtained, thereby achieving the goal of efficiently extracting lithium and potassium elements from clay lithium ore.

[0004] This invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore, characterized by the following steps:

[0005] Step 1

[0006] Clay lithium ore is crushed and ball-milled to obtain clay lithium ore powder. The clay lithium ore powder is then thoroughly ground and mixed with a certain amount of chlorinating agent to obtain a uniform mixture. The clay lithium ore is an independent mineral phase containing lithium and potassium, and the independent mineral phase includes lithium chlorite and illite. The chlorinating agent consists of A and B, wherein A is selected from at least one of calcium hydroxide, calcium carbonate, calcium oxalate, and calcium oxide, and B is selected from at least one of manganese chloride and ammonium chloride. By mass ratio, B / A is greater than or equal to 0.8, preferably greater than or equal to 1, and more preferably 1 to 2.5.

[0007] Step Two

[0008] The uniform mixture obtained in step one is roasted, and the appropriate roasting temperature and time are controlled. After it is completely cooled, roasted cooked material is obtained.

[0009] Step 3

[0010] The roasted clinker obtained in step two is leached with deionized water under stirring. The appropriate leaching liquid-to-solid ratio, leaching temperature and leaching time are controlled. After the reaction is complete and cooled, the mixture is filtered. The filter cake is washed with clean water. The solution obtained from washing is mixed with the filtrate to obtain a lithium- and potassium-rich leaching solution.

[0011] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore, wherein the lithium and potassium in the clay lithium ore exist in the form of independent phases, rather than in the form of ions adsorbed in the layered structure of other clay minerals.

[0012] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore, wherein the lithium in the clay lithium ore is present in the lithium chlorite phase and the potassium is present in the illite phase.

[0013] Preferably, the present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore, wherein in step one, the chlorinating agent is a mixture of calcium hydroxide and manganese chloride, or; the chlorinating agent is a mixture of calcium hydroxide and ammonium chloride, or; the chlorinating agent is a mixture of calcium carbonate and ammonium chloride, or; the chlorinating agent is a mixture of calcium oxalate and ammonium chloride, or; the chlorinating agent is one or more of a mixture of ammonium chloride and calcium oxide.

[0014] As a further preferred option, the chlorinating agent is composed of calcium oxide and ammonium chloride in a mass ratio of 1:1.7 to 2.5; or the chlorinating agent is composed of calcium hydroxide and manganese chloride in a mass ratio of 1:1.7 to 2.5.

[0015] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. In step one, the particle size of the clay lithium ore powder is -100 to -300 mesh, preferably -100 to -200 mesh.

[0016] According to claim 1, the method for simultaneously extracting lithium and potassium from clay lithium ore, in step one, the mass ratio of chlorinating agent to clay lithium ore is 0.6~3:1, preferably 0.8~2:1.

[0017] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. In step two, the roasting temperature is 500~1000 ℃, preferably 750~850 ℃.

[0018] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. In step two, the roasting time is 0.5 to 2.5 hours, preferably 1 to 2 hours.

[0019] This invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. In step three, the water leaching temperature is 25~90℃, preferably 60~90℃, the leaching time is 0.5~4 h, preferably 0.5~2 h, the solid-liquid ratio is 1:0.5~8, preferably 1:2~3, and the leaching residue is washed with a washing solid-liquid ratio of 1:3~5.

[0020] As one of the optimal solutions, the present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore. A mixture of calcium hydroxide and manganese chloride is used as the chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:1.9~2.1, and the mass ratio of chlorinating agent to ore is 1.7~1.9:1. The resulting mixture is roasted at 790~810 °C for 80~100 min. The leaching solid-liquid ratio is 1:2.5~3.5, the leaching temperature is 85~90 °C, the leaching time is 50~70 min, and the washing solid-liquid ratio is 1:4~5. The resulting washing liquid and leaching filtrate are collected.

[0021] This invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. Using this method, the extraction rates of lithium and potassium in clay lithium ore can reach 80% and 70% or more, respectively. After optimization, the extraction rates of lithium and potassium can reach 85% and 74% or more, respectively.

[0022] Principles and advantages

[0023] This invention, guided by theoretical thermodynamic calculations, employs a specific chlorinating agent and clay lithium ore powder, which are thoroughly ground and mixed before high-temperature roasting. During the roasting process, the lithium-containing mineral phase lithium chlorite [LiAl4(Si3Al)O] in the clay lithium ore is released. 10 [(OH)8] and potassium-bearing mineral phase illite [KAl2(Si3Al)O] 10 [OH)2] reacts simultaneously with the chlorinating agent, converting lithium and potassium into water-soluble lithium chloride and potassium chloride, while aluminum, magnesium, silicon, etc., are converted into MgAl2Si2O8, CaAl2Si2O8, Al2SiO5, and Ca3Al2Si3O 12 Al6Si2O 13 The complex silicate phases that are difficult to dissolve in water are then leached with water to achieve efficient separation of lithium and potassium from impurity elements such as magnesium, aluminum, and silicon. This achieves the goal of efficiently extracting lithium and potassium from clay lithium ore containing both lithium chlorite and illite independent phases.

[0024] Compared with existing technologies, the technical concept and process principle of this invention have significant characteristics and technical advantages, specifically manifested in:

[0025] (1) This invention combines the thermodynamic characteristics of the independent phases of lithium chlorite and illite in clay lithium ore, selects a specific chlorinating agent to roast and react with it, and then leaches it with water, so as to achieve the purpose of extracting lithium and potassium from the ore at the same time. This not only improves the comprehensive utilization rate of mineral resources, but also avoids the environmental impact caused by acid leaching or acid roasting processes.

[0026] (2) In the extraction process of lithium and potassium, the aluminum and magnesium in the ore are converted into MgAl2Si2O8, CaAl2Si2O8, Al2SiO5, and Ca3Al2Si3O during roasting. 12 Al6Si2O 13 Complex silicate phases that are difficult to dissolve in water will not enter the leaching solution, reducing the burden on subsequent leaching solution purification processes and helping to improve the overall lithium recovery rate.

[0027] (3) After the roasted ore is leached with water, the main impurity ions in the leachate obtained in this invention are calcium ions, in addition to lithium and potassium. The calcium carbonate or calcium oxalate produced during the purification of the leachate can be recycled as a component of the chlorinating agent. Therefore, the removal of impurities will not cause a large loss of lithium, thereby further improving the overall lithium recovery rate of the process and reducing the discharge of waste.

[0028] (4) The low-melting-point component in the chlorinating agent used in this invention can form a molten state at a lower temperature, thereby ensuring that it can fully contact the lithium-containing mineral phase and potassium-containing mineral phase in the clay lithium ore in a liquid-solid phase contact manner at a lower temperature. This provides a material transport channel for the two components in the chlorinating agent to synergistically achieve efficient conversion of lithium and potassium in the clay ore, ensuring that both lithium and potassium have a high recovery rate. At the same time, it does not require the raw materials and roasting materials to be squeezed or repeatedly ground, and the process is simple. Detailed Implementation

[0029] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0030] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available products or products that can be prepared by known methods.

[0031] The specific embodiments of the present invention are as follows:

[0032] Example 1

[0033] Weigh 25.00 g of clay lithium ore (containing both lithium chlorite and illite in a mass ratio of approximately 3:7) and grind it to -200 mesh. Use a mixture of calcium hydroxide and manganese chloride as the chlorinating agent, with a mass ratio of calcium hydroxide to manganese chloride of 1:2 and a chlorinating agent to ore mass ratio of 1.8:1. Grind and mix the two thoroughly, and calcine the resulting mixture at 850 °C for 2 h. After the calcined material cools to room temperature, grind and disperse it thoroughly again, and add deionized water at a solid-liquid ratio of 1:3 to form a slurry. Place the slurry in a constant temperature water bath and heat and stir for leaching at 90 °C for 0.5 h. After leaching, the slurry was filtered, and the leaching residue was washed once with water at a solid-liquid ratio of 1:5. The washing liquid and leaching filtrate were collected and mixed. The filter cake obtained from filtration was dried at 120 °C to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and the mixed liquid were measured. Based on this, the leaching rates of lithium and potassium were calculated to be 80.24% and 71.01%, respectively, and aluminum, silicon, and magnesium were not detected in the leaching solution.

[0034] Example 2

[0035] The operation process for clay lithium ore is the same as in Example 1, except that a mixture of calcium carbonate and ammonium chloride is used as the chlorinating agent, with a mass ratio of calcium carbonate to ammonium chloride of 1:1. The clay lithium ore particle size is -150 mesh, the chlorinating agent:ore mass ratio is 2:1, the roasting temperature is 850 ℃, the roasting time is 1.5 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ℃, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:3. The washing liquid and leaching filtrate obtained from the mixture are collected, and the filter cake obtained from the filtration is dried at 120 ℃ to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and the mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 81.20% and 69.98%, respectively, and aluminum, silicon, and magnesium are not detected in the leaching solution.

[0036] Example 3

[0037] The clay lithium ore and operation process are the same as in Example 1, except that a mixture of ammonium chloride and calcium oxide is used as the chlorinating agent, with a calcium oxide to ammonium chloride mass ratio of 1:2. The clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 1.5:1, the roasting temperature is 800 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 85 ℃, the leaching time is 1 h, and the washing solid-liquid ratio is 1:3. The mixed washing liquid and leaching filtrate are collected, and the filter cake obtained from filtration is dried at 120 ℃ to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 84.01% and 71.38%, respectively, and aluminum, silicon, and magnesium are not detected in the leaching solution.

[0038] Example 4

[0039] The clay lithium ore and operation process are the same as in Example 1, except that a mixture of calcium oxalate and ammonium chloride is used as the chlorinating agent, wherein the mass ratio of calcium oxalate to ammonium chloride is 1.2:1, the clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 2:1, the roasting temperature is 900 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 90 ℃, the leaching time is 1 h, and the washing solid-liquid ratio is 1:5. The resulting washing liquid and leaching filtrate are collected, and the filter cake obtained is dried at 120 ℃ to obtain leaching residue. The contents of lithium, potassium, etc., in the leaching residue and the mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 78.81% and 65.30%, respectively, and aluminum, silicon, and magnesium are undetectable in the leaching solution.

[0040] Example 5

[0041] The clay lithium ore and the operation process are the same as in Example 1. A mixture of calcium hydroxide and manganese chloride is used as the chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:2, and the mass ratio of chlorinating agent to ore is 1.8:1. The resulting mixture is roasted at 800 °C for 1.5 h. The leaching solid-liquid ratio is 1:3, the leaching temperature is 90 °C, the leaching time is 1 h, and the washing solid-liquid ratio is 1:5. The washing liquid and leaching filtrate obtained from the mixture are collected. The filter cake obtained from the filtration is dried at 120 °C to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and the mixture are measured. Based on this, the leaching rates of lithium and potassium are calculated to be 86.94% and 74.51%, respectively, and aluminum, silicon, and magnesium are not detected in the leaching solution.

[0042] Example 6

[0043] The clay lithium ore and the operation process are the same as in Example 1. A mixture of calcium hydroxide and manganese chloride is used as the chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:4, and the mass ratio of chlorinating agent to ore is 1.8:1. The resulting mixture is roasted at 800 °C for 1.5 h. The leaching solid-liquid ratio is 1:3, the leaching temperature is 90 °C, the leaching time is 1 h, and the washing solid-liquid ratio is 1:5. The washing liquid and leaching filtrate obtained from the mixture are collected. The filter cake obtained from the filtration is dried at 120 °C to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and the mixture are measured. Based on this, the leaching rates of lithium and potassium are calculated to be 68.92% and 20.82%, respectively. The magnesium concentration in the leaching solution is 0.7 g / L, the aluminum concentration is 0.12 g / L, and the silicon concentration is 0.061 g / L.

[0044] Comparative Example 1

[0045] The clay lithium ore and operation process are the same as in Example 1, except that sodium chloride is used as the chlorinating agent, the clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 1:1, the roasting temperature is 850 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 90 ℃, the leaching time is 1 h, and the washing solid-liquid ratio is 1:5. The mixed washing liquid and leaching filtrate are collected, and the filter cake obtained from filtration is dried at 120 ℃ to obtain leaching residue. The lithium, potassium, and other contents in the leaching residue and mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 12.72% and 10.79%, respectively. The magnesium concentration in the leaching solution is 0.1 g / L, the aluminum concentration is 0.035 g / L, and the silicon concentration is 0.076 g / L.

[0046] Comparative Example 2

[0047] The clay lithium ore and operation process are the same as in Example 1, except that a mixture of sodium sulfate, sodium chloride, and calcium oxide is used as the chlorinating agent in a mass ratio of 4:1:1. The clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 1:1, the roasting temperature is 850 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 90 ℃, the leaching time is 1 h, and the washing solid-liquid ratio is 1:5. The mixed washing liquid and leaching filtrate are collected, and the filter cake obtained from filtration is dried at 120 ℃ to obtain leaching residue. The lithium, potassium, and other contents in the leaching residue and mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 62.12% and 11.19%, respectively. The magnesium concentration in the leaching solution is 0.9 g / L, the aluminum concentration is 0.05 g / L, and the silicon concentration is 0.087 g / L.

[0048] Comparative Example 3

[0049] The operation process for clay lithium ore is the same as in Example 1, except that a mixture of calcium carbonate and ammonium chloride is used as the chlorinating agent, with a mass ratio of calcium carbonate to ammonium chloride of 1:1. The clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 0.5:1, the roasting temperature is 850 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ℃, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:5. The washing liquid and leaching filtrate obtained from the mixture are collected, and the filter cake obtained from the filtration is dried at 120 ℃ to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and the mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 35.67% and 26.88%, respectively. Aluminum, silicon, and magnesium are not detected in the leaching solution.

[0050] Comparative Example 4

[0051] The clay lithium ore and operation process are the same as in Example 1, except that a mixture of calcium chloride and sodium chloride is used as the chlorinating agent, with a mass ratio of calcium chloride to sodium chloride of 1:1. The clay lithium ore particle size is -200 mesh, the chlorinating agent:ore mass ratio is 0.5:1, the roasting temperature is 850 ℃, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ℃, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:5. The mixed washing liquid and leaching filtrate are collected, and the filter cake obtained by filtration is dried at 120 ℃ to obtain leaching residue. The contents of lithium, potassium, etc. in the leaching residue and mixed liquid are measured. The leaching rates of lithium and potassium are calculated to be 26.19% and 20.71%, respectively. The magnesium concentration in the leaching solution is 0.2 g / L, the aluminum concentration is 0.022 g / L, and the silicon concentration is 0.12 g / L.

Claims

1. A method for simultaneously extracting lithium and potassium from clay lithium ore, characterized by comprising the following steps: Step one The clay lithium ore is crushed and ball milled to obtain clay lithium ore powder, which is uniformly mixed with a certain chlorinating agent by grinding to obtain a uniform mixture; the clay lithium ore contains independent mineral phases of lithium and potassium, and the independent mineral phases include lithium chlorite and illite; the chlorinating agent is composed of A and B, wherein A is at least one selected from calcium hydroxide, calcium carbonate, calcium oxalate and calcium oxide, and B is at least one selected from manganese chloride and ammonium chloride, and the mass ratio of B / A is greater than or equal to 0.8; Step two The uniform mixture obtained in step one is calcined at a proper calcination temperature and time, and after complete cooling, a calcined clinker is obtained; Step three The calcined clinker obtained in step two is stirred and leached with deionized water, and the proper solid-liquid ratio, leaching temperature and leaching time are controlled, and after the reaction is complete and cooling, the filter cake is washed with clean water, the leaching solution obtained by washing is mixed with the filtrate, and a lithium and potassium-rich leaching solution is obtained.

2. A process for the simultaneous extraction of lithium and potassium from a clay lithium ore as claimed in claim 1, characterized in that: The chlorinating agent is a mixture of calcium hydroxide and manganese chloride, or; the chlorinating agent is a mixture of calcium hydroxide and ammonium chloride, or; the chlorinating agent is a mixture of calcium carbonate and ammonium chloride, or; the chlorinating agent is a mixture of calcium oxalate and ammonium chloride, or; the chlorinating agent is a mixture of ammonium chloride and calcium oxide.

3. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The chlorinating agent is composed of calcium oxide and ammonium chloride in a mass ratio of 1:1.7~2.5; or the chlorinating agent is composed of calcium hydroxide and manganese chloride in a mass ratio of 1:1.7~2.

5.

4. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The particle size of the clay lithium ore powder in step one is -100~-300 mesh.

5. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The mass ratio of the chlorinating agent to the clay lithium ore in step one is 0.6~3:

1.

6. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The calcination temperature in step two is 500~1000 ℃.

7. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The calcination time in step two is 0.5~2.5 h.

8. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The water leaching temperature in step three is 25~90 ℃, the time is 0.5~4 h, and the solid-liquid ratio is 1:0.5~8.

9. A process for simultaneous extraction of lithium and potassium from clay lithium ores as claimed in claim 1, wherein: The method can extract lithium and potassium from clay lithium ore with an extraction rate of more than 80% and 70%, respectively.