Method for simultaneously extracting lithium and potassium from clay lithium ore

Abstract

The invention relates to a method for simultaneously extracting lithium and potassium from clay lithium ore, which mainly comprises the following steps of: fully grinding and uniformly mixing crushed and ball-milled clay lithium ore powder and a specific chlorinating agent, and roasting, so that lithium and potassium in the clay ore are converted into soluble salts, and aluminum, magnesium, silicon and the like are transferred into a complex silicate phase which is difficult to dissolve in water; and leaching the obtained roasted clinker with deionized water, and carrying out solid-liquid separation to obtain a leaching solution rich in lithium and potassium, thereby achieving the purpose of efficiently extracting lithium and potassium from the clay lithium ore. According to the method, the clay lithium ore which is low in grade and large in reserves is comprehensively utilized, the process design is reasonable, the resource utilization rate is high, the method is green and environmentally friendly, and large-scale industrial production is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive resource utilization, and in particular relates to a method for simultaneously extracting lithium and potassium from a clay lithium ore containing lithium and potassium through a roasting-water leaching process. Background Art

[0002] With the vigorous development of electric vehicles and new energy storage technologies, the demand for lithium-ion batteries has increased significantly, which has directly led to the rapid growth of lithium raw material consumption. Therefore, it is necessary to develop efficient processes for extracting lithium from various lithium resources to meet the rapidly growing market demand. At present, there are three main types of lithium resources in my country: salt lake brine, hard rock lithium ore and unconventional lithium-containing ores. Among them, high-grade salt lake brine and hard rock lithium ore, as conventional lithium resources, are the main sources of lithium compound production. However, due to limited resource reserves and rapid reserve consumption, it can be foreseen that these conventional lithium resources will be difficult to meet the current volatile market demand.

[0003] Lithium clay ore is usually a companion mineral in sedimentary deposits such as bauxite and coal. It has large reserves and wide distribution. It is a typical unconventional lithium resource. In recent years, a large number of lithium-containing clay rock deposits have been discovered in my country, which has attracted widespread attention and has been extensively developed and utilized. People have tried different technical methods, including direct leaching, roasting acid leaching, additive roasting water leaching and roasting ion exchange leaching, to extract lithium from these lithium-containing clay rock resources. However, due to the low lithium content and complex composition of lithium-containing clay rock, the leaching solution obtained by these methods usually contains a large amount of impurity ions, such as Al 3+ Mg 2+ The subsequent purification of the leaching solution is difficult. The Al(OH)3 and Mg(OH)2 produced during purification have strong adsorption to lithium ions, which seriously affects the recovery rate of lithium. In addition, the treatment technology currently reported is mainly aimed at clay lithium ores without independent lithium mineral phases. The lithium in this type of clay lithium ores is mainly adsorbed between the mineral structure layers of montmorillonite, kaolinite, etc., so it is difficult to recover other valuable metals such as potassium when extracting lithium. Summary of the invention

[0004] The purpose of the present invention is to provide a method for simultaneously extracting lithium and potassium from a clay lithium ore containing independent mineral phases of lithium and potassium (lithium chlorite and illite). The method focuses on fully grinding and mixing the clay lithium ore powder after crushing and ball milling with a chlorinating agent and then roasting. During the roasting process, the lithium chlorite and illite phases in the clay ore react with the chlorinating agent at the same time to be converted into a thermodynamically stable and water-insoluble complex silicate phase and a water-soluble lithium salt phase. The obtained roasted clinker is leached with deionized water, and after solid-liquid separation, a leaching solution rich in lithium and potassium but not containing aluminum and magnesium ions is obtained, thereby achieving the purpose of efficiently extracting lithium and potassium elements from the clay lithium ore.

[0005] The present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore, which is characterized by comprising the following steps: Step 1 The clay lithium ore is crushed and ball-milled to obtain clay lithium ore powder, and the clay lithium ore powder is fully ground and mixed with a certain 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 is composed 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, and in terms of 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; Step 2 The uniform mixture obtained in step 1 is roasted, and the roasting temperature and time are controlled appropriately, and after being completely cooled, a roasted clinker is obtained; Step 3 The roasted clinker obtained in step 2 is stirred and leached with deionized water, and the appropriate leaching liquid-solid ratio, leaching temperature and leaching time are controlled. After the reaction is complete and cooled, it is filtered, and the filter cake is washed with clean water. The washing solution is mixed with the filtrate to obtain a lithium- and potassium-rich leaching solution.

[0006] 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 ore.

[0007] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore, wherein the lithium in the clay lithium ore exists in the lithium chlorite phase, and the potassium exists in the illite phase.

[0008] Preferably, the present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore. 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.

[0009] As a further preference, 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.

[0010] The present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore. In step 1, the particle size of the clay lithium ore powder is -100 to -300 mesh, preferably -100 to -200 mesh.

[0011] The present invention relates to a method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, wherein in step 1, the mass ratio of the chlorinating agent to the clay lithium ore is 0.6-3:1, preferably 0.8-2:1.

[0012] The present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore. In step 2, the roasting temperature is 500-1000°C, preferably 750-850°C.

[0013] The present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore. In step 2, the roasting time is 0.5 to 2.5 hours, preferably 1 to 2 hours.

[0014] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. In step 3, the water immersion temperature is 25-90°C, preferably 60-90°C, the leaching time is 0.5-4 hours, preferably 0.5-2 hours, the solid-liquid ratio is 1:0.5-8, preferably 1:2-3, and the leached residue is washed, and the washing solid-liquid ratio is 1:3-5.

[0015] As one of the best solutions, the present invention provides a method for simultaneously extracting lithium and potassium from clay lithium ore, using a mixture of calcium hydroxide and manganese chloride as a chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:1.9-2.1, the mass ratio of chlorinating agent: ore is 1.7-1.9:1, the obtained mixture is roasted at 790-810°C, the roasting time is 80-100min, the leaching solid-liquid ratio is 1:2.5-3.5, the leaching temperature is 85-90°C, the leaching time is 50-70min, the washing solid-liquid ratio is 1:4-5, and the washing liquid and the leaching filtrate obtained by mixing are collected.

[0016] The present invention discloses a method for simultaneously extracting lithium and potassium from clay lithium ore. By adopting the method, the extraction rates of lithium and potassium in the clay lithium ore can reach 80% and 70% or more respectively, and after optimization, the extraction rates of lithium and potassium can reach 85% and 74% or more respectively.

[0017] Principles and advantages The invention is guided by theoretical thermodynamic calculation, and adopts a specific chlorinating agent to fully grind and mix with clay lithium ore powder and then roast at high temperature. During the roasting process, lithium-containing mineral phase lithium chlorite [LiAl4(Si3Al)O 10 (OH)8] and potash-bearing illite [KAl2(Si3Al)O 10 (OH)2] reacts with the chlorinating agent at the same time, converting the lithium and potassium in it into lithium chloride and potassium chloride soluble in water, while aluminum, magnesium, silicon, etc. are converted into MgAl2Si2O8, CaAl2Si2O8, Al2SiO5, Ca3Al2Si3O 12 、Al6Si2O 13Finally, through water leaching, lithium, potassium and impurity elements such as magnesium, aluminum and silicon are efficiently separated, so as to achieve the purpose of efficiently extracting lithium and potassium from clay lithium ore containing independent phases of lithium chlorite and illite.

[0018] Compared with the existing technology, the technical ideas and process principles of the present invention have significant characteristics and technical advantages, which are specifically manifested in: (1) The present invention combines the thermodynamic properties of the independent phases of lithium chlorite and illite in the clay lithium ore, selects a specific chlorinating agent to react with it with roasting and then leaching in water, thereby achieving the purpose of simultaneously extracting lithium and potassium from the ore, which not only improves the comprehensive utilization rate of mineral resources, but also avoids the environmental impact caused by processes such as acid leaching or acid roasting; In the process of extracting lithium and potassium, the aluminum and magnesium in the ore are converted into MgAl2Si2O8, CaAl2Si2O8, Al2SiO5, Ca3Al2Si3O 12 、Al6Si2O 13 Complex silicate phases that are difficult to dissolve in water will not enter the leaching solution, which reduces the burden of the subsequent leaching solution purification process and is conducive to improving the comprehensive recovery rate of lithium; After the roasted ore is water-leached in the present invention, the main impurity ions in the obtained leaching solution, in addition to lithium and potassium, are calcium ions. The calcium carbonate or calcium oxalate produced when the leaching solution is purified can be recycled as a component of a chlorinating agent, so that a large amount of lithium loss will not be caused due to impurity removal, thereby further improving the comprehensive lithium recovery rate of the overall process and reducing the discharge of three wastes.

[0019] (4) The low melting point component in the chlorinating agent used in the present invention can form a molten state at a relatively low temperature, thereby ensuring that it can fully contact the lithium-containing ore phase and the potassium-containing ore phase in the clay lithium ore in a liquid-solid contact manner at a relatively low temperature, providing a material transmission channel for the two components in the chlorinating agent to synergistically realize the efficient conversion of lithium and potassium in the clay ore, ensuring that both lithium and potassium have a high recovery rate, and at the same time, there is no need to extrude or repeatedly grind the raw materials and roasting materials, and the process is simple. DETAILED DESCRIPTION

[0020] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0021] Unless otherwise specified, all reagents and raw materials used in the present invention are commercially available products or products that can be prepared by known methods.

[0022] The specific implementation of the present invention is as follows:

[0023] Embodiment 1

[0024] Weigh 25.00 g of clay lithium ore (containing lithium chlorite and illite at the same time, with a mass ratio of about 3:7) and grind it to -200 mesh. Use a mixture of calcium hydroxide and manganese chloride as a chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:2, and the mass ratio of chlorinating agent: ore is 1.8:1. Grind and mix the two thoroughly, and calcine the resulting mixture at 850 °C for 2 h. After the calcined material is cooled to room temperature, it is fully ground and dispersed again, and deionized water is added at a solid-liquid ratio of 1:3 to prepare a slurry, which is placed in a constant temperature water bath for heating and stirring for leaching. The leaching temperature is 90 °C and the leaching time is 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 mixed washing liquid and leaching filtrate were collected, and the filter cake obtained by filtration was dried at 120 °C to obtain the 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 no aluminum, silicon and magnesium were detected in the leachate.

[0025] Embodiment 2 The clay lithium ore and the operation process are the same as in Example 1, except that a mixture of calcium carbonate and ammonium chloride is used as a chlorinating agent, wherein the mass ratio of calcium carbonate to ammonium chloride is 1:1, the particle size of the clay lithium ore is -150 mesh, the chlorinating agent: ore mass ratio is 2:1, the roasting temperature is 850 ° C, the roasting time is 1.5 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ° C, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:3. The washing liquid and the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain a leaching residue, and the contents of lithium, potassium, etc. in the leaching residue and the mixed solution 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 leachate.

[0026] Embodiment 3 The clay lithium ore and the operation process are the same as in Example 1, except that a mixture of ammonium chloride and calcium oxide is used as a chlorinating agent, wherein the mass ratio of calcium oxide to ammonium chloride is 1:2, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 1.5:1, the roasting temperature is 800 ° C, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 85 ° C, the leaching time is 1 h, and the washing solid-liquid ratio is 1:3. The washing liquid and the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain the leaching residue, and the contents of lithium, potassium, etc. in the leaching residue and the mixed solution 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 leachate.

[0027] Embodiment 4 The clay lithium ore and the operation process are the same as in Example 1, except that a mixture of calcium oxalate and ammonium chloride is used as a chlorinating agent, wherein the mass ratio of calcium oxalate to ammonium chloride is 1.2:1, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 2:1, the roasting temperature is 900 ° C, the roasting time is 2 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 the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain a leaching residue, and the contents of lithium, potassium, etc. in the leaching residue and the mixed solution 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 not detected in the leachate.

[0028] Embodiment 5 Clay lithium ore, the operation process is the same as in Example 1, using a mixture of calcium hydroxide and manganese chloride as a chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:2, and the chlorinating agent: ore mass ratio is 1.8:1, and the obtained mixture is roasted at 800 ° C, the roasting time is 1.5 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 90 ° C, the leaching time is 1 h, the washing solid-liquid ratio is 1:5, the washing liquid and the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain a leaching residue, and the contents of lithium, potassium, etc. in the leaching residue and the mixed solution are measured. 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 leachate.

[0029] Embodiment 6 Clay lithium ore, the operation process is the same as that in Example 1, using a mixture of calcium hydroxide and manganese chloride as a chlorinating agent, wherein the mass ratio of calcium hydroxide to manganese chloride is 1:4, and the mass ratio of chlorinating agent: ore is 1.8:1, and the obtained mixture is roasted at 800 ° C, the roasting time is 1.5 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 90 ° C, the leaching time is 1 h, the washing solid-liquid ratio is 1:5, the washing liquid and the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain a leached residue, and the contents of lithium, potassium, etc. in the leached residue and the mixed solution are measured. The leaching rates of lithium and potassium are calculated to be 68.92% and 20.82%, respectively, and the magnesium concentration in the leachate is 0.7 g / L, the aluminum concentration is 0. 12 g / L, and the silicon concentration is 0.061 g / L.

[0030] Comparative Example 1 The clay lithium ore and the operation process are the same as in Example 1, except that sodium chloride is used as the chlorinating agent, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 1:1, the roasting temperature is 850 ° C, the roasting time is 2 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 the leaching filtrate obtained by mixing are collected, and the filter cake obtained by filtration is dried at 120 ° C to obtain the leaching residue, and the contents of lithium, potassium, etc. in the leaching residue and the mixed solution are measured. The leaching rates of lithium and potassium are calculated to be 12.72% and 10.79%, respectively, and 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.

[0031] Comparative Example 2 Clay lithium ore, the operation process is the same as in Example 1, except that a mixture of sodium sulfate, sodium chloride and calcium oxide is used as a chlorinating agent, the mass ratio of which is 4:1:1, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 1:1, the roasting temperature is 850 ° C, the roasting time is 2 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. Collect the mixed washing liquid and the leaching filtrate, dry the filter cake obtained by filtration at 120 ° C to obtain the leaching residue, and measure the contents of lithium, potassium, etc. in the leaching residue and the mixed solution. 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.

[0032] Comparative Example 3 The clay lithium ore and the operation process are the same as in Example 1, except that a mixture of calcium carbonate and ammonium chloride is used as a chlorinating agent, wherein the mass ratio of calcium carbonate to ammonium chloride is 1:1, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 0.5:1, the roasting temperature is 850 ° C, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ° C, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:5. Collect the mixed washing liquid and the leaching filtrate, dry the filter cake obtained by filtration at 120 ° C to obtain the leaching residue, and measure the content of lithium, potassium, etc. in the leaching residue and the mixed solution. The leaching rates of lithium and potassium are calculated to be 35.67% and 26.88%, respectively, and aluminum, silicon and magnesium cannot be detected in the leachate.

[0033] Comparative Example 4 Clay lithium ore, the operation process is the same as in Example 1, except that a mixture of calcium chloride and sodium chloride is used as a chlorinating agent, wherein the mass ratio of calcium chloride to sodium chloride is 1:1, the particle size of the clay lithium ore is -200 mesh, the chlorinating agent: ore mass ratio is 0.5:1, the roasting temperature is 850 ° C, the roasting time is 2 h, the leaching solid-liquid ratio is 1:3, the leaching temperature is 80 ° C, the leaching time is 1.5 h, and the washing solid-liquid ratio is 1:5. Collect the mixed washing liquid and the leaching filtrate, dry the filter cake obtained by filtration at 120 ° C to obtain the leaching residue, and measure the contents of lithium, potassium, etc. in the leaching residue and the mixed solution. The leaching rates of lithium and potassium are calculated to be 26.19% and 20.71%, respectively, the magnesium concentration in the leachate 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 in that it comprises the following steps: Step 1 The clay lithium ore is crushed and ball-milled to obtain clay lithium ore powder, and the clay lithium ore powder is fully ground and mixed with a certain chlorinating agent 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 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, and in terms of mass ratio, B / A is greater than or equal to 0.8; Step 2 The uniform mixture obtained in step 1 is roasted, and the roasting temperature and time are controlled appropriately, and after being completely cooled, a roasted clinker is obtained; Step 3 The roasted clinker obtained in step 2 is stirred and leached with deionized water, and the appropriate leaching liquid-solid ratio, leaching temperature and leaching time are controlled. After the reaction is complete and cooled, it is filtered, and the filter cake is washed with clean water. The washing solution is mixed with the filtrate to obtain a lithium- and potassium-rich leaching solution.

2. A method for simultaneously extracting lithium and potassium from clay lithium ore according to 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 one or more of a mixture of ammonium chloride and calcium oxide.

3. A method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: 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. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: The particle size of the clay lithium ore powder in step 1 is -100~-300 mesh.

5. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: The mass ratio of the chlorinating agent to the clay lithium ore in step 1 is 0.6-3:

1.

6. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: The calcination temperature in step 2 is 500-1000°C.

7. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: The calcination time in step 2 is 0.5~2.5 h.

8. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: In step three, the water immersion temperature is 25~90°C, the time is 0.5~4 h, and the solid-liquid ratio is 1:0.5~8.

9. The method for simultaneously extracting lithium and potassium from clay lithium ore according to claim 1, characterized in that: By using this method, the extraction rates of lithium and potassium in clay lithium ore can reach over 80% and 70% respectively.