Hydrometallurgical process for recovering lithium from lithium-containing minerals and aqueous lithium solution recovered therefrom

Abstract

To provide a hydrometallurgical method for recovering lithium from a lithium-containing mineral through calcination and water leaching with a metal oxide without excessive use of chemicals, and a lithium aqueous solution recovered therefrom.SOLUTION: A hydrometallurgical method for recovering lithium from a lithium-containing mineral comprises the steps of: crushing and pulverizing a lithium-containing mineral; heat-treating the crushed and pulverized lithium-containing mineral; mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, water leaching the mixture, followed by solid-liquid separation into a primary lithium water leachate and a primary leach residue; calcining the primary leach residue; water leaching the calcined primary leach residue, followed by solid-liquid separation into a secondary lithium water leachate and a secondary leach residue; and recovering lithium from the primary lithium water leachate or the secondary lithium water leachate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrometallurgical process for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive chemical use, and to the aqueous lithium solutions recovered therefrom. [Background technology]

[0002] Lithium is the lightest metal element, and industries that utilize lithium are diverse, including batteries (74%), glass and ceramics (14%), lubricants (3%), continuous casting (2%), polymer production (2%), and air treatment (1%).

[0003] In particular, the battery market has grown significantly in recent years as demand for lithium-ion batteries used in electric vehicles, energy storage systems, and portable electronic products has increased dramatically.

[0004] This is expected to lead to explosive growth in demand for lithium compounds, which are key raw materials for the cathode, anode, and electrolyte of lithium-ion batteries.

[0005] To meet this demand, lithium production has increased significantly from 28,100 tons in 2010 to 82,500 tons in 2020, and is expected to increase to approximately 100,000 tons in 2021.

[0006] Demand for lithium-ion batteries, which was 244 GWh in 2021, is expected to grow significantly to 3,254 GWh with an average annual growth rate of approximately 34% until 2030. In other words, the production volume of lithium compounds is expected to continue to increase.

[0007] Lithium is produced from mineral resources and salt lake resources, mostly in the form of lithium carbonate. However, mineral resources are concentrated in Australia, while salt lake resources are concentrated in South America, such as Argentina, Bolivia, and Chile. Thus, lithium resources are highly unevenly distributed.

[0008] Lithium-containing mineral resources include spodumene (LiAlSi2O6), lepidolite (K(Li,Al)3(Si,Al)4O 10 (F,OH)2), zinnwaldite(KLiFeAl(AlSi3)O 10 (F,OH)2), and amblygonite ((Li,Na)Al(PO4)(F,OH)).

[0009] A typical lithium mineral is spodumene, which contains 6-9% Li2O, and commercial processes for recovering lithium from spodumene include the sulfuric acid method and the SiLeach (registered trademark) process in Australia.

[0010] In the sulfuric acid method, a highly concentrated sulfuric acid solution of 93% or more is used to extract lithium from β-spodumene in the form of lithium sulfate.

[0011] The SiLeach® process uses a mixture of sulfuric acid and hydrofluoric acid to leach lithium from α-spodumene.

[0012] Thus, the recovery of lithium from lithium minerals requires highly concentrated acidic solutions, which inevitably necessitates excessive use of chemicals.

[0013] Therefore, the applicant has made various efforts and researches to obtain a hydrometallurgical method for recovering lithium from lithium-containing minerals by calcination and water leaching of metal oxides without using excessive chemicals, and has thus completed the present invention. [Prior art documents] [Patent documents]

[0014] Korean Patent Publication No. 10-2021-0010576 (Patent Publication Date: January 27, 2021) Summary of the Invention [Problem to be solved by the invention]

[0015] It is therefore an object of the present invention to provide a hydrometallurgical process for recovering lithium from lithium-containing minerals by calcination and water leaching of the metal oxides without excessive chemical usage.

[0016] It is also an object of the present invention to provide an aqueous lithium solution recovered by a hydrometallurgical process for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive chemical use.

[0017] The problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0018] In order to solve the above problem, according to one aspect of the present invention, 1. A hydrometallurgical process for recovering lithium from lithium-bearing minerals by calcination and aqueous leaching of alkali metal or alkaline earth metal oxides, comprising: (a-1) crushing and pulverizing a lithium-containing mineral; (a-2) heat-treating the crushed and pulverized lithium-containing mineral; (a-3) mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation; (a-4) calcining the primary leaching residue; (a-5) leaching the calcined primary leaching residue with water, followed by solid-liquid separation to separate the secondary lithium aqueous leaching solution and the secondary leaching residue; and (a-6) recovering lithium from the first lithium aqueous leachate or the second lithium aqueous leachate; A hydrometallurgical process for recovering lithium from lithium-bearing minerals is provided.

[0019] According to one embodiment of the present invention, in the step (a-1) of crushing and pulverizing the lithium-containing mineral, crushing and pulverizing the lithium-containing mineral with one or more pieces of equipment selected from the group consisting of a Jaw Crusher, a Gyratory Crusher, a Roller Crusher, a Cone Crusher, a Hammermill Crusher, a Tumbling Mill, a Vibration Mill, an Attrition Mill, a Ball Mill, a Rod Mill, a Pebble Mill, and an Autogeneous Mill to produce a crushed and pulverized lithium-containing mineral; The crushed and pulverized lithium-containing mineral may have a particle size of 5 to 300 μm.

[0020] According to one embodiment of the present invention, the lithium-containing mineral is spodumene (LiAlSi2O6), lepidolite (K(Li,Al)3(Si,Al)4O 10 (F,OH)2), Zinnwaldite (KLiFeAl(AlSi3)O 10 The crystalline ...

[0021] According to one embodiment of the present invention, in the step (a-2) of heat treating the crushed and pulverized lithium-containing mineral, The heat treatment is carried out at a temperature of 500 to 1000°C for 10 minutes to 6 hours, by introducing at least one gas selected from nitrogen, argon, and air under pressure conditions at atmospheric pressure; When the lithium-containing mineral is spodumene (LiAlSi2O6), The method may further include a step of heat treating to effect a phase transformation from the α-phase to the β-phase.

[0022] According to one embodiment of the present invention, in the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The type of the alkali metal or alkaline earth metal oxide may be at least one selected from calcium oxide (CaO), magnesium oxide (MgO), potassium oxide (K2O), and sodium oxide (Na2O).

[0023] According to one embodiment of the present invention, in the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The water leaching is carried out by adding a mixture of a lithium-containing mineral (A) and a metal oxide (B) to water so that the mixture has a mass ratio (B / A) of 1 to 6, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0024] According to an embodiment of the present invention, the lithium leaching rate of the primary lithium aqueous leaching solution may be 1 to 35 wt%.

[0025] According to one embodiment of the present invention, in the step (a-4) of calcining the primary leaching residue, Under the above calcination process conditions, the leaching residue is heat-treated at a temperature equal to or higher than the temperature at which the Gibbs free energy of the calcination reaction becomes 0, The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0026] According to one embodiment of the present invention, in the step (a-5) of leaching the calcined primary leaching residue with water and then separating the secondary lithium aqueous leaching solution and the secondary leaching residue by solid-liquid separation, The water leaching is carried out by adding the calcined primary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0027] According to one embodiment of the present invention, the step (a-5) of separating the calcined primary leaching residue into a secondary lithium aqueous leachate and a secondary leach residue by solid-liquid separation after leaching the calcined primary leach residue with water includes: (a-7) further comprising the step of calcining the secondary leaching residue; The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0028] According to one embodiment of the present invention, the step (a-7) of calcining the secondary leaching residue comprises: (a-8) further comprising a step of leaching the calcined secondary leaching residue with water and then separating the calcined secondary leaching residue into a third lithium aqueous leachate and a third leach residue through solid-liquid separation; The water leaching is carried out by adding the calcined secondary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0029] According to one embodiment of the present invention, the step (a-8) of separating the calcined secondary leaching residue into a third lithium aqueous leachate and a third leach residue by solid-liquid separation after leaching the calcined secondary leach residue with water includes: (a-9) further comprising the step of calcining the tertiary leaching residue; The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0030] According to one embodiment of the present invention, the step (a-9) of calcining the tertiary leaching residue comprises: (a-10) further comprising a step of subjecting the calcined third leach residue to water leaching and then separating the calcined third leach residue into a fourth lithium aqueous leachate and a fourth leach residue by solid-liquid separation; The water leaching is carried out by adding the calcined tertiary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0031] According to another aspect of the present invention, The present invention provides an aqueous lithium solution recovered by the hydrometallurgical method for recovering lithium from the lithium-containing mineral. [Effects of the Invention]

[0032] The present invention provides a hydrometallurgical process for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive chemical usage, thereby reducing chemical waste disposal costs and reducing lithium recovery costs.

[0033] Furthermore, the present invention provides an aqueous lithium solution recovered by a hydrometallurgical method for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive use of the chemicals, making it applicable to industry, and therefore has a wide range of applications.

[0034] It should be understood that the effects of the present invention are not limited to the above effects, but include any effects that can be inferred from the configuration of the invention described in the detailed description of the present invention or the claims. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a process flow diagram of a hydrometallurgical method for recovering lithium from lithium-bearing minerals according to one embodiment of the present invention. [Figure 2]1 is a particle size cumulative distribution diagram obtained by particle size analysis of spodumene according to an embodiment of the present invention. [Figure 3] 1 shows XRD analysis results of a spodumene sample before and after heat treatment according to an embodiment of the present invention. [Figure 4] 1 shows the XRD analysis results of the leaching residue obtained after water leaching of a CaO / Spodumene mixture according to an embodiment of the present invention. [Figure 5] 1 shows the XRD analysis results of the calcined product of the leaching residue of the water leaching according to one embodiment of the present invention after calcining at 900° C. for 6 hours. [Figure 6] 1 shows an XRD analysis result of a leaching residue obtained after a fourth water leaching according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0036] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] The advantages and features of the present invention, as well as the manner in which they are achieved, will become more apparent from the following detailed description of the preferred embodiments in conjunction with the accompanying drawings.

[0038] However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. However, these embodiments are provided to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

[0039] Furthermore, when describing the present invention, if it is determined that related publicly known techniques may obscure the gist of the present invention, detailed description thereof will be omitted.

[0040] The present invention will be described in detail below.

[0041] [Hydrometallurgical process for recovering lithium from lithium-bearing minerals] The present invention provides a hydrometallurgical process for recovering lithium from lithium-bearing minerals by calcination and water leaching with metal oxides without excessive chemical usage.

[0042] The present invention provides a hydrometallurgical process for recovering lithium from lithium-bearing minerals by calcination and aqueous leaching of alkali metal or alkaline earth metal oxides, comprising: (a-1) crushing and pulverizing a lithium-containing mineral; (a-2) heat-treating the crushed and pulverized lithium-containing mineral; (a-3) mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation; (a-4) calcining the primary leaching residue; (a-5) leaching the calcined primary leaching residue with water, followed by solid-liquid separation to separate the secondary lithium aqueous leaching solution and the secondary leaching residue; and (a-6) recovering lithium from the primary lithium aqueous leachate or the secondary lithium aqueous leachate;

[0043] The present invention provides a hydrometallurgical method for recovering lithium from lithium-bearing minerals by calcination and water leaching with metal oxides without excessive chemical usage, thereby reducing chemical waste disposal costs and reducing lithium recovery costs.

[0044] Lithium is the lightest metal element, and industries that utilize lithium are diverse, including batteries (74%), glass and ceramics (14%), lubricants (3%), continuous casting (2%), polymer production (2%), and air treatment (1%).

[0045] In particular, the battery market has grown significantly in recent years as demand for lithium-ion batteries used in electric vehicles, energy storage systems, and portable electronic products has increased dramatically.

[0046] This is expected to lead to explosive growth in demand for lithium compounds, which are key raw materials for the cathode, anode, and electrolyte of lithium-ion batteries.

[0047] To meet this demand, lithium production has increased significantly from 28,100 tons in 2010 to 82,500 tons in 2020, and is expected to increase to approximately 100,000 tons in 2021.

[0048] Demand for lithium-ion batteries, which was 244 GWh in 2021, is expected to grow significantly to 3,254 GWh with an average annual growth rate of approximately 34% until 2030. In other words, the production volume of lithium compounds is expected to continue to increase.

[0049] Lithium is produced from mineral resources and salt lake resources, mostly in the form of lithium carbonate. However, mineral resources are concentrated in Australia, while salt lake resources are concentrated in South America, such as Argentina, Bolivia, and Chile. Thus, lithium resources are highly unevenly distributed.

[0050] Lithium-containing mineral resources include spodumene (LiAlSi2O6), lepidolite (K(Li,Al)3(Si,Al)4O 10 (F,OH)2), Zinnwaldite(KLiFeAl(AlSi3)O 10 (F,OH)2), and Amblygonite ((Li,Na)Al(PO4)(F,OH)).

[0051] A typical lithium mineral is spodumene, which contains 6-9% Li2O, and commercial processes for recovering lithium from spodumene include the sulfuric acid method and the SiLeach (registered trademark) process in Australia.

[0052] In the sulfuric acid method, a highly concentrated sulfuric acid solution of 93% or more is used to extract lithium from β-spodumene in the form of lithium sulfate.

[0053] The SiLeach® process uses a mixture of sulfuric acid and hydrofluoric acid to leach lithium from α-spodumene.

[0054] Thus, the recovery of lithium from lithium minerals requires highly concentrated acidic solutions, which inevitably necessitates excessive use of chemicals.

[0055] Therefore, the applicant has made various efforts and researches to obtain a hydrometallurgical method for recovering lithium from lithium-containing minerals by calcination and water leaching of metal oxides without using excessive chemicals, and has thus completed the present invention.

[0056] Here, in the step (a-1) of crushing and pulverizing the lithium-containing mineral, crushing and pulverizing the lithium-containing mineral with one or more pieces of equipment selected from the group consisting of a Jaw Crusher, a Gyratory Crusher, a Roller Crusher, a Cone Crusher, a Hammermill Crusher, a Tumbling Mill, a Vibration Mill, an Attrition Mill, a Ball Mill, a Rod Mill, a Pebble Mill, and an Autogeneous Mill to produce a crushed and pulverized lithium-containing mineral; The crushed and pulverized lithium-containing mineral may have a particle size of 5 to 300 μm.

[0057] In this case, the particle size of the crushed and pulverized lithium-containing mineral may be preferably 5 to 298 μm, and more preferably 5 to 295 μm.

[0058] The lithium-containing minerals include spodumene (LiAlSi2O6), lepidolite (K(Li,Al)3(Si,Al)4O 10(F,OH)2), Zinnwaldite (KLiFeAl(AlSi3)O 10 The crystalline ...

[0059] In addition, in the step (a-2) of heat treating the crushed and pulverized lithium-containing mineral, The heat treatment is carried out at a temperature of 500 to 1000°C for 10 minutes to 6 hours, by introducing at least one gas selected from nitrogen, argon, and air under pressure conditions at atmospheric pressure; When the lithium-containing mineral is spodumene (LiAlSi2O6), The method may further include a step of heat treating to effect a phase transformation from the α-phase to the β-phase.

[0060] If the heat treatment conditions are outside the above ranges, the heat treatment efficiency may decrease, which may be uneconomical.

[0061] In this case, the heat treatment temperature may be preferably 500 to 980°C, and more preferably 500 to 950°C.

[0062] The heat treatment time may preferably be 10 minutes to 5.8 hours, and more preferably 10 minutes to 5.5 hours.

[0063] Here, in the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The type of the alkali metal or alkaline earth metal oxide may be at least one selected from calcium oxide (CaO), magnesium oxide (MgO), potassium oxide (K2O), and sodium oxide (Na2O).

[0064] In addition, in the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The water leaching is carried out by adding a mixture of the lithium-containing mineral (A) that has undergone a phase transition to water and the metal oxide (B) so that the mass ratio (B / A) of the mixture is 1 to 6, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0065] Here, if the mixing ratio of the mixture of the phase-transformed lithium-containing mineral (A) and the metal oxide (B) during the water leaching is outside the above range, the water leaching efficiency may decrease, which may be uneconomical.

[0066] In this case, the mixture ratio of the lithium-containing mineral (A) that has undergone a phase transition during the water leaching and the metal oxide (B) may preferably be a mass ratio (B / A) of 1 to 5.8, more preferably a mass ratio (B / A) of 1 to 5.5.

[0067] Furthermore, if the reaction temperature during the water leaching is outside the above range, the efficiency of the water leaching may decrease, which may be uneconomical.

[0068] In this case, the reaction temperature during the water leaching may be preferably 25 to 98°C, and more preferably 25 to 95°C.

[0069] Furthermore, if the solid-liquid ratio during the water leaching is outside the above range, the efficiency of the water leaching decreases, which may be uneconomical.

[0070] At this time, the solid-liquid ratio during the water leaching may preferably be 1 / 20 to 1 / 8, and more preferably 1 / 15 to 1 / 8.

[0071] If the reaction time during the water leaching is outside the above range, the efficiency of the water leaching may decrease, which may be uneconomical.

[0072] In this case, the reaction time during the water leaching may preferably be 0.5 to 11.5 hours, and more preferably 0.5 to 11 hours.

[0073] The lithium leaching rate of the primary lithium aqueous leachate may be 1 to 35 wt %.

[0074] Then, in the step (a-4) of calcining the primary leaching residue, Under the above calcination process conditions, the leaching residue is heat-treated at a temperature equal to or higher than the temperature at which the Gibbs free energy of the calcination reaction becomes 0, The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0075] If the heat treatment temperature of the calcination reaction is outside the above range, the efficiency of the calcination reaction may decrease, which may be uneconomical.

[0076] At this time, the heat treatment temperature for the calcination reaction may be preferably 600 to 980°C, and more preferably 600 to 950°C.

[0077] In addition, in the step (a-5) of leaching the calcined primary leaching residue with water and then separating the secondary lithium aqueous leachate and the secondary leach residue by solid-liquid separation, The water leaching is carried out by adding the calcined primary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0078] Here, when the calcined primary leaching residue is leached with water, if the reaction temperature is outside the above range, the efficiency of leaching may decrease, which may be uneconomical.

[0079] At this time, the reaction temperature during the water leaching of the calcined primary leaching residue may be preferably 25 to 98°C, and more preferably 25 to 95°C.

[0080] Furthermore, if the solid-liquid ratio during the water leaching of the calcined primary leaching residue is outside the above range, the water leaching efficiency decreases, which may be uneconomical.

[0081] In this case, when the calcined primary leaching residue is leached with water, the solid-liquid ratio may preferably be 1 / 20 to 1 / 8, and more preferably 1 / 15 to 1 / 8.

[0082] Furthermore, if the reaction time during the water leaching of the calcined primary leaching residue is outside the above range, the water leaching efficiency may decrease, which may be uneconomical.

[0083] In this case, the reaction time during the water leaching of the calcined primary leaching residue may be 0.5 to 11.5 hours, and more preferably 0.5 to 11 hours.

[0084] The step (a-5) of subjecting the calcined primary leaching residue to aqueous leaching and then separating the resultant into a secondary lithium aqueous leaching solution and a secondary leaching residue by solid-liquid separation includes: (a-7) further comprising the step of calcining the secondary leaching residue; The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0085] If the heat treatment temperature of the calcination reaction is outside the above range, the efficiency of the calcination reaction may decrease, which may be uneconomical.

[0086] At this time, the heat treatment temperature for the calcination reaction may be preferably 600 to 980°C, and more preferably 600 to 950°C.

[0087] The step (a-7) of calcining the secondary leaching residue is (a-8) further comprising a step of leaching the calcined secondary leaching residue with water and then separating the calcined secondary leaching residue into a third lithium aqueous leachate and a third leach residue through solid-liquid separation; The water leaching is carried out by adding the calcined secondary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0088] Here, when the calcined secondary leaching residue is subjected to water leaching, if the reaction temperature is outside the above range, the efficiency of water leaching may decrease, which may be uneconomical.

[0089] At this time, the reaction temperature during the water leaching of the calcined secondary leaching residue may be preferably 25 to 98°C, and more preferably 25 to 95°C.

[0090] Furthermore, if the solid-liquid ratio during the water leaching of the calcined secondary leaching residue is outside the above range, the water leaching efficiency decreases, which may be uneconomical.

[0091] In this case, when the calcined secondary leaching residue is leached with water, the solid-liquid ratio may be preferably 1 / 20 to 1 / 8, and more preferably 1 / 15 to 1 / 8.

[0092] Furthermore, if the reaction time during the water leaching of the calcined secondary leaching residue is outside the above range, the water leaching efficiency may decrease, which may be uneconomical.

[0093] In this case, the reaction time during the water leaching of the calcined secondary leaching residue may be preferably 0.5 to 11.5 hours, and more preferably 0.5 to 11 hours.

[0094] The step (a-8) of subjecting the calcined secondary leaching residue to aqueous leaching and then separating the resultant into a tertiary lithium aqueous leachate and a tertiary leach residue by solid-liquid separation may further comprise the steps of: (a-9) further comprising the step of calcining the tertiary leaching residue; The heat treatment temperature for the calcination reaction may be 500 to 1000°C.

[0095] If the heat treatment temperature of the calcination reaction is outside the above range, the efficiency of the calcination reaction may decrease, which may be uneconomical.

[0096] At this time, the heat treatment temperature for the calcination reaction may be preferably 600 to 980°C, and more preferably 600 to 950°C.

[0097] The step (a-9) of calcining the tertiary leaching residue is also (a-10) further comprising a step of subjecting the calcined third leach residue to water leaching and then separating the calcined third leach residue into a fourth lithium aqueous leachate and a fourth leach residue by solid-liquid separation; The water leaching is carried out by adding the calcined tertiary leaching residue to water, The reaction can be carried out at a reaction temperature of 25 to 100°C, a solid-liquid ratio of 1 / 20 to 1 / 5, and a reaction time of 0.5 to 12 hours.

[0098] Here, when the calcined tertiary leaching residue is subjected to water leaching, if the reaction temperature is outside the above range, the water leaching efficiency may decrease, which may be uneconomical.

[0099] At this time, the reaction temperature during the water leaching of the calcined tertiary leaching residue may be preferably 25 to 98°C, and more preferably 25 to 95°C.

[0100] Furthermore, if the solid-liquid ratio during the water leaching of the calcined tertiary leaching residue is outside the above range, the water leaching efficiency decreases, which may be uneconomical.

[0101] In this case, when the calcined tertiary leaching residue is leached with water, the solid-liquid ratio may be preferably 1 / 20 to 1 / 8, and more preferably 1 / 15 to 1 / 8.

[0102] Furthermore, if the reaction time during the water leaching of the calcined tertiary leaching residue is outside the above range, the water leaching efficiency may decrease, which may be uneconomical.

[0103] In this case, the reaction time during the water leaching of the calcined tertiary leaching residue may be preferably 0.5 to 11.5 hours, more preferably 0.5 to 11 hours.

[0104] FIG. 1 is a process flow diagram of a hydrometallurgical process for recovering lithium from lithium-bearing minerals according to one embodiment of the present invention.

[0105] Referring to FIG. 1, after crushing and pulverizing the lithium-containing mineral (S110), the crushed and pulverized lithium-containing mineral may be heat-treated (S120).

[0106] Thereafter, the heat-treated lithium-containing mineral and an oxide of an alkali metal or alkaline earth metal are mixed and leached with water, and then subjected to solid-liquid separation to separate the primary lithium aqueous leachate and the primary leach residue (S130).

[0107] Thereafter, the primary leaching residue may be calcined (S140), and the calcined primary leaching residue may be subjected to water leaching and then separated into a secondary lithium aqueous leachate and a secondary leach residue by solid-liquid separation (S150).

[0108] Thereafter, lithium can be recovered from the primary lithium aqueous leachate or the secondary lithium aqueous leachate (S160).

[0109] Here, the step of separating the calcined primary leaching residue into a secondary lithium aqueous leachate and a secondary leach residue by solid-liquid separation after leaching the calcined primary leach residue with water includes: The method may further comprise the step of calcining the secondary leach residue.

[0110] and calcining the secondary leaching residue, The method may further include a step of separating the calcined secondary leach residue into a tertiary lithium aqueous leachate and a tertiary leach residue by solid-liquid separation after leaching the calcined secondary leach residue with water.

[0111] In addition, the step of separating the calcined secondary leaching residue into a tertiary lithium aqueous leachate and a tertiary leach residue by solid-liquid separation after leaching the calcined secondary leach residue with water may include: The method may further comprise the step of calcining the tertiary leach residue.

[0112] and calcining the tertiary leaching residue, The method may further include a step of separating the calcined tertiary leach residue into a quaternary lithium aqueous leachate and a quaternary leach residue by solid-liquid separation after leaching the calcined tertiary leach residue with water.

[0113] Thereafter, lithium can be recovered from the tertiary lithium aqueous leachate or the quaternary lithium aqueous leachate.

[0114] [Lithium aqueous solution recovered by hydrometallurgical method for recovering lithium from lithium-containing minerals] The present invention provides an aqueous lithium solution recovered by a hydrometallurgical method for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive chemical use, which can be applied to industry.

[0115] The present invention provides an aqueous lithium solution recovered by the hydrometallurgical method for recovering lithium from the lithium-containing mineral.

[0116] The present invention has a wide range of applications because it provides an aqueous lithium solution recovered by a hydrometallurgical method for recovering lithium from lithium-containing minerals by calcination and water leaching with metal oxides without excessive use of the chemicals, making it applicable to industry.

[0117] The present invention will be described in more detail below with reference to examples. However, the following examples are intended to more specifically explain the present invention, and the scope of the present invention is not limited to the following examples. The following examples can be appropriately modified or changed by those skilled in the art within the scope of the present invention.

[0118] <Example> Example 1: Particle size analysis and phase transition of spodumene Spodumene containing lithium was crushed and pulverized to prepare a powder.

[0119] The particle size distribution of the spodumene is shown in FIG. 2 and Table 1 below.

[0120] FIG. 2 is a particle size cumulative distribution diagram obtained by particle size analysis of spodumene according to Example 1 above.

[0121] [Table 1]

[0122] Referring to Figure 2 and Table 1 above, the particle size analysis of α-spodumene revealed that the most prevalent particle size was 55.8 μm, with 10% (D10) being 24.306 μm, 50% (D50) being 59.14 μm, and 90% (D90) being 134.751 μm. In other words, it was confirmed that the median particle size of the supplied α-spodumene was 59.14 μm, and that more than 90% of the sample had a particle size of 100 mesh (150 μm) or less.

[0123] The composition of the spodumene used in Example 1 above is shown in Table 2 below.

[0124] [Table 2]

[0125] Referring to Table 2 above, spodumene contains 2.35 wt% Li, 31.7 wt% Si, 13.4 wt% Al, 0.2 wt% Ca, 0.1 wt% Fe, 0.32 wt% Na, 0.33 wt% K, and 0.02 wt% Mg.

[0126] FIG. 3 shows the results of XRD analysis of the spodumene sample of Example 1 before and after heat treatment.

[0127] Figure 3 shows the XRD analysis results of α-spodumene before heat treatment and β-spodumene formed by heat treating α-spodumene at 1000°C for 12 hours.

[0128] Referring to FIG. 3, the XRD analysis results of the spodumene sample before and after heat treatment confirmed that the phase changed from α-spodumene to β-spodumene.

[0129] <Example 2> Water leaching of phase-transformed spodumene according to particle size Water leaching was carried out based on the particle size of the spodumene that had undergone a phase transformation to β-spodumene in Example 1 above.

[0130] In order to investigate the tendency of lithium leaching depending on the particle size of β-spodumene, particle size separation was carried out on 100, 200, and 270 mesh standards. β-spodumene samples of each particle size were mixed with CaO in a 1:1 mass ratio, and a leaching experiment was carried out under the following conditions: solid-liquid ratio 1 / 10 (30g / 300mL), reaction temperature 100°C, stirring speed 200rpm, and reaction time 12 hours. The leaching rate by particle size is shown in Table 3 below.

[0131] [Table 3]

[0132] Referring to Table 3 above, when spodumene undersized at 150 μm was used, 23.7 wt% Li, 0.1 wt% Ca, 26.5 wt% Na, 20.8 wt% K, 0.4 wt% Al, and 0.01 wt% Si were leached. When spodumene undersized at 75 μm was used, 29.2 wt% Li, 0.1 wt% Ca, 40.6 wt% Na, 41.4 wt% K, 0.6 wt% Al, and 0.02 wt% Si were leached. When spodumene undersized at 53 μm was used, 29.1 wt% Li, 0.1 wt% Ca, 44.1 wt% Na, 43.4 wt% K, 0.5 wt% Al, and 0.03 wt% Si were leached.

[0133] Therefore, as the particle size of Spodumene became smaller, the leaching rate of metal ions also increased. In the case of lithium, the leaching rates at 75 μm undersize and 53 μm undersize were similar, at approximately 29 wt%.

[0134] Example 3: Water leaching at reaction temperature The phase-transformed β-spodumene in Example 1 was mixed with CaO, and then the results of water leaching were evaluated depending on the reaction temperature.

[0135] A leaching experiment was conducted using 75μm undersized β-spodumene mixed with CaO at a 1:1 ratio, a solid-liquid ratio of 1 / 10 (30g / 300mL), a stirring speed of 200rpm, and a reaction time of 12 hours. The reaction temperatures were 25, 50, and 100°C, and the leaching yields by reaction temperature are shown in Table 4 below.

[0136] [Table 4]

[0137] Referring to Table 4 above, when the reaction temperature was 25°C, 0.45 wt% Li, 2.1 wt% Ca, 2.6 wt% Na, 7.2 wt% K, and 0.001 wt% Si were leached. At 50°C, 4.0 wt% Li, 1.2 wt% Ca, 8.1 wt% Na, 10.8 wt% K, 0.16 wt% Al, and 0.001 wt% Si were leached. At 100°C, 29.5 wt% Li, 0.05 wt% Ca, 40.6 wt% Na, 42.9 wt% K, 0.55 wt% Al, and 0.02 wt% Si were leached. It was confirmed that the lithium leaching rate increased rapidly as the reaction temperature increased.

[0138] <Example 4> Water leaching depending on reaction time The phase-transformed β-spodumene in Example 1 was mixed with CaO, and the results of the water leaching were evaluated depending on the reaction time.

[0139] A leaching experiment was conducted using 75μm undersized β-spodumene mixed with CaO at a 1:1 ratio, a solid-liquid ratio of 1 / 10 (30g / 300mL), a reaction temperature of 100℃, and a stirring speed of 200rpm. The reaction times were 1, 2, 4, 6, 9, 10, and 12 hours, and the leaching rates as a function of reaction time are shown in Table 5 below.

[0140] [Table 5]

[0141] Referring to Table 5, it was confirmed that the leaching rate of Li increased with increasing reaction time, maintaining a leaching rate of approximately 33 wt% after 9 hours. In the case of Ca, the leaching rate was approximately 0.8 wt% after 1 hour, but decreased to approximately 0.1 wt% after 4 hours. In the cases of Na, K, Al, and Si, the leaching rates increased with time, reaching 51 wt%, 38.4 wt%, 0.7 wt%, and 0.02 wt%, respectively, after 12 hours. Fe and Mg were not leached.

[0142] <Example 5> Water leaching with different mass ratios of CaO and β-spodumene The phase-transformed β-spodumene in Example 1 was mixed with CaO, and then the results of water leaching were evaluated depending on the mass ratio of CaO to β-spodumene during water leaching.

[0143] Leaching experiments were conducted using 75 μm undersized β-spodumene mixed with CaO at a 1:1 ratio, a solid-liquid ratio of 1 / 10 (30 g / 300 mL), a reaction temperature of 100°C, a stirring speed of 200 rpm, and a reaction time of 9 hours. The CaO / β-spodumene mass ratio (CaO / β-spodumene) was set to 1, 2, 3, and 4, and the leaching rates for each mass ratio are shown in Table 6 below.

[0144] [Table 6]

[0145] Referring to Table 6 above, when the CaO / β-spodumene ratio was 1, 31.7 wt% Li, 0.1 wt% Ca, 33.7 wt% Na, 25.2 wt% K, 0.6 wt% Al, and 0.02 wt% Si were leached, and when the CaO / β-spodumene ratio was 2, 38.2 wt% Li, 0.1 wt% Ca, 47.6 wt% Na, 39.4 wt% K, 0.5 wt% Al, and 0.02 wt% Si were leached. When the CaO / β-spodumene ratio was 3, 39.2 wt% Li, 0.1 wt% Ca, 51.8 wt% Na, 42.9 wt% K, 0.5 wt% Al, and 0.02 wt% Si were leached, and when the CaO / β-spodumene ratio was 4, 39.1 wt% Li, 0.1 wt% Ca, 54.3 wt% Na, 47.3 wt% K, 0.5 wt% Al, and 0.01 wt% Si were leached.

[0146] Therefore, it was confirmed that the Li leaching rate increases significantly when the CaO / β-spodumene ratio is 1 or more.

[0147] <Example 6> Calcination of water leaching residue The phase-transformed β-spodumene in Example 1 was mixed with CaO, and then subjected to water leaching. The separated water leaching residue was then calcined.

[0148] 75 μm undersized β-spodumene was leached for 9 hours in water under the conditions of a CaO / β-spodumene mass ratio of 3, a solid-liquid ratio of 1 / 10 (30 g / 300 mL), a stirring speed of 200 rpm, and a reaction temperature of 100°C. The XRD analysis results of the obtained leaching residue are shown in Figure 4.

[0149] FIG. 4 shows the XRD analysis results of the leaching residue obtained after water leaching of the CaO / Spodumene mixture according to Example 6 above.

[0150] As shown in Figure 4, unreacted β-spodumene, Ca(OH)2, and CaCO3 were observed in the leaching residue obtained after water leaching. To convert the Ca(OH)2 and CaCO3 present in the leaching residue back to CaO, the leaching residue was heat-treated at 900°C for 6 hours. The XRD analysis results of the calcined product are shown in Figure 5.

[0151] FIG. 5 shows the XRD analysis results of the calcined product of the leaching residue from the water leaching in Example 6 above, after calcining at 900° C. for 6 hours.

[0152] 5, it was confirmed that both Ca(OH)2 and CaCO3 were converted to CaO. The calcined product was again subjected to water leaching under the conditions of a solid-liquid ratio of 1 / 10, a reaction temperature of 100°C, a stirring speed of 200 rpm, and a reaction time of 9 hours. In order to further leach lithium, these water leaching and calcination processes were repeated to continue leaching lithium.

[0153] Example 7: Continuous calcination and water leaching The phase-transformed β-spodumene in Example 1 was mixed with CaO, and then subjected to water leaching. The separated water leaching residue was subjected to successive calcination and water leaching.

[0154] 75 μm undersized β-spodumene was subjected to water leaching for 9 hours under the conditions of a CaO / β-spodumene mass ratio of 3, a solid-liquid ratio of 1 / 10 (30 g / 300 mL), a stirring speed of 200 rpm, and a reaction temperature of 100°C. The obtained water leaching residue was then subjected to continuous calcination and water leaching. The leaching yields obtained after four consecutive water leaching runs are shown in Table 7 below.

[0155] [Table 7]

[0156] Referring to Table 7 above, after the first, second, third, and fourth water leaching experiments, 38.9 wt%, 31.7 wt%, 18.5 wt%, and 8.1 wt% of lithium were leached, respectively, resulting in a total of 97.2 wt% of lithium being leached from the spodumene. Ca 0.9 wt%, Na 94.7 wt%, K 82.8 wt%, Al 2.2 wt%, and Si 0.05 wt% were also leached, with no Fe or Mg leaching. When the leachates obtained from each water leaching experiment were mixed, the analyzed values ​​were Li 197.2 mg / L, Ca 155.3 mg / L, Na 31.9 mg / L, K 29.3 mg / L, Al 22.2 mg / L, and Si 1.5 mg / L.

[0157] When the mass balance of lithium in each water leach was examined, 70.4, 57.3, 33.4, and 14.6 mg of lithium were leached from the spodumene containing a total of 180.6 mg of lithium in the first, second, third, and fourth water leaches, respectively, for a total of 175.7 mg of Li (97.2 wt%).

[0158] After the fourth water leaching, the XRD analysis results of the obtained leaching residue are shown in Figure 6.

[0159] FIG. 6 shows the XRD analysis results of the leaching residue obtained after the fourth water leaching according to Example 7 above.

[0160] Referring to Figure 6, the leaching residue obtained after the fourth water leaching is composed of Ca(OH), CaCO, and CaSiO. It is believed that the leaching residue can be reused in the next leaching process if it is converted to CaO through a calcination process at 900°C.

[0161] So far, specific examples of the hydrometallurgical method for recovering lithium from lithium-containing minerals according to the present invention and the lithium aqueous solution recovered therefrom have been described. However, it is obvious that various modifications can be made without departing from the scope of the present invention.

[0162] Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined not only by the claims set forth below, but also by equivalents to these claims.

[0163] In other words, it should be understood that the above-described embodiments are illustrative in all respects and not limiting, and the scope of the present invention is indicated by the claims set forth below rather than by the detailed description, and all modifications or variations that come within the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of the present invention.

Claims

1. Lithium-containing minerals are calcined and leached into alkali metal or alkaline earth metal oxides. Thus, there is provided a hydrometallurgical process for recovering lithium, comprising: (a-1) crushing and pulverizing a lithium-containing mineral; (a-2) heat-treating the crushed and pulverized lithium-containing mineral; (a-3) The heat-treated lithium-containing mineral and an alkali metal or alkaline earth metal After mixing with the oxide and leaching with water, the solid-liquid separation is carried out to separate the primary lithium aqueous leachate and the primary leach residue. separating the (a-4) calcining the primary leaching residue; (a-5) The calcined primary leaching residue is leached with water, and then subjected to solid-liquid separation to obtain a secondary lithium aqueous solution. Separating the leachate and the secondary leach residue; and (a-6) Recovering lithium from the primary lithium aqueous leachate or the secondary lithium aqueous leachate collecting the In the step (a-2) of heat treating the crushed and pulverized lithium-containing mineral, The heat treatment is carried out under gas conditions by introducing at least one gas selected from nitrogen, argon, and air, and under pressure conditions at atmospheric pressure. The lithium-containing mineral is spodumene (LiAlSi ２ O ６ ) and The spodumene (LiAlSi ２ O ６ ) contains 6-9% Li 2 O, In the step (a-2), the spodumene (LiAlSi 2 O 6 ) is heat-treated to cause a phase transition from an α-phase to a β-phase; In the immersion reaction time of the (a-3) step, 1 to 12 hours, The Na leaching rate of the primary lithium aqueous leachate is 23.4 to 52.3 wt%; The K leaching rate of the primary lithium aqueous leaching solution is 13.9 to 39.0 wt%; A hydrometallurgical process for recovering lithium from lithium-bearing minerals.

2. In the step (a-1) of crushing and pulverizing the lithium-containing mineral, crushing and pulverizing the lithium-containing mineral with one or more pieces of equipment selected from the group consisting of a Jaw Crusher, a Gyratory Crusher, a Roller Crusher, a Cone Crusher, a Hammermill Crusher, a Tumbling Mill, a Vibration Mill, an Attrition Mill, a Ball Mill, a Rod Mill, a Pebble Mill, and an Autogeneous Mill to produce a crushed and pulverized lithium-containing mineral; The particle size of the crushed or pulverized lithium-containing mineral is 5 to 300 μm.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

3. In the step (a-2) of heat-treating the crushed and pulverized lithium-containing mineral, The heat treatment is performed at a temperature of 500 to 1000°C for 10 minutes to 6 hours.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

4. In the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The types of the alkali metal or alkaline earth metal oxides include calcium oxide (CaO), magnesium oxide (MgO), potassium oxide (K ２ O), and sodium oxide (Na ２ O) is at least one selected from the following:

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

5. In the step (a-3) of mixing the heat-treated lithium-containing mineral with an oxide of an alkali metal or alkaline earth metal, leaching the mixture with water, and then separating the mixture into a primary lithium aqueous leachate and a primary leach residue by solid-liquid separation, The water leaching is carried out by adding a mixture of the lithium-containing mineral (A) that has undergone a phase transition to water and the metal oxide (B) so that the mass ratio (B / A) of the mixture is 1 to 6; The reaction temperature is 25 to 100°C, the solid-liquid ratio is 1 / 20 to 1 / 5, and the reaction time is 0.5 to 12 hours.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

6. The lithium leaching rate of the primary lithium aqueous leaching solution is 1 to 35 wt%.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

7. In the step (a-4) of calcining the primary leaching residue, Under the above calcination process conditions, the primary leaching residue is heat-treated at a temperature equal to or higher than the temperature at which the Gibbs free energy of the calcination reaction becomes zero, The heat treatment temperature of the calcination reaction is 500 to 1000 ° C.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

8. In the step (a-5) of leaching the calcined primary leaching residue with water and then separating the secondary lithium aqueous leaching solution and the secondary leaching residue by solid-liquid separation, The water leaching is carried out by adding the calcined primary leaching residue to water; The reaction temperature is 25 to 100°C, the solid-liquid ratio is 1 / 20 to 1 / 5, and the reaction time is 0.5 to 12 hours.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

9. The step (a-5) of subjecting the calcined primary leaching residue to aqueous leaching and then separating the secondary lithium aqueous leaching solution and the secondary leaching residue by solid-liquid separation includes: (a-7) further comprising the step of calcining the secondary leaching residue; The heat treatment temperature of the calcination reaction is 500 to 1000 ° C.

10. A hydrometallurgical process for recovering lithium from the lithium-containing mineral of claim 1.

10. The step (a-7) of calcining the secondary leaching residue comprises: (a-8) further comprising a step of leaching the calcined secondary leaching residue with water and then separating the resulting leached residue into a tertiary lithium aqueous leachate and a tertiary leach residue by solid-liquid separation; The water leaching is carried out by adding the calcined secondary leaching residue to water; The reaction temperature is 25 to 100°C, the solid-liquid ratio is 1 / 20 to 1 / 5, and the reaction time is 0.5 to 12 hours.

10. A hydrometallurgical process for recovering lithium from lithium-containing minerals according to claim 9.

11. The step (a-8) of subjecting the calcined secondary leaching residue to aqueous leaching and then separating the resultant into a tertiary lithium aqueous leachate and a tertiary leach residue by solid-liquid separation includes: (a-9) further comprising the step of calcining the tertiary leaching residue; The heat treatment temperature of the calcination reaction is 500 to 1000 ° C.

11. A hydrometallurgical process for recovering lithium from lithium-containing minerals according to claim 10.

12. The step (a-9) of calcining the tertiary leaching residue is (a-10) further comprising a step of subjecting the calcined third leach residue to water leaching and then separating the resultant into a fourth lithium aqueous leachate and a fourth leach residue by solid-liquid separation; The water leaching is carried out by adding the calcined tertiary leaching residue to water; The reaction temperature is 25 to 100°C, the solid-liquid ratio is 1 / 20 to 1 / 5, and the reaction time is 0.5 to 12 hours.

12. A hydrometallurgical process for recovering lithium from lithium-containing minerals according to claim 11.

13. 2. An aqueous lithium solution recovered by the hydrometallurgical method for recovering lithium from a lithium-containing mineral according to claim 1.

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