Recovering method of lithium and simulation method for recovering of lithium

Abstract

A method for recovering lithium according to the present invention comprises the steps of: preparing an ore containing lithium; and heat-treating the ore containing lithium to remove mineral impurities; wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into Formula 1, and confirming whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

Description

Technology Field

[0001] The present invention relates to a method for recovering lithium and a simulation method for recovering lithium. Background Technology

[0002] A rotary kiln is a furnace facility designed to achieve uniform heat treatment of raw materials by having a constant angle and rotational speed.

[0003] Spodumene, a representative raw material for lithium ore, undergoes a calcination process in a rotary kiln to transition from the α phase to the β phase. At this time, due to various factors inside the kiln, a fused material called a clinker or kiln ring (or ring) may be formed.

[0004] From a raw material perspective, impurity minerals within spodumene can be cited as one of the causes of kiln ring formation. Types of impurity minerals within spodumene that do not contain lithium include quartz (SiO2), microcline, orthoclase (Kokchetavite, KAlSi3O8), sanidine, and albite (NaAlSi3O8).

[0005] These remain in the spodumene concentrate even after undergoing appropriate beneficiation steps, and the impurity mineral content varies depending on the location of mining or the degree of beneficiation.

[0006] In addition, since it has a relatively low melting point, it softens or melts due to high temperatures in the vicinity of the flame during the calcination process, and subsequently acts to induce physicochemical mixing with spodumene concentrate to form kiln rings.

[0007] The formation of such kiln rings can have negative effects, such as reducing the phase transition efficiency of spodumene, damaging refractories, and causing eccentricity in rotary kiln rotation. Therefore, it is very important to suppress the formation of kiln rings during the calcination process.

[0008] Therefore, there is a need to develop methods to suppress kiln ring formation during the calcination process. The problem to be solved

[0009] The present invention aims to provide a method for recovering lithium capable of removing impurities that induce the formation of calcination kiln fusion products.

[0010] In addition, the present invention aims to provide a method for recovering lithium that can obtain high-quality spodumene concentrate by separately removing impurity minerals through a pretreatment process.

[0011] In addition, the present invention aims to provide a simulation method for lithium recovery that can easily select a heat treatment temperature for a pretreatment process of a lithium recovery method by deriving a ternary phase diagram for the composition of K-containing minerals, Na-containing minerals, and SiO2, and a liquid phase region within said ternary phase diagram. means of solving the problem

[0012] The present invention provides a method for recovering lithium, comprising the steps of: preparing an ore containing lithium; confirming the content of K-containing minerals, Na-containing minerals, and SiO2 of the ore containing lithium; and heat-treating the ore containing lithium to remove mineral impurities; wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content of the K-containing minerals, Na-containing minerals, and SiO2 into Formula 1 below, and confirming whether the content of the K-containing minerals, Na-containing minerals, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C in the ternary phase diagram of the K-containing minerals, Na-containing minerals, and SiO2.

[0013] [Equation 1]

[0014] 0% ≤ x ≤ 68%, 0% ≤ y ≤ 88%, 0% ≤ z ≤ 50%

[0015] In the above Equation 1,

[0016] x is the content (%) of K-containing minerals, and

[0017] y is the content (%) of Na-containing minerals, and

[0018] z is the SiO2 content (%), and

[0019] x+y+z = 100%.

[0020] In addition, the present invention provides a simulation method for recovering lithium, comprising the steps of: preparing a lithium-containing ore; confirming the content of K-containing minerals, Na-containing minerals, and SiO2 of the prepared lithium-containing ore; and predicting the heat treatment temperature of the lithium-containing ore using a ternary phase diagram obtained by calculating the quantitative melting points of the K-containing minerals, Na-containing minerals, and SiO2 using thermodynamic software. Effects of the invention

[0021] The lithium recovery method according to the present invention has the advantage of being able to separately remove impurities, including minerals, within the lithium-containing ore.

[0022] In addition, the lithium recovery method according to the present invention has the advantage of being able to provide an effective range of impurities for obtaining high-grade lithium ore through a suitable heat treatment temperature and compositional combination capable of separately removing impurities containing minerals within the ore.

[0023] In addition, the simulation method for lithium recovery according to the present invention has the advantage of easily selecting a heat treatment temperature for the pretreatment process of the lithium recovery method by deriving a ternary phase diagram for the composition of K-containing minerals, Na-containing minerals, and SiO2, and a liquid phase region within said ternary phase diagram. Brief explanation of the drawing

[0024] FIGS. 1 to 6 are diagrams showing the KAlSi3O8-NaAlSi3O8-SiO23 phase diagram and the liquid phase region thereof at 1,000 to 1,100°C according to some embodiments of the present invention. Specific details for implementing the invention

[0025] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0026] In the present invention, when it is stated that a certain member is located "on" another member, this includes not only cases where a certain member is in direct contact with another member, but also cases where another member is interposed between the two members.

[0027] In the present invention, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0029] Lithium Recovery Method

[0030] One aspect of the present invention relates to a method for recovering lithium, comprising the steps of: preparing an ore containing lithium; confirming the content of a K-containing mineral, a Na-containing mineral, and SiO2 of the lithium-containing ore; and heat-treating the lithium-containing ore to remove mineral impurities; wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into Formula 1 below, and confirming whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0031] [Equation 1]

[0032] 0% ≤ x ≤ 68%, 0% ≤ y ≤ 88%, 0% ≤ z ≤ 50%

[0033] In the above Equation 1,

[0034] x is the content (%) of K-containing minerals, and

[0035] y is the content (%) of Na-containing minerals, and

[0036] z is the SiO2 content (%), and

[0037] x+y+z = 100%.

[0039] The lithium recovery method according to the present invention has the advantage of reducing the burden of subsequent processes, such as lithium leaching, by removing fusion-inducing impurity minerals, such as kiln rings contained in lithium-containing ore, under liquid conditions, thereby suppressing the formation of fusion during the calcination process, and furthermore, by using only high-purity concentrate as a raw material for lithium production.

[0041] The method for recovering lithium according to the present invention includes the step of preparing an ore containing lithium.

[0042] In one embodiment of the present invention, the lithium-containing ore may comprise one or more selected from the group consisting of spodumene, petalite, lepidolite, hectorite, eucryptite, jadarite, zinnwaldite, and amblygonite.

[0043] In another embodiment of the present invention, the lithium-containing ore may include spodumene.

[0044] Specifically, the lithium-containing ore may be spodumene. The present invention has the advantage of obtaining high-purity spodumene concentrate by theoretically evaluating conditions under which fusion-inducing impurities within the spodumene appear in a liquid form and removing them. In addition, it has the advantage of suppressing the phenomenon of fusion formation, such as kiln rings in a rotary kiln.

[0046] The lithium recovery method according to the present invention includes the step of confirming the content of K-containing minerals, Na-containing minerals, and SiO2 of the lithium-containing ore.

[0047] The content of the above K-containing minerals, Na-containing minerals, and SiO2 can be measured through XRD quantitative / qualitative analysis, but is not limited thereto.

[0048] Although I do not wish to be limited by theory, the minerals acting as impurities in spodumene are mainly K-feldspar, Na-feldspar, and SiO2.

[0049] Accordingly, in the present invention, the three types of minerals—K-containing minerals, Na-containing minerals, and SiO2—are defined as being primarily present as stoichiometric impurities.

[0051] In one embodiment of the present invention, the K-containing mineral may include KAlSi3O8.

[0052] In another embodiment of the present invention, the Na-containing mineral may include NaAlSi3O8.

[0054] The method for recovering lithium according to the present invention comprises the step of heat-treating the ore containing lithium to remove mineral impurities; wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into the following formula 1, and confirming whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0055] [Equation 1]

[0056] 0% ≤ x ≤ 68%, 0% ≤ y ≤ 88%, 0% ≤ z ≤ 50%

[0057] In the above Equation 1,

[0058] x is the content (%) of K-containing minerals, and

[0059] y is the content (%) of Na-containing minerals, and

[0060] z is the SiO2 content (%), and

[0061] x+y+z = 100%.

[0064] Specifically, the content of the above K-containing mineral, Na-containing mineral, and SiO2 is homogenized to 100%, and at this time, the content of the K-containing mineral, Na-containing mineral, and SiO2 is defined as x, y, and z, respectively.

[0065] In short, the above x represents the content (weight%) of K-containing minerals relative to the total content of K-containing minerals, Na-containing minerals, and SiO2.

[0066] Specifically, the heat treatment temperature can be determined by checking whether the K-containing mineral, Na-containing mineral, and SiO2 are located within the liquid phase region of the ternary phase diagram for each temperature of the K-containing mineral, Na-containing mineral, and SiO2.

[0067] In short, the step of determining the heat treatment temperature by substituting the content of the K-containing mineral, Na-containing mineral, and SiO2 into the above Equation 1 can be determined by checking whether the composition of the K-containing mineral, Na-containing mineral, and SiO2 in the ternary phase diagram of the above K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C.

[0068] The above ternary phase diagram of K-containing minerals, Na-containing minerals, and SiO2 can be obtained by using thermodynamic software.

[0069] Specifically, the ternary phase diagram of the above K-containing mineral, Na-containing mineral, and SiO2 can be calculated by applying the equilibrium module and normal and transition phases using thermodynamic software and DB data of FToxid and the solution and pure solid phases that the three impurity minerals may have.

[0070] Although not intended to be limited by theory, the temperature range of 1,000 to 1,100°C is a temperature at which the spodumene mineral does not melt and can be liquefied by appropriately combining the K-containing mineral, the Na-containing mineral, and SiO2. Specifically, the temperature of 1,000 to 1,100°C may be a temperature corresponding to the melting point of the K-containing mineral, the Na-containing mineral, and SiO2 when an appropriate compositional combination of the K-containing mineral, the Na-containing mineral, and SiO2 is present.

[0072] In another embodiment of the present invention, the heat treatment may be performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into the following Equation 2, and checking whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,080°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0073] [Equation 2]

[0074] 0% ≤ x ≤ 66%, 0% ≤ y ≤ 77.5%, 0% ≤ z ≤ 49%

[0075] In the above Equation 2,

[0076] x, y, and z are as defined in Equation 1 above.

[0078] In another embodiment of the present invention, the heat treatment may be performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into the following Equation 3, and checking whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,060°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0079] [Equation 3]

[0080] 0% ≤ x ≤ 64%, 0% ≤ y ≤ 63.5%, 5% ≤ z ≤ 47.5%

[0081] In the above Equation 3,

[0082] x, y, and z are as defined in Equation 1 above.

[0084] In another embodiment of the present invention, the heat treatment may be performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into the following Equation 4, and checking whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,040°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0085] [Equation 4]

[0086] 7.5% ≤ x ≤ 61%, 0% ≤ y ≤ 57.5%, 17% ≤ z ≤ 47.5%

[0087] In the above Equation 4,

[0088] x, y, and z are as defined in Equation 1 above.

[0090] In another embodiment of the present invention, the heat treatment may be performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, the Na-containing mineral, and SiO2 into the following Equation 5, and checking whether the content of the K-containing mineral, the Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,020°C in the ternary phase diagram of the K-containing mineral, the Na-containing mineral, and SiO2.

[0091] [Equation 5]

[0092] 15% ≤ x ≤ 59%, 0% ≤ y ≤ 48.5%, 22.5% ≤ z ≤ 45%

[0093] In the above Equation 5,

[0094] x, y, and z are as defined in Equation 1 above.

[0096] In another embodiment of the present invention, the heat treatment may be performed at a heat treatment temperature determined by substituting the content of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 6, and checking whether the content of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,010°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2.

[0097] [Equation 6]

[0098] 23% ≤ x ≤ 58%, 0% ≤ y ≤ 41%, 28% ≤ z ≤ 45%

[0099] In the above Equation 6,

[0100] x, y, and z are as defined in Equation 1 above.

[0101] Specifically, the heat treatment can be performed at a heat treatment temperature determined by substituting the contents of the K-containing mineral, Na-containing mineral, and SiO2 into Equation 6 and checking whether the contents of the K-containing mineral, Na-containing mineral, and SiO2 satisfy the liquid phase region of the ternary phase diagram at 1,000°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2.

[0102] More specifically, the heat treatment can be performed at 1,000°C by checking whether the content of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000°C when the content of the K-containing mineral, Na-containing mineral, and SiO2 satisfies Equation 6.

[0104] In another embodiment of the present invention, the liquid phase region can be obtained by calculating a quantitative melting point using thermodynamic software.

[0105] In short, the lithium recovery method according to the present invention can obtain a ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2 from thermodynamic software, and a liquid phase region within the ternary phase diagram where the K-containing mineral, Na-containing mineral, and SiO2 can exist in a liquid state.

[0106] The above thermodynamics software can apply the aforementioned content.

[0108] The method for recovering lithium according to the present invention includes the step of heat-treating the lithium-containing ore at the heat treatment temperature to remove mineral impurities.

[0109] Since the lithium recovery method according to the present invention includes a pretreatment process of heat-treating the lithium-containing ore at the heat treatment temperature, the formation of fused materials such as kiln rings in the calcination process can be suppressed, and furthermore, only high-purity lithium concentrate can be used as a raw material for lithium production, thereby reducing the burden of subsequent processes.

[0111] Specifically, when the lithium-containing ore is heat-treated at the above heat treatment temperature, the K-containing mineral, Na-containing mineral, and SiO2 are melted into a liquid state in the lithium-containing ore.

[0112] Therefore, in the calcination process described later, the phenomenon in which the K-containing mineral, Na-containing mineral, and SiO2 are melted to form a fused material such as a kiln ring can be suppressed.

[0114] In another embodiment of the present invention, the heat treatment may be performed for 30 minutes to 3 hours, preferably 30 minutes to 2 hours, and more preferably 30 minutes to 1 hour.

[0115] When the above heat treatment is performed within the above time range, it is desirable to minimize the heat treatment time while ensuring sufficient melting of the K-containing mineral, Na-containing mineral, and SiO2.

[0117] In another embodiment of the present invention, the method may further include the step of heat-treating the lithium-containing ore at the heat treatment temperature to remove mineral impurities; the step of subsequently roasting the ore from which the mineral impurities have been removed with sulfuric acid; the step of leaching lithium from the roasted ore to obtain a leaching slurry; and the step of separating the solid and liquid of the leaching slurry.

[0118] The method may further include, but is not limited to, a step of sulfuric acid roasting the ore from which the mineral impurities have been removed; and a step of calcining the ore from which the mineral impurities have been removed previously.

[0119] Specifically, depending on the heat treatment time, it may further include a step of calcining the ore from which mineral impurities have been removed if necessary.

[0120] The step of calcining the ore from which the mineral impurities have been removed can be performed at a temperature of 950 to 1,100°C for 5 minutes to 5 hours, preferably 10 minutes to 3 hours.

[0121] When the step of calcining the above ore is performed within the above range, the α-phase phase transition remaining in the lithium-containing ore can be sufficiently achieved, and it is desirable to suppress the phenomenon in which the lithium leaching rate decreases due to under-calcination or under-calcination.

[0123] By roasting the above-mentioned calcined ore with sulfuric acid, the lithium within the ore can be transformed into a water-soluble substance.

[0124] The above sulfuric acid roasting can be performed at a temperature range of 175 to 250°C, preferably 200 to 250°C, for 30 minutes to 2 hours, preferably 30 minutes to 1 hour.

[0125] It is desirable that the above-mentioned sulfuric acid roasting is performed within the above-mentioned time range at the above-mentioned temperature range, as this minimizes the roasting time and energy consumption.

[0127] Afterwards, a leaching slurry can be obtained by mixing the above-described roasted ore with a solvent and leaching it with water.

[0128] The above solvent may be pure water or distilled water, but is not limited thereto.

[0129] It is preferable that the above solvent does not contain acidic substances such as sulfuric acid, but is not limited thereto. It is desirable for the solvent not to contain acidic substances such as sulfuric acid because it is environmentally friendly. Furthermore, it may be economically and environmentally desirable if a material containing a small amount of acid within a complex process can be recycled within a range that does not cause problems to the overall production process.

[0131] In the step of obtaining the above-mentioned leaching slurry, an additive may be added to prepare the slurry, but is not limited thereto.

[0132] The above additive may be one or more selected from, for example, alkali metal compounds or alkaline earth metal compounds, and specifically, may be one or more selected from alkali metal oxides, alkali metal hydroxides, alkali metal salts, alkaline earth metal oxides, alkaline earth metal hydroxides, or alkaline earth metal salts. More specifically, the above additive may be one or more selected from NaOH, Na2CO3, NaHCO3, NaCl, Na2SO4, KOH, K2CO3, KHCO3, KCl, K2SO4, Ca(OH)2, CaO, Ca(NO3)2, CaSO4, Mg(OH)2, MgO, Mg(NO3)2, MgSO4, or CaCO3.

[0133] The additive may be mixed with the above-described roasted ore in a range of 10 to 60 weight percent based on weight, specifically in a range of 30 to 60 weight percent, but is not limited thereto.

[0134] When the above additive is mixed within the above range, it is desirable to efficiently recover lithium while minimizing the generation of downstream contaminants.

[0135] In addition to the above additives, auxiliary additives may be additionally mixed, but are not limited thereto.

[0136] The above auxiliary additive may be a compound containing one or more metal elements selected from, for example, Al or Ca.

[0137] Specifically, the above auxiliary additive may be one or more selected from Al(OH)3, Al(NO3)3, Al2(SO4)3, AlCl3, Ca(OH)2, Ca(NO3)2, CaSO4 and their hydrates or CaCl2, but is not limited thereto.

[0138] The above auxiliary additive may be mixed in an amount of 5 to 40 weight percent based on weight with respect to the above-described roasted ore, but is not limited thereto.

[0140] The above solvent may be added in an amount of 1 to 4 times, preferably 1.5 to 3 times, and more preferably 2 to 3 times by weight with respect to the above-burned ore.

[0141] When the above solvent is introduced to satisfy the above content, it is desirable to minimize the content of the solvent while maintaining excellent lithium leaching efficiency, thereby reducing process costs.

[0142] The time for leaching the lithium above can be performed for 30 minutes to 5 hours, preferably 30 minutes to 4 hours, and more preferably 1 to 3 hours.

[0143] If the time for leaching the lithium satisfies the above range, it is desirable because it allows for excellent lithium leaching efficiency while reducing energy consumption.

[0144] At this time, the leaching of the lithium can be carried out at room temperature and can be performed while stirring at 50 to 500 RPM, preferably 100 to 400 RPM, more preferably 200 to 300 RPM.

[0145] It is desirable that the leaching of the lithium is performed while stirring at the above stirring speed, as this allows for maximizing lithium leaching efficiency while minimizing the lithium leaching time.

[0147] By separating the above leaching slurry into solid and liquid phases, it is possible to separate the solid leaching residue and the leaching water in which the lithium is dissolved.

[0148] The above method of separating solids and liquids is not limited in the present invention.

[0149] For example, the above-mentioned solid-liquid separation can be performed using a microfilter, but is not limited thereto, and can be performed by conventional methods used in the industry.

[0151] The method for recovering lithium from ore according to the present invention may further include the step of purifying the leachate.

[0152] The above purification may be performed two or more times, but is not limited thereto. Specifically, the purification step may include a first purification step and a second purification step.

[0153] The above purification can be performed by a method conventionally carried out in the industry using purification auxiliary materials, and the present invention does not limit the purification method.

[0155] The method for recovering lithium according to the present invention may further include, but is not limited to, a step of concentrating the leachate.

[0157] The lithium recovery method according to the present invention has the advantage of suppressing the formation of calcination kiln fusions and obtaining high-quality lithium concentrate by separately removing impurities that induce the formation of calcination kiln fusions through a pretreatment process.

[0159] <Simulation Method for Lithium Recovery>

[0160] Another aspect of the present invention relates to a simulation method for recovering lithium, comprising the steps of: preparing a lithium-containing ore; determining the content of K-containing minerals, Na-containing minerals, and SiO2 of the prepared lithium-containing ore; and predicting the heat treatment temperature of the lithium-containing ore using a ternary phase diagram obtained by calculating the quantitative melting points of the K-containing minerals, Na-containing minerals, and SiO2 using thermodynamic software.

[0161] The step of preparing the lithium-containing ore; and the step of confirming the content of K-containing minerals, Na-containing minerals, and SiO2 of the prepared lithium-containing ore; may apply the aforementioned details.

[0163] In another embodiment of the present invention, the step of predicting the heat treatment temperature of the lithium-containing ore may include the step of calculating the quantitative melting point of the lithium-containing ore using an equilibrium and phase diagram module within the thermodynamic software and indicating a liquid phase region within the ternary phase diagram.

[0164] Specifically, the above heat treatment temperature is the thermodynamic software FactSage TM 7.0 software may be used, but is not limited to this.

[0165] More specifically, the above heat treatment temperature can be calculated by using thermodynamic software and considering / applying the equilibrium module and normal and transition using FToxid and DB data of the liquid and pure solid states that each of the three input impurity minerals, namely K-containing minerals, Na-containing minerals, and SiO2, and by simulating the heating process in the compositional combination of the three impurity minerals, the temperature at which it becomes a perfect liquid state can be defined as the melting point.

[0167] The content of impurities in the lithium-containing ore may have some mineralogical variation. For example, if the lithium-containing ore is spodumene ore, since there are spodumene ores with different content of each impurity mineral, it is expected that the composition of impurity minerals can be controlled by intentionally mixing spodumenes with different content of each impurity mineral.

[0169] In summary, the simulation method for a lithium recovery method according to the present invention derives a ternary phase diagram for the composition of K-containing minerals, Na-containing minerals, and SiO2 of a lithium-containing ore, and derives a liquid phase region within the ternary phase diagram in which the K-containing minerals, Na-containing minerals, and SiO2 exhibit a 100% perfect liquid phase, thereby enabling easy selection of a heat treatment temperature for the pretreatment process of the lithium recovery method. Furthermore, by mixing lithium-containing ores with different impurity mineral contents, not only can the composition of impurity minerals be controlled, but a range of appropriate compositional combinations of impurity minerals can also be presented based on this.

[0171] Preferred embodiments and comparative examples of the present invention are described below. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0173] Confirmation of impurities in spodumene

[0174] The types of impurity minerals in spodumene were identified through quantitative and qualitative XRD analysis of the spodumene concentrate. Excluding the lithium-containing spodumene mineral (LiAlSi2O6), the remaining minerals were homogenized to 100% and were identified mainly as K-feldspar series, Na-feldspar series, and SiO2.

[0175] The types of impurity minerals in the above spodumene were defined as mainly existing as three stoichiometric impurities: K-feldspar (KAlSi3O8), Na-feldspar (NaAlSi3O8), and SiO2, and their respective proportions are shown in Table 1 below.

[0177] Types of impurity minerals KAlSi3O8 NaAlSi3O8 SiO2 Content (wt%) 50.3 17.6 32.1

[0179] Heat treatment temperature prediction method

[0180] To determine the heat treatment temperature In calculating the melting point, the thermodynamics software FactSage TM Software version 7.0 was used. Calculations were performed by selecting and utilizing both FToxid and the solution and pure solid databases for each of the three input impurity minerals (KAlSi3O8, NaAlSi3O8, SiO2). Calculations were carried out by considering and applying the equilibrium module and normal and phase transitions (normal + transition). The temperature at which a perfect liquid phase is achieved was defined as the melting point by simulating the heating process for the compositional combinations of the three impurity minerals.

[0181] The impurity content in spodumene may have mineralogical deviations from the standards obtained in the present invention (Table 1). Since there are spodumene ores with different contents of each impurity mineral, it is expected that the composition of impurity minerals can be controlled by intentionally mixing spodumenes with different impurity mineral contents. However, although the distribution of the range of impurity minerals varies, the combination of impurity minerals was intended to be selected within conditions that do not deviate significantly from the conditions in Table 1, and an appropriate effective range was selected from the standards by representing the KAlSi3O8-NaAlSi3O8-SiO23 phase diagram.

[0182] The same software, the same database, and the phase diagram module were used to calculate the above three-way phase diagram. The calculation was performed by setting the parameters to display only the liquidus region and configuring the projections for each temperature. The phase diagram obtained from the calculation was re-verified by comparing and confirming the equilibrium calculation results to verify the complete liquid phase region for each temperature.

[0184] Samples 1 to 14

[0185] Samples combined according to the content of x, y, and z are shown in Table 2 below along with the reference values ​​in Table 1. x was defined as KAlSi3O8, y as NaAlSi3O8, and z as SiO2, where x+y+z=100%.

[0187] Sample x(=KAlSi3O8) y(=NaAlSi3O8) z(=SiO2) Melting point (°C) standard 50.3 17.6 32.1 1050.1 Sample 1 20 30 50 1190.2 Sample 2 30 20 50 1154.2 Sample 3 40 10 50 1122.6 Sample 4 20 40 40 1068.7 Sample 5 30 30 40 1030.7 Sample 6 40 20 40 996.9 Sample 7 50 10 40 972.4 Sample 8 30 40 30 1010.2 Sample 9 40 30 30 984.5 Sample 10 50 20 30 1018.7 Sample 11 60 10 30 1066.8 Sample 12 40 40 20 1028.3 Sample 13 50 30 20 1056.0 Sample 14 60 20 20 1100.4

[0189] Depending on the content of x, y, and z and the given temperature, a perfect liquid phase or a solid and liquid phase may coexist. Therefore, for the purpose of creating a perfect liquid phase, the combination of impurity minerals may depend on the given temperature, so the liquidus line (indicated by the red line) for each temperature and the corresponding combination range are shown in Figures 1 to 6.

[0190] Specifically, Figures 1 to 6 are shown at intervals of 20°C at temperatures ranging from 1,000 to 1,100°C. The inequalities of x, y, and z for the calculated temperature-dependent compositional combination samples existing in a perfect liquid phase for a given group can be shown in Table 3 below, and the corresponding samples are shown together.

[0192] condition temperature x maximum range y maximum range z maximum range The sample in question 1 1,000℃ 23% ≤ x ≤ 58% 0% ≤ y ≤ 41% 28% ≤ z ≤ 45% 6, 7, 9 2 1,020℃ 15% ≤ x ≤ 59% 0% ≤ y ≤ 48.5% 22.5% ≤ z ≤ 45% 6, 7, 8, 9 3 1,040℃ 7.5% ≤ x ≤ 61% 0% ≤ y ≤ 57.5% 17% ≤ z ≤ 47.5% 5, 6, 7, 8, 9, 10 4 1,060℃ 0% ≤ x ≤ 64% 0% ≤ y ≤ 63.5% 5% ≤ z ≤ 47.5% 5, 6, 7, 8, 9, 10, 12 5 1,080℃ 0% ≤ x ≤ 66% 0% ≤ y ≤ 77.5% 0% ≤ z ≤ 49% 5, 6, 7, 8, 9, 10, 11, 12 6 1,100℃ 0% ≤ x ≤ 68% 0% ≤ y ≤ 88% 0% ≤ z ≤ 50% 4, 5, 6, 7, 8, 9, 10, 11, 12,

[0194] If all conditions within the maximum ranges of x, y, and z are satisfied, then all can be in a fully liquid phase at the temperatures within Table 3 given. For example, in the case of samples 1, 2, 3, and 14, the melting points are all above 1,100°C, which corresponds to the extreme maximum range. However, since chemical melting at high temperatures is not a one-dimensional function of compositional combinations, in order to accurately evaluate the melting point at a specific composition, it is necessary to simultaneously compare and evaluate the fully liquid regions of Figures 1 to 6, including the maximum combination range given in Table 3.

[0195] Based on the above approach, it is expected that if dissolved by an effective compositional combination of impurity minerals within spodumene, the molten material containing only impurities can be removed through physical separation from the spodumene mineral by an appropriate methodology, thereby securing high-quality spodumene.

[0197] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

Claim 1 A step of preparing a lithium-containing ore; a step of confirming the content (weight%) of K-containing minerals, Na-containing minerals, and SiO2 of the lithium-containing ore; A method for recovering lithium, comprising the step of heat-treating the lithium-containing ore to remove mineral impurities; wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 1, and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,100°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 1] 0% ≤ x ≤ 68%, 0% ≤ y ≤ 88%, 0% ≤ z ≤ 50% In the above Equation 1, x is the content (weight%) of the K-containing mineral, y is the content (weight%) of the Na-containing mineral, z is the content (weight%) of SiO2, and x+y+z = 100%. Claim 2 A method for recovering lithium according to claim 1, wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 2 and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,080°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 2] 0% ≤ x ≤ 66%, 0% ≤ y ≤ 77.5%, 0% ≤ z ≤ 49% In the above Equation 2, x, y, and z are as defined in the above Equation 1. Claim 3 A method for recovering lithium according to claim 1, wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 3 and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,060°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 3] 0% ≤ x ≤ 64%, 0% ≤ y ≤ 63.5%, 5% ≤ z ≤ 47.5% In the above Equation 3, x, y, and z are as defined in the above Equation 1. Claim 4 A method for recovering lithium according to claim 1, wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 4 and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,040°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 4] 7.5% ≤ x ≤ 61%, 0% ≤ y ≤ 57.5%, 17% ≤ z ≤ 47.5% In the above Equation 4, x, y, and z are as defined in the above Equation 1. Claim 5 A method for recovering lithium according to claim 1, wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 5 and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,020°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 5] 15% ≤ x ≤ 59%, 0% ≤ y ≤ 48.5%, 22.5% ≤ z ≤ 45% In the above Equation 5, x, y, and z are as defined in the above Equation 1. Claim 6 A method for recovering lithium according to claim 1, wherein the heat treatment is performed at a heat treatment temperature determined by substituting the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 into the following Equation 6 and confirming whether the content (weight%) of the K-containing mineral, Na-containing mineral, and SiO2 satisfies the liquid phase region of the ternary phase diagram at 1,000 to 1,010°C in the ternary phase diagram of the K-containing mineral, Na-containing mineral, and SiO2: [Equation 6] 23% ≤ x ≤ 58%, 0% ≤ y ≤ 41%, 28% ≤ z ≤ 45% In the above Equation 6, x, y, and z are as defined in the above Equation 1. Claim 7 A method for recovering lithium according to claim 1, wherein the heat treatment is performed for 30 minutes to 3 hours. Claim 8 A method for recovering lithium according to claim 1, wherein the K-containing mineral comprises KAlSi3O8. Claim 9 A method for recovering lithium according to claim 1, wherein the Na-containing mineral comprises NaAlSi3O8. Claim 10 A method for recovering lithium according to claim 1, wherein the liquid phase region is obtained by calculating a quantitative melting point using thermodynamic software. Claim 11 A method for recovering lithium according to claim 1, further comprising: a step of heat-treating the lithium-containing ore to remove mineral impurities; subsequently, a step of sulfuric acid roasting the ore from which mineral impurities have been removed; a step of leaching lithium from the roasted ore to obtain a leaching slurry; and a step of solid-liquid separation of the leaching slurry. Claim 12 A method for recovering lithium according to claim 1, wherein the lithium-containing ore comprises one or more selected from the group consisting of spodumene, petalite, lepidolite, hectorite, eucryptite, jadarite, zinnwaldite, and amblygonite. Claim 13 A method for recovering lithium according to claim 12, wherein the lithium-containing ore comprises spodumene. Claim 14 A simulation method for recovering lithium, comprising: a step of preparing a lithium-containing ore; a step of confirming the content (weight%) of K-containing minerals, Na-containing minerals, and SiO2 of the prepared lithium-containing ore; and a step of predicting the heat treatment temperature of the lithium-containing ore using a ternary phase diagram obtained by calculating the quantitative melting points of the K-containing minerals, Na-containing minerals, and SiO2 using thermodynamic software. Claim 15 A simulation method for recovering lithium according to claim 14, wherein the step of predicting the heat treatment temperature of the lithium-containing ore comprises: calculating the quantitative melting point of the lithium-containing ore using an equilibrium and phase diagram module within the thermodynamic software, and indicating a liquid phase region within the ternary phase diagram.

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