KR102400897B1 - Method of extracting lithium from lithium-containing ore - Google Patents

Abstract

Lithium extraction method from lithium-containing ores according to an embodiment of the present invention, the lithium-containing ores are chlorinated to obtain a chloride; and removing impurities by dissolving the chloride in an organic solvent having a selective solubility for lithium chloride in the chloride.

Description

METHOD OF EXTRACTING LITHIUM FROM LITHIUM-CONTAINING ORE

The present invention relates to a method for extracting lithium from lithium containing ores. More specifically, it relates to a method for selectively extracting lithium chloride from lithium-containing ores.

Lithium ore is easier to secure than salt lakes, and there are no climate restrictions, so mine development and lithium extraction around the world are expanding. Recently, as lithium is used in various fields, interest in methods and technologies for recovering lithium resources is increasing. For example, by extracting LiCl from spodumene (LiAlSi ₂ O ₆ ) light, it can be used as a raw material of Li ₂ CO ₃ Do. Conventionally, LiCO ₃ was prepared from spodumene (LiAlSi ₂ O ₆ ) light by a wet method using sulfuric acid. Specifically, oxidative roasting of spodumene, leaching and neutralization using a sulfuric acid method, followed by purification, evaporation, and concentration processes, and the like are used to prepare Li ₂ CO ₃ . However, in the case of extracting lithium by the wet method using sulfuric acid, the process is complicated and there is a problem that various expenses such as labor and management costs are high, as well as environmental problems due to waste residues. We want to develop an eco-friendly lithium extraction technology through development, and when using a technology to extract lithium by a dry method, the process is simple, and there are no impurities in the residue, so it is easy to generate profits and solves environmental pollution problems. In the present invention, it was intended to present a technique for selective extraction of lithium using a chlorination method.

The present invention provides a method for extracting lithium from lithium containing ores. More specifically, it provides a method for selectively extracting lithium chloride from lithium-containing ores.

A method of extracting lithium from a lithium-containing ore according to an embodiment of the present invention comprises the steps of chlorinating the lithium-containing ore to obtain a chloride; and removing impurities by dissolving the chloride in an organic solvent having a solubility selective for lithium chloride in the chloride.

In the step of removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride; the organic solvent may be one that dissolves LiCl and does not dissolve NaCl and KCl.

In the step of removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride; In, the organic solvent may be an alcohol-based solvent.

In the step of removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride; in, the organic solvent is amyl alcohol, methanol, ethyl alcohol, isopropyl alcohol, isobutanol, or a combination thereof can

removing impurities by dissolving the chloride in an organic solvent having a selective solubility for lithium chloride in the chloride; dissolving the chloride in the organic solvent; and vaporizing the organic solvent.

Chlorizing the lithium-containing ore to obtain a chloride; is, by injecting a gas containing Cl ₂ to the lithium-containing ore may be a step of obtaining a chloride.

The step of chlorinating the lithium-containing ore to obtain a chloride; may be to chlorinate the lithium-containing ore at 900 to 1400 ℃.

removing impurities by dissolving the chloride in an organic solvent having a selective solubility for lithium chloride in the chloride; Previously, the method may further include the step of removing impurities in lithium chloride by a vapor pressure difference by increasing the temperature of the chloride.

The step of removing impurities in lithium chloride by a difference in vapor pressure by increasing the temperature of the chloride; may be to remove impurities by raising the temperature of the chloride to 400 ℃ or more.

The step of removing impurities in lithium chloride by a difference in vapor pressure by increasing the temperature of the chloride; may be removing a material having a vapor pressure higher than that of LiCl.

Lithium extraction method from lithium-containing ore according to an embodiment of the present invention, when utilizing spodumene ore for lithium extraction used in lithium batteries, high-purity chlorination as an eco-friendly process rather than by-product generation by the conventional wet process Lithium extraction is possible. Therefore, it is possible to secure technology to reduce process cost and waste treatment cost, and through this, it is possible to enhance the competitiveness of the lithium smelting business.

In the lithium extraction method from lithium-containing ore according to an embodiment of the present invention, impurities are removed by vapor pressure difference from the primarily collected chloride, and the solubility of alkali chloride in the organic solvent in the secondary residual alkali chloride By removing impurities by selectively dissolving only LiCl with tea, high purity LiCl can be obtained.

1 is a schematic diagram of the chlorination process of lithium-containing ores according to an embodiment of the present invention.
2 is a graph of vapor pressure of spodumene chloride components.
3 is a graph of the residual amount according to the temperature of the spodumene chloride components.
4 is a schematic process diagram of a step of removing impurities by dissolving a chloride in an organic solvent according to an embodiment of the present invention.
5 is a schematic diagram of a step of removing impurities by dissolving a chloride in an organic solvent according to an embodiment of the present invention.

In this specification, terms such as first, second and third are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are used only to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.

In the present specification, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

In this specification, the terminology used is for the purpose of referring to specific embodiments only, and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" specifies a particular characteristic, region, integer, step, operation, element and/or component, and the presence or absence of another characteristic, region, integer, step, operation, element and/or component It does not exclude additions.

In the present specification, the term "combination of these" included in the expression of the Markush format means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the Markush format, and the components It means to include one or more selected from the group consisting of.

In this specification, when a part is referred to as being “on” or “on” another part, it may be directly on or on the other part, or the other part may be accompanied in between. In contrast, when a part is referred to as being "directly above" another part, the other part is not interposed therebetween.

Although not defined otherwise, all terms including technical terms and scientific terms used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the present invention belongs. Commonly used terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed content, and unless defined, are not interpreted in an ideal or very formal meaning.

In addition, unless otherwise specified, % means weight %, and 1 ppm is 0.0001 weight %.

In an embodiment of the present invention, the meaning of further including the additional element means that the remaining iron (Fe) is included by replacing the additional amount of the additional element.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

Lithium extraction method from lithium-containing ores according to an embodiment of the present invention, the lithium-containing ores are chlorinated to obtain a chloride; and removing impurities by dissolving the chloride in an organic solvent having a solubility selective for lithium chloride in the chloride.

Each step is described below.

First, the lithium-containing ore is chlorinated to obtain a chloride.

The lithium-containing ore at this stage may be spodumene ore.

This step may be a step of obtaining a chloride by injecting a gas containing Cl ₂ to the lithium-containing ore.

In addition, the gas including Cl ₂ may include C(s) and Cl ₂ (g).

Since spodumene ore has the chemical formula of LiAlSi ₂ O ₆ , it can react with C and Cl ₂ to derive LiCl (g). Its reaction formula is shown in Equation 1 below.

[Formula 1] 2LiAlSi ₂ O ₆ (s)+ C(s)+Cl ₂ (g) = 2LiCl(g) +CO(g)+Al ₂ Si ₄ O ₁₁ (s)

In this step, since Al ₂ O ₃ and other impurities may be chlorinated together from the raw ore such as spodumene, chlorides of various impurities such as AlCl ₃ , FeCl ₃ , NaCl, KCl as well as LiCl according to the above reaction formula are generated. can Since the purpose of the present invention is to extract high-purity LiCl, it may be necessary to selectively re-extract LiCl in chlorides including impurity chlorides and the like. Therefore, in the following, the above impurities may be removed.

The chlorination reaction in this step may be carried out using a flow process or a rotary kiln process.

The chlorination reaction temperature in this step may be 900 to 1400 °C. More specifically, it may be 1000 to 1300 °C.

The chlorination reaction time in this step may be 30 minutes to 2 hours.

In other words, since Al ₂ O ₃ and other impurities may be chlorinated together from raw ore such as spodumene, chlorides of various impurities such as AlCl ₃ , FeCl ₃ , NaCl, KCl are produced as well as LiCl according to the above reaction formula can be Since the purpose of the present invention is to extract high-purity LiCl, it may be necessary to selectively re-extract LiCl in chlorides including impurity chlorides and the like. Therefore, in the following step, the primary impurity may be removed using vapor pressure, and the secondary impurity may be removed in order to selectively extract LiCl from alkali chloride using an organic solvent. High purity LiCl can be obtained through this step.

Next, by increasing the temperature of the chloride, impurities in lithium chloride can be removed by the difference in vapor pressure.

More specifically, the impurity may be primarily removed by heating the chloride to 400° C. or higher. More specifically, it may be 700° C. or higher. More specifically, it may be 900° C. or higher.

In this step, a material having a higher vapor pressure than LiCl may be removed. That is, FeCl ₃ , AlCl ₃ , SiCl ₄ and the like having a higher vapor pressure than LiCl may be removed in this step. In this step, impurities are primarily removed by using the vapor pressure difference between the chlorides.

Next, impurities are removed by dissolving the chloride in an organic solvent having a solubility selective for lithium chloride in the chloride.

This step may be a step of first dissolving the chloride in an organic solvent, and then vaporizing the organic solvent to obtain high-purity LiCl.

Chloride, more specifically, residual alkali chloride is dissolved in an organic solvent, and since the solubility of LiCl in the organic solvent is significantly greater than the solubility of KCl and NaCl, a much larger amount of LiCl than KCl and NaCl is dissolved in the organic solvent do.

More specifically, the organic solvent may dissolve LiCl and not dissolve NaCl and KCl.

In this case, the organic solvent may be an alcohol-based solvent, and more specifically, may be amyl alcohol, methanol, ethyl alcohol, isopropyl alcohol, isobutanol, or a combination thereof. More specifically, it may be amyl alcohol.

Secondary purification can be performed by removing secondary impurities by removing KCl and NaCl present in a solid phase from a solution of an organic solvent.

By raising the temperature of the organic solvent to a temperature equal to or higher than the boiling point of the organic solvent, the organic solvent is given an opportunity to obtain high-purity LiCl. More specifically, when the organic solvent is amyl alcohol, the temperature may be raised to 138° C. or higher to vaporize the amyl alcohol.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only for illustrating the present invention, and the present invention is not limited thereto.

Example

1. Preparation of lithium-containing ores

Lithium-containing ore was prepared for the experiment.

The initial component composition of the ore raw material was shown in Table 1. In Table 1, the content unit of each component is weight %.

ore
Raw material Li ₂ O Fe ₂ O ₃ MnO Al ₂ O ₃ SiO ₂ Na ₂ O K ₂ O P ₂ O ₅ CaO TiO ₂ weight% 7.1 0.17 0.04 25.7 65.7 0.28 0.34 0.16 0.07 0.01

2. Chlorination process of lithium-containing ores

The prepared spodumene ore was chlorinated for 60 minutes by injecting C and Cl ₂ gas at 1200 ° C. A schematic diagram of the reactor in this process is shown in FIG. 1 . The sample at a distance of 20 cm from the center of the chloride generated by the chlorination reaction is sample (1), the sample 30 cm away from the sample (2), the sample 40 cm away from the sample (3), and the sample 50 cm away from the sample ( 4), the composition of the chloride produced after the chlorination process of each sample is shown in Table 2. In Table 2, the content unit of each component is weight %.

sample LiCl AlCl ₃ SiCl ₄ FeCl ₃ CaCl ₂ MgCl ₂ NaCl KCl (One) 29.111 37.756 9.307 14.633 0.241 0.384 5.192 3.375 (2) 31.536 34.108 3.479 20.414 0.216 0.395 5.783 4.069 (3) 25.959 37.330 1.227 24.785 0.172 0.261 5.989 4.277 (4) 19.865 34.114 34.640 6.340 0.198 0.298 2.741 1.803

3. Removal of primary impurities using vapor pressure difference

Thereafter, an experiment was performed using the sample (2). For samples (1), (3), and (4), subsequent experiments were not carried out, but the same raw material was used, and it is expected that the experiment will proceed with the same mechanism.

The temperature of the collected chlorides was maintained at 900°C or higher, or the product was separately extracted and heated to 900°C or higher. Since the vapor pressures of components present in each sample are different, FeCl ₃ , AlCl ₃ , SiCl ₄ and the like having a relatively high vapor pressure may be removed by first melting and vaporizing in this step.

The vapor pressures of the components of spodumene chloride are shown in FIG. 2 . In addition, the residual amount according to the temperature of each component is shown in FIG.

Table 3 shows the chloride composition during the refining operation of the primary impurity removal using the vapor pressure difference. It means the composition in the chloride solution according to each temperature.

Temperature (℃) NaCl KCl LiCl FeCl ₃ AlCl ₃ raw 12.97 8.79 39.90 6.69 31.65 400 20.59 13.47 62.01 0.59 3.33 700 22.15 10.96 66.59 0.04 0.27 900 24.59 12.85 62.49 0.01 0.05

4. Removal of secondary impurities using solubility difference in organic solvents

Thereafter, secondary impurities were removed using amyl alcohol in the remaining chloride. Table 4 shows the solubility of LiCl, NaCl, and KCl in amyl alcohol. That is, LiCl has the highest solubility in amyl alcohol as a solvent at 9.02.

Solubility
(100g, based on 20℃) menstruum
(amyl alcohol) - LiCl 9.02 NaCl 0.002 KCl 0.0022

First, amyl alcohol was added to the remaining chloride, and the chloride was dissolved in the amyl alcohol. Since only the solubility of LiCl in amyl alcohol is high, it is thought that LiCl is dissolved in amyl alcohol in a large amount.

Thereafter, undissolved NaCl and KCl were separated, and the amyl alcohol solution was heated to 138°C. At 138° C. or higher, amyl alcohol was vaporized, and high-purity LiCl could be extracted.

4 shows a schematic process diagram of a step of dissolving chloride in an organic solvent to remove impurities. 5 shows a schematic diagram of a step of removing impurities by dissolving chloride in an organic solvent.

In this step, the ICP analysis results of the solution before vaporizing the amyl alcohol solution (① in FIG. 5) and LiCl (② in FIG. 5) after vaporizing the amyl alcohol solution are shown in Table 5.

weight% Li Na K ① 0.54 20.67 15.19 ② 4.77 0.015 0.012

Through the above analysis, it was found that LiCl was of high purity.

The present invention is not limited to the embodiments, but can be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains can use other specific forms without changing the technical spirit or essential features of the present invention. It will be appreciated that this may be practiced. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (10)

chlorinating the lithium-containing ore to obtain a chloride; and
removing impurities by dissolving the chloride in an organic solvent having a solubility selective for lithium chloride in the chloride;
including,
removing impurities by dissolving the chloride in an organic solvent having a solubility selective for lithium chloride in the chloride; Before,
Further comprising the step of removing impurities in lithium chloride by a vapor pressure difference by increasing the temperature of the chloride,
removing impurities in lithium chloride by vapor pressure difference by increasing the temperature of the chloride;
To remove impurities by raising the temperature of the chloride to 400 ℃ or higher,
A method for extracting lithium from lithium-containing ores.
According to claim 1,
removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride;
The organic solvent dissolves LiCl and does not dissolve NaCl and KCl,
A method for extracting lithium from lithium-containing ores.
According to claim 1,
removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride;
The organic solvent is an alcohol-based,
A method for extracting lithium from lithium-containing ores.
4. The method of claim 3,
removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride;
The organic solvent is amyl alcohol, methanol, ethyl alcohol, isopropyl alcohol, isobutanol, or a combination thereof, lithium extraction method from lithium-containing ores.
According to claim 1,
removing impurities by dissolving the chloride in an organic solvent having a selective solubility in lithium chloride in the chloride;
dissolving the chloride in an organic solvent; and
vaporizing the organic solvent;
which includes,
A method for extracting lithium from lithium-containing ores.
According to claim 1,
Chlorizing the lithium-containing ore to obtain a chloride;
By injecting a gas containing Cl ₂ to the lithium-containing ore, the step of obtaining a chloride,
A method for extracting lithium from lithium-containing ores.
According to claim 1,
Chlorizing the lithium-containing ore to obtain a chloride;
To chlorinate lithium-containing ores at 900 to 1400 ° C.
A method for extracting lithium from lithium-containing ores.
delete delete According to claim 1,
removing impurities in lithium chloride by vapor pressure difference by increasing the temperature of the chloride;
To remove substances with a vapor pressure higher than LiCl,
A method for extracting lithium from lithium-containing ores.

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