KR102242686B1 - Method for manufacturing lithium concentrate and method for manufacturing lithium compound using lithium concentrate manufactured therefrom - Google Patents

Abstract

The present invention a method for manufacturing a lithium concentrate and a method for manufacturing a lithium compound using the lithium concentrate manufactured therefrom. After preparing a lithium fluoride by reacting a low-concentration lithium solution with a fluorine compound, the lithium fluoride is sulphated with an aqueous sulfuric acid compound, and lithium is acid leached to prepare a high-concentration lithium concentrate, and then each lithium in the lithium concentrate is subjected to a hydroxylation or carbonation reaction to prepare the lithium compound of lithium hydroxide or lithium carbonate.

Description

Lithium concentrate manufacturing method and lithium compound manufacturing method using lithium concentrate prepared therefrom {METHOD FOR MANUFACTURING LITHIUM CONCENTRATE AND METHOD FOR MANUFACTURING LITHIUM COMPOUND USING LITHIUM CONCENTRATE MANUFACTURED THEREFROM}

The present invention relates to a method for preparing a lithium concentrate and a method for preparing a lithium compound using the lithium concentrate prepared therefrom, and more particularly, to prepare lithium fluoride by reacting a low-concentration lithium solution with a fluorine compound, and then converting the lithium fluoride to a sulfate compound. A lithium concentrate manufacturing method and method for preparing a lithium compound of lithium hydroxide or lithium carbonate by reacting with an aqueous solution by sulfation reaction and acid-leaching lithium to prepare a high-concentration lithium concentrate, and then reacting lithium in the lithium concentrate to a hydroxyl reaction or carbonic acid reaction, respectively. It relates to a method for producing a lithium compound using the lithium concentrate prepared from.

In general, a method of preparing a lithium compound of lithium hydroxide or lithium carbonate from a lithium solution is to prepare a lithium solution through a hydroxylation reaction or a carbonic acid reaction of a high concentration lithium solution.

Such high-concentration lithium solutions are concentrated by natural evaporation in a salt lake located in South America, and other methods include heat concentration, electrodialysis, and chemical treatment (precipitation/separation/acid leaching or sulfation reaction/water treatment of insoluble lithium compounds). Leaching).

The method of preparing an insoluble lithium compound by applying a precipitation method from a lithium solution, which is a chemical treatment method, uses phosphoric acid to _{convert to a lithium phosphate compound (Li 3} PO ₄ ) with low solubility to precipitate and separate.

In addition, methods of separating and separating in the form _{of Li-Al LDH (layered double hydroxide, LiAl 2} (OH) _7· 2H ₂ O), an insoluble lithium-aluminum cargo using aluminum compounds, have been proposed.

In the process of preparing an insoluble lithium compound and concentrating a lithium solution through acid leaching or sulfation reaction/water leaching, the concentration rate of the lithium solution is different according to the solid/liquid ratio or reaction ratio, and the lithium content per unit weight of the lithium compound is high. The more it has, the more advantageous it is to concentrate.

Among the insoluble lithium compounds, lithium phosphate per theoretical unit weight is about 17.9%, lithium-aluminum compounds are 2.8~3.2%, and lithium fluoride is about 26.7%. The lithium content per unit weight is the largest.

Therefore, it is very advantageous to use lithium fluoride to concentrate the lithium solution.

The present applicant obtained a method for preparing a lithium concentrate using lithium fluoride, which is very advantageous for concentrating a lithium solution, through several studies, and obtained a method for preparing a lithium compound of lithium carbonate or lithium hydroxide from such lithium fluoride, thereby completing the present invention. Became.

Republic of Korea Patent Publication No. 10-2016-0075679 (Patent publication date: June 29, 2016)

Accordingly, the present invention provides a lithium concentrate manufacturing method for preparing lithium fluoride, which is an insoluble lithium compound having a high lithium content per unit weight, and sulfation reaction and acid leaching of the lithium fluoride with an aqueous solution of a sulfuric acid compound to prepare a high concentration lithium concentrate. I have to.

In addition, the present invention is to provide a method for producing a lithium compound using a lithium concentrate in which lithium in a lithium concentrate is subjected to a hydroxyl reaction to prepare a lithium compound of lithium hydroxide.

In addition, the present invention is to provide a method for producing a lithium compound using a lithium concentrate in which lithium in a lithium concentrate is carbonated to produce a lithium compound of lithium carbonate.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problem, according to an aspect of the present invention,

Adding a fluorine compound as a precipitating agent to a low-concentration lithium solution, sedimenting and separating, to prepare a high-concentration lithium fluoride (LiF); And

Comprising: Sulfation reaction and acid leaching of the lithium fluoride with a high concentration of lithium fluoride with an aqueous solution of a sulfuric acid compound to leach lithium at a high concentration to prepare a high concentration lithium concentrate;

It provides a method for preparing a lithium concentrate.

In addition, the method for preparing the lithium concentrate may further include concentrating and recycling the filtrate in the step of preparing the lithium fluoride to improve a lithium fluoride production yield.

In addition, the low-concentration lithium solution may have a lithium ion concentration of 1500 ppm or less, and the high-concentration lithium concentrate may have a lithium ion concentration of 1500 ppm or more.

Here, the high-concentration lithium concentrate may include lithium ions, fluorine ions, sulfate ions, or metal ions as ionic components.

In addition, the fluorine compound of the lithium concentrate preparation method is sodium fluoride (NaF), ammonium fluoride (NH ₄ F), potassium fluoride (KF), ferrous fluoride (FeF ₂ ), ferric fluoride (FeF ₃ ), aluminum fluoride (AlF ₃ ) and hydrogen fluoride (HF) may include at least one selected from the group consisting of, and the shape of the fluorine compound may include a powder, a solution, or a slurry.

In addition, the ratio of the content of lithium (Li) in the low-concentration lithium solution to fluorine (F) in the fluorine compound may be Li:F = 1: 0.1 to 10 in a molar ratio.

Here, the sulfuric acid compound aqueous solution is

Sulfuric acid (H ₂ SO ₄ ) aqueous solution, sulfurous acid (H ₂ SO ₃ ) aqueous solution, magnesium sulfate (MgSO ₄ ) aqueous solution, calcium sulfate (CaSO ₄ ) aqueous solution, potassium sulfate (K ₂ SO ₄ ) aqueous solution and aluminum sulfate (Al ₂ (Al 2 ( SO ₄ ) ₃ ) may be one or more selected from the group consisting of aqueous solutions.

Further, according to another aspect of the present invention,

Precipitating a lithium concentrate prepared by a method for preparing a lithium concentrate of sulfation/acid leaching with a hydroxide compound to prepare an impurity precipitate excluding lithium;

Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And

Containing the step of concentrating and crystallizing the filtrate containing lithium to prepare lithium hydroxide, which is a lithium compound.

It provides a method for producing a lithium compound.

Here, the hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ). It may be one or more selected from the group consisting of.

At this time, the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr may be 1:0.5 to 1:5.

And, the lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na may be 1:0.5 to 1:2.

In addition, the lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: Ca may be 1:0.5 to 1:2.

Further, according to another aspect of the present invention,

Precipitating a lithium concentrate prepared by a method for preparing a lithium concentrate of sulfation/acid leaching with a hydroxide compound to prepare an impurity precipitate excluding lithium;

Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And

Comprising: the filtrate containing lithium is reacted with carbonic acid to produce lithium carbonate, which is a lithium compound.

It provides a method for producing a lithium compound.

Here, the hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ). It may be one or more selected from the group consisting of.

At this time, the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr may be 1:0.5 to 1:5.

And, the lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na may be 1:0.5 to 1:2.

In addition, the lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: Ca may be 1:0.5 to 1:2.

In addition, the carbonate compound in the step of producing lithium carbonate, which is a lithium compound, by carbonicating the filtrate containing lithium with a carbonate compound may be sodium carbonate (Na ₂ CO ₃ ) or carbon dioxide (CO ₂ ).

At this time, the filtrate containing lithium and the sodium carbonate (Na ₂ CO ₃ ) are Li in a molar ratio: Na ₂ CO ₃ may be 1:0.2 to 1:5.

In addition, the filtrate containing lithium and the carbon dioxide (CO ₂ ) are Li: CO ₂ may be 1:0.2 to 1:5.

According to the present invention, lithium to prepare a high concentration lithium fluoride, which is an insoluble lithium compound having a high lithium content per unit weight, and to prepare a high concentration lithium concentrate by sulfation reaction and acid leaching of the high concentration lithium fluoride with an aqueous solution of a sulfuric acid compound. Cost is reduced by providing a method for preparing a concentrate, and since the concentration of the lithium concentrate is high, it is advantageous for an additional process.

In addition, since the present invention provides a method for producing a lithium compound using a lithium concentrate to prepare a lithium compound of lithium hydroxide by hydration reaction of lithium in a lithium concentrate, the prepared lithium hydroxide can be used as an economical raw material for a secondary battery.

In addition, since the present invention provides a method for producing a lithium compound using a lithium concentrated solution for producing a lithium compound of lithium carbonate by carbonicating lithium in a lithium concentrated solution, the prepared lithium carbonate can be used as an economical raw material for a secondary battery.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a process flow diagram of a method for producing a high-concentration lithium concentrate according to an embodiment of the present invention.
2 is a flow chart of a process for preparing a lithium compound from a lithium concentrated solution of sulfation reaction and acid leaching according to an embodiment of the present invention.
3 is an XRD crystal structure analysis graph of lithium fluoride prepared by precipitation/separation with ammonium fluoride according to an embodiment of the present invention.
4 is an XRD crystal structure analysis graph of lithium fluoride prepared by precipitation/separation with sodium fluoride according to an embodiment of the present invention.
5A and 5B are graphs of XRD crystal structure analysis of precipitates of converted impurities prepared by a hydroxylation reaction according to an embodiment of the present invention.
6A is an XRD crystal structure analysis graph of lithium hydroxide prepared after concentration/crystallization of a conversion filtrate containing lithium prepared by a hydroxide reaction according to an embodiment of the present invention, and FIG. 6B is a reference to lithium sulfate and lithium hydroxide. For XRD data.
7 is an XRD crystal structure analysis graph of lithium carbonate prepared by carbonicating a conversion filtrate containing lithium prepared by a hydroxide reaction according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Advantages and features of the present invention, and a method of achieving the same will become apparent with reference to the embodiments described below in detail together with the accompanying drawings.

However, the present invention is not limited by the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments are intended to complete the disclosure of the present invention, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

In addition, in describing the present invention, when it is determined that related known technologies or the like may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Hereinafter, the present invention will be described in detail.

Method for preparing lithium concentrate using sulfation reaction/acid leaching

The present invention provides a method for preparing a high-concentration lithium concentrate using a fluorine compound as a precipitating agent and using a sulfuric acid reaction with an aqueous solution of a sulfuric acid compound and acid leaching.

A method for preparing a high-concentration lithium concentrate using a fluorine compound as a precipitating agent of the present invention and using a sulfuric acid reaction with an aqueous solution of a sulfuric acid compound and acid leaching

Adding a fluorine compound as a precipitating agent to a low-concentration lithium solution, sedimenting and separating, to prepare a high-concentration lithium fluoride (LiF); And

And preparing a high-concentration lithium concentrate by leaching lithium at a high concentration by sulfation reaction and acid leaching of the high concentration lithium fluoride with an aqueous solution of a sulfuric acid compound.

And, the low-concentration lithium solution refers to a solution of at least one lithium compound selected from the group consisting _{of LiOH, LiCl, LiBr, Li 2} CO ₃ , Li ₂ SO ₄ , Li ₃ PO ₄ , and LiAl(Si ₂ O ₅ ) ₂ However, it is not limited thereto.

In addition, the method for preparing the lithium concentrate may further include concentrating and recycling the filtrate in the step of preparing the lithium fluoride to improve a lithium fluoride production yield.

In addition, the low-concentration lithium solution may have a lithium ion concentration of 1500 ppm or less, and the high-concentration lithium concentrate may have a lithium ion concentration of 1500 ppm or more, but is not limited thereto.

Here, the high-concentration lithium concentrate may include lithium ions, fluorine ions, sulfate ions, or metal ions as ionic components.

In addition, the fluorine compound is sodium fluoride (NaF), ammonium fluoride (NH ₄ F), potassium fluoride (KF), ferrous fluoride (FeF ₂ ), ferric fluoride (FeF ₃ ), aluminum fluoride (AlF ₃ ), and hydrogen fluoride ( HF) may include one or more selected from the group consisting of, and the shape of the fluorine compound may include a powder, a solution, or a slurry.

In addition, a high concentration lithium fluoride can be prepared and precipitated using a low concentration lithium solution and the fluorine compound precipitating agent, and then separated to prepare a high concentration lithium fluoride.

Here, the ratio of the content of lithium (Li) in the low-concentration lithium solution to fluorine (F) in the fluorine compound may be Li:F = 1: 0.1 to 10 in a molar ratio.

In this case, when the ratio of the content of lithium (Li) in the low-concentration lithium solution to fluorine (F) in the fluorine compound is less than Li:F = 1: 0.1 in a molar ratio, the prepared lithium fluoride content is insufficient, and the low-concentration lithium solution When the ratio of the content of lithium (Li) and fluorine (F) in the fluorine compound exceeds Li:F = 1: 10 in a molar ratio, economical efficiency may be deteriorated.

In addition, in the step of preparing a high-concentration lithium concentrate by leaching lithium at a high concentration by sulfation reaction and acid leaching of the lithium fluoride with a high concentration of lithium fluoride with an aqueous solution of a sulfuric acid compound,

The high concentration lithium fluoride may be subjected to sulfation reaction and acid leaching with the sulfuric acid compound aqueous solution to prepare a high concentration lithium concentrate in which a high concentration of lithium ions, fluorine ions, sulfate ions, or metal ions are dissolved.

Then, a high-concentration lithium concentrate in which the high-concentration lithium ions, fluorine ions, sulfate ions, or metal ions are dissolved may be recovered.

In addition, the sulfuric acid compound aqueous solution is

Sulfuric acid (H ₂ SO ₄ ) aqueous solution, sulfurous acid (H ₂ SO ₃ ) aqueous solution, magnesium sulfate (MgSO ₄ ) aqueous solution, calcium sulfate (CaSO ₄ ) aqueous solution, potassium sulfate (K ₂ SO ₄ ) aqueous solution and aluminum sulfate (Al ₂ (Al 2 ( SO ₄ ) ₃ ) may be one or more selected from the group consisting of aqueous solutions.

1 is a process flow diagram of a method for producing a high-concentration lithium concentrate according to an embodiment of the present invention.

Referring to FIG. 1, in the step of preparing a low-concentration lithium solution (S110), LiOH, LiCl, LiBr, Li ₂ CO ₃ , Li ₂ SO ₄ , Li ₃ PO ₄ , and LiAl (Si ₂ O ₅ ) ₂ A solution of one or more low-concentration lithium compounds selected from the group may be prepared.

And, in the step of reacting a low-concentration lithium solution with a fluorine compound, precipitation/separation to form a high-concentration lithium fluoride (S120), sodium fluoride (NaF), ammonium fluoride (NH ₄ F), and potassium fluoride (KF) as the fluorine compound. , Ferrous fluoride (FeF ₂ ), ferric fluoride (FeF ₃ ), aluminum fluoride (AlF ₃ ), and hydrogen fluoride (HF), and the shape of the fluorine compound is powder, solution or A slurry may be included, and a lithium fluoride precipitate may be prepared by reacting the low-concentration lithium solution and the fluorine compound, and the prepared lithium fluoride precipitate may be separated to produce a high-concentration lithium fluoride.

Here, in the lithium fluoride forming step, the filtrate is concentrated and recycled (S130) to improve a lithium fluoride production yield.

Then, the high concentration of lithium fluoride is sulfuric acid (H ₂ SO ₄ ) aqueous solution, sulfurous acid (H ₂ SO ₃ ) aqueous solution, magnesium sulfate (MgSO ₄ ) aqueous solution, calcium sulfate (CaSO ₄ ) aqueous solution, potassium sulfate (K ₂ SO _{4 ).} ) Aqueous solution and aluminum sulfate (Al ₂ (SO ₄ ) ₃ ) A high concentration of lithium ions, fluorine ions, and sulfate ions through a sulfation reaction and an acid leaching step (S140) with an aqueous solution of at least one sulfuric acid compound selected from the group consisting of an aqueous solution. Alternatively, a high-concentration lithium concentrate in which metal ions are dissolved may be prepared (S160).

A method for producing lithium hydroxide in which lithium in a lithium concentrate prepared by sulfation/acid leaching is subjected to a hydroxylation reaction

The present invention provides a method for producing lithium hydroxide in which lithium in a lithium concentrate prepared by sulfation/acid leaching is subjected to a hydroxylation reaction.

The lithium hydroxide production method in which lithium in the lithium concentrate prepared by sulfation reaction/acid leaching of the present invention is subjected to a hydroxylation reaction is

Precipitating a lithium concentrate prepared by a method for preparing a lithium concentrate of sulfation/acid leaching with a hydroxide compound to prepare an impurity precipitate excluding lithium;

Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And

And concentrating and crystallizing the filtrate containing lithium to prepare lithium hydroxide, which is a lithium compound.

Here, the hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ). It may be one or more selected from the group consisting of.

At this time, the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr may be 1:0.5 to 1:5.

The lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: When Sr is less than 1:0.5, there may be a problem that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium hydroxide, and the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO _{4 in an equivalent ratio.} : When Sr is greater than 1:5, there may be a problem in that strontium hydroxide remains in the finally prepared lithium hydroxide.

And, the lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na may be 1:0.5 to 1:2.

The lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: When Na is less than 1:0.5, there may be a problem in that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium hydroxide, and the lithium concentrate and the sodium hydroxide (NaOH) are in an equivalent ratio of F·SO ₄ : When Na is greater than 1:2, there may be a problem that sodium hydroxide remains in the finally prepared lithium hydroxide.

In addition, the lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: Ca may be 1:0.5 to 1:2.

The lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: When Ca is less than 1:0.5, there may be a problem that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium hydroxide, and the lithium concentrate and the calcium oxide (CaO) are in an equivalent ratio of F·SO ₄ : Ca of 1 If it exceeds :2, there may be a problem that calcium oxide remains in the finally prepared lithium hydroxide.

At this time, when the lithium concentrate prepared by the sulfation reaction/acid leaching is subjected to a precipitation reaction with the hydroxide compound, impurity precipitates excluding lithium may be generated. Then, the impurity precipitate excluding lithium may be separated from the filtrate containing lithium. Thereafter, the filtrate containing lithium may be concentrated and crystallized to prepare lithium hydroxide, which is a lithium compound.

In addition, when the strontium hydroxide (Sr(OH) ₂ ) is mixed with the calcium oxide (CaO), the quality of lithium hydroxide is not degraded and the expensive strontium hydroxide (Sr(OH) ₂ ) can be used less, so it is economical. .

FIG. 2 is a flow chart of a process for preparing a lithium compound of lithium hydroxide from a lithium concentrate of sulfation reaction and acid leaching according to an embodiment of the present invention.

Referring to FIG. 2, in the step of preparing a lithium concentrate prepared by sulfation/acid leaching (S200), a lithium concentrate containing lithium ions, fluorine ions, sulfate ions, or metal ions as ionic components may be prepared. .

Then, in the step (S210) of separating the impurity precipitate and the lithium filtrate after a hydroxide reaction between the lithium concentrate and the hydroxide compound, the lithium concentrate is used as calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH)). ₂ ) Precipitating reaction with at least one hydroxide compound selected from the group consisting of to prepare an impurity precipitate excluding lithium, and then separating the impurity precipitate excluding lithium from the filtrate containing lithium, and then the filtrate containing lithium. Is concentrated/crystallized (S220) to prepare lithium hydroxide (S240).

Method for producing lithium carbonate by carbonicating lithium in lithium concentrate prepared by sulfation/acid leaching

The present invention provides a method for producing lithium carbonate in which lithium in a lithium concentrate prepared by sulfation/acid leaching is reacted with carbonic acid.

The lithium carbonate production method of carbonicating lithium in the lithium concentrate prepared by sulfation/acid leaching of the present invention

Precipitating a lithium concentrate prepared by a method for preparing a lithium concentrate of sulfation/acid leaching with a hydroxide compound to prepare an impurity precipitate excluding lithium;

Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And

And a step of carbonicating the filtrate containing lithium with a carbonate compound to produce lithium carbonate, which is a lithium compound.

At this time, when the lithium concentrate prepared by the sulfation reaction/acid leaching is subjected to a precipitation reaction with the hydroxide compound, impurity precipitates excluding lithium may be generated. Then, the impurity precipitate excluding lithium may be separated from the filtrate containing lithium. Thereafter, the filtrate containing lithium may be carbonicated with the carbonate compound to prepare lithium carbonate.

Here, the hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ). It may be one or more selected from the group consisting of.

At this time, the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr may be 1:0.5 to 1:5.

The lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: If Sr is less than 1:0.5, there may be a problem that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium carbonate, and the lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO _{4 in an equivalent ratio.} : When Sr is greater than 1:5, there may be a problem that strontium hydroxide remains in the finally prepared lithium carbonate.

And, the lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na may be 1:0.5 to 1:2.

The lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: When Na is less than 1:0.5, there may be a problem in that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium carbonate, and the lithium concentrate and the sodium hydroxide (NaOH) are in an equivalent ratio of F·SO ₄ : When Na is greater than 1:2, there may be a problem that sodium hydroxide remains in the finally prepared lithium carbonate.

In addition, the lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: Ca may be 1:0.5 to 1:2.

The lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: When Ca is less than 1:0.5, there may be a problem in that lithium sulfate, which is an unreacted product, is added to the finally prepared lithium carbonate, and the lithium concentrate and the calcium oxide (CaO) are in an equivalent ratio of F·SO ₄ : When Ca is greater than 1:2, there may be a problem that calcium oxide remains in the finally prepared lithium carbonate.

In addition, the carbonate compound in the step of producing lithium carbonate, which is a lithium compound, by carbonicating the filtrate containing lithium with a carbonate compound may be sodium carbonate (Na ₂ CO ₃ ) or carbon dioxide (CO ₂ ).

At this time, the filtrate containing lithium and the sodium carbonate (Na ₂ CO ₃ ) are Li in a molar ratio: Na ₂ CO ₃ may be 1:0.2 to 1:5.

Here, the filtrate containing lithium and the sodium carbonate (Na ₂ CO ₃ ) are Li in a molar ratio: When Na ₂ CO ₃ is less than 1:0.2, there may be a problem in that the yield of the finally prepared lithium carbonate decreases, and the molar ratio of _{the filtrate containing lithium and the sodium carbonate (Na 2} CO _{3 ):} When Na ₂ CO ₃ exceeds 1:5, there may be a problem that sodium carbonate remains in the finally prepared lithium carbonate.

In addition, the filtrate containing lithium and the carbon dioxide (CO ₂ ) are Li: CO ₂ may be 1:0.2 to 1:5.

Here, the filtrate containing lithium and the carbon dioxide (CO ₂ ) are Li in a molar ratio: When CO ₂ is less than 1:0.2, there may be a problem in that the yield of the finally prepared lithium carbonate decreases, and the filtrate containing lithium and the carbon dioxide (CO ₂ ) are in a molar ratio of Li: CO ₂ is If it exceeds 1:5, there may be a problem that economic efficiency is deteriorated due to the use of excessive carbon dioxide.

FIG. 2 is a flow chart of a process for preparing a lithium compound of lithium carbonate from a lithium concentrated solution of sulfation reaction and acid leaching according to an embodiment of the present invention.

Referring to FIG. 2, in the step of preparing a lithium concentrate prepared by sulfation/acid leaching (S200), a lithium concentrate containing lithium ions, fluorine ions, sulfate ions, or metal ions as ionic components may be prepared. .

Then, in the step (S210) of separating the impurity precipitate and the lithium filtrate after a hydroxide reaction between the lithium concentrate and the hydroxide compound, the lithium concentrate is used as calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH)). ₂ ) Precipitating reaction with at least one hydroxide compound selected from the group consisting of to prepare an impurity precipitate excluding lithium, and then separating the impurity precipitate excluding lithium from the filtrate containing lithium, and then the filtrate containing lithium. Lithium carbonate may be produced (S250) through a step (S230) of precipitation/separation after a carbonation reaction with a carbonated compound of sodium carbonate (Na ₂ CO ₃ ) or carbon dioxide (CO _{2 ).}

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are for explaining the present invention more specifically, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

<Analysis method>

Elemental analysis was performed using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) (Optima 7300D, Perkinelmer).

In addition, the crystal structure analysis was analyzed using X-ray Diffraction (XRD; D/MAX 2200, Rigaku).

<Preparation example>

A lithium hydroxide (LiOH) solution having a lithium ion concentration of 1000 ppm was prepared as a low concentration lithium solution.

<Example>

<Example 1> Preparation of lithium fluoride as a low-concentration lithium solution and ammonium fluoride precipitating agent (A-1, A-2, A-3)

Lithium hydroxide solution having a lithium ion concentration of about 1000 ppm _{was reacted with a solution of ammonium fluoride (NH 4} F) as a precipitating agent in the molar ratio shown in Table 1 below, and lithium fluoride (A-1, A-2, A-) in which lithium was concentrated at a high concentration. 3) was prepared.

Then, the lithium ion concentration and the lithium recovery rate of the sample remaining after preparing the high concentration lithium fluoride were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES; Optima 7300D, Perkinelmer), and are shown in Table 1 below.

LiOH solution/NH ₄ F Sample number Molar ratio Reaction conditions Reaction time(day) Li ion concentration (ppm) Li recovery rate (%) A-0 Li: F = 1: 0 LiOH solution: 300 mL
(Li concentration: 1000 ppm)
NH ₄ F solution: 50 mL
Agitation speed: 300 rpm One 1161.850 A-1 Li: F = 1: 1 One 492.290 50.567 A-2 Li: F = 1: 1.5 One 277.250 72.160 A-3 Li: F = 1: 2 One 205.060 79.409

The lithium ion concentration of the original sample without using the ammonium fluoride precipitant was 1161.850 ppm, but when the ammonium fluoride precipitant was used in a molar ratio of F: Li = 1: 1, the lithium ion concentration of the remaining sample was 492.290 ppm, and the lithium recovery rate was 492.290 ppm. It exceeded 50%, and lithium fluoride (A-1) was produced.

When the ammonium fluoride precipitant was used in a molar ratio of F: Li = 1: 1.5, the lithium ion concentration of the remaining sample was 277.250 ppm, and the lithium recovery rate exceeded 72%, and lithium fluoride (A-2) was prepared.

When the ammonium fluoride precipitant was used in a molar ratio of F: Li = 1: 2, the lithium ion concentration of the remaining sample was 205.060 ppm, and the lithium recovery rate exceeded 79%, and lithium fluoride (A-3) was prepared.

In addition, the crystal structure of the prepared lithium fluoride (A-1, A-2, A-3) was analyzed as shown in FIG. 3 using X-ray diffraction analysis (XRD; D/MAX 2200, Rigaku).

3 is an XRD crystal structure analysis graph of lithium fluoride (A-1, A-2, A-3) prepared by precipitating/separating a low-concentration lithium solution with ammonium fluoride as a precipitant.

Referring to FIG. 3, the diffraction angles of lithium fluoride of A-1, A-2, and A-3 were measured at the same diffraction angle position as that of the reference lithium fluoride reagent (LiF Reagent).

Thus, the lithium fluoride (A-1, A-2, A-3) of Example 1 prepared by precipitating/separating a low-concentration lithium solution with ammonium fluoride as a precipitant is the same compound as the lithium fluoride reagent (LiF Reagent), which is a reference material. Was confirmed.

<Example 2> Preparation of lithium fluoride as a low-concentration lithium solution and sodium fluoride precipitating agent (B-1, B-2, B-3)

Lithium fluoride (B-1, B-2, B-3) in which lithium is concentrated in a high concentration by reacting a lithium hydroxide solution having a lithium ion concentration of about 1000 ppm with a slurry of sodium fluoride (NaF) as a precipitating agent in the molar ratio shown in Table 2 below. Was prepared.

Then, the lithium ion concentration and the lithium recovery rate of the sample remaining after the preparation of the high concentration lithium fluoride were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES; Optima 7300D, Perkinelmer), and are shown in Table 2 below.

LiOH solution/NH ₄ F Sample number Molar ratio Reaction conditions Reaction time(day) Li ion concentration (ppm) Li recovery rate (%) B-0 Li: F = 1: 0 LiOH solution: 300 mL
(Li concentration: 1000 ppm)
NaF slurry: 50 mL
Agitation speed: 300 rpm One 1177.600 B-1 Li: F = 1: 1 One 618.600 38.714 B-2 Li: F = 1: 1.5 One 277.250 72.532 B-3 Li: F = 1: 2 One 184.800 81.692

The lithium ion concentration of the original sample without sodium fluoride precipitant was 1177.600 ppm, but when the ammonium fluoride precipitant was used in a molar ratio of F: Li = 1: 1, the lithium ion concentration of the remaining sample was 618.600 ppm, and the lithium recovery rate was 618.600 ppm. It exceeded 38%, and lithium fluoride (B-1) was produced.

When the sodium fluoride precipitant was used in a molar ratio of F: Li = 1: 1.5, the lithium ion concentration of the remaining sample was 277.250 ppm, and the lithium recovery rate exceeded 72%, and lithium fluoride (B-2) was prepared.

When the sodium fluoride precipitant was used in a molar ratio of F: Li = 1: 2, the lithium ion concentration of the remaining sample was 184.800 ppm, and the lithium recovery rate exceeded 81%, and lithium fluoride (B-3) was prepared.

In addition, the crystal structure of the prepared lithium fluoride (B-1, B-2, B-3) was analyzed as shown in FIG. 4 using X-ray diffraction analysis (XRD; D/MAX 2200, Rigaku).

4 is an XRD crystal structure analysis graph of lithium fluoride (B-1, B-2, B-3) prepared by precipitating/separating a low-concentration lithium solution with sodium fluoride as a precipitant.

Referring to FIG. 4, the diffraction angles of lithium fluoride of B-1, B-2, and B-3 were measured at the same diffraction angle position as that of the reference lithium fluoride reagent (LiF Reagent).

Thus, the lithium fluoride (B-1, B-2, B-3) of Example 2 prepared by precipitating/separating a low-concentration lithium solution with sodium fluoride as a precipitant is the same compound as the lithium fluoride reagent (LiF Reagent), which is a reference material. Was confirmed.

<Example 3> Preparation of lithium concentrate using sulfation reaction/acid leaching

Using 50 g of lithium fluoride (A-3) of high concentration prepared in Example 1 and 1 L of 2M sulfuric acid, sulfuration reaction and acid leaching were performed, and lithium ions, fluorine ions, sulfate ions, or metals were used as ionic components. A lithium concentrate containing ions was prepared.

At this time, the lithium ion concentration of the lithium concentrate according to the sulfation reaction between the high concentration of lithium fluoride (A-3) and sulfuric acid was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES; Optima 7300D, Perkinelmer).

As a result, it was confirmed that the lithium ion concentration of the lithium concentrate prepared by the sulfation reaction and acid leaching was 13,836 ppm.

<Example 4> Preparation of lithium hydroxide by hydration reaction of lithium concentrate prepared by sulfation reaction/acid leaching

The lithium concentrate prepared by the sulfation reaction/acid leaching in Example 3 was subjected to a _{hydroxylation reaction with strontium hydroxide (Sr(OH) 2} ) to prepare lithium hydroxide.

First, the lithium concentrate prepared by the sulfation reaction/acid leaching in Example 3 was F·SO _{4 in an equivalent ratio with strontium hydroxide (Sr(OH) 2} ): Sr was reacted to be 1:0.8, 1:1.0, 1:1.1, 1:1.2 to form a converted precipitate excluding lithium, and then the converted precipitate excluding lithium was separated from the filtrate containing lithium.

Then, the filtrate containing lithium was concentrated and crystallized to prepare lithium hydroxide, which is a lithium compound.

At this time, the crystal structure of the converted impurity precipitate excluding lithium was analyzed as shown in FIGS. 5A and 5B using X-ray diffraction analysis (XRD; D/MAX 2200, Rigaku).

5A and 5B are XRD crystal structure analysis graphs of converted impurity precipitates excluding lithium formed when a lithium concentrate prepared by sulfation/acid leaching is reacted with strontium hydroxide (Sr(OH) _{2 ).}

5A, the lithium concentrate prepared by sulfation/acid leaching is F·SO _{4 in an equivalent ratio with strontium hydroxide (Sr(OH) 2} ), which is a hydroxide compound: It was confirmed that the crystal structure of the precipitate of the converted impurity excluding lithium formed by reacting so that Sr became 1:0.8, 1:1.0, 1:1.1, and 1:1.2 had the same crystal structure.

In addition, referring to FIG. 5B, _{it was confirmed that the crystal structure of the precipitate formed by reacting strontium hydroxide (Sr(OH) 2} ) and ammonium fluoride in an equivalent ratio of Sr:F to 1:2.2 is similar to that of strontium fluoride. I did.

And, referring again to FIG. 5B, _{the crystal structure of the precipitate formed by reacting strontium hydroxide (Sr(OH) 2} ) and sulfuric acid in an equivalent ratio of Sr: SO ₄ to 1:1.1 is similar to that of strontium sulfate. Confirmed. Accordingly, it was confirmed that the impurities formed by reacting the lithium concentrate with strontium hydroxide were a mixture of strontium sulfate and strontium fluoride.

Then, the filtrate containing lithium was concentrated at 70° C. and crystallized to prepare lithium hydroxide.

In addition, the crystal structure of the powder prepared after concentration/crystallization of the lithium-containing conversion filtrate was analyzed as shown in FIG. 6A using X-ray diffraction analysis (XRD; D/MAX 2200, Rigaku).

6A is an XRD crystal structure analysis of a powder prepared after concentration/crystallization of a conversion filtrate containing lithium formed when a lithium concentrate prepared by sulfation reaction/acid leaching is reacted with strontium hydroxide (Sr(OH) ₂₎ It is a graph, and FIG. 6B is XRD data for reference of lithium sulfate and lithium hydroxide.

6A, the lithium concentrate prepared by sulfation/acid leaching is F·SO _{4 in an equivalent ratio with strontium hydroxide (Sr(OH) 2} ), which is a hydroxide compound: After concentration/crystallization of the conversion filtrate containing lithium by reacting so that Sr becomes 1:0.8, 1:1.0, 1:1.1, 1:1.2, the crystal structure of the powder prepared is all crystal structures containing lithium hydroxide. I did.

6B is XRD data of lithium sulfate and lithium hydroxide used for reference.

<Example 5> Preparation of lithium carbonate by carbonic acid reaction of lithium concentrate prepared by sulfate reaction/acid leaching

The lithium concentrate prepared by the sulfation reaction/acid leaching in Example 3 was F·SO _{4 in an} equivalent ratio with calcium oxide (CaO): Ca was reacted to be 1:1 to form a precipitate of converted impurities excluding lithium, and then the precipitate of converted impurities excluding lithium was separated from the filtrate containing lithium.

Then, the filtrate containing lithium was carbonated with sodium carbonate (Na ₂ CO ₃ ) in a molar ratio of Li: Na ₂ CO ₃ = 1: 2.22 to prepare lithium carbonate.

At this time, the crystal structure of the lithium carbonate was analyzed as shown in FIG. 7 using X-ray diffraction analysis (XRD; D/MAX 2200, Rigaku).

7 is a lithium carbonate prepared by reacting a lithium concentrate prepared by sulfation/acid leaching with calcium oxide (CaO) to separate impurities, and then carbonating a conversion filtrate containing lithium with sodium carbonate (Na ₂ CO ₃ ). It is a graph of XRD crystal structure analysis.

Referring to FIG. 7, the crystal structure of lithium carbonate prepared by carbonicating the conversion filtrate containing lithium with sodium carbonate (Na ₂ CO ₃ ) is a crystal structure of a lithium carbonate reagent (Li ₂ CO ₃ Reagent), which is a reference material. In the same way, it was confirmed that the compound prepared by carbonicating the conversion filtrate containing lithium with sodium carbonate (Na ₂ CO _{3) was lithium carbonate.}

So far, specific examples of the method for preparing a lithium concentrate according to the present invention and a method for preparing a lithium compound using the lithium concentrate prepared therefrom have been described, but various implementation modifications are possible within the limit not departing from the scope of the present invention. It's self-evident.

Therefore, the scope of the present invention should not be defined by being limited to the described embodiments, and should be defined by the claims and equivalents as well as the claims to be described later.

That is, 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 to be described later rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be construed as being included in the scope of the present invention.

Claims (20)

Adding a fluorine compound as a precipitating agent to a low-concentration lithium solution, separating and precipitating, to prepare lithium fluoride (LiF), an insoluble lithium compound, at a high concentration; And
Comprising: preparing a high-concentration lithium concentrate by leaching lithium at a high concentration by sulfation reaction and acid leaching of lithium fluoride (LiF), which is an insoluble lithium compound at a high concentration, with an aqueous solution of a sulfuric acid compound.
Lithium concentrate manufacturing method.
The method of claim 1,
The lithium concentrate manufacturing method further comprises the step of concentrating and recycling the filtrate in the step of preparing the lithium fluoride to improve a lithium fluoride production yield.
Lithium concentrate manufacturing method.
The method of claim 1,
The low-concentration lithium solution has a lithium ion concentration of 1500 ppm or less, and the high-concentration lithium concentrate has a lithium ion concentration of 1500 ppm or more.
Lithium concentrate manufacturing method.
The method of claim 1,
The high-concentration lithium concentrate contains lithium ions, fluorine ions, sulfate ions, or metal ions as ionic components.
Lithium concentrate manufacturing method.
The method of claim 1,
The fluorine compounds are sodium fluoride (NaF), ammonium fluoride (NH ₄ F), potassium fluoride (KF), ferrous fluoride (FeF ₂ ), ferric fluoride (FeF ₃ ), aluminum fluoride (AlF ₃ ), and hydrogen fluoride (HF). Including one or more selected from the group consisting of,
The shape of the fluorine compound is characterized in that it includes a powder, a solution, or a slurry.
Lithium concentrate manufacturing method.
The method of claim 1,
The ratio of the content of lithium (Li) in the low-concentration lithium solution to fluorine (F) in the fluorine compound is Li:F = 1: 0.1 to 10 in a molar ratio.
Lithium concentrate manufacturing method.
The method of claim 1,
The sulfuric acid compound aqueous solution is
Sulfuric acid (H ₂ SO ₄ ) aqueous solution, sulfurous acid (H ₂ SO ₃ ) aqueous solution, magnesium sulfate (MgSO ₄ ) aqueous solution, calcium sulfate (CaSO ₄ ) aqueous solution, potassium sulfate (K ₂ SO ₄ ) aqueous solution and aluminum sulfate (Al ₂ (Al 2 ( SO ₄ ) ₃ ) characterized in that at least one selected from the group consisting of aqueous solutions
Lithium concentrate manufacturing method.
Prepared by the lithium concentrate manufacturing method according to any one of claims 1 to 7
Precipitating the lithium concentrate with a hydroxide compound to prepare an impurity precipitate excluding lithium;
Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And
Containing the step of concentrating and crystallizing the filtrate containing lithium to prepare lithium hydroxide, which is a lithium compound.
Lithium compound manufacturing method.
The method of claim 8,
The hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is a group consisting of calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ) Characterized in that at least one selected from
Lithium compound manufacturing method.
The method of claim 9,
The lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr is 1:0.5 to 1:5, characterized in that
Lithium compound manufacturing method.
The method of claim 9,
The lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na is 1:0.5 to 1:2, characterized in that
Lithium compound manufacturing method.
The method of claim 9,
The lithium concentrate and the calcium oxide (CaO) are F·SO ₄ in an equivalent ratio: Characterized in that Ca is 1:0.5 to 1:2
Lithium compound manufacturing method.
Prepared by the lithium concentrate manufacturing method according to any one of claims 1 to 7
Precipitating the lithium concentrate with a hydroxide compound to prepare an impurity precipitate excluding lithium;
Separating the impurity precipitate excluding lithium from the filtrate containing lithium; And
Comprising: the filtrate containing lithium is reacted with carbonic acid to produce lithium carbonate, which is a lithium compound.
Lithium compound manufacturing method.
The method of claim 13,
The hydroxide compound in the step of preparing an impurity precipitate excluding lithium by precipitating the lithium concentrated solution with a hydroxide compound is a group consisting of calcium oxide (CaO), sodium hydroxide (NaOH), and strontium hydroxide (Sr(OH) ₂ ) Characterized in that at least one selected from
Lithium compound manufacturing method.
The method of claim 14,
The lithium concentrate and the strontium hydroxide (Sr(OH) ₂ ) are F·SO ₄ in an equivalent ratio: Sr is 1:0.5 to 1:5, characterized in that
Lithium compound manufacturing method.
The method of claim 14,
The lithium concentrate and the sodium hydroxide (NaOH) are F·SO ₄ in an equivalent ratio: Na is 1:0.5 to 1:2, characterized in that
Lithium compound manufacturing method.
The method of claim 14,
The lithium concentrate and the calcium oxide (CaO) have an equivalent ratio of F·SO ₄ : Characterized in that Ca is 1:0.5 to 1:2
Lithium compound manufacturing method.
The method of claim 13,
The carbonate compound in the step of carbonicating the lithium-containing filtrate with a carbonate compound to produce lithium carbonate, which is a lithium compound, is sodium carbonate (Na ₂ CO ₃ ) or carbon dioxide (CO ₂ ).
Lithium compound manufacturing method.
The method of claim 18,
The filtrate containing lithium and the sodium carbonate (Na ₂ CO ₃ ) are Li in a molar ratio: Na ₂ CO _{3 characterized in} that 1:0.2 to 1:5
Lithium compound manufacturing method.
The method of claim 18,
The filtrate containing lithium and the carbon dioxide (CO ₂ ) are Li in a molar ratio: CO ₂ is characterized in that 1:0.2 to 1:5
Lithium compound manufacturing method.

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