JP2012201510A - Method for producing manganese carbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing manganese carbonate suppressing contamination with impurities such as sodium and more easily and economically giving high-purity manganese carbonate.SOLUTION: This method for producing manganese carbonate comprises: a hydroxylation step of adding an alkali agent to a manganese solution to adjust pH and preparing manganese hydroxide; a washing step of washing the obtained manganese hydroxide in pure water; and a carbonation step of blowing carbon dioxide gas into manganese hydroxide after washing.

Description

  The present invention relates to a method for producing manganese carbonate, and more particularly to a method for producing manganese carbonate from a manganese solution.

  In recent years, manganese has been actively used in alloys and other various materials in addition to battery materials such as electronic devices and lithium ion secondary batteries. In these devices, batteries, materials, etc., not only manganese but also other metal components are used in combination. For this reason, when recycling manganese used in equipment and batteries, it is necessary to separate only manganese from these metal components.

  As one of the methods for separating manganese, there is a method using an acidic extractant, which is generally used as disclosed in Japanese Patent Application Laid-Open No. 2008-231522 (Patent Document 1). However, when an acidic extractant is used, it must be contacted with an acid to extract the metal component from the extractant into the aqueous phase. In order to transfer most of the manganese contained in the extractant to the aqueous phase, the aqueous phase in contact with the extractant must be changed to strongly acidic. Thus, the manganese aqueous solution obtained through the extraction process is strongly acidic.

  When pH adjustment is performed in order to obtain manganese oxide or manganese carbonate from the acidic manganese solution thus obtained, for example, when hydroxide such as caustic soda or caustic potash is used, aqueous phase sodium or potassium ions Generally, it is considered that the concentration is increased and impurities are easily mixed into the target manganese carbonate. The method considered there is a method of using ammonia as a neutralizing agent disclosed in JP2011-016668A (Patent Document 2). However, the use of ammonia causes an increase in manufacturing costs due to its treatment. Therefore, a method for obtaining a high-purity manganese compound at a lower cost has been demanded.

JP 2008-231522 A JP 2011-016668 A

  In order to obtain manganese carbonate from a manganese solution at a low cost, the simplest method is to form a precipitate of manganese carbonate using sodium carbonate as a pH adjuster / carbonic acid supply agent and to separate it by filtration. As a next conceivable method, a method of using caustic soda or caustic potash for the purpose of raising the pH to the pH range where the carbonation reaction occurs, and then carbonating with carbonate is also conceivable. However, in these methods, there is a possibility that a sodium component contained in the solution is mixed with manganese carbonate during carbonation.

  Especially when the acid concentration is high as in the back extract obtained from the extraction process as described above, the amount of sodium in the solution increases due to pH adjustment. Become. If a large amount of washing water is used to remove such contamination of sodium, manganese carbonate flows out into the filtrate, and even if washing is continued, the sodium content contained in the manganese carbonate is not reduced.

  Therefore, the present invention provides a method for producing manganese carbonate that can suppress the mixing of impurities such as sodium and can obtain high-purity manganese carbonate more easily and inexpensively.

  As a result of intensive studies by the inventor to solve the above problems, the pH of the manganese solution is adjusted to an appropriate range to produce manganese hydroxide, and after washing, carbon dioxide gas is added to the obtained manganese hydroxide. It was found that by blowing, the concentration of sodium in the manganese solution was significantly reduced, and high-purity manganese carbonate could be obtained easily and inexpensively.

  In one aspect, the present invention completed based on such knowledge, in one aspect, an alkaline agent is added to the manganese solution to adjust the pH to produce manganese hydroxide, and the obtained manganese hydroxide is washed in pure water. And a carbonation step of blowing carbon dioxide into the washed manganese hydroxide.

  In one embodiment of the method for producing manganese carbonate of the present invention, the hydroxylation step includes adjusting the pH of the manganese solution to 9 or more.

  In another embodiment of the method for producing manganese carbonate of the present invention, the washing step includes washing so that the sodium concentration in the manganese hydroxide after washing becomes 100 massppm or less.

  In another embodiment of the method for producing manganese carbonate of the present invention, the alkaline agent is sodium hydroxide.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of manganese carbonate which can suppress mixing of impurities, such as sodium, and can obtain highly purified manganese carbonate more simply and cheaply can be provided.

It is a processing flow which shows the one aspect | mode of the manufacturing method of the manganese carbonate based on the Example of this invention. 2 shows an XRD pattern of a manganese carbonate precipitate according to an example of the present invention.

  In the method for producing manganese carbonate according to the embodiment of the present invention, the manganese concentration of the manganese solution used as a raw material can be any. First, an alkaline agent is added to the manganese solution, and the pH is raised until manganese precipitates in the solution with hydroxide. Caustic soda, caustic potash, etc. can be used as the alkaline agent used for pH adjustment. In order to obtain manganese hydroxide with high efficiency, it is desirable to adjust the pH of the manganese solution to 9 or more, preferably to 9.0 to 9.5.

  After producing the manganese hydroxide, the obtained manganese hydroxide and the sodium content dissolved in the liquid side are subjected to solid-liquid separation by filtration or the like. Solid-liquid separation is usually performed by filtration. Repeat the washing with pure water to remove sodium. Although there is no restriction | limiting in particular in the frequency | count of washing | cleaning, It is preferable to wash | clean so that the sodium concentration in the slurry containing manganese hydroxide may be reduced to 100 mass ppm or less. Thereby, the impurity (sodium) density | concentration of manganese carbonate finally obtained can be reduced and highly purified manganese carbonate is obtained. Although it does not restrict | limit below, the washing | cleaning process can reduce the sodium concentration in the slurry containing manganese hydroxide to 100 mass ppm or less by repeating washing | cleaning 4 times or more, for example. In addition, when it is desired to suppress the oxidation of manganese, it is preferable to prevent oxidation due to contact with air using decantation.

  Carbon dioxide gas is blown into the washed manganese hydroxide slurry to produce manganese carbonate. By using carbon dioxide gas, contamination of impurities such as sodium can be suppressed as compared with the conventional production process, and high-concentration manganese carbonate can be produced more easily and inexpensively.

  The amount of carbon dioxide blown is from 1 to 100 g / L of a manganese hydroxide aqueous solution, 10 to 1000 ml / min of carbon dioxide (carbon dioxide) per 1 L, and preferably from 1 to 1200 min at 50 to 200 ml / min. it can. After the reaction, manganese carbonate obtained by filtration or the like is subjected to solid-liquid separation, and the resulting manganese carbonate can be dried to produce manganese carbonate.

Thus, according to the method for producing manganese according to the embodiment of the present invention, the following effects can be obtained.
(1) Manganese carbonate having a low sodium concentration can be easily obtained.
(2) When recovering manganese from the solution after extraction, manganese carbonate with few impurities such as sodium can be easily obtained from the highly acidic solution in the production of manganese carbonate.

  Examples of the present invention are shown below, but the present invention is not intended to be limited to the following examples.

Example 1
Manganese carbonate was produced along the processing flow shown in FIG. First, 45 ml of 25% NaOH was added to an aqueous manganese solution (pH 4.8, manganese concentration 50 g / L, 200 ml). The manganese liquid slurry was separated into solid and liquid by filtration. The pH of the filtrate was 9, and the Na concentration was 24.26 g / L. The filtered Mn slurry was repulped into pure water to wash Na. The washing operation was repeated 4 times. The Na concentration of the cleaning solution was 12.35 g / L, 0.109 g / L, 0.017 g / L, and 0.008 g / L in order from the first time. When the Na quality of the powder obtained by partially drying the slurry after washing four times was measured, it was 96 mass ppm.

The slurry after washing four times was repulped into pure water again, and carbon dioxide was blown in for 120 minutes under the condition of 100 ml / min. After blowing carbon dioxide, the residue was filtered to separate the residue from the liquid phase. When the porridge was dried and subjected to XRD analysis, it was found that the porridge was mainly manganese carbonate. The XRD pattern of the obtained precipitate is shown in FIG.
It was 70 massppm when the sodium impurity quality in manganese carbonate was measured.

(Comparative Example 1)
1 L of manganese aqueous solution (pH 6, manganese concentration 35 g / L) was prepared, and 1 L of 100 g / L-sodium carbonate solution was added. The pH after the addition was 10.5. The manganese liquid slurry was separated into solid and liquid by filtration. Next, Na was washed by repulping in pure water. The washing operation was repeated 6 times, and the Na concentration of the washing solution was measured and found to be 0.005 mg / L.
When the sodium impurity concentration in manganese carbonate was measured, it was 3500 massppm.

Claims (4)

A hydroxylation step of adjusting the pH by adding an alkali agent to the manganese solution to produce manganese hydroxide;
A washing step of washing the obtained manganese hydroxide in pure water;
A method for producing manganese carbonate comprising: a carbonation step of blowing carbon dioxide into manganese hydroxide after washing.   The method for producing manganese carbonate according to claim 1, wherein the hydroxylation step includes adjusting the pH of the manganese solution to 9 or more.   The said washing | cleaning process is a manufacturing method of the manganese carbonate of Claim 1 or 2 including wash | cleaning so that the sodium concentration in the manganese hydroxide after washing | cleaning may be 100 massppm or less.   The method for producing manganese carbonate according to claim 1, wherein the alkaline agent is sodium hydroxide.

Images