JPH0256289B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a highly pure manganese compound, and particularly to a method for producing a manganese compound suitable as a raw material for manganese ferrite. [Prior art] Conventionally, high-purity manganese compounds were prepared by dissolving manganese ore in sulfuric acid, other heavy metals as impurities were removed by the sulfide method, solvent extraction method, alcoholate method, etc., and iron was oxidized as hydroxide. After separating and removing manganese, methods are used to recover it as various salts. Recently, in order to produce manganese compounds with even higher purity, ferromanganese or metallic manganese, which has fewer impurity elements such as alkali metals than manganese ore, are used, and these are directly dissolved in acid, and heavy metals and iron are separated as in the conventional method. There is a method of purifying high-purity manganese compounds by combining removal and recrystallization. [Problems to be solved by the present invention] However, since the above-mentioned conventional method directly treats the raw material with acid to dissolve manganese, almost all of the impurities in the raw material are dissolved at the same time as the manganese. It requires several steps to remove , and also requires a purification step using a complicated recrystallization method, which has the disadvantage that not only is the processing efficiency low, but it is not always possible to obtain a highly pure product. . The object of the present invention is to improve the above-mentioned conventional drawbacks and provide a method for producing a high-purity manganese compound simply and at low cost. [Means for Solving the Problems] The present invention involves adding one or both of ferromanganese and metallic manganese to an aqueous solution containing an electrolyte, stirring the solution, adding acid, and maintaining the pH between 2 and 9 to dissolve manganese and manganese. This is a method for producing a high-purity manganese compound, in which after iron is dissolved, undissolved substances are separated and removed, and manganese and iron in the solution are separated and recovered by precipitation. [Functions and Effects] The present invention has the above configuration, and the electrolyte used in the electrolyte is one or more of ammonium chloride, ammonium nitrate, ammonium acetate, or an alkali metal salt. Furthermore, the manganese compound referred to in the present invention includes not only a manganese compound alone but also a mixture of a manganese compound and an iron compound. Ferromanganese and metallic manganese, which are the raw materials of the present invention, are ground (preferably under 60 mesh) and added to the electrolyte solution. When ferromanganese and metallic manganese as described above are added to water, some of the manganese and iron react with the water to produce hydroxides, and the pH of the liquid rises to around 9.7. On the other hand, when the ferromanganese and metal manganese are added to a solution containing an electrolyte such as ammonium chloride, manganese and iron similarly produce hydroxides, but the buffering effect of the electrolyte lowers the pH of the solution. The degree to which the PH decreases depends on the concentration of the electrolyte, but for example, 2% of ammonium chloride
In the case of a solution, the pH is approximately 9.0, and in the case of a 20% solution, it is approximately 7.8. Manganese hydroxide () or iron hydroxide ()
Since the pH at which the hydroxide completely precipitates is about 9 or above and about 8 or above, respectively, the produced manganese hydroxide and iron hydroxide are partially dissolved and the other part is in a precipitated state.
On the other hand, noble elements that tend to ionize more than manganese and iron, that is, heavy metal elements, remain unreacted. When an acid is added to the manganese hydroxide and iron hydroxide produced as described above, the manganese hydroxide and iron hydroxide become salts and dissolve, and the heavy metal elements can be completely separated. The acid used here may be hydrochloric acid, sulfuric acid, acetic acid or nitric acid. Next, FIG. 1 will be explained as an example. Figure 1 shows the PH change when ferromanganese powder is added to an electrolyte solution and hydrochloric acid is added dropwise to it. It decreases rapidly and becomes similar to conventional acid dissolution. Therefore, in such a case, since all of the impurities in the ferromanganese are dissolved, conventional methods must be used to separate the impurities. On the other hand, in a solution containing an electrolyte, the pH change due to the addition of hydrochloric acid is reduced due to the buffering effect of the electrolyte. In such a PH range (at least PH=2 or higher), unreacted substances are not affected by the acid and are therefore not dissolved at all, allowing complete separation of impurities. Furthermore, as is clear from Figure 1, the buffering effect that keeps the pH constant increases as the electrolyte concentration increases;
In the above cases, it is recognized that the buffering effect changes in almost the same way. Therefore, in the present invention, it is preferable that the electrolyte concentration is 5% or more. Figures 2 and 3 respectively show the content of impurities due to the extracted PH in the present invention. still,
In this case, manganese and iron in solutions at various PHs were recovered as carbonates, and the oxide samples were calcined at 800°C. As is clear from Figure 2, it is recognized that heavy metals such as Cr, V, and Ni decrease rapidly at pH 2 or higher. Furthermore, what is noteworthy about the present invention is that elements whose ionization tendency is more base than manganese and iron and nonmetallic elements can be removed at the same time. That is, as is clear from FIGS. 2 and 3, not only Mg and Ca but also nonmetallic elements such as P and Si can be removed. It is thought that such nonmetallic elements are probably adsorbed by unreacted substances. Regarding P, no relationship with extraction pH is recognized, but P in the raw material ferromanganese is
If approximately 1400 ppm is taken into consideration, P can be efficiently removed regardless of the extraction pH, regardless of the pH. Further, Co has a higher value than Cr, V, Ni, etc., but like Cr, V, Ni, etc., it can be removed to a large extent by setting the pH to 2 or more. The reason for this is probably that Co forms an ammine complex in solution, which is adsorbed by unreacted substances. As shown in Figures 2 and 3 above, the present invention can remove and separate impurities other than manganese and iron, but if a nitric acid compound is used as the electrolyte or nitric acid is used as the acid, iron can also be separated. Can be done. That is, if an oxidizing acid such as nitric acid is used,
Iron hydroxide () is oxidized to become iron hydroxide (), and since the iron hydroxide () precipitates almost completely at pH 5 or higher, it can be easily separated by overseparation along with unreacted substances. . This phenomenon is similar even when other oxidizing agents such as hydrogen peroxide are added or air is blown. Therefore, the present invention takes into consideration the use of the final product, etc.
If an appropriate acid is selected and used, a high purity manganese compound consisting of a mixture of manganese and iron or manganese alone can be obtained. Manganese and iron dissolved and separated as described above may be precipitated and separated as carbonates, oxalates or hydroxides by a conventional method, and if necessary, they can be recovered as oxides. The high purity manganese compound thus obtained can be used as a raw material for ferrite. As described above, the present invention uses a simple method not only for heavy metal elements in ferromanganese metal manganese, but also for P,
Non-metallic elements such as Si can be removed efficiently, and since expensive equipment is not required, a high purity manganese compound can be provided at a low price. [Example] A specific configuration of the present invention will be explained using an example. Example 1 Add 20 g of ferromanganese powder crushed to 60 mesh or less to 200 ml of 10% ammonium chloride solution, and while stirring the solution, adjust the pH of the solution.
6M hydrochloric acid was successively added while maintaining the ferromanganese powder at 5 or higher to dissolve and extract manganese and iron in the ferromanganese powder. When the pH of the solution could no longer be maintained at 2 or more, the addition of 6M hydrochloric acid was stopped to terminate the reaction. The reaction time is about 3 hours, and the consumption of 6M hydrochloric acid is
The reaction rate (dissolution rate) of manganese and iron in the ferromanganese was approximately 90%, calculated from the amount of hydrochloric acid consumed. Next, the reaction-completed solution was filtered to separate and remove undissolved substances, and then 25 g of ammonium hydrogen carbonate and 43 ml of 7.5M ammonia water were added to the solution to adjust the pH of the solution to 7.8. was precipitated as a carbonate. The precipitated carbonate was separated by filtration and recovered. In order to confirm the purification effect of the carbonate, the recovered carbonate was dried at 110°C and then calcined at 800°C for 90 minutes to produce manganese and iron oxides (mainly composed of Mn ₂ O ₃ and Fe ₂ O ₃ ). The trace impurities were analyzed. The results are shown in Table 1 in comparison with the content of trace impurities in ferromanganese used as a raw material, and the trace impurities in the product are significantly reduced.

[Table] Example 2 12% ammonium chloride aqueous solution 150% in reaction vessel
into the reaction vessel, gradually adding powder of a 2:1 mixture of ferromanganese crushed to 60 mesh or less and metallic manganese while stirring the solution,
Furthermore, 6M hydrochloric acid was gradually poured into the solution to dissolve and extract the manganese and iron in the powder. During the dissolution and extraction, the amount of the powder added and the amount of 6M hydrochloric acid injected were adjusted so that the pH of the solution was maintained at 5 or higher.
Kg, metal manganese 5Kg) was melted. The time required for this dissolution treatment was approximately 10 hours, and the amount of 6M hydrochloric acid used was 78. After leaving the solution after dissolution for 12 hours,
It was filtered to separate and remove undissolved substances. Subsequently, 17 kg of ammonium hydrogen carbonate and 26 kg of 7.5M aqueous ammonia were added to the solution, which was left to stand for about 1 hour, and the precipitated manganese carbonate and iron carbonate were separated by filtration and recovered. The amount produced was 23.7 kg in dry weight. A part of the generated carbonate was calcined in the same manner as in Example 1 and analyzed as an oxide. The results are shown in Table 2.

[Table] Example 3 Ferromanganese powder 20g (60 mesh or less)
Add to 200ml of 15% ammonium nitrate solution,
While stirring and keeping the pH of the solution at 5 or higher, 7MHNO ₃ was added successively to dissolve and extract manganese and iron. The pH of the solution is 5 or more
The end point of the reaction was when 7MHNO ₃ could no longer be added. At this time, the amount of 7MHNO ₃ consumed was 84 ml, and it took about 2 hours to complete the reaction. Next, undissolved substances in the solution were separated by filtration, and 22 g of ammonium hydrogen carbonate and 38 ml of 7.5M ammonium water were added to the filtrate to adjust the pH of the solution to 7.6, and the manganese in the solution was precipitated as carbonate. It was collected by filtration and separation. At this time, iron is oxidized by nitrate and nitric acid, and is filtered and separated as the undissolved material. In order to confirm the purification effect of the carbonate, the recovered carbonate was dried at 110°C and then calcined at 800°C for 90 minutes. The composition of the obtained manganese oxide is shown in Table 3 in comparison with the composition of ferromanganese used as a raw material. When nitric acid is used as the acid as shown in Table 3, not only trace impurities but also iron can be separated and removed at a high rate.

[Table] Example 4 20g of manganese metal crushed to 60 mesh or less
was added to a 15% ammonium acetate solution, and 7.5M acetic acid was added while stirring to dissolve and extract manganese at pH 5 or higher. The amount of 7.5M acetic acid consumed at this time was 95ml.
The time required for extraction was approximately 4 hours. Next, after filtering the solution to remove undissolved substances, 28 g of ammonium hydrogen carbonate was added while stirring.
48 ml of 7.5M ammonium water was added to adjust the pH of the solution to 7.2, and manganese was precipitated as carbonate, which was collected by filtration. To confirm the purity of the carbonate, it was dried at 110°C and then calcined at 800°C for 90 minutes. Table 4 shows the raw material manganese metal, the amount of impurities and the Mn content of the product.

【table】

【table】 [Brief explanation of the drawing]

Figure 1 shows the titration curve of the electrolytic solution, Figures 2 and 3.
Each figure is a graph showing the relationship between impurity content and pH.

Claims (1)

[Claims] 1. One or both of ferromanganese and metallic manganese are added to an aqueous solution containing an electrolyte, and while stirring, acid is added to maintain the pH between 2 and 9 to dissolve manganese and iron, and the remaining A method for producing a high-purity manganese compound, which comprises separating and removing dissolved substances, and then precipitating and recovering manganese and iron in the solution. 2. The method for producing a high-purity manganese compound according to claim 1, characterized in that iron is precipitated and separated using a nitric acid compound as an electrolyte and/or nitric acid as an acid.