JPS621582B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for purifying a manganese sulfate solution for electrolytic manganese dioxide, in which K in the manganese sulfate solution,
The purpose is to easily remove Mo. As is well known, electrolytic manganese dioxide (hereinafter referred to as EMD) is used as a depolarizer for dry batteries. In recent years, in order to improve the characteristics of dry batteries,
There is a demand for improvement in the quality of EMD. Generally, EMD is made from manganese carbonate such as rhodochrosite, manganese ore, soft manganese ore, etc., which is reacted with sulfuric acid to form a manganese sulfate solution, and the pH of the manganese sulfate solution is adjusted to around 5. After iron is precipitated and removed, hydrogen sulfide is blown into this, and Ni and Co are further precipitated and purified to form an electrolyte. However, the manganese sulfate solution obtained by the above method still contains K and Mo as impurities, and when such a manganese sulfate solution is electrolyzed as a raw material, K and Mo are mixed into the EMD obtained. This has a negative impact on EMD battery performance. As a method for removing K and Mo from the manganese sulfate solution, it is possible to use raw material manganese ore with a low K content, but this is difficult in terms of resources. In addition, in order to remove and purify K, the pH is set to around 1.5 under a certain iron content, and it is removed as a sulfuric acid complex salt of Fe and K [K ₂ Fe ₆ (SO ₄ ) ₄ (OH) ₁₂ ]. (Dialosite method) is known, but the sulfuric acid complex of Fe and K not only has poor permeability, but also Mo cannot be removed by this method. Therefore, in order to remove Mo, it is necessary to separately adjust the pH of the manganese sulfate solution to around 2 and remove it by blowing in hydrogen sulfide. Further complexity and increased costs cannot be avoided. The inventors have discovered that K from manganese sulfate solution for EMD
As a result of intensive research on methods of removing Mo,
By adopting the configuration described in the claims, it was possible to easily remove K and Mo at the same time. That is, the present invention is an electrolytic dioxide method characterized by adding an activated product of manganese dioxide to a manganese sulfate solution to adsorb K and Mo in the manganese sulfate solution, and then over-separating the activated product of manganese dioxide. This is a method for purifying manganese sulfate solution for manganese. Activated manganese dioxide (hereinafter referred to as ACM) is a porous body of manganese dioxide with excellent adsorption ability.It is made by roasting manganese dioxide ores at 600 to 900℃ and then pulverizing them. However, it is a porous material obtained by immersing it in sulfuric acid and has excellent adsorption ability. The present invention is made from a manganese sulfate solution according to a conventional method.
ACM powder is added to the solution from which Fe, Ni and Co have been removed, and reacted with stirring to remove K and Mo contained in the manganese sulfate solution. Next, the present invention will be explained in detail using experimental examples. Experimental example (1) Production method and properties of ACM. 1 to 3 100Kg of soft manganese ore containing 75.0% MnO ₂
Grind to 850 mm using rotary kiln
After baking at ℃ for 2 hours, the baked product was ground into 30 to 150 meshes, and 50 kg of the ground material was mixed with 1.2M/
Add 600% of sulfuric acid and treat at 80℃ for 2 hours.
Filter, wash with water, and dry to obtain ACM35Kg. The properties and composition of the obtained ACM are shown in Tables 1 and 2, respectively.
Shown in the table.

【table】

[Table] For the ACM used in the present invention, crushed waste of chemical manganese dioxide or EMD may be used as a raw material. (2) Method for producing manganese sulfate solution. 100 kg of manganese ore was crushed to 1-3 mm, put into a rotary kiln together with 8 kg of coke, and fired at 850℃ for 2 hours.
Grind to 150 pieces, 1.2M/50Kg of crushed product
After adding 450% of sulfuric acid and treating at 80°C for 2 hours, the pH was adjusted to 5.0 to precipitate Fe and Al, which was filtered out along with the undissolved matter, and then hydrogen sulfide was blown into it. Ni and Co are separated and removed to obtain a manganese sulfate solution 430. . The composition is the third
As shown in the table.

[Table] (3) Removal test of K ⁺ and Mo ⁺⁶ from manganese sulfate solution. To the manganese sulfate solution obtained in (2) above, add the above
(1) of the properties and composition shown in Tables 1 and 2.
After adding ACM and reacting with stirring to make ACM adsorb K and Mo in the manganese sulfate solution,
After over-separation, K and Mo in the manganese sulfate solution were investigated, and the results shown in Tables 4 to 7 were obtained.

[Table] Intermediate processing.

【table】

[Table] Intermediate processing.

Processed with [Table].
Table 8 compares the adsorption states of K ⁺ and Mo ⁺⁶ between ACM used in the present invention and various manganese dioxides.

[Table] From the results in Tables 4 to 8 above, ACM has superior adsorption ability for Mo ⁺⁶ in manganese sulfate solution compared to other cases where manganese dioxide is added and adsorbed. Mo ⁺⁶ adsorption can reduce Mo ⁺⁶ in manganese sulfate solution to 0.02 ppm regardless of the conditions. Regarding K ⁺ , we increased the amount of ACM added to the manganese sulfate solution, raised the reaction temperature, and lengthened the reaction time.
An increase in K ⁺ adsorbed to ACM was observed;
Furthermore, it is observed that the amount of adsorption increases when the pH of the manganese sulfate solution is in the range of 1.3 and 2.0. On the other hand, regarding the dry battery characteristics of EMD, if K ⁺ in the manganese sulfate solution is about 100 ppm, the EMD characteristics will not be affected substantially, and Mo ^{+ 6} will have a concentration of 0.02 ppm in the manganese sulfate solution. If so, there is no problem. Therefore, in the present invention, in manganese sulfate solution,
In order to adsorb and remove K ⁺ and Mo ⁺⁶ , the amount of ACM added should be 100 g/or more, and the pH during the adsorption reaction should be 1 to 3, the reaction temperature should be 50 to 80°C, and the reaction time should be 2 to 3. It is preferable to treat K+ and K ⁺ in the manganese sulfate solution.
Mo ⁺⁶ can be removed at the same time without adversely affecting the characteristics of EMD dry cells. Furthermore, the ACM used in the present invention also includes K ⁺ and
After adsorbing Mo ⁺⁶ and over-separating it from the manganese sulfate solution, if it was treated with sulfuric acid, it was adsorbed to ACM.
Since K ⁺ and Mo ⁺⁶ can easily leave the ACM,
Can be used repeatedly to remove K ⁺ and Mo ⁺⁶ . As described above, in the present invention, by adding ACM to a manganese sulfate solution containing K and Mo, K and Mo can be simultaneously removed from the manganese sulfate solution in one action, so the treatment process is simple. Moreover, it is possible to prevent the adverse effects on dry battery characteristics caused by K and Mo in the obtained EMD. In addition, if the ACM used in the present invention adsorbs and removes K and Mo and then treats it with sulfuric acid, the adsorbed K and Mo can be easily released, so ACM can be used repeatedly to remove K and Mo. There are great things that will benefit the industry.

Claims (1)

[Claims] 1 Add activated manganese dioxide to a manganese sulfate solution to reduce K and
1. A method for purifying a manganese sulfate solution for electrolytic manganese dioxide, which comprises adsorbing Mo and then excessively separating an activated product of the manganese dioxide.