A method of producing manganese dioxide

 

(57) Abstract:

The invention concerns a method of producing manganese dioxide gamma modification hydrometallurgical method and is aimed at improving the quality of the end product that meets the increased regulatory requirements of the consuming industry chemical current sources. The method includes the processing of raw materials by leaching the circulating sulfuric acid electrolyte, the classification obtained pulp, treatment of the resulting solution from impurities by precipitation with lime milk and filtering and extraction of the purified solution of manganese dioxide by electrolysis followed by regeneration of the spent electrolyte and its application on leaching. According to the invention the processing of raw materials is carried out in two stages: the first stage is subjected to a preliminary leaching feedstock in the presence of an oxidant, and the second stage is subjected to a final pre-leaching partially leached feedstock in the presence of a reducing agent. This leaching in the first stage to produce a solution obtained after the second stage leach produced the regenerated electrolyte, and the clearing of note is supplemented flax temperature during the precipitation of the impurities lime milk is 90 - 95^oC. 1 C.p. f-crystals, 1 tab., 1 Il.

The invention relates to the technology for extraction of metal compounds from ores or concentrates by wet method and is directly related to manganese dioxide gamma-modification used by the electrical industry in the manufacture of chemical current sources.

The prior art method of obtaining manganese dioxide (prototype - RF patent N 2054494, MKI C 22 B 47/00, 1992), including the processing of the mn containing raw material by leaching the circulating sulfuric acid electrolyte in the presence of a reducing agent, the classification obtained pulp, treatment of the resulting solution from impurities by precipitation with lime milk and filtering and extraction of the purified solution of manganese dioxide by electrolysis followed by regeneration of the spent electrolyte and its application on leaching. At the same time to improve the quality of the final product after leaching produce additional classification with intermediate processing solution fresh portion of the feedstock, and the cleaning solution from the impurities is carried out at a temperature of 95 - 98^oC. This allows to reduce the content of impurities in the resulting manganese dioxide and those who are given to achieve the level of quality manganese dioxide meets the requirements of the manufacturers of chemical current sources, regulated, in particular, the standard GOST 25823-83.

The problem solved by the present invention, consists in that the improvement described known method of producing manganese dioxide, which would improve the quality of the final product to a level corresponding to the increased regulatory requirements of manufacturers of chemical current sources.

This task is solved in that in the known method of producing manganese dioxide, including the processing of the mn containing raw material by leaching the circulating sulfuric acid electrolyte in the presence of a reducing agent, the classification obtained pulp, treatment of the resulting solution from impurities by precipitation with lime milk and filtering and extraction of the purified solution of manganese dioxide by electrolysis followed by regeneration of the spent electrolyte and its application on leaching, according to the present invention, the processing margaritaperale raw materials is carried out in two stages, with the first stage is subjected to a preliminary leaching feedstock in the presence of an oxidant, and the second Stanovites, this leaching in the first stage to produce a solution obtained after the second stage leach produced the regenerated electrolyte and cleaning from impurities and subsequent electrolysis send the solution obtained after the first stage of leaching. The preferred temperature for conducting the process of deposition of impurities lime milk is 90 - 95^oC.

As determined experimentally, from the point of view of the quality of the final product is a major problem when removing hydrolytic cleaning solution is directed to electrolysis, ferrous iron, which can precipitate as hydroxide only at unacceptably high pH > 8.0 in. When the two-stage processing margaritaperale raw materials according to the invention this problem is solved due to the fact that in the first stage to produce a preliminary leaching of the feedstock in the presence of stronger oxidant than oxygen. When ferrous iron is oxidized to ferric, which during the hydrolytic treatment can precipitate as hydroxide at operating pH < 7,0. As such an oxidizing agent may use any connections, N. oxidative components, already contained directly in the source mn containing raw materials. These components are primarily oxides of manganese, certainly not deteriorating the process and does not introduce additional contaminants. In addition, lowering the temperature of the hydrolytic process of cleaning solution with 95-98 ^oC and 90-95^oC allows you to limit the coprecipitation useful component, while maintaining the required quality of the final product.

More in detail the invention is illustrated below for a practical example of its preferred implementation, involving drawing, which schematically illustrates a simplified flow chart of the process of obtaining manganese dioxide according to the invention.

The proposed method of producing manganese dioxide as described known, includes the processing of the mn containing raw material by leaching the circulating sulfuric acid electrolyte in the presence of a reducing agent, the classification obtained pulp, treatment of the resulting solution from impurities by precipitation with lime milk and filtering and extraction of the purified solution of manganese dioxide by electrolysis followed by regeneration of the electrolyte and its application on leaching.

The proposed method of producing manganese dioxide is implemented by the following process:

Source mn containing raw material 5 in powdered form is served on the first stage 1 leach in the presence of an oxidant more active than oxygen. As such an oxidizing agent used is contained in the raw material oxides of manganese. Leaching at this stage produce a solution of 6 obtained after the second stage 2 leach, under mechanical stirring. In the first stage 1 be partial leaching of manganese and oxidation of divalent iron to trivalent, while the acidity of the solution is lowered to pH 3.5 to 4.5. The resulting slurry is classified by gidrotsiklonirovaniya the partially leached mn containing raw materials, served on the second stage 2 leach.

Cleaning 3 solution 8 from impurities is carried out by the precipitation of lime milk 10 at a pH of 6.5-7.0 and a temperature of 90 - 95^oC under mechanical stirring followed by filtration 11. The filtered slurry 12 in the form of iron hydroxide and other hydroxides of polluting elements sent to the dump, and filtered sulfate solution is fed to the electrolysis 4.

Deposited on the anodes of the electrolytic cell 4 manganese dioxide 13 is sent for further processing, and the spent electrolyte regenerate the sulfuric acid 14 and the regenerated solution 15 serves on the phase 2 leach in the presence of a reducing agent 16. As the reductant 16 use of metallic iron in the form of crushed chips.

In the second stage 2 perform the final leaching of raw materials 9, previously partially leached in the first stage of leaching 1. While manganese in excess of sulfuric acid (pH of about 2.0) almost completely transferred into the solution and at the same time is the hydrolysis of ferric sulfate with the formation of iron hydroxide. The resulting slurry is classified by gidrotsiklonirovaniya 1 a silica-containing product, send in the dump.

Example:

On pilot line was processed according to the invention carbonate partially oxidized ore Midnight group of fields (Northern Urals). After preliminary preparation and grinding to a particle size of 0.4 mm mn containing source raw materials contained technologically important components in the amount indicated in the table.

In the first stage leach was almost complete neutralization of the free sulfuric acid (pH 3-4), and the solution was extracted up to 76% manganese. In the second stage leaching with excess sulfuric acid manganese was almost completely transferred into the solution, which before hydrolytic purification contained technologically important components in the amount indicated in the table.

Hydrolytic cleaning solution with the milk of lime to remove impurities was carried out at a pH of 6.5 approximately-7.0 and a temperature of 90 - 95^oC. After filtration, the solution supplied to the electrolysis contained technologically important components in the amount indicated in the table.

Electrolysis obtained sulphate solution was carried out at a temperature of 95^oC and anode current density of 175 a/m2

1. A method of producing manganese dioxide, including the processing of the mn containing raw material by leaching the circulating sulfuric acid electrolyte in the presence of a reducing agent, the classification obtained pulp, treatment of the resulting solution from impurities by precipitation with lime milk and filtering and extraction of the purified solution of manganese dioxide by electrolysis followed by regeneration of the spent electrolyte and its application on leaching, characterized in that the processing of the mn containing raw material is carried out in two stages, with the first stage is subjected to a preliminary leaching feedstock in the presence of an oxidant, and the second stage is subjected to a final pre-leaching partially leached feedstock in the presence of a reducing agent, when blasted regenerated electrolyte, and for purification from impurities and subsequent electrolysis send the solution obtained after the first stage of leaching.

2. The method according to p. 1, characterized in that the deposition of impurities lime milk is carried out at a solution temperature of 90 - 95^oC.