Method for preparing high-purity manganese sulfate and high-purity manganese carbonate by reduction leaching of pyrolusite through scrap iron

Abstract

The invention discloses a method for preparing high-purity manganese sulfate and high-purity manganese carbonate by reduction leaching of pyrolusite through scrap iron. The method comprises the following steps of: performing reduction leaching on the pyrolusite with the scrap iron in a sulfuric acid medium to obtain manganese, regulating the pH value to be 5-6 by using a neutralization method, hydrolyzing ferric iron in the solution into an iron hydroxide precipitate, and filtering to obtain primary filtrate of manganese sulfate and filter residue; adding a vulcanizing agent into the primary filtrate for vulcanization to remove heavy metal ions, adding a fluorinating agent for removing calcium, magnesium and other ions in the solution, standing the solution and removing sediments; and concentrating and crystallizing the purified solution to prepare the high-purity manganese sulfate, or adding ammonium carbonate to prepare high-purity manganese carbonate, concentrating the filtrate and recovering the ammonium carbonate, wherein the filter residue in the first step is leached by solution of dilute sulfuric acid, and the filtrate after filtration is subjected to calcium removal, standing and concentration to form polyferric sulfate. The method is low in cost and investment, is suitable for comprehensive exploitation and utilization of different grades of pyrolusite, can effectively utilize natural resources and also can create obvious economic benefit.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a method for leaching pyrolusite by using iron filings as a reducing agent, preparing high-purity manganese sulfate and high-purity manganese carbonate, and simultaneously recovering ammonium sulfate and polyferric sulfate. Background technique [0002] Manganese sulfate is one of the important basic manganese salts, and most manganese products are prepared through manganese sulfate or manganese sulfate solution. In the traditional production process, leaching rhodochrosite with sulfuric acid to prepare high-purity manganese sulfate and its manganese products has higher quality requirements for rhodochrosite, which is mainly because the impurity content is too high in the process of leaching rhodochrosite, especially magnesium. The content (calculated as MgO) is generally required to be less than 1%. For my country's manganese ore resources, there are not many high-grade rhod...

AI Technical Summary

Problems solved by technology

Using pyrolusite as raw material to convert Mn 4+ reduced to Mn 2+ Prepare a manganese sulfate solution, which requires the manganese sulfate solution to be clear and transparent, with a rose red color, a concentration of more than 60g / L, and a pH value of 5-6, and then add a precipitant to produce manganese carbonate; the production of manganese carbonate with manganese salt solution is often industrial production The manganese-containing waste liquid or by-products produced in the process have a large amount of impurities and are not easy to purify; high-purity manganese carbonate can be obtained by using electrolytic manganese as raw material to produce manganese carbonate. After dissolving, the solution is clear and transparent and has a rose red color. Finally, a precipitant is added to produce high-purity manganese carbonate. This method contains the least impurities, but the process is complicated, the investment is large, and the production cost is high.

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