Method for preparing mangano manganic oxide in high purity by using pyrolusite as raw material

Abstract

This invention provides a method for preparing high-quality Mn3O4 from pyrolusite. The method comprises: soaking powdery pyrolusite in diluted acid (H2SO4, HNO3 or HCl) for 1-24 h, pulping, introducing SO2 reducer at a pH value not lower than 5 to obtain MnSO4 solution with low Ca2+ and Mg2+ content, chemically purifying to obtain pure MnSO4 solution, introducing air in an alkaline condition, oxidizing, washing and drying to obtain high-purity Mn3O4 particles. The method has such advantages as low cost and high product purity.

Description

Technical field: [0001] The invention belongs to the technical field of chemical production, and in particular relates to a method for preparing high-purity manganese tetraoxide by using pyrolusite as a raw material. Background technique: [0002] Trimanganese tetroxide is the main raw material for the production of soft ferrite, which requires high purity, especially the content of calcium and magnesium ions. At present, the preparation methods of high-purity manganese tetraoxide mainly include reduction-electrolysis method and reduction-oxidation method. Reduction-electrolysis method is a mature preparation method, but this method needs to go through the step of electrolytic impurity removal, which consumes a lot of power and costs more. The reduction-oxidation method is generally to directly reduce pyrolusite to manganese sulfate solution, and then air oxidation to prepare trimanganese tetraoxide after chemical removal of impurities. In this method, a large amount of impu...

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Problems solved by technology

[0003] Aiming at the problem that a large number of impurity ions in the reduction-oxidation method are dissolved in manganese sulfate solution, which greatly increases the difficulty and cost of chemical removal of impurities, the present invention provides a method for preparing high-purity trimanganese tetraoxide by using pyrolusite as a raw material. In this preparation method, pyrolusite is soaked with acid to remove most of the metal ions such as calcium and magnesium, and then reduced to manganese sulfate solution