Method for preparing high-purity trimanganese tetraoxide in ammonia medium using manganese sulfate solution

Abstract

The invention discloses a method to produce high purity manganous-manganic oxide by manganese sulfate solution in ammonia medium. Adding ammonia into manganese sulfate solution that the concentration is 2g.L-1-120g.L-1, controlling the adding speed to make the pH value rising speed at 0-1.00 / minute, using air or oxygen as oxidizing agent to oxide bivalent manganese into manganous-manganic oxide, the reaction temperature is 20-100 degree centigrade, controlling the highest pH value of the solution at the range of 6.0-14.0 in reacting process, and the lowest pH value range at 4.0-9.0. The invention has the advantage of fast reaction, the amount of precipitation of impurity calcium and magnesium could be controlled, and the yield of manganese would be improved, the cost is low.

Description

technical field [0001] The invention relates to a method for preparing high-purity trimanganese tetraoxide, in particular to a method for preparing high-purity trimanganese tetraoxide by direct oxidation of a manganese sulfate solution in an ammoniacal medium, and belongs to the technical field of manganese compound synthesis. Background technique [0002] High-purity trimanganese tetraoxide is an important raw material for the synthesis of soft magnetic manganese-zinc ferrite. At present, the main method for preparing trimanganese tetraoxide is the catalytic oxidation method of metal manganese powder plus ammonium salt. The process is mature, the production process is simple, and the investment is small. There are three most prominent shortcomings: one is high production cost; the other is high impurity content; the third is small specific surface area. For this reason, various other preparation methods have been studied at home and abroad, these methods include roasting m...

AI Technical Summary

Problems solved by technology

The process is mature, the production process is simple, and the investment is small. There are three most prominent shortcomings: one is high production cost; the other is high impurity content; the third is small specific surface area.

The method has a slow oxidation rate; the manganese recovery rate is low (about 85%); a large amount of calcium and magnesium ions in the solution are precipitated, so that the calcium and magnesium in the product exceed the standard in a large amount

In addition, because the divalent manganese ion hydrolyzate contains a large amount of refractory basic manganese sulfate, the sulfur in the product seriously exceeds the standard