High-purity trimanganese tetroxide and preparation method thereof

Abstract

The invention relates to an oxide of manganese, and in particular discloses high-purity trimanganese tetroxide and a preparation method thereof, wherein the Mn content in the high-purity trimanganese tetroxide is larger than 71.5 percent, and the S content is smaller than 0.03 percent. The preparation method thereof comprises the following steps of: 1. firstly dissolving high-purity manganese sulfate into water to obtain a manganese sulfate solution, then neutralizing the manganese sulfate solution with ammonia water, using the pH value of a neutralization system reaching 9.0-10.0 as the end point of a neutralization reaction, filtering, and rinsing to obtain a manganese hydroxide suspension; 2. introducing air into the manganese hydroxide suspension prepared in the step 1 at the temperature of 45-85 DEG C for oxidation, and filtering, rinsing and drying to obtain the high-purity trimanganese tetroxide after the manganese hydroxide in an oxidation system is completely converted into trimanganese tetroxide. The high-purity trimanganese tetroxide has the advantages of lower impurity content, good quality, controllable specific surface area, low preparation cost and the like.

Description

technical field [0001] The invention relates to a manganese compound and a preparation method thereof, in particular to a manganese oxide and a preparation method thereof. Background technique [0002] Manganese-zinc ferrite has developed rapidly in recent years, and my country's manganese-zinc ferrite has formed two major pieces of pellets and magnetic cores. At present, the output of manganese zinc ferrite pellets in my country has exceeded 60,000 tons, which makes the production of soft ferrite popular and improved. According to incomplete statistics, there are more than 100 manganese-zinc ferrite manufacturers in my country, with a total production capacity of nearly 250,000 tons. 60% of the manufacturers are located in Zhejiang, Jiangsu and Shanghai, which makes my country the world's largest manganese-zinc ferrite producer. Ferrite producing countries. my country's magnetic material industry has also made great breakthroughs in high-end products by virtue of abundant ...

AI Technical Summary

Problems solved by technology

More than 90% of the existing manganese tetraoxide production process in my country is the electrolytic metal manganese powder suspension oxidation method. This method is mature, but its shortcomings are also very obvious: first, the production cost is high, and the raw material of electrolytic manganese metal The cost accounts for 80% of the cost of trimanganese tetroxide; second, the impurity content is generally high, especially impurities such as calcium and magnesium are difficult to drop below 100ppm

Trimanganese tetraoxide can also be prepared by direct roasting and oxidation of manganese carbonate, but this process consumes a lot of energy, manganese carbonate needs to be heated above 1000°C to be roasted into trimanganese tetraoxide, and the specific surface area of ​​trimanganese tetraoxide obtained by roasting is 1.0 m 2 Below / g, it does not meet the requirements of trimanganese tetroxide for manganese zinc soft ferrite

However, the reduction method is difficult to carry out large-scale practical application due to the difficulty of process operation.

In recent years, many researchers have used low-cost industrial manganese sulfate as raw material to prepare trimanganese tetraoxide, but the quality of trimanganese tetraoxide is difficult to guarantee due to the lack of effective impurity removal methods.

[0005] It can be seen from the above that although the output and production capacity of trimanganese tetraoxide have been greatly improved in recent years, the quality and performance of trimanganese tetraoxide products and the preparation process of trimanganese tetraoxide need to be improved

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