Method for extracting high-purity manganese dioxide from manganese slag

Abstract

The invention discloses a method for extracting high-purity manganese dioxide from manganese slag, which comprises the following steps of: at normal temperature, adding dilute sulfuric acid in an amount 1.1-1.5 times the theoretical amount into the manganese slag and leaching metal impurity ions in the manganese slag; filtering to obtain an acid solution with the pH of 1.0-2.0, adding a sodium chlorate or potassium chlorate solution in an amount 1.1-1.5 times the theoretical amount into the acid solution, carrying out hydro-thermal reaction for 1-3 hours at the temperature of 120-150 DEG C, filtering manganese dioxide precipitates generated by the reaction, carrying out acid washing with 0.05-0.15mol / L-1 of dilute sulfuric acid, drying at the temperature of 60-120 DEG C after water washing, and calcining for 1-2 hours at the temperature of 350-450 DEG C to obtain the manganese dioxide with the product purity of larger than 98 percent. In the invention, the extraction ratio of the manganese in the manganese slag can reach more than 93 percent, the purity of the obtained manganese dioxide can reach more than 98 percent, the economic value of products is high, and the method has short process flow and simple operation.

Description

technical field [0001] The invention belongs to the separation and extraction technology of useful components in the leaching solution of manganese slag, and particularly relates to a method for extracting high-purity manganese dioxide from manganese slag. Background technique [0002] my country is a country with a large demand for manganese resources. Although my country is rich in manganese resources, manganese-rich ore reserves only account for 6.4%, manganese carbonate ore accounts for 73%, and the average grade of manganese carbonate ore is only 18%. The grade of manganese ore is too low, and the cost of developing manganese resources is getting higher and higher. At the same time, my country's ferroalloy enterprises and manganese ore enterprises will also produce a large amount of manganese slag every year. The manganese resources used only account for 40% of the total manganese resources, so 50% of the manganese ore resources in my country are imported, and the import...

AI Technical Summary

Problems solved by technology

However, because there are many impurities in the manganese slag, the leaching solution contains a large amount of other ions, and the removal of Fe 3+ 、Al 3+ It is especially easy to form colloids when it is used, which makes it difficult to filter. At the same time, a lot of manganese ions will be lost due to precipitation coating (or adsorption), which not only greatly reduces the extraction rate of manganese, but also reduces the utilization rate of manganese. recovery; and the final product manganese sulfate because a large amount of NH was introduced during the impurity removal process 4 + with Na + , resulting in low product purity, which reduces the value of the product