Method for performing reduction roasting on pyrolusite by using sludge as reducing agent

Abstract

The invention discloses a method for performing reduction roasting on pyrolusite by using sludge as a reducing agent. The method comprises the following steps of: grinding pyrolusite until the granularity of the pyrolusite is smaller than 2mm; uniformly mixing the sludge from a sewage treatment plant and the pyrolusite to obtain an ore and sludge mixture, wherein the mass ratio of the sludge to the pyrolusite is 0.5-2.0:1; naturally drying the ore and sludge mixture by air or airing the ore and sludge mixture until the water content is less than 20 percent; placing the ore and sludge mixture into a roasting furnace for roasting; in the roasting process, first heating by an external heat source; when the ore and sludge mixture is completely ignited by the external heat source and the surface temperature of the ore and sludge mixture reaches over 550 DEG C, stopping external heating; and when the ore and sludge mixture is completely burned and the surface temperature is reduced to be lower than 200 DEG C, taking the ore and sludge mixture out from the roasting furnace and quickly cooling the ore and sludge mixture with water so as to obtain the pyrolusite reduction product. The method provides the reducing agent which has the advantages of cheapness and wide resource for the reduction roasting of the pyrolusite; and the treatment of sludge and resource utilization can be synchronously realized.

Description

technical field [0001] The invention relates to a method for reducing and roasting pyrolusite by using sludge as a reducing agent. Background technique [0002] Pyrolulurite is an important manganese chemical raw material, and about 60% of manganese salts in the world are processed from pyrolusite. Manganese sulfate is the most important and basic manganese salt, and about 80% of manganese sulfate is prepared from pyrolusite. Since the manganese in pyrolusite is mainly MnO 2 form exists, while MnO 2 It is insoluble in dilute sulfuric acid. It is necessary to reduce the high-valent manganese (IV) in pyrolusite to low-valent manganese (II) before leaching manganese with sulfuric acid. The traditional process uses coal (charcoal) to reduce and roast pyrolusite and then leaches manganese in acidic solution. This process consumes a lot of coal and produces air pollution. The development of a reducing agent that can replace coal to reduce pyrolusite has positive significance f...

AI Technical Summary

Problems solved by technology

However, as an organic part of the sewage treatment system, the development of sludge treatment and disposal technology is slow, which restricts the process of sewage treatment to a certain extent.

At present, most of the sludge in our country has only undergone preliminary treatment, and then it is temporarily stored in disorder or simply landfilled, which not only occupies a large area of ​​land resources, destroys the ecological environment, affects human health, but also wastes resources.