Method for preparing zinc oxide by using zinc-contained raw ores

Abstract

The invention relates to a method for preparing zinc oxide by using zinc-contained raw ores. The method comprises a primary leaching step, an optional purifying step, a decarbonization step, a calciumzincate synthesis step, a primary calcining step, a secondary leaching step, a pressing crystallization step, a decompression decomposing step, an optional rinsing step and a secondary calcining step. The method combines wet leaching with the synthesis process, so that the economical and environment-friendly utilization of low-grade zinc ores is realized, the application range is wide, the ammonia evaporation is not needed, both convenience and feasibility are achieved, the energy consumption of the process is greatly reduced, the high-temperature and high-pressure potential safety hazards and the equipment corrosion problem caused by the ammonia evaporation are prevented, the process recovery rate and the finish product grade problem are solved, and the pollution is low; auxiliary materials can be recycled; the synthesis of calcium zincate under a zinc ammonia environment is realized for the first time; zinc oxide products are prepared by calcium zincate; the decomposition conditionsof ammonia carbonate are creatively used; and the recycling of carbon dioxide is realized through pressure difference.

Description

technical field [0001] The invention belongs to the technical field of inorganic chemical industry, relates to resource utilization of low-grade zinc-containing raw ore, in particular to a method for producing zinc oxide by using low-grade zinc oxide raw ore. Background technique [0002] The production and consumption of zinc in my country ranks first in the world. Domestic zinc resources cannot meet the production requirements, and a large amount of zinc raw materials need to be imported every year. my country is a country rich in zinc oxide resources. The reserves of zinc metal in zinc oxide ore in my country are about 28 million tons, accounting for about 27.7% of the zinc metal reserves in zinc oxide ore in the world. Zinc oxide mines in my country generally have a low zinc grade, with an average grade of less than 5%. At present, the stagnant ore and lean ore reserves that cannot be economically utilized account for the vast majority, among which the mining tailings co...

AI Technical Summary

Problems solved by technology

The selectivity of sulfuric acid leaching method is low, and a large amount of soluble silicon in the ore will be leached, and the generated colloidal silicon is difficult to filter, and the acid leaching method generates a large amount of sulfate residue, which causes great environmental protection treatment pressure; sulfuric acid leaching cannot effectively Treat the zinc silicate, zinc ferrite and other components in the ore

The calcium chloride method cannot effectively deal with the leaching of zinc silicate, zinc ferrite and other components in the raw ore, and the leaching rate is not ideal, requiring high temperature leaching, and the comprehensive economic benefits are not good

In the ammonium chloride method, after the raw ore is leached, the process of recovering the zinc component from the leaching solution is very difficult, which is not suitable for industrial application.

[0007] Therefore, the existing technology is not satisfactory for the utilization of low-grade zinc-containing raw ore