A method for recovering zinc from zinc-like zinc resources containing zinc silicate

Abstract

The invention discloses a method for recovering zinc from willemite resources and belongs to the technical field of mineral processing. The method comprises the following steps that (1) raw ore is crushed to form willemite of preset fineness; (2) a sodium agent is added into the willemite, pelletizing is carried out after sufficient mixing, the mixture is subjected to sodium salt roasting under the oxidizing atmosphere, and a sodium salt roasted product is obtained after cooling is carried out; and (3) the sodium salt roasted product is crushed and immersed in water, so that zinc leachate is obtained. According to the method, zinc is extracted through a mineral phase reconstitution-water immersion method, a zinc silicate mineral phase is converted to zinc oxide through sodium salt roastingof the willemite, the conversion effect is good, and subsequent water immersion and extraction are easy; the sodium agent adopts sodium carbonate and is low in cost and easy to obtain; and compared with a pyrogenic process carbon reduction, no coke needs to be added as a reduction agent, the energy consumption is low, the reaction rate is high, and the zinc leaching rate is 90% or above. According to the method, the zinc extraction effect is good, the leaching cost is low, selectivity is good, no silica gel is produced compared with acid-process leaching, and subsequent leaching, filtering and separation are easy.

Description

technical field [0001] The invention belongs to the technical field of mineral processing and relates to a method for recovering zinc from zinc resources containing zinc silicate. Background technique [0002] Zinc is an important non-ferrous metal. As the world's largest zinc production and consumption country, my country's demand for zinc concentrate is increasing year by year. At present, the main source of raw materials for the zinc industry is zinc sulfide ore, whose reserves are rapidly decreasing, and the supply of raw materials is increasingly insufficient, which has become one of the restrictive links for the development of the zinc industry. Zinc oxide ore accounts for 20% of my country's zinc resource reserves. Therefore, the development and utilization of low-grade zinc oxide resources is very important to the development of my country's zinc industry. In addition, secondary zinc resources include zinc-containing leaching slag, blast furnace dust, electric furna...

AI Technical Summary

Problems solved by technology

These zinc oxide ores contain 3% to 10% willemite, and its main phase is zinc silicate, which has an island silicate structure, stable crystal structure and difficult to extract; secondary zinc resources containing zinc silicate include The leaching slag of high-silicon zinc sulfide ore or low-grade zinc oxide ore has a large annual output of these secondary zinc resources and high zinc content, and it is difficult to recycle zinc compounds such as zinc silicate in the slag

[0004] At present, the research methods for extracting zinc from silicon-containing zinc ore resources mainly include fire reduction volatilization and wet leaching, etc. These methods can effectively recover zinc resources in the zinc oxide phase, but the zinc in the zinc silicate phase is Recycling is less effective

The fire reduction method needs to rely on reduced coal or coke as the reducing agent and fuel, and recovers zinc through high-temperature reduction and volatilization. The reduction and volatilization temperature of willemite is higher than that of zinc oxide, which makes the reduction difficult, high energy consumption, and poor economy

Wet leaching mainly includes two categories: acid leaching and alkali leaching. Acid leaching requires high acid and high temperature environment to obtain a high zinc leaching rate, low temperature and low energy consumption, but it is easy to form a large amount of zinc during acid leaching. Silica gel makes solid-liquid separation difficult, and a large amount of impurity elements such as Fe, Ca, Mg, Al, etc. are dissolved during the leaching process, resulting in increased acid consumption and increased difficulty in purifying the leachate

Alkaline leaching methods mainly include NaOH strong alkali leaching method and ammonia leaching method. Compared with acid leaching method, alkaline leaching method has good selective leaching characteristics, but the zinc leaching rate is low when used for silicon-containing zinc ore resources, which limits The application of alkaline leaching method in the treatment of willemite, so far, no zinc recovery method suitable for willemite resources has been developed

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