Method for producing high-purity zinc oxide through fume ash in steel works

Abstract

The invention discloses a method for producing high-purity zinc oxide through fume ash in steel works. Ammonia-ammonium bicarbonate liquid is used as leaching solvent to perform leaching; 0.3 to 0.5 kg of sodium fluosilicate is added in each cubic meter of the leaching solvent; before an impurity removal step, leaching liquid subjected to leaching is heated to 95 to 105 DEG C to be subjected to ammonia pre-steaming; and by applying ammonia process to the treatment of the fume ash in the steel works and performing adaptive improvement on the existing ammonia process, zinc in the fume ash in the steel works can be rapidly leached completely as far as possible, the zinc in the fume ash in the steel works can be sufficiently recycled, and the purity of zinc oxide obtained can reach more than 99.7 percent. The method has the advantages that the energy consumption is low; the efficiency is high; the leaching solvent is circularly utilized; the problem of zinc load in the fume ash in the steel works is thoroughly solved; not only the requirement of purification of noxious constituent zinc and alkali metal by the steel works is satisfied, and the virtuous cycle of production is achieved, but also valued iron and coal resources in the steel works are recovered, and iron and coal are enriched; and not only energy is saved, but also good economic benefit is created.

Description

technical field [0001] The invention relates to a method for producing high-purity zinc oxide by utilizing soot from steel mills. Background technique [0002] At present, soot ash from steel mills (including blast furnace ash, converter ash, electric furnace ash), also known as soot storage ash, will produce 35-90kg of soot ash for every ton of steel produced. This soot ash generally contains 15-30% iron %, containing 4-5% silicon oxide, 5-22% zinc, 25-55% combustible fixed carbon (C), 2-5% calcium oxide, 1-2% magnesium oxide, titanium, vanadium and alkali metals, etc. . Under normal conditions, the sintered ore is generally used as a raw material for sintering, and is recycled in the steel plant. With the enrichment of the cycle, the zinc load into the furnace is getting higher and higher, which seriously affects the normal operation of the blast furnace. [0003] At present, the methods of limiting the zinc load of blast furnaces are as follows: one is to limit the amou...

AI Technical Summary

Problems solved by technology

The first method is not an economical and effective method to reduce the zinc load of blast furnace, but also brings environmental pollution

The second is to enrich zinc into the tailings, but the three products of iron concentrate, carbon concentrate, and tailings are out of balance, and high iron and carbon resources are still lost

[0009] 1. Due to the low zinc content in dust storage ash from steel mills (generally containing Zn%=5-22), the zinc concentration in the leaching solution is low, the consumption of leaching agents is large, and the cost is high, which cannot be afforded by the enterprise

[0010] 2. Due to the complex composition of impurities, the production can only be ordinary active zinc oxide products and the pass rate is low, the product price is low and the economic benefit is poor

[0011] 3. During leaching by conventional means, the leaching rate of soot and ash is low, the recovery rate is low, and the recovery of iron and carbon resources has not formed a complete chain, and the value of soot and ash has not been reflected