High-efficiency resource transformation method of nonferrous metal zinc-smelting fly ash

Abstract

The invention relates to a high-efficiency resource transformation method of nonferrous metal zinc-smelting fly ash. The method comprises the following steps: firstly, zinc-smelting fly ash, excessive ammonia water and ammonium sulfate solution are mixed and reacted; then, the solid-liquid separation is performed for the reacted mixed solution; soluble zinc-ammonia complexing solution is fed into a heating ammonia distilling unit; excessive ammonia gas in the solution is removed by a steam gas stripping method; one part of the treated zinc-ammonia complexing solution is fed into a zinc recovery tank, and the other part of the zinc-ammonia complexing solution, serving as desulfurization slurry, is sprayed into a smoke desulfurization tower to desulfurize the smoke, and is fed into a desulfurization slurry tank; then, ammonium bicarbonate is added in the zinc recovery tank and the desulfurization slurry tank for treating to obtain basic zinc carbonate and ammonium sulfate; the basic zinc carbonate is separated and purified to sell as a product; and the ammonium sulfate is purified for recycling. Compared with the prior art, the method has such advantages as high resource utilization rate, high recovery rate of zinc in the zinc-smelting fly ash, simple treatment process, energy conservation, cleanness and environmental protection.

Description

technical field [0001] The invention relates to resource recovery and reuse technology in the field of environmental protection, in particular to a method for efficiently converting non-ferrous metal zinc smelting fly ash into resources. Background technique [0002] In recent years, the output of non-ferrous metals in my country has continued to increase, especially the output of ten heavy metals such as zinc and lead has ranked first in the world for more than ten consecutive years, making important contributions to the development of my country's national economy. However, the massive mining and smelting of non-ferrous metals has also brought about very serious environmental problems, among which the recycling of zinc ash (its main component is sub-zinc oxide) in the non-ferrous metal smelting industry is particularly prominent. [0003] At present, the recovery method of zinc ash in the non-ferrous smelting industry is mainly the acid extraction technology, that is, the ...

AI Technical Summary

Problems solved by technology

However, the acid leaching technology has the following disadvantages: First, the composition of zinc ash from the nonferrous smelting industry is relatively complex. If acid leaching is used, other components (such as lead, iron, arsenic, etc.) will enter the leaching together. Extracting the liquid will bring difficulties to the subsequent purification and processing; secondly, the acid leaching method will also cause valuable metals such as indium and silver to be leached in a scattered form, making it difficult to recover

Third, it is difficult to recover and comprehensively utilize the waste acid produced by leaching, the consumption of acid is large, and there are many problems such as secondary pollution.

If the zinc oxide raw material containing a large amount of impurities is used for desulfurization, due to the existence of a large amount of insoluble matter and the limited pH range in the desulfurization process, the leaching rate of zinc oxide in the raw material is not high, and the impurity content is too high, which directly affects the Subsequent processing and utilization of its desulfurization product (zinc sulfate)

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