Treatment method of zinc-bearing dust for steel works

Abstract

The invention relates to a treatment method of zinc-bearing dust for steel works. The treatment method includes mixing the zinc-bearing dust, pulverized coal and binder prior to pelletizing, feeding pellets into a rotary hearth furnace, reducing ferric oxide into sponge iron and cinder in the high-temperature reducing atmosphere in the rotary hearth furnace, exhausting the reduced zinc out of the rotary hearth furnace with smoke of the rotary hearth furnace, using the high-temperature smoke to preheat rotary hearth furnace combustion air, introducing the smoke into a wet dust remover, allowing the zinc in the rotary hearth furnace to react with dilute sulfuric acid sprayed into the wet dust remover to generate zinc sulfate solution, electrolyzing the zinc sulfate solution to obtain high purity zinc, and exhausting the purified smoke from a dispersing chimney. By the treatment method, affection of operation of a whole smoke treatment system by accumulation and bulging of zinc vapor in the smoke treatment system is avoided, and operating efficiency of the rotary hearth furnace is improved. In addition, the invention provides the zinc-bearing dust treatment method which can also be used to produce high purity zinc.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for treating zinc-containing dust in iron and steel plants. Background technique [0002] There will be a lot of dust in steel production, its main component is iron oxide, but it contains a certain amount of zinc oxide. If it is not used, it will not only waste resources but also pollute the environment. The traditional treatment method is to return the dust to sintering, but this The treatment method will enrich the zinc in the blast furnace, cause nodules in the furnace, affect the smooth operation of the blast furnace and damage the smelting equipment. [0003] After years of technical research, the coal-based rotary hearth furnace method has become a mature and reliable treatment technology for zinc-containing dust. This technology can not only reduce the iron element in zinc-containing dust to sponge iron, but also convert zinc to The form of steam ...

AI Technical Summary

Problems solved by technology

However, since zinc vapor can re-solidify at lower temperatures (the melting point of zinc is 419.5°C and the boiling point is 906°C), the solidified zinc tends to accumulate and grow in the waste heat boiler or heat exchanger, which will eventually lead to Or the heat exchanger cannot operate normally, which is one of the main reasons for the abnormal operation of the rotary hearth furnace. The existing flue gas treatment system usually needs to be shut down for maintenance once every three months, which seriously affects the operation rate of the rotary hearth furnace. Therefore, How to reasonably remove zinc in iron and steel plant zinc dust has become a difficult problem in the prior art

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