Method for directly preparing zinc oxide by wet treatment of zinc-containing fumes in iron and steel plants

Abstract

The invention relates to the field of comprehensive utilization of solid waste resources in iron and steel plants, in particular to a method for preparing zinc oxide by wet treatment of zinc-containing smoke and dust in iron and steel plants. Selectively leaching the valuable metals Zn, Pb and Cd in the zinc-containing fumes of iron and steel plants in weak alkaline amino acetate aqueous solution, the leaching solution is reduced and purified with zinc powder to obtain lead and cadmium slag; the purified leaching solution is purified with CaO or Ca(OH )2 carry out alkali adjustment and zinc precipitation to obtain crude zinc oxide, and after the crude zinc oxide is washed with water to remove residual Ca(OH)2, the finished product zinc oxide is obtained after drying; Regeneration, the regenerated leaching agent can be directly returned to leaching. The invention is easy to operate and has a mild leaching system; the aqueous solution of the complexing agent used can be regenerated during the treatment process; it can treat zinc-containing fumes with high iron content and realize the deep separation of iron and zinc; it can effectively remove poisonous zinc-containing fumes from iron and steel plants Heavy metal elements Zn, Pb and Cd can be used to prepare high value-added ZnO products and effectively enrich the valuable metals lead and cadmium.

Description

technical field [0001] The invention relates to the field of comprehensive utilization of solid waste resources in iron and steel plants, in particular to a method for preparing zinc oxide by wet treatment of zinc-containing fumes in iron and steel plants. Background technique [0002] Zinc oxide is an important chemical raw material, which is widely used in rubber, paint, ceramics, medicine, chemical industry, glass and electronics industries. With the development of industry, the demand for zinc oxide is increasing day by day. [0003] A large amount of zinc-containing dust is produced in the process of steel production, which cannot be effectively recycled and utilized, and it contains a small amount of toxic heavy metals lead and cadmium, forming a potential environmental hazard; therefore, clean and efficient recovery of valuable metals in zinc-containing dust in steel plants It is even more important, and it is a practical method to prepare high value-added zinc oxide ...

AI Technical Summary

Problems solved by technology

[0005] The disadvantage of the acid method is that the acid consumption is high during acid leaching, the impurity content in the leaching solution is high, and the purification of the leaching solution is complicated; when precipitating zinc, only the precursor basic zinc carbonate can be produced, and zinc oxide products can only be produced after high-temperature calcination by fire method (Refer to Li Ruifen, Ye Deming, Yu Ronghua, Song Qianqian. Process research on the production of zinc oxide from industrial waste [J]. Liaoning Chemical Industry, 2011, 40(2): 113-114. Kang Junfeng. Zinc soot to produce basic zinc carbonate and active zinc oxide[J]. Nonferrous Metallurgy, 2003,19(3):28-31.)

[0006] The disadvantage of the ammonia method is that an additional ammonia distillation device is required when precipitating zinc in the leaching solution, and the investment is high, and the zinc precipitating process can only produce the precursor basic zinc carbonate, and cannot directly produce zinc oxide products through the wet method; in addition , it is difficult to avoid the volatilization of ammonia during the ammonia treatment process, and the on-site operating environment is harsh (see Chinese patent document CN102826589B)

[0007] The disadvantage of the alkaline method is that the zinc precipitation rate is not high during zinc precipitation, especially when the zinc concentration in the leaching solution is low. Therefore, it is difficult to realize the recycling of the zinc-precipitated liquid after alkali treatment (see Jiang Xuexian, He Guixiang. Experimental research on the preparation of zinc oxide with zinc-lead soot [J]. Hydrometallurgy, 2010 ,29(2):120-122.)

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