Direct smelting method and system for producing metallic lead and zinc at the same time

Abstract

The invention relates to a direct smelting method and system for producing metallic lead and zinc at the same time. The method includes the steps that lead and zinc concentrate, lead and zinc oxidized ore and / or lead and zinc containing secondary materials and flux are mixed and pelleted; the pelleted furnace charges are added to a smelting zone of a dual-zone oxygen-enriched side-blowing furnace, oxygen-enriched air is blown, the weakly-reducing atmosphere is controlled for smelting, a lead phase and a slag phase are formed, coarse lead is discharged through a syphonic mouth, and high-zinc furnace slag enters a fuming zone of the oxygen-enriched side-blowing furnace; coal needed for zinc reducing is added to the fuming zone, the oxygen-enriched air is blown, and the fuming zone is controlled to be in a strongly-reducing atmosphere; zinc obtained after reducing forms zinc steam which enters a steam condenser along with furnace gas, zinc containing lead liquid is formed, cooled zinc liquid is separated from the lead liquid, and coarse zinc is obtained. By means of the method, the raw materials do not need to be sintered or calcined, and technological processes are greatly shortened; raw materials with a low lead and zinc grade can be smelted, especially zinc leached residues can be treated, and the environmental protection purpose is achieved for zinc hydrometallurgy; the coal can replace coke, and therefore production cost is reduced.

Description

technical field [0001] The invention belongs to the field of non-ferrous metal smelting, and in particular relates to a direct smelting method and system for simultaneously producing metal lead and zinc. Background technique [0002] Mineral lead and zinc that use lead sulfide or zinc sulfide concentrate as raw materials are basically smelted separately. Lead smelting mainly uses lead concentrate as raw material. At present, crude lead is basically produced by pyrometallurgy in the world, and then electric lead is obtained through pyrorefining and electrolytic refining. Zinc smelting mainly uses zinc sulfide concentrate as raw material, and more than 80% of the production capacity uses the hydrometallurgy method to directly produce electric zinc. Only the closed blast furnace zinc smelting method (also known as ISP) can produce lead and zinc in the same furnace, and produce crude lead and crude zinc at the same time. [0003] However, ISP zinc smelting has several defects:...

AI Technical Summary

Problems solved by technology

[0003] However, ISP zinc smelting has several defects: First, the raw material of lead and zinc sulfide must be sintered and roasted, and cannot be directly smelted in the furnace

However, the process of sintering and roasting is very long, with a lot of equipment and low efficiency. More than 80% of the sintered product must be crushed and screened in four stages, returned to the ingredients, mixed again, granulated, and sintered. 25% of the raw material is diluted to about 6% sulfur to meet the sintering process requirements

Second, the amount of sintering flue gas is large, and flue gas SO 2 The concentration is low, which is not conducive to the acid production process of the two-transformation and two-absorption process

Fourth, the dust pollution during the crushing and screening of sintered blocks is serious, and a huge ventilation and dust removal system needs to be installed

Fifth, there is no production practice of a large number of matching or separate treatment of zinc leaching slag, which cannot solve the environmental protection problem of slag treatment for hydrometallurgy

Sixth, when the sintered block is added to the blast furnace for reduction and smelting, coke must be used as the reducing agent, and the coke rate reaches more than 40%, and the energy cost is relatively high

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