Method for smelting lead-bismuth concentrate in oxygen-rich side-blown duplex furnace

Abstract

The invention discloses a method for smelting a lead-bismuth concentrate in an oxygen-rich side-blown duplex furnace, belonging to the technical field of smelting bismuth concentrates. The method comprises the steps of preparing raw materials, and smelting in the oxygen-rich side-blown oxidation-reduction duplex furnace to directly produce a crude bismuth alloy. According to the method, scrap iron is not required to be added, so that the production cost is low; the concentration of SO2 in flue gases generated from oxidizing smelting reaches 10 to 25 percent, and the SO2 can be recycled to prepare acid, so that the problem of environmental pollution caused by the flue gases is solved; and the oxidation-reduction duplex smelting ensures that the direct yield of bismuth is greatly promoted.

Description

technical field [0001] The invention relates to a method for smelting lead-bismuth concentrate in an oxygen-enriched side-blown double furnace, belonging to the technical field of smelting lead-bismuth concentrate. Background technique [0002] Lead-bismuth concentrate is made of lead-bismuthite (PbS·Bi 2 S 2 ) obtained by flotation, the main weight percentage composition of common lead-bismuth concentrate is as follows: Bi5-50; Pb3-55 S10-25; Cu1-3; Fe2-25; Ag0.09-0.10; SiO 2 2.0-2.1; CaO 0.35-0.40; the particle size of the concentrate material is less than 50mm, and the moisture is less than 10%. [0003] The traditional pyrometallurgy of lead-bismuth concentrate needs to use soda ash and quartz stone as solvent, and add enough iron filings as reducing agent to produce coarse bismuth alloy, soot and smelting slag. The main disadvantages of this method are: 1. A large amount of iron filings and soda ash need to be added in the smelting process, resulting in increased pr...

AI Technical Summary

Problems solved by technology

The main disadvantages of this method are: 1. The smelting process needs to add a large amount of iron filings and soda ash, resulting in increased production costs and energy consumption, and the smelting slag contains high bismuth, resulting in low direct yield of bismuth

2. The amount of smoke and dust in pyro-smelting is large. Although the sulfur content of lead-bismuth concentrate is as high as 10-25%, the SO produced by pyro-smelting 2 The concentration is lower than 6%, so it cannot be directly sent to the acid system for recovery

Direct discharge cannot meet environmental protection requirements and increase environmental protection costs

3. The traditional metallurgical process fails to realize the combination of the oxidation furnace and the reduction furnace. The metallurgical process is time-consuming and labor-intensive

However, this process is mainly specifically designed for lead-based materials, and for lead-bismuth concentrates containing up to 5-50% Bi, due to the different mineral phases of the materials, if the above-mentioned process is directly used, it will result in a large amount of Bismuth soot can not directly produce coarse bismuth alloy, and even cause the material to condense in the furnace

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