Molten pool melting method of bismuth sulphide concentrate

Abstract

A molten pool melting method of bismuth sulphide concentrate of the invention comprises the following steps: blending bismuth sulphide concentrate with a flux, flue dust and pulverized coal according to a certain ratio, adding into melt oxidation bottom slag, injecting oxygen-rich air, performing oxidation melting to obtain crude bismuth alloy, flue dust and bismuth-rich slag; mixing liquid bismuth-rich slag, the flux and reducing coal according to a certain ratio, adding into melt reduction bottom slag, injecting proper amount of oxygen-rich air, performing reduction melting to obtain crude bismuth alloy, flue dust and slag for fuming furnaces. Molten pool melting of bismuth sulphide concentrate can produce crude bismuth alloy directly, does not require the addition of scrap iron, and islow in production cost; when the SO2 concentration of the flue gas in oxidation melting reaches 10%-22%, the flue gas can be used to prepare acids, which effectively recovers the sulfur in raw materials, and solves the pollution problem of low-concentration SO2; bismuth-rich slag is treated by reduction melting, which further increases the recovery rate of bismuth smelting.

Description

technical field [0001] The invention relates to a pyrometallurgical process in the field of metallurgy, in particular to a molten pool smelting method for bismuth sulfide concentrate. Background technique [0002] Bismuth-containing ores can be processed to produce bismuth sulfide concentrates, of which bismuth is mainly bismuthite (Bi 2 S 3 ) form, there are two main processes for extracting bismuth metal from bismuth concentrate: fire method and wet method. [0003] The pyrometallurgy of bismuth mainly includes three methods: precipitation smelting, reduction smelting and mixed smelting. Reduction smelting is suitable for processing raw materials containing bismuth oxides, mixed smelting is suitable for processing raw materials containing both bismuth sulfide ore and bismuth oxide ore or slag, and precipitation smelting is mainly used for processing bismuth sulfide concentrates with higher bismuth content. At present, the precipitation smelting method is the most widel...

AI Technical Summary

Problems solved by technology

[0006] (1) A large amount of iron filings and soda ash need to be added in the precipitation smelting process, resulting in an increase in production cost and energy consumption. At the same time, a large amount of smelting slag and smoke are produced, which may easily cause the dispersion loss of bismuth;

[0007] (2) The wet treatment process is oxidative leaching in the chloride system, which has the disadvantages of severe equipment corrosion, poor operating environment, large amount of wastewater, large consumption of reagents, low bismuth recovery rate and high cost;

[0008] (3) The valuable element sulfur in the bismuth sulfide concentrate has not been recovered and utilized. During the precipitation smelting process, most of the sulfur enters the lead matte, and a small part enters the flue gas. The environmental pollution is serious and subsequent recovery is difficult.

Images