A two-stage smelting method for producing precious lead from lead anode slime

Abstract

The invention relates to a two-stage smelting method for producing noble lead from lead anode slime, which belongs to the precious metal pyrometallurgy technology. This method improves the traditional pyro-reductive smelting process of producing noble lead from lead anode slime. Compared with the existing traditional process of producing noble lead from lead anode slime, in the same converter, the process is two processes of low-temperature oxidation and high-temperature reduction smelting , the way of adding auxiliary materials is changed to after the lead anode slime is completely oxidized and blown, then add reducing agent and flux for reduction smelting. This process greatly reduces the amount of reducing agent anthracite, flux soda ash and fuel consumption, and removes arsenic and antimony High efficiency, high-grade noble lead can be obtained, and the production capacity of the original converter has increased by 50%.

Description

technical field [0001] The invention relates to a two-stage smelting method for producing noble lead from lead anode slime, which belongs to the noble metal pyrometallurgical technology, specifically the noble metal pyrometallurgical technology. Background technique [0002] There are basically two methods for the treatment of lead anode slime: fire process and wet process. The wet production process is long, the cycle is long, the production cost is high, and the amount of wastewater treatment is large; the treatment of lead anode slime at home and abroad generally adopts the traditional pyrotechnic process. The process principle is to mix lead anode slime, reducing agent, and solvent into the smelting furnace to reduce and smelt to produce precious lead, and then oxidize and refine the precious lead to produce gold-silver alloy with a purity greater than 97%. There are many researches on the treatment methods of lead anode slime in China: [0003] The title of the invent...

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Problems solved by technology

[0008] From the above invention patents, it can be seen that the treatment of lead anode slime is basically using a smelting furnace at 900-1000°C or 1000-1200°C or 1200-1300°C Under high temperature conditions, noble lead can be obtained by reduction smelting, which has the following process defects: 1) Anode slime and reducing agent are added together. During the smelting process, arsenic and antimony that have been naturally oxidized are reduced into noble lead, and the consumption of reducing agent is large. The yield of noble lead produced is high, the grade of noble lead containing Ag is low, the amount of noble lead processed in the later stage is large, the refining cycle is long, and the amount of slag produced is also large, and the probability of mechanical entrainment of silver during slag discharge is high; 2) anode slime and When the flux is mixed and added, the As, Sb oxide, lead oxide and soda ash in the lead anode slime form high-alkali slag earlier, covering the surface of the melt, hindering the volatilization of As and Sb, resulting in low volatilization rates of As and Sb, and the consumption of soda ash as a flux A large amount of slag containing high arsenic and antimony is produced, which is not conducive to the recovery of arsenic and antimony; 3) The direct reduction smelting temperature is relatively high, and the consumption of fuel, reducing agent and flux is large, which directly leads to high production costs; 4) Direct reduction smelting Reduction smelting process, the production cycle is relatively long, and the processing capacity of the smelting furnace is low

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