China Nonferrous Metallurgy

In the process of crude lead smelting, arsenic, cadmium and thallium in lead concentrate and other lead-containing materials are distributed in each process, which is not conducive to the recovery of valuable metal resources, but also increases the difficulty of smelting waste treatment, and has a negative impact on human health and the environment. The distribution and trend of arsenic, cadmium and thallium in the smelting process of crude lead have not been reported in the existing literature. Based on the actual production situation of a smelting enterprise, this paper statistics two sets of material balance data for 14 days in 2021 and 2022 respectively, and analyzes the distribution of arsenic, cadmium and thallium in each smelting process. The distribution of arsenic is as follows. In the bottom blowing process, about 85% arsenic enters into high lead slag, about 9% arsenic enters into dust, and about 6% arsenic enters into sulfuric acid purification system; In the process of the reduction furnace, about 70% of the arsenic forms lead copper matte into the crude lead, about 20% of the arsenic enters the reduction furnace dust, and less than 10% enters the fuming furnace through the reduction slag. The cadmium and thallium is highly enriched in the bottom blown furnace and side blown furnace soot, of which the enrichment ratio of the bottom blown furnace dust is 85% to 95%, only 5% to 15% enter the process of transferring the high lead slag to the reduction furnace, and very little enters the sulfuric acid system. Enterprises adopt transferring bottom-blown furnace dust to reduce the content of arsenic, cadmium and thallium in the crude lead smelting system. The transfer standard is when the dust contains more than 20% cadmium, and stop transfer when the dust contains less than 15% cadmium. The dust taken out can be directly sold as raw materials for cadmium recovery. The analysis results and the solution in this paper can provide reference for similar enterprises to control the distribution of arsenic, cadmium and thallium in smelting system.