China Nonferrous Metallurgy

In view of the problems of jarosite slag, such as the large amount of jarosite slag stockpiled in the plant, and the routine treatment process with high investment, high operating cost and low economic benefit, a lead-zinc smelter explored the process route of two stages weak acid leaching-washed slag making bricks after long-term research and laboratory tests. The filtrate and washing slag water in the process can be returned to the system for recycling, and the zinc sediment slag is returned to the zinc hydrometallurgy system, and the washed slag is used to make bricks. By improving the traditional brick-making process and material ratio, the compressive strength of pressed non-fired brick reaches MU15 after 28 days of curing, which exceeds the national standards, and the qualified rate of products increased from 37.3% to 98.63%. After the project was completed and put into operation, the average annual total cost was CNY 25.798 million, the annual income was CNY 39.159 million, and the positive economic benefit of jarosite slag was CNY 13.361 million. The reformed process has the advantages of less investment and low cost, and the bricks are not easy to collapse. It is a new type of environmental protection material with high market recognition, and the process is worthy of promotion in copper, lead and zinc smelting enterprises.