Sustainable Mining and Metallurgy

A copper smelter adopts the oxygen-enriched bottom-blowing furnace bath smelting process for the production of copper matte. In production, low melting point substances such as Pb, Zn, As and Bi in copper concentrate volatilize into the vertical offgas duct and form large coke, seriously hindering the long-term stable operation of the oxygen-enriched bottom-blowing furnace. This paper studied the mechanism of coking in the vertical offgas duct of the oxygen-enriched bottom-blowing furnace, analyzed the factors affecting coking, and proposed counter measures to solve the coking problem. The formation of coking in vertical flue is related to copper concentrate composition, oxygen lance pressure, copper matte grade, flue gas temperature and melt depth.Through reasonable dosing, standardized control of bottom-blowing furnace smelting technical indicators, strict control of the upper-section temperature in the vertical offgas duct, and the addition of coking inhibitors, coking was reduced and the coke pieces became smaller and looser. Cleaning time was cut down significantly, and heat exchange efficiency of water wall and the bottom-blowing furnace operation rate steadily improved.