China Nonferrous Metallurgy

A smelting company used a rotary kiln process to recover zinc oxide from the iron slag in hydrometallurgical zinc process, and originally used the traditional calcium desulfurization process to treat the flue gas from rotary kiln, which had the problems such as poor desulfurization effect, substandard exhaust gas, difficult disposal of gypsum slag, and low operating rate. After many verifications, the company decided to switch to zinc oxide-acid desulfurization process. The desulfurization agent adopts self-produced zinc oxide fume or calcine. The sulfur dioxide produced is returned to the acid production system, and the acid hydrolysis liquid is returned to the zinc system. The system does not produce secondary solid waste. After the new system was put into production, the operation was stable, which increased the economic benefits of the enterprise, and the exhaust emission index was better than the national standard. This article introduces the technological process, technological parameters and equipment of the modified technology in detail, and summarizes and explains the problems that should be paid attention to in production practice.