China Nonferrous Metallurgy

Application of oxygen enriched air roasting technology in zinc concentrate roaster has stayed in the experimental stage in China over the years. Chihong Zn & Ge is the first to have realized large-scale production of zinc concentrate by oxygen enriched air roasting. The company adds oxygen-enriched air distribution device on the original blast system piping, provided with fittings such as high concentration oxygen regulating valve group and instrumentations for flow and pressure monitoring, along with equipment optimization to fluidizing cooler, high-temperature ID fan and blower. Production practice shows that under proper process parameters, the production capacity of oxygen-enriched air roasting technology can be fully released, and the specific capacity of fluidized-bed roaster can be increased to 8.03t/m2·d; the quality of roasted ore can be improved effectively and the sulfur content of roasting dust can be lowered to 3.5%; the energy consumption per ton of zinc is greatly reduced the unit consumption of compressed air, electricity and high concentration oxygen are 194.0Nm3/t , 135.80kWh/t and 81Nm3/t respectively. In conclusion, the application of oxygen-enriched air roasting technology with 109m2 roaster can obtain better economic benefits. It also improves the utilization rate of facilities of roasting system and sulfuric acid system, reduces the volume of blast, and effectively prevents fugitive dust, improving the production environment on site.