Oxidation and condensation of zinc fume in steelmaking off-gas systems

Off-gas dust wastes from steelmaking processes contain a number of by-product metals, which are hazardous to dispose of by landfill. With the increased use of electric arc furnaces, zinc has become a significant by-product in the off-gas dust and a main inhibiter of off-gas dust disposal as common waste. Zinc's low vaporization temperature (907 C) causes the zinc to evaporate from the melt and become entrained in the off-gas stream. Zinc then deposits as zinc, zinc oxide, and zinc ferrite spinel, which are difficult to separate postprocess from ferrous and other entrained oxides. If the zinc could be separated from the residual entrained particulates through an in-process method, the cost of processing the dust for recycling would go down. In addition, if the zinc-rich portion of the separated dust has high enough zinc content the dust could be sold for a profit. Zinc recovery could increase the steelmaker's profitability while reducing the environmental toll. The focus of thi