Dry processing technology of exhaust gas emitted by roasting of rare earth concentrates with concentrated sulfuric acid

At present, wet spraying is the main process for treatment of exhaust gas emitted by concentrated sulfuric acid roasting method decomposition rare earth concentrates, which not only consumes a large amount resources but also wastes residual heat corresponding to temperatures approximately 300 °C. In this paper, an dry processing technology that completely different from original spray proposed and successfully implemented in kiln. The has realized dust removal, cooling condensation through cyclone separator exchange-condensing system, waste can be converted into steam drum, greatly simplifies gas. Compared with spraying, advantages operational simplicity, small footprint, low energy consumption, maintenance cost no wastewater production, makes it promising roasting.