Extraction of Chromium from Stainless Steel Dust

Abstract

A process based on soda ash roasting of stainless steel dust may be considered an attractive route to produce sodium chromate. This investigation deals with the prod-uction of pure (99.5%) sodiu m chromate from stainless steel dust obtained from stainless steel processing plants. The stainless steel dust was examined for miner-ographic and chemical analysis. It was found that mostly iron is present in oxide form along with chromium, nickel and manganese. As nickel and manganese is in low quantity, the chromium content found to be suitable for its reco-very. In order to recover chromium, soda ash roasting followed by water leaching was found suitable to recover chromium as sodium chromate. It was found that at 1073 K in 90 minutes of time maximum (95%) chromium can be reco-vered. Kinetics of sodium chromate formation indicated that it follows topochemical model with activation energy of 22.13kj/mol. TG/DTA, XRD and SEM-EDX confirm the expe-rimental fact and support the process to develop a tech-nology.