Recovery of Chromium from Chromium-bearing Slags Produced in the Stainless-steel Smelting: A review

Abstract Chromium-bearing slags produced during the stainless-steel smelting (SSS) are important recyclable secondary resources. Recovery of chromium from these slags is not only beneficial to increase the slag’s economic potential but also favorable to solve the environmental problems induced by the chromium (VI) in the slags. This study aims to review the technologies for recovering chromium from the chromium-containing SSS slags. To begin with, chromium resources and consumption around the world were analyzed. Then, the physicochemical characteristics of the SSS slags were provided, followed by a deep discussion on varieties of the normal and lately developed methods for recovering chromium from the slags, including physical separation, smelting reduction, thermal plasma, alkaline roasting-water leaching, alkaline leaching, and bioleaching processes. Specific attention was paid to the technical challenge appearing in the recovery of chromium from the SSS slags and to the possible measures for enhancing the chromium recovery by promoting the processing efficiency.