Research progress on hazardous chromite ore processing residue treatment and utilization: a critical review

Abstract

Chromite ore processing residue (COPR), which is created during the chromite preparation process of chromite compounds, is considered hazardous waste because it contains chromium trivalent and chromium hexavalent. Recently, the harmless disposal of COPR has received a lot of research interest. COPR is a type of resource attributable to its abundant content of chromium, iron, aluminum, etc. This article starts from the main sources, properties, and pollution characteristics of COPR. It summarizes the methods and approaches used by scholars in recent years to handle COPR: chemical reduction, dry detoxification, pyrolysis, mineralization, solidification/stabilization, biotechnology, electrochemical methods, and resource utilization, achieving harmless treatment of COPR. Among them, research on resource utilization stands out, not only improving resource utilization efficiency but also reducing environmental pollution. This provides new ideas and directions for our future treatment of COPR.