A process for simultaneous recovery of chromium and iron from chromite ore processing residue

摘要

The present invention relates to a process for simultaneous recovery of chromium and iron from Chromite Ore Processing Residue (COPR) and more particularly, the present invention relates to an economical and environment-friendly process for recovering chromium as a chromite salt and iron as an iron salt from non-leachable Chromite Ore Processing Residiue and avoids landfilling of toxic metals. The process includes treatment of the COPR with sodium-hydroxide (and Na nitrate or nitrite) at a temperature of above 350{C, followed by aqueous leaching, thereby obtaining a chromite solution and an iron rich solid residue. After liquid/solid separation a chromite salt powder is obtained by drying the liquid. The iron rich residue is dissolved in mineral acid and treated with sodium sulfate to obtain an iron salt solution and a solid residue.