Hydrothermal recovery of chromium and manganese using pyrolusite with chromite ore processing residue
The industrial production of chromium salt generates a large amount of chromite ore processing residue(COPR).The residual Cr(Ⅵ)and Cr(Ⅲ)in COPR not only pose the risk of"re-yellowing"and polluting the ecological environment,but also cause waste of chromium resources.Herein MnO2 in pyrolusite was utilized to oxidize the residual Cr(Ⅲ)in chromium residue to Cr(Ⅵ)under acidic condition,then recover manganese and chromium through leaching to eradicate the risk of"re-yellowing"of COPR.The results indicated that the leaching rate of Cr(Ⅵ)reached 100%and Mn 89.15%under reaction temperature of 150℃,reaction time of 1.5 h,mass ratio of COPR to pyrolusite of 1∶1,solid-liquid ratio of 1∶20,and 3 mol·L-1 of sulfuric acid.The leaching concentration of the remaining total chromium in the detoxified slag under such conditions was lower than the ICP detection limit(1 μg·L-1),and the contents of Cr(Ⅵ)and total chromium met the national standard(GB 5085.3-2007),which provided a new way for detoxification and resource utilization of COPR as well as effective leaching of pyrolusite.
国家科技期刊平台
NSTL
万方数据
维普
