Research on High-Pressure Hydrochloric Acid Leaching of Scandium, Aluminum and Other Valuable Components from the Non-Magnetic Tailings Obtained from Red Mud after Iron Removal

Red mud is a hazardous waste of the alumina industry that contains high amounts iron, aluminum, titanium and rare-earth elements (REEs). One promising methods for extraction iron from red carbothermic reduction with addition sodium salts. This research focuses on process hydrochloric high-pressure acid leaching using 10 to 20% HCl two samples non-magnetic tailings obtained by 60 min roasting at 1300 °C mixture 84.6 wt.% 15.4 Na2SO4 1150 °C, respectively, subsequent magnetic separation metallic iron. The influence temperature, duration, solid-to-liquid-ratio concentration dissolution behavior Al, Ti, Mg, Ca, Si, Fe, Na, La, Ce, Pr, Nd, Sc, Zr was studied. Based investigation residues, mechanism passing valuable into solution proposed. It has shown 90% 91% Sc above 80% other REEs can be dissolved under optimal conditions; Ti extracted or residue depending temperature concentration. results, novel flowsheets treatment were developed.