Mechanism and kinetics of iron extraction from high silica boehmite–kaolinite bauxite by hydrochloric acid leaching

The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine (Arkhangelsk region, Russia) were studied by XRD, ICP-OES, TG/DSC, SEM, TEM, Mössbauer spectroscopy. iron-containing minerals bauxites found to comprise alumogoethite (α-Fe1–xAlxOOH), alumohematite (α-(Fe1–xAlx)2O3), alumoakaganeite (β-Fe1–xAlxO(OH,Cl)), chromite (FeCr2O4). efficiency Fe extraction HCl leaching was 82.5% at 100 °C, concentration 10%, solid/liquid ratio 1:10, process duration 60 min, with aluminum loss below 4.5% total Al contents in bauxite. Analysis kinetics iron proved diffusion be limiting stage 90–100 °C. residue after presented traces α-Fe1–xAlxOOH β-Fe1–xAlxO(OH,Cl), most content FeCr2O4. In leaching, addition oxide, chromium calcium oxides significantly decreased. chloride liquor contained rare earth elements (REE) 6.8 mg/L Sc, 4.1 Ce 2.3 Ga.