Jornal de Química Analítica Ambiental

This study was performed on disseminated low-grade chromite ore, Gedarif State, Umm Saqata-Qala Elnahal, to treatment the ore by Heavy media separation (HMS) with low intensity magnetic separation (LIMS) for course fraction size (-212+75) μm and selective flocculation for chromite slimes (-75) μm. The ore of the study area is low grade contains 21.5% Cr₂O₃ with the liberation size of chromite mineral in the range (0.30-0.05) mm. The main gangue of the ore is mineral silicates as the Antigorite mineral. The ore was crushed, ground, and then classified to tow fraction size (-212+75) μm and slimes (-75) μm. Fractions size (-212+75) μm contained 25.58% Cr₂O₃ was treated by HMS via Bromofrom mixed with carbon tetrachloride flowed by low intensity magnetic separator. HMS with LIMS obtained the highest recovery 82.52% and grade 46.62% Cr₂O₃ for chromite concentrate with 2.54 Cr/Fe. The slimes (-75) μm contained 22.17% Cr₂O₃ was treated by selective flocculation method. Optimum grade 42.71% Cr₂O₃ and recovery 37.10% for chromite concentrate, were achieved at sodium silicate concentration 100 mg/l, starch concentration 45 mg/l, pH=9, and solid percentage 5%.