Flotation of smithsonite from Angouran mine tailings

The flotability of smithsonite mineral from Angouran mine tailings containing calcite and quartz as the main gangue minerals was investigated. Using Armac C as a cationic and oleic acid as an anionic collector successful results were obtained in mico flotation experiments showing the cationic flotation at pH=11 is more effective than anionic one. Sodium hexa metaphosphate and sodium silicate were selected as suitable depressants for calcite and quartz minerals, respectively. In the presence of sodium sulfide (Na₂S) the optimal dosage of Armac C, sodium silicate and sodium hexa methaphosphate were determined 800, 500 and 250 g/t, respectively. Using sodium hydroxide (415 g/t) as the pH adjuster, the optimal dosage of Na₂S is decreased to a half (3000 g/t) while the use of sodium carbonate reduces the Zn grade and recovery without significant decrease in Na₂S consumption. At the optimal condition a smithsonite concentrate with 23 % Zn and 79% recovery is obtained.