Dissolution of chalcopyrite concentrate by dichromate ions in sulphuric acid medium
In this study, the leaching conditions of chalcopyrite (CuFeS2) concentrate enriched through flotation of Menka Corporation Cu-Pb-Zn complex ore in sulphuric acid medium under effect of potassium dichromate were investigated. Effects of stirring speed in the range of 100-600 rpm, sulphuric acid (H2SO4) concentration in the range of 0.1-0.5 M, potassium dichromate (K2Cr2O7) concentration in the range of 0.02-0.2 M, leaching temperature in the range of 20-90°C, particle size fractions of -212 +106, -106 +75, -75 +45, -45 +38 to minus 38 ?m and solid/liquid ratio in the range of 10-200 g/L on copper dissolution were investigated in the experimental study. According to obtained results, it was determined that the copper dissolution from chalcopyrite under the effect of potassium dichromate ions in sulphuric acid medium was directly proportional to stirring speed, sulphuric acid and potassium dichromate concentrations and leaching temperature. On the other hand, it increased with decreasing particle size and solid/liquid ratio. The copper dissolution of 94.94% was obtained with following conditions: leaching time of 120 minutes, stirring speed of 400 rpm, sulphuric acid concentration of 0.5 M, potassium dichromate concentration of 0.1 M, leaching temperature of 50°C, particle size of minus 38 ?m and solid/liquid ratio of 10 g/L. At the same leaching condition, the copper dissolution of 96.82% was obtained for 90°C.