Selective dissolution of copper and iron from molybdenite concentrate using acidic sodium nitrate solution

In this study, the selective dissolution of copper and iron from the molybdenite (MoS2) concentrate consisting of chalcopyrite and pyrite by acidic sodium nitrate leaching has been investigated to improve the quality of molybdenite. The influence of various leaching parameters, namely sodium nitrate (NaNO3) and sulfuric acid (H2SO4) concentration, temperature, contact time, and solid: liquid phase ratio, was examined on the dissolution of copper (Cu) and iron (Fe) from the concentrate. Under the optimized conditions, the extraction of Cu and Fe can achieve 81.4% and 74.1%, respectively, along with a minor amount of molybdenum (Mo) loss in the solution from the concentrate in 240 min leaching. The kinetic study indicated that the impurities removal process was controlled by a mixed mechanism with a corresponding activation energy of 35.77 kJ/mol at the temperature range of 70-97 ?. The XRD and SEM-EDS analysis of the solid residues from the leaching revealed the insolubility of molybdenite in the leaching media. As a result, the molybdenite grade reached 90.73 wt% from an initial value of 81.33 wt%.

Automated summary

This study investigates the selective dissolution of copper and iron from molybdenite concentrate to improve its quality. The results show that under optimized conditions, the extraction of Cu and Fe can achieve 81.4% and 74.1% respectively, with a minor loss of molybdenum.