Investigating the effect of pyrite addition on the leaching of Sarcheshmeh copper concentrate in glycine medium

Extraction of copper from sulphidic resources by hydrometallurgical methods is one of the greatest challenges in mining industries. Glycine is a new reagent for the leaching of copper and gold minerals, which has a high potential from treating copper sulphide concentrates and applying in the industry from environmental, technical and economic point of views. The aim of this research is to investigate the effect of pyrite content on the copper leaching from the chalcopyrite concentrate in a glycine medium. Leaching experiments and electrochemical analyses were carried out on the Sarcheshmeh copper flotation concentrate. Leaching experiments were performed at the three added pyrite to the concentrate (20% and 40% pyrite addition). Results showed that by increasing pyrite to concentrate mass ratio, copper extraction was enhanced significantly, in which by increasing pyrite addition from zero to 40%, at pH of 10.5, temperature of 60 ˚C, solid content of 5%, oxygen flowrate of 1 L.min-1 glycine concentration of 0.7 M and the stirring rate of 500 rpm copper extraction was increased from 50.6% to 73.8% (after 12 hours), while dissolved iron concentration was at a low level (<0.7%). Results of electrochemical analyses by cyclic voltammetry and polarization showed that maximum and minimum anodic oxidation currents were related to the copper concentrate and pyrite samples, respectively, which had a good accordance with the leaching results. This results show the high potential of glycine reagent to extract copper from pyritic concentrates.