Effect of Nonionic Surfactants on Chalcopyrite Leaching under Dump Chemical Conditions, Part 2

摘要

Nonionic surfactants were found to promote the leaching of chalcopyrite with ferric sulfate under dump chemical conditions if sufficient Fe(3+) is present. A polyoxyethylene lauryl ether was selected as the superior nonionic surfactant tested at 25 and 50 C. The addition of the surfactant increased copper leaching by 116 pct at 25 C and 1.0 pct solids and by 61 pct at 50 C and 0.5 pct solids at Fe(3+) concentrations greater than 1 g/L. At 0.10 g/L Fe(3+) and below, the addition of the surfactant produced as much as a 35 pct decrease in leaching. The tests were conducted in shaking water baths using 250 mL Erlenmeyer flasks in statistical experimental design formats. The decrease in leaching with surfactant addition at low Fe(3+) concentrations was found to be related to the chalcopyrite surface area present in the leaching system. Each of the nonionic surfactants studied was found to be heavily adsorbed by a typical chalcopyrite ore, which poses a serious barrier to the application of nonionic surfactants in an actual chalcopyrite dump.