Abstract

A study of leaching kinetics of djurleite (Cu1.97S) using Cu(II) solutions in a chloride medium was carried out. Copper sulfate and sodium chloride in an acid solution were reacted in order to obtain the aqueous solution medium for the study. Leaching of djurleite occurs as:Cu1.97S + 0.97Cu2+ (chlorocomplexes) → CuS + 1.94Cu+ (chlorocomplexes)Where the conditions were: copper concentration = 0.02-0.23 M, chloride concentration = 0.6-1.3 M, temperature = 20-80 °C. At room temperature, a complex solid-phase transformation with formation of intermediate Cu1.97-xS phases is observed. Different variables such as total chloride and total copper concentrations, temperature, and particle size were used for obtaining kinetic data. The concentration of cupric chlorocomplexes using thermodynamic data available in the literature was calculated. The kinetics is governed by chemical reaction control, with activation energy of 35 kJ/mol (8.4 kcal/mol). The apparent reaction orders with respect to the total Cu(II) and total Cl- were 0.23 and 0.53, respectively. © 2006 Elsevier B.V. All rights reserved.