Dissolution kinetics of metallic copper with CuSO4-NaCl-HCl

A study was made on the dissolution kinetics of metallic copper flat packs using solutions of Cu(II) in a chloride medium which was obtained via reaction between copper sulfate and sodium chloride. The effect of stirring, chloride and Cu(II) concentrations, distribution of Cu(II) chlorocomplexes and temperature were investigated. The leaching data showed the reaction to be under chemical kinetics control, with an activation energy of 28 KJ/mol (7 kcal/ mol). Leaching occurred at an apparent order of -1 with respect to the total chloride concentration and an apparent first order with respect to the total copper concentration. The Cu(II) ion was the main active species based on calculation of copper species distribution and the solution kinetics may be interpreted as rate=k[Cu2+] For ratios of C-CI/C-Cu(2+) of less than about 8, a layer of CuCl(s) formed which impeded the solubilization process. (c) 2005 Elsevier B.V. All rights reserved.