Copper leaching from dust generated by grinding computer printed circuit boards

Abstract

The acid leaching is the most used process for recovering copper from oxidized ores, and this is characterized by being an aggressive process with environment; so in this paper the use of thiosulfate as a leaching agent for copper is proposed, because it has the fundamental characteristic of a lesser impact on environment. To determine the effect of concentration of thiosulfate and temperature on the reaction rate in the leaching of copper from milling printed circuit boards of computers, it was conducted a preliminary kinetic study using as leaching medium O₂-S₂O₃^2-, determining so that under that the following experimental conditions: [S₂O₃^2-] = 0.5M, 500 mL, 750 min^-1, P/P_O2 = 1atm, 5g sample, pH = 10, 338 K and a reaction time 10800 seconds, we obtained an order of reaction, n=0.18 and an energy of activation of Ea = 24,106 kJ·mol^- ction. We also found that under these conditions previously mentioned it was possible is leached up to 97.35% copper in solution.