Preliminary Study of the Effect of Stirring Rate, Temperature and Oxygen Pressure on the Leach Rate of Copper Powder, Generated by Grinding of Printed Circuit Boards of Computer

摘要

For this study, a sample of 5 g of copper powders obtained by grinding printed circuit boards of computers fixe to 50 mesh (270 μm) according Tyler series was used. This sample was wholly characterized by XRD, SEM-EDS and AAS. The leaching medium used was O_2-S_2O_3~(2-). From the evaluated variables it was obtained an apparent order of the reaction of n = 2.34 s~(-1), whereas according the effect of partial oxygen pressure it was obtained an apparent order of reaction of n = 0.9516 and the activation energy of system was of 6.5 kJ mol~(-1), the results so achieved suggest a transport control to the solid-liquid interface. Under certain work conditions such as: S_2O_3~(2-) = 0.5 M, 500 mL, 750 min~(-1), P/PO_2 = 1 atm, 338 K, 5 g of sample and 9000 s of reaction time, it is possible get up to 97.35% of leached copper.