Citation:
Abstract:
The cementation of copper and cadmium by zinc powder was investigated in order to assess the influence of different parameters in the process. The results showed that the process follows a first order reaction with two stages in both systems. In the system Cu/Zn, the second stage is faster than the first while in the system Cd/Zn the second stage is slower than the first. In the system Cu/Zn, the variation on the surface area of copper cement followed a power law and a straight line was obtained by plotting –ln([Cu2+]/[Cu2+] 0 ) against t3/2, the activation energy was calculated as 16.3kJ. In the system Zn/Cd the surface area available for reaction decreased as a result of the cement agglomeration. On the experiments carried out with ions Cu2+ and Cd2+ in solution, purer copper cement was obtained when the experiments were carried out in the presence of less than stoichiometric amount of zinc powder and longer reaction times.