THE KINETICS OF DISSOLUTION OF COPPER AND IRON IN AQUEOUS CUPRIC AMMINE SOLUTIONS

The dissolution rate of metallic copper plate in aqueous cupric ammine solutions was studied at 0.05-1.0 mol/l CuSO4 concentration, 0-3000 r pm rotation speed and temperatures between 10-90 degrees C. The dissol ution rate was mainly controlled by chemical reaction at the temperatu re below 30 degrees C, and by diffusion of cupric complex at temperatu res higher than 40 degrees C. It was found that the dissolution rate o f copper increases with an increase in temperature and rotation speed, while a maximum rate was observed for increasing Cu(II) concentration . The effect of different anion showed significant results on dissolut ion rate of copper and iron, and carbonate ion was found to prevent th e corrosion of iron. The selective dissolution of copper from iron scr ap was suggested.