-4-4255 P J F

Although it has been recognized only relatively recently that the electrowinning process could be employed for the recovery of metals from wastewaters, the basic process is well established. Electroref ining, a process closely related to electrow inning, was introduced about a hundred years ago. Today, practically a l l of the world's copper (approx. 8,000,000 metric tons/year) i s electroref ined. A1 though copper electrow inning is by far the most common, other metals such as zinc, nickel, cadium are also electrowon t o a significant extent.