Recovering copper and copper chemicals from spent alkaline etchant

As the demand for printed wiring boards in electronic components has increased, the amount of spent-alkaline etchant as an industrial waste has also increased. This article provides a brief review of the methods employed at Meltex for recovering copper and chemicals from alkaline etchant. T. Kawashima earned his B.S. in chemistry from Waseda University, Tokyo in 1955. He is currently president and representative director of Meltex.