Copper recycling technology from alkaline etchant

The alkaline etchant is used in large quantities for producing printed wiring boards (PWB) of electric appliances. As the demand for PWBs in electronic components has increased, the amount of spent-alkaline etchant as an industrial waste has also increased. The alkaline waste contains high concentration of ammonia and copper, and this waste treatment is very difficult. Meltex merchandises alkaline etchant for PWB manufacturing, recovers from spent solution and adjusts solution after the recovery to produce replenisher. This article provides a brief review of the methods employed at Meltex for recovering copper and chemicals from alkaline etchant.