Zinc Dross Problem in Galvanising and its use to produce Electrolytic Zinc Powder

Abstract

A process based on direct electro winning of zinc containing waste, used as anodic feed material may be considered an attractive route to produce zinc powder. This investigation deals with the production of electro-lytic zinc powder from zinc dross in an alkaline medium by using it as anodic feed material. The zinc dross obtained from galvanizing plant was examined for micro-graphic and chemical analysis. It was found that mostly zinc is present in metallic state with some amount of zinc-iron locking. In an electrolytic cell, various parameters such as current density, current efficiency, voltage and concentration of electrolyte etc. have been studied It was found that at 5 amp/dm2 current density, the formation of zinc powder is possible with 1.23 kWh per kg of energy consumption. The impressed voltage was found 1.2 V with a current efficiency of 90%.