In the process of galvanizing the zinc reacts chemically with iron of ferrous sulphate Producing zinc residue.In the melting of zinc pigs its are oxidated by oxygen in the air to be zinc ash. Those waste.materials not only impair the quality of galvanizing but also spend the rare metal zinc. The mechanism of formatibn of zinc residue and ash and the practice of using those wastes to reclaim zinc and compound zinc sulphate are discribed.