Recovery of Zinc from Zinc Ash

Abstract

The ever increasing need of zinc as a coating material on steels has compelled the galvanizers to have a rclook on the economic and effective use of this material. The annual world wide consumption of zinc for hot Clip galv-anizing is around 600000t. The effective utilisation of zinc in different galvanizing plant throughout the world averages 78% but in our plant it comes to 58% only. The world average of zinc loss as zinc ash is 3% in hot dip galvanizing while at Tata Steel zinc loss is about 14 - 16% (shown in Fig. 1). Of late, increased attention is being paid the world over for the recovery of scarce material from industrial waste. Particularly in India, it has drawn a great deal of importance as the country at present is not self sufficient in the production of zinc and has to import a substantial amount every year