Alkali Roasting and Leaching : A Process for the Tungsten Sludge

The present study has been carried out to explore the dissolution of tungsten bearing sludge by soda roasting followed by water leaching and hydrochloric acid (HCl)leaching. Ammonia leaching is being done to the soda roasted tungsten containing product and the leached residue containing tungsten. The process consists of i) disintegration of tungsten containing powdered sludge in
a mass with sodium carbonate, thereof, the amount being substantially more than stoichiometric to the tungsten constituent, ii) leaching of roasted product with water, iii) leaching of roasted product with hydrochloric acid and water. The process is easy to be carried out and could be applied in any existing plant without requiring any additional equipment. Extensive study in detail is to be recommended.