Electrogenerated Gas Bubbles in Flotation

Abstract

Electrolytic gas evolution plays a very significant part in a number of electrochemical processes. In the electrowinning of metals the evolution of gases at the electrodes is a very important phenonenon. Gas evolution is common in chlorine and water electrolysis and in a number of other processes. Electro-generated gas bubbles have been used in the treatment of waste water and considerable amount of work has been done on the electroflotation of mineral fines which are unsuited for treatment by conventional flotation techniques. The physical process of gas evolution viz nucleation, growth and detachment are discussed. The dynamic process of electrogeneration of gas bubbles as affected by the interaction amongst a large number of process variables has been dealt with in detail. Flotation of mineral fines as affected by the size and charge of the bubbles is also discussed.