Electrochemical aspects in some of the hydrometallurgical processes

Abstract

Hydrometallurgy deals with extraction of metal values from ore minerals through aqueous processing by solubilizing the specific metal value into the aqueous phase and subsequently taking it out of the solution. These steps may be chemical or electrochemical in nature. The electrochemical phenomena depends on the electrical properties of the solid material and the redox characteristics of the solution. The present paper discusses electrochemical aspects of some hydrometallurgical operations involving the following phenomena: (i) corrosion coupling, (ii) galvanic coupling, (iii) dissolution via cyclic action of a redox couple, (iv) displacement or cementation reaction, (v) precipitation under reducing conditions, (vi) dissolution under high pressure, and (vii) dissolution influenced by hole transfer.