Passivation Studies using Group VIA Anions III Anodic treatment of zinc

Abstract

The behaviour of zinc in solutions of sodium chromate, molybdate and tungstate has been studied and compared using anodic polarisation techniques. The results indicate that a passivation process may be based on the optimal conditions of concentration 0·1 M, pH 9–11. Chromate solutions gave best results at 20°c while molybdates and tungstates improved with increase in temperature. The results are discussed in terms of superimposed pH-potential diagrams.