Fibre shortages and a move towards closed cycle operation have resulted in a renewed interest in polysulphide kraft pulping. Recently, a process has been developed whereby polysulphide is formed directly in the kraft mills causticizers by the addition of air or oxygen. The purpose of this work was to identify materials of construction for polysulphide enriched kraft liquors and to characterize the effect of polysulphide on existing carbon steel equipment. Weight loss arrd D.C electrochemical experiments were carried out in white, green and weak-wash liquors, with and without polysulphide. It was found that 304L and 316L stainless steels cm experience corrosion rates of ...
Kevwords: carbon steel, corrosion, kraft liquors, passivity, polysulphide pulping, stainless steel