Corrosion – Erosion Characteristics of Rock Phosphate in the Manufacture of Wet Process Phosphoric Acid

AbstractLaboratory studies have been carried out to study the corrosion-erosion behaviour of constructional materials in the manufacture of wet process phosphoric acid. Experiments were conducted in the static and simulated premixer condition of the Nissan process based on the hemihydrate–dihydrate route. Static corrosion tests were carried out with stainless steels AISI 316L, HV–9A and Sanicro–28 in a sulphuric–p, osphoric acid mixture, and the effect of additions of hydrofluoric acid, hydrofluosilicic acid and chloride were also studied. In the second series, tests were conducted in the simulated premixer condition with HV–9A. The behaviour of imported and indigenous rock has been compared and the effect of kieselguhr was studied. The effect of the coarseness of the rock and temperature on the corrosivity of the system was also investigated.