Evolution of Soluble Impurities Concentrations in Industrial Phosphoric Acid during the Operations of Desupersaturation

Abstract : The desupersaturation of industrial phosphoric acid is a unit operation integrated either explicitly or implicitly in the Wet Process for Phosphoric Acid production (WPPA). This operation aims to improve the acid quality by elimination or reduction of impurities, which impair the acid quality and affect the process downstream performance. Given the importance and impact of the phosphoric acid quality and its treatment on the performance of the whole production chain, we studied the operation of desupersaturation of this acid under various conditions of temperature and residence time. This allows determination, on one hand of the concentration evolution and the nature of various mineral phases of impurities present in the solution acid, and on the other hand the determination of the optimum treatment conditions of the acid to be adopted for improving production units performances. These measures can reduce the negative impacts of impurities in terms of fouling, corrosion, abrasion and produced acid quality.