Study of the Rheological Behavior of Phosphate Slurry and Its Derivatives Products

Abstract

The aim of this work is the elaboration and modeling of the rheological behaviors of the phosphate slurry and its derivatives products. Such as the phosphogypsum slurry and the phosphoric acid. Phosphoric acid H3PO4 is a fundamental element for the manufacture of fertilizer. In this work we focus on the study of the rheological behavior of the phosphate slurry, and the phosphogypsum slurry generated during the attack of phosphate rock by sulfuric acid H2SO4, this slurry is a mixture between crystals of calcium sulphate dihydrate CaSO4.H2O and phosphoric acid 29% in P2O5 and some impurities occurring from crude phosphate. Experiments were conducted to determine the effect of temperature on the rheology of the phosphogypsum slurry. Concerning the modeling, we try to adjust the experimental rheological behavior of the phosphate slurry, the phosphogypsum slurry and the phosphoric acid to the 4 rheological models, Casson, Bingham, Power Law and Herschel-Bulkley, to identify the most suitable theoretical model for the description of the rheological behavior for these materials. The adjustment of theoretical models to experimental rheological data allows us to predict the viscosity and yield stress of phosphate slurry, phosphogypsum slurry and phosphoric acid.