Study of Solubility and Speciation of Iron Sulfates in Phosphoric Acid Milieu

Industrial phosphoric acid contains free metal impurities and / or complexed one. Moreover, each element of the chemical forms and each proportions form are still unknown. However, the total contents of each element have been known up to now. It is necessary restraining the elimination or recuperation of the species in solution, to understand their deportment and know what form they may exist. This work examin the behavior and speciation of iron sulfates ions by monitoring the kinetics reaction of the iron sulfates dissociation in the phosphoric acid in various capacities (1- 5.5 M) and by the characterization of the product precipitated by the ray X diffractions. The results obtained have allowed us to determine the equilibrium time of the dissociation reaction of iron sulfates in different phosphoric acid milieu at ambient temperature and the influence of acid content on the sulfate ions (SO42-) and iron II (Fe2+) behavior. This work allowed us to retain the following The variation of the phosphoric acid content has no significant influence on the equilibrium time of the dissociation reaction of the iron sulfates or on the precipitated product nature. The precipitated structural analysis confirms the absence of iron phosphate (Fe3 (PO4) 2) and the compound obtained is always iron sulfates (FeSO4).