Continuous crystallization experiments on FeSO4 · H2O in aqueous solutions containing Zn2+ were carried out, at temperatures of 140-165°C, in a stainless steel/glass autoclave. The incorporation of Zn2+ in FeSO4 · H2O as a function of process parameters such as the temperature and the residence time was determined. Additionally, the solubility of FeSO4 · H2O in this temperature region in the presence of ZnSO4 was determined. The crystallization of FeSO4 · H2O yielded a product which contained between 2 and 3 wt% Zn2+, depending on the process conditions. The incorporation of Zn2+ was also quantified using a partition coefficient which, together with the calculated results for the supersaturation in the various experiments, revealed that the incorporation of Zn2+ in FeSO4 · H2O increased with the supersaturation, but was mainly influenced by the thermodynamic value of the partition coefficient; that is, a value equal to 0.3 at zero supersaturation. The separation of Fe2+ and Zn2+ from aqueous solutions by crystallization of FeSO4 · H2O has too low a selectivity to justify its use in an integrated hydrometallurgical jarosite treatment process.
ASJC Scopus subject areas
- Industrial and Manufacturing Engineering
- Metals and Alloys
- Materials Chemistry