Use of Phytic Acid for the Removal of Iron in Hot Acidic Leachate from Zinc Hydrometallurgy

• Published in: JOM (1989) Vol. 73; no. 6; pp. 1652 - 1660
• Main Authors: Comel, Julien, Meux, Eric, Leclerc, Nathalie, Diliberto, Sebastien, Pierrat, Philippe, Muhr, Herve
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2021; Springer Nature B.V; Springer Verlag (Germany)
• Subjects: Advances in Process Metallurgy; Calcines; Catalysis; Caustic soda; Cereals; Chemical Sciences; Chemistry/Food Science; Design of experiments; Earth Sciences; Economic impact; Engineering; Environment; Environmental impact; Hematite; Hydrometallurgy; Impact analysis; Iron; Jarosite process; Laboratories; Leachates; Leaching; Organic chemistry; Physics; Phytic acid; Residues; Scientific imaging; Sulfuric acid; Zinc
• ISSN: 1047-4838; 1543-1851
• DOI: 10.1007/s11837-021-04640-y

In zinc hydrometallurgy, hot-acidic leaching of calcines leads to Fe/Zn solutions in sulfuric acid medium. Three distinct processes have been previously developed to remove iron: jarosite, goethite and hematite. Each process displays their own drawbacks: important loss of zinc (jarosite, goethite), significant environmental impact of residue (jarosite) or economic cost (hematite). The work reported herein investigated the possibility of using phytic acid, a compound extractable from cereals, to remove iron. Precipitation was studied first at the laboratory-scale using DOE methodology and then with a laboratory pilot. At pH = 2.1, we showed that it is possible to remove up to 99.5% of iron with a loss of zinc equal to 0.6% and a residual concentration of Fe III of 130 mg L −1 . Even if the amount of residue is more important than in the jarosite process, leaching tests showed that iron phytate could be stored in less drastic conditions than jarosite.