Patricia N. Olvera Venegas, Leticia E. Hernández Cruz, Gretchen T. Lapidus, ?Dissolution of Iron from Oxides in Solutions of Citric Acid and Sodium Thiosulfate?, Advanced Materials Research, Vol. 976 (2014) pp 114-118 (2014) Trans Tech Publications, Switzerland, doi:10.4028/www.scientific.net/AMR.976.114
In this work, the dissolution of iron from a kaolinitic mineral (Veracruz, México) is compared with that from an iron ore (Michoacán, México), a specular hematite (México), a magnetite (southeastern Utah, USA) and a hematite (from Arizona, USA), using sodium thiosulfate and citric acid, as the reducing and complexing agents, respectively. The minerals were dry sieved to obtain particle sizes between-100 +250 mesh. The minerals were then characterized by X-ray diffraction (XRD), energy dispersive spectroscopy EDS and atomic absorption (AA). Leaching experiments were using 0.5 M of both reactants at temperature of 363.15 K and pH = 3; this one last parameter was controlled with ammonium hydroxide. The experimental results showed removal of dissolved iron above 99% in the kaolinitic clay and the magnetite, but only 79% for the iron ore, 46% for the hematite and 30% for the hematite, in 180 minutes.