Abstract

HERNANDEZ HERNANDEZ, Román Ángel; LEGORRETA GARCIA, Felipe; HERNANDEZ CRUZ, Leticia Esperanza  and  MARTINEZ LUEVANOS, Antonia. Statistical Treatment of Bleaching Kaolin by Iron Removal. J. Mex. Chem. Soc [online]. 2013, vol.57, n.4, pp.261-266. ISSN 1870-249X.

Abstract In the present study, oxalic acid was used as a leaching reagent to remove iron from a kaolin mineral. Statistical analysis was conducted to determine the most influential factors in the dissolution of iron from the kaolin mineral. Our goal was ferric iron solubilization and its reduction to ferrous iron to improve the iron removal in the acid medium. Leaching experiments were conducted at atmospheric pressure. A two-level factorial design of the type 2⁴ was utilized. The dependent variable was the percentage of dissolved iron, and the dependent variables in this study were acid concentration (0.35 and 0.50 M), temperature (75 °C and 100 °C), leaching time (2 and 4 h), and pH (1.5 and 2.5). An analysis of variance revealed that the effects of the factors temperature (b), pH (d), and the combined effects of temperature and time (bc) resulted in the maximum dissolution of iron of 88% at 100 °C, giving a kaolin mineral with a whiteness index 93.50%.

Keywords : Kaolin mineral; dissolution of iron; oxalic acid; factorial design.

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