Comportamiento de óxihidroxidos de hierro en soluciones que contienen acidos tánico y fosfórico

A study of the action of tannic and phosphoric acids and its mixture on lepidocrocite, akaganeite, magnetic goethite and superparamagnetic goethite is presented. To 500 mg of each oxyhydroxide were added 20 mL of each one of the acids and they were allowed to react spontaneously during one day and one month. The synthesized samples and the products of the reaction were characterized by means of Mossbauer spectroscopy at room temperature, X-ray diffraction and infrared spectroscopy. Among the iron oxyhydroxides, magnetic goethite exhibited the greatest resistance to the action of the acids, whereas superparamagnetic goethite and lepidocrocite were the phases which more reaction exhibited.