Estudio preliminar de la síntesis de ferrita de cobalto con potencial aplicación para la oxidación catalítica de efluentes cianurados.

Abstract

Abastract.-Cobalt ferrite particles (CoFe2O4) were synthesized by the hydrothermal route with nitrate precursors and with the addition of the surfactant cetyltrimethylammonium bromide (CTAB) and they were used as catalyst for the oxidation of a cyanide solution. The influence of the reaction time, pH, calcination, and CTAB addition over the cobalt ferrite crystallinity and particle size was studied. The resultant solid was characterized by X-Ray Diffraction (XRD) which determined the successful formation of the crystalline phase of cobalt ferrite without impurities. The ideal synthesis conditions were: reaction temperature of 150 °C, a reaction time of 18 h, a pH of 10, and calcination at 350 °C for 2 h. From the Debye-Scherrer equation, an average particle size of 11.9 nm was calculated. Nitrogen physisorption analysis indicated a specific surface area of 83 m2/g for the cobalt ferrite, which meant an increase of 28% compared to the cobalt ferrite without CTAB. The catalytic test with cobalt ferrite achieved a 40% oxidation of the cyanide ion compared to the 10% oxidation attributed only to aeration, which confirmed the catalytic properties of the cobalt ferrite synthesized. Finally, it was proven that there is practically no leaching of the cobalt ferrite in the cyanide solution.