Hydrometallurgical processing of Brazilian iron ore tailings for the synthesis of pigments

Abstract

The aim of this study was to investigate the synthesis of iron oxide pigments from IOT. The sample of IOT was obtained through mining activity of the Quadrilátero Ferrífero in the state of Minas Gerais, Brazil. The procedure was carried out by hot acid leaching with hydrochloric acid (HCl) which allowed the recovery of about 95% of the iron in a liquor. The iron-based pigments— red (IBP_R), black (IBP_B), and yellow (IBP_Y)—were synthetised from the liquor by selective precipitation, crystallisation, and thermal procedures. The pigments were characterised by particle size distribution, mineral and chemical compositions, as well as colourimetric properties. The process of synthesis was successful and the procedure was shown to maximise the utilisation of mineral resources and minimise the environmental, social, and economic impacts associated with IOT disposal.