Carreadores de níquel no minério laterítico e sua influência no mecanismo de extração desse metal por sulfatação seletiva

Abstract

The efficiency of a hydro-pyrometallurgy route on nickel and cobalt extraction from nickel laterite ores was investigated. X-ray diffraction, scanning electron microscopy coupled to energy dispersive spectroscopy, and chemical analyses by atomic absorption spectrometry were the techniques employed to characterize ore samples, intermediate products, and solid leaching residues. Phase quantification was carried out by the Rietveld method. The highest nickel and cobalt recoveries (93.0%Ni and 91.9%Co) was achieved with the sample in which goethite was the main nickel carrier and its serpentine content was the lowest. The worst nickel and cobalt recoveries (76.1%Ni and 81.1%Co) were obtained with the sample in which its association was predominantly with silicate minerals and the amorphous phase.