Evaluación del proceso de reducción aluminotérmica de un concentrado cromífero del yacimiento Merceditas

Abstract

In many ore deposits chromium is present as complex oxides known as chromospineless which show high
chemical stability especially towards halides, affecting negatively its possible use as a chromium source in diffusive
treatments. In this work, the aluminothermy reduction of one chromite concentrate from Merceditas deposit was studied
and their products were characterized, with the objective of using it as raw material in chromizing. In order to make the
grain size analysis, two samples were prepared. First the concentrate was crushed in a ball mill and later was screened in
two sieve sets, with maximum openings of 100 and 200 μm . The mixture of the reduction products of the concentrate was
characterized, using RX difractometry and infrared spectroscopy. It was corroborated that when using treatment D (55 mm;
4 h; 950 oC), the metallic aluminum peaks disappears; the relative intensity of chromopicotite diminished and the higher
relative intensity of reflection peaks were occupied by chromium and ferrochromium. These results allow to anticipate
that the resulting compound is suitable as chromium source in diffusive treatments