CORRELATION OF NICKEL EXTRACTION WITH IRON REDUCTION IN OXIDIC NICKELORE BY A THERMOGRAVIMETRIC METHOD

The reduction roasting of chromite overburden with CO/CO2/N-2 gas mixt ure in the temperature range 700-750 degrees C has been shown to resul t in the formation of metallic nickel and different lower valence stat es of iron, viz: magnetite, wustite and metallic iron. The reduced cal cine was cooled to room temperature under an inert atmosphere and leac hed with ammonia-ammonium carbonate solution to bring the metallic nic kel into soluble form. This paper reports the results from estimation, by thermogravimetric (TG) and chemical methods, of the percentage iro n reduced to lower oxide stages such as magnetite and wustite in the c alcine under different experimental conditions. Further, the percentag e extraction of nickel is correlated with iron reduction.y