Content area
Abstract
A systematic investigation has been carried out to determine the effects of temperature, reduction/oxidation time, and partial pressure of hydrogen on the extent of the oxygen and sulfur removal during basic nickel carbonate (BNC) processing under laboratory conditions. It has been shown that increasing the temperature and reduction time increases the extent of oxygen and sulfur removal. Decreasing the hydrogen partial pressure tenfold lowers the extent of oxygen removal and results in the formation of residual NiO (incomplete reduction). The microstructure characteristics of industrial plant samples are correlated with the results obtained from the laboratory studies to identify the underlying elementary reactions and phenomena occurring and to understand the mechanisms of formation of the residual NiO in the final nickel product during industrial processing. As a result of these studies, it is recommended that the actual process is carried out at temperatures below 600 °C to avoid the formation of this residual NiO. [PUBLICATION ABSTRACT]