Kinetics of sulfation of chalcopyrite with steam and oxygen in the presence of ferric oxide

Abstract

The kinetics of suifation of chalcopyrite with/without ferric oxide addition has been studied in the fixed bed for the temperature range 673 to 773 K in the absence of external mass transfer effects such as particle size of ore and flow rate of oxidizing gases such as steam and oxygen. The suifation reaction was observed to be topochemical. The activation energy value of 30.5 kJ/mol was found when no catalytic addition was made. The rate of suifation increases with the addition of ferric oxide. The rate constant values obtained without and with 10 pct Fe₂O₃ were 5.5 × 10³ min⁻¹ and 7.00 × 10³ min⁻¹, respectively. The activation energy value for the roasting in the presence of the catalyst was 29.2 kJ/mol under these conditions. Examination of the kinetic data indicates that the reaction occurred on the surface of the mineral particles and proceeded through the reactant and product phase boundary. The sulfated products were also characterized by metallography, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and X-ray diffractometry (XRD) studies.