KINETICS OF SULFATION OF CHALCOPYRITE WITH STEAM AND OXYGEN IN THE PRESENCE OF FERRIC-OXIDE

The kinetics of sulfation of chalcopyrite with/without ferric oxide ad dition 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 par ticle size of ore and flow rate of oxidizing gases such as steam and o xygen. The sulfation reaction was observed to be topochemical. The act ivation energy value of 30.5 kJ/mol was found when no catalytic additi on was made. The rate of sulfation increases with the addition of ferr ic oxide. The rate constant values obtained without and with 10 pet Fe 2O3 were 5.5 x 10(3) min(-1) and 7.00 x 10(3) min(-1), respectively. T he activation energy value for the roasting in the presence of the cat alyst was 29.2 kJ/mol under these conditions. Examination of the kinet ic data indicates that the reaction occurred on the surface of the min eral particles and proceeded through the reactant and product phase bo undary. The sulfated products were also characterized by metallography , scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS ), and X-ray diffractometry (XRD) studies.