Oxidation kinetics of molten copper sulphide

Abdelmonem H. Alyaser
The oxidation kinetics of molten copper sulphide were investigated by quantitative measurements and qualitative observations. Off-gas analyses for SO2 and 02 were conducted to determine the oxidation rates of approximately 200-gram samples, ofmolten 99.5% Cu2S. The molten sulphide was held in alumina crucibles (approximately 44 mm diameter and 75 mm height), and top-lanced with Ar-02 gas mixtures in the hotzone of a vertical tube furnace. During the oxidation reaction, gravimetric measurements
more » ... etric measurements of the copper sulphide baths were also conducted to further support the results of the gas analysis measurements. A series of laboratory tests, involving reaction gas ranging in composition from 20-78% 02, was conducted to determine the effect of oxygen concentration on the kinetics of the oxidation reaction. To determine the influence of volumetric gas flow rate on the kinetics of the oxidation reaction and to study the gas phase mass transfer, a series of laboratory tests was carried out utilizing a gas flow rate range of 1-4 liters/min. The effects of other operating conditions, on the oxidation rates, such as bath mixing, and reaction temperature (1200-1300 °C), were also determined. The effect of surface-tension driven flow (the Marangoni effect) on the reaction kinetics was also investigated via surface observation and photography. The overall surface behavior was monitored for spontaneous motion, and the eruption of gas bubbles from the melt.The quantitative analysis of reaction rates was also aided by the micro-examination of quenched bath samples via optical microscopy. Approximately 4-gram samples were extracted at specific reaction times, using U-shaped quartz tubes. The samples were examined microscopically to determine the reaction progress based on the characteristics of gas bubbles, copper droplets and the phases present. The oxidation reaction of molten copper sulphide was found to take place in two distinct kinetic stages. During the primary stage, simultaneous partial desulphurization andoxygen saturation [...]
doi:10.14288/1.0078455 fatcat:ntrkp4ygufbhtinmatxh7eh2xe