Showing papers by "Peter C. Hayes published in 1991"

The kinetics of S35 exchange between SO2/CO/CO2 gas mixtures and copper sulfide melts at 1523 K

Abstract: The kinetics and mechanisms of oxidation of copper sulfide melts have been investigated using a radioisotope exchange technique. Copper sulfide melts were doped with S35. The transfer of the radioisotope between the melt and SO2/CO/CO2 gas mixtures in chemical equilibrium with the melt was monitored by analyzing the changes in radioactivity of the gas. Analysis of the results indicates that the rate-limiting chemical reaction involves the formation of an activated complex SO, and the rate of exchange of the sulfur isotope at 1523 K is described by the relationshipR = 6.4(±2) (P CO /P CO2 )P SO2 g atom S m−2 s−1.

A review of the mechanisms of decomposition of solids and their relevance to extractive metallurgical processes

Abstract: This review examines the progress which has been made in understanding the chemical reactions and the microstructural changes which occur during the decomposition of solids. A number of common product morphologies are described, and the relationships between reaction mechanisms, the product microstructures and kinetics are explained. From the analysis of a number of systems it is argued that changes in product morphology take place when changes occur in the relative rates of the chemical reactions and mass transport processes on or in the product or original solids. The factors affecting these transitions and ways of control ling product microstructure are discussed.