Research and Teaching Interests
Hydrometallurgy process analysis and design, mathematical modelling, heap leaching, fluid flow and mass transfer, leaching kinetics, fixed bed processing
Current Research Work
My research has focused on two key areas. The first is fixed-bed leaching (the subject of my Ph.D. dissertation), including heap leaching of copper and gold ores, and microbial heap and dump leaching of copper sulfides and of copper concentrates supported on inert substrates (the GeoCoat ä process). The bulk of my refereed journal publications are in this area. Specific accomplishments in this area include mathematical models for heap leaching processes, (including the HeapSim simulation package, currently in use at several major mining firms), a mathematical model for rinsing reagents from spent heaps, advances in the hydrology of heap leaching, and a novel enthalpy balance model for sulfide heap leaching which has led to advances in the design and control of heaps which support extremely thermophilic microbes for the breakdown of refractory sulfides.
The second key area is the fundamentals of hydrometallurgical reactors, specifically pressure leaching autoclaves. In this field, I have developed an entirely new approach to the modeling of multistage continuous leaching reactors based on the statistical convolution principle, called the multiple convolution integral . This approach presents distinct advantages over the segregated flow and population balance methods currently in use. I have also applied this method to several reactors of industrial interest through my consulting activities, including most recently a novel combined autoclave + atmospheric leaching process for secondary copper ores which is currently being commissioned at the Sepon copper-gold mining complex in Laos at an estimated capital cost of US$190,000,000.
Most recently, my research has shifted toward process development, with the invention of a potentially important new atmospheric leaching process for the rapid and efficient recovery of copper from primary copper (chalcopyrite) concentrates, one of the most elusive and highly sought after process goals in the history of hydrometallurgy.
Refereed Journal Publications
Refereed Conference Proceedings