Applications of microwave energy in extractive metallurgy, a review

In the last few decades, microwave energy has been widely employed in food processing, rubber and plastics curing, and in ceramic sintering. Recently, the application of microwaves as an energy source in extractive metallurgy has received considerable attention from a number of researchers. During the period from the mid-1960s to about 1988, the majority of the research was focussed on the behaviour of materials in microwave radiation. These research activities will continue to be important, since fundamental data on the interaction of microwaves with materials are vital for the successful application of the technology. Since 1990, a number of potential applications of microwave processing have been investigated. These include: pretreatment of ores and concentrates, leaching, reduction, preheating of refractories, heating of slags and waste treatment. In this paper, the interaction of microwaves with materials of interest in extractive metallurgy are reviewed and potential applications are discussed.