High powered microwave treatment of carbonate copper ore

C. Sahyoun1,*, S.W. Kingman2, N.A. Rowson1

1Department of Chemical Engineering, University of Birmingham, Edgbaston,
Birmingham B15 2TT, UK
2School of Chemical, Environmental and Mining Engineering, University of Nottingham,
University Park, Nottingham, NG7

Received 19 June 2003; accepted 15 June 2004


The effect of microwave radiation on the grindability of Palabora ore has been investigated. Significant reductions in comparative Bond work index (kWh/t) were exhibited in microwave treated samples. The results were sensitive to applied power level and the mode of application of energy. Exposure at 2.6kW in a multimode cavity was found to reduce the relative work index but the energy expended to get this change was high. Experiments were also carried out using a Sairem 15kW industrial monomode microwave unit. With a microwave exposure time of 0.28 second at 10kW, a 61.3% reduction in Bond work index was obtained, compared to 0.78kWh/t of energy expended due to microwave pretreatment, which gives a more favourable energy balance. Finally, Quantitative Evaluation of Materials using Scanning Electron Microscopy (QEM*SEM) was employed to determine if any liberation at the grain boundaries and evidence of intergranular fracture could be observed. There was evidence of an increase in liberation of copper sulphide and iron oxide in the coarser size fractions for Palabora ore.

Keywords: Microwave energy; Copper ore; Grindability; Bond work index

* Corresponding author
   E-mail : cxs010@bham.ac.uk