Recent developments in microwave-assisted comminution
The influence of high electric field strength microwave energy on copper carbonatite ore has been elucidated. It has been shown that very short exposures times can lead to significant reductions in ore strength as determined by point load tests. Comparative drop weight tests were carried out to determine any potential change in required comminution energy for microwave-treated material. It was shown that reductions in required comminution energy of over 30% could be achieved for microwave energy inputs of less than 1 kW h t-1. Comparative specific rate of breakage grinding studies showed that significant increases in grindability could also be achieved after short microwave exposure times, changes being related to particle size. QEM*SEM liberation studies showed that the amount of locked and middling copper sulphides was reduced from 69.2% to 31.8% in the +500 μm size fraction. Conclusions are made regarding the potential future development of this technology. © 2003 Elsevier B.V. All rights reserved.