Effect of microwave pretreatment on grinding and flotation kinetics of copper complex ore

The present work initially studies the kinetics of microwave-assisted grinding and flotation in a porphyry copper deposit. The kinetics tests were carried out on the untreated and microwave irradiated samples by varying the exposure time from 15-150 sec. Optical microscopy, energy-dispersive X-ray spectroscopy and scanning electron microscopy were used for determining the mineral liberation, particle surface properties and mineralogical analyses. Results disclosed that the ore’s breakage rate constant monotonically increased by increasing the exposure time particularly for the coarsest fraction size (400 µm) owing to the creation of thermal stress fractures alongside grain boundaries. Exceeded irradiation time (>60 sec) led to the creation of oxidized and porous surfaces along with a dramatic change of particle morphologies resulting in a substantial reduction of both chalcopyrite and pyrite’s flotation rate constants and ultimate recoveries. We concluded that MW-pretreated copper ore was ground faster than untreated one but their floatabilities were somewhat similar.