Effect of microwave irradiation on the aspect ratio of treated mica

Abstract

Muscovite mica is a plate-like mineral composed of potassium and aluminum silicate. The mica morphology, characterised by aspect ratio, allows this mineral to be used as structural filler in plastics, adding rigidity and dimensional stability. In this study, two chemical leaching experiments were designed to examine their effect on mica aspect ratio. After chemical treatment, the mica underwent microwave irradiation and grinding. After leaching with concentrated HCl, the aspect ratio of mica was examined with and without microwave irradiation. In a separate experiment, the aspect ratio of mica was examined after leaching with lithium nitrate, with and without microwave irradiation. The aspect ratio of the mica was calculated by dividing the average particle size (d50) of the ground mica by the average mica plate thickness. Average particle size was determined using laser diffraction, while average plate thickness was determined using SEM imagery. The HCl treatment-microwave irradiation did not increase the aspect ratio of the mica plates. However, the lithium nitrate treatment-microwave irradiation resulted in mica plates with a higher aspect ratio than lithium nitrate treatment alone