Quantitative Leaching of Awo Mica Ore in Acetic Acid Solutions

Abstract

Mica is mined and processed throughout the world and used as functional filler in many applications, such as in joint compound, electrical insulation, and plastics. The single most important feature of mica is high aspect ratio, the ratio of width to thickness. High aspect ratio mica filler is desirable in specialty applications, such as in automotive plastics, electrical industry. Considering these applications, Awo mica was quantitatively leached using acetic acid with focus on the determination of elemental composition of the ore using XRF technique, the determination of mineralogical purity of the ore using XRD, SEM and EDS techniques, the determination of the dissolution rate using acetic acid so as to predict the optimum conditions for the beneficiation of the ore for industrial applications and lastly, to investigate the potential for developing flake muscovite deposits in Southwestern Nigeria. Various parameters like effect of leachant concentration, temperature and the particle size have been investigated. Increase in leachant concentration and temperature brings about increase in dissolution rate and decrease in particle size increases the dissolution rate. The calculated reaction order and Activation energy (Ea) was 0.9437 and 21 kJ/mol respectively. The shrinking core model employed showed diffusion-controlled mechanism as the rate determining step for the dissolution process. Detailed ore characterization, for example the XRF for the elemental analysis shows that SiO2 is the most abundant compound (58.30%). It also contains other major compound like Al203 (18.70%) with the other detected compounds found to occur in minor to trace levels (< 1%). The residual product was quantitatively characterized by XRD and SEM instrumentations.