Physicochemical characteristics and industrial application of Ammacio kaolin in the southwestern central Main Ethiopian Rift

Abstract

Geological, mineralogical, and physicochemical information were used to analyze the possible industrial applications and general observations of the Ammacio kaolin occurrence, which is located southwest of the Central Main Ethiopian Rift. The principal lithologic units present in the study area are basalt, unwelded tuff, and Quaternary sediment. The parent rock for the kaolin is the unwelded tuff unit. The petrographic study of the parent rock indicates the presence of plagioclase, alkali-feldspar, and quartz phenocrysts in a fine-glassy groundmass. X-ray diffraction, Fourier transforms infrared, and scanning electron microscopy analyses suggest that the kaolin samples are made up mostly of kaolinite and quartz minerals, with traces of halloysite and feldspar. The distributions of major and selective trace elements in the parent rocks and the kaolin samples, along with the higher chemical index of alteration (CIA = 84.4%) and chemical index of weathering (CIW = 92.4%), indicate that the kaolin is formed by intense chemical weathering of the unwelded tuff. The overall mineralogical and physicochemical findings suggest that Ammacio kaolin may be employed in a variety of sectors, including in paper coating, as a filler (in the paper, rubber, plastic, and paint industries), ceramics, agriculture, pottery, brick, soap and detergent, cosmetics, fiberglass, pharmaceutical, Portland cement, and synthetic zeolites productions industries.