Physical and mineral characterisation of natural zeolites from Taiz, South-western Yemen

Abstract

Aim: To investigate the physical, minerals and geochemical composition of Taiz natural zeolites. Methodology: Each zeolite sample were assessed for its characterization via optical microscopy, X-ray Diffraction (XRD) techniques, X-ray Fluorescence Methods (XRF), Inductively Coupled Plasma- Optical Emission Spectrometry (ICP-OES) to examine their mineral composition and geochemistry properties. Further, physical properties like pH, electrical conductivity (EC), plasticity, specific surface area, water content and brightness were estimated by standard methods. Results: Natural zeolite in the studied area occurs within pyroclast of volcanic tuffs. It consists mainly of perlite and rhyolite as lenses grey to light green in color with fine granulation texture. Petrography analysis showed that the Taiz zeolites are mainly classified as clinoptilolite – heulandite and are mixed with various types of others zeolite minerals such as analcime, chabazite and mazzite. Small amounts of impurities like K-.feldspar (orthoclase) and clay mineral such as montmorillonite, kaolinite and illite were also detected. The mean ratio of SiO2:Al2O3 for representative zeolite sample from the study area ranged between of 6.34-6.98. Interpretation: Zeolites showed fairly medium to high brightness and on comparing with the commercial zeolites, Taiz zeolite showed significant industrial potential to be used as a filler in paper industry.