Preparation of mesoporous silica from a Nigerian talc ore by acetic acid treatment (original) (raw)

2018, Communications Faculty Of Science University of Ankara Series B Chemistry and Chemical Engineering

A study on the preparation of porous silica from a Nigerian talc ore by acetic acid leaching was investigated. The initial and leached talc products were characterized by Energy Dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive spectroscopy (EDS) and the N2 adsorption techniques. The influence of acetic acid concentration, reaction temperature and particle size on the ore leaching kinetics were examined. The results of the dissolution rates were found to be significantly influenced by leachant concentration, temperature and decreasing particle size. The dissolution mechanism process followed the diffusion control shrinking core model with the calculated activation energy of 34.53 kJ/mol supporting the proposed mechanism. The leached product has a specific surface area increased to 2.056 m 2 /g from the initial ore surface area of 0.15 m 2 /g. At optimal leaching conditions, the pore size distribution calculated by Barret-Joyner-Halenda (BJH) method based on N2 gas isotherms showed the presence of peaks from micropores and mesopores formation, indicating the porous nature of the leached product.