Low Energy Mesoporous Silica Recovery from a Nigerian Kaolinite Ore for Industrial Value Additions

The increasing industrial demands for mesoporous silica warrant the continuous development of less energy intensive, cheaper, and eco-friendly technologies. Mesoporous silica from an indigenous kaolinite ore was synthesized by hydrochloric acid dissolution. Experimental reaction parameters were optimized to maximize silica recovery and the solid product was characterized using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET) Nitrogen adsorption–desorption measurements. The dissolution data show the rate of reaction increase with increasing concentration temperature but with decreasing solid-to-liquid ratio. The Avrami model proved most suitable model for describing the leaching process with Avrami parameter n value of 0.8 and calculated apparent activation energy of 7.22 kJ/mol suggested a diffusion controlling rate mechanism. The mesoporous product as characterized gave a pore size of 3.67 nm at the maximum probability and possessed suitable morphological applications as additive in polymers and catalysis.