Evaluation of acid leaching process and calcination temperature on the silica extraction efficiency from the sustainable sources
Sami A. Ajeel, Khalid A. Sukkar, Naser Korde Zedin
Abstract
Abstract In the present work, amorphous silica (SiO 2 ) is prepared from agricultural waste (rice husks) as a sustainable source by acid leaching process followed with the calcination process. RH treated with 3N HCl, then burned at (500, 600, 700, and 800°C) for 4 hrs. The final product of silica was characterized by X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and thermogravimetric analysis (TGA). The results by XRD and XRF indicate that the obtained white powder was amorphous silica at calcination temperature less than 700°C with a purity of 96.976% but at 800°C the purity was 96.983%. SEM and visual inspection analyses show that RHA morphologies with acid pre-treatment at 700°C and 800°C surfaces of un-leached rice husk have a greater degree of roughness than those that have been leached with dilute acids.