The Production of Biogenic Silica from Different South African Agricultural Residues through a Thermo-Chemical Treatment Method

A thermo-chemical treatment method was used to produce biogenic amorphous silica from South African sugarcane and maize residues. Different fractions of (leaves, pith, fiber) were processed for production. The biomass samples leached with either 7 wt% citric acid or sulfuric at 353 K 2 h prior being rinsed, dried combusted using a four-step program ranging room temperature 873 in furnace. characterization the pre-treated conducted thermogravimetric analysis (TG/DTA), X-ray fluorescence (XRF) elemental (CHN), while final products characterized by XRF, diffraction (XRD), analysis, nitrogen physisorption scanning electron microscopy (SEM). Citric pre-treatment proved be an attractive alternative mineral acids. Amorphous produced leaves good quality (0.1 residual carbon up 99.3 content). also had great textural properties such as surface area 323 m2 g−1, average pore diameter 5.0 nm, volume 0.41 cm3 g−1.