The last stage between 950 C and 1300 C can be attributed to the reactive carbon in the composite SiO2/C, which is oxidized faster in higher temperatures with weight loss of 10 wt%. SiO2/C composite synthesis using electric power, have reported the oxidation of carbon at lower temperatures (400–700 C) and also with higher mass loss (29–37 wt%) (Pang et al., 2005; Yokoi et al., 2009; Wang et al., 2008).