J. Węgrzyn Silesian University of Technology, Faculty of Materials Engineering and Metallurgy, Katowice, Poland In the process of carbothermic reaction of SiO2 + mC, key reactions appear on the surfaces of both SiO2 and C grains. However, the values of these surfaces are not known. Assuming the simplest case, quartzite and carbon grains are spheres, total surfaces of reaction were calculated fo...