Refractory Micro silica/Silica fume in refractory is a highly effective pozzolanic material. Refractory Micro silica/Silica fume Another Feature : RefractoryRefractory Micro silica/Silica fume is a very fine pozzolanic material, composed of amorphous silica produced by electric arc furnaces as a byproduct of the production of elemental silicon or ferro silicon alloys. Micro silica/Silica fume is ...