... called microsilica, silicon ash, condensed or densified silica fume, its color is grey. Silica fume is also called microsilica, silicon ash, ... the strength of high temperature and shock performance. Silica fume high-strength concrete is easily to pour, long-term keep stability ... 45umMax. 0.5%Bulk density< 700 kg/m3Silica fume can be supplied as your reuirements. Silica fume for concrete and refractory