... bulk density below 300kg/m3 Materials used in refractory widely,has high fluidity SiO2 95%min Microsilica , it's a byproduct of ... and woodchips etc..Silica fume consists primarily of amorphous (non-crystalline) silicon dioxideMicrosilica can be ... of cementation products, such as concrete, grouts, and mortars as well as elastomeric, polymer, refractory, ceramic and rubber applications. Semi bulk density ...