... .Low permeability 4.Meets the ASTM C-1240 Silicon Micro-Powder Microsilica , also called silica fume or micro silica, is a ... , such as concrete, grouts, and mortars as well as elastomeric, polymer, refractory, ceramic and rubber applications.HS No.: 28112200 China Origin ... feedback service to ensure the service is good. Silicon Micro-Powder