Quartz powder, silica fume, all refers to the crystalline sio2 powder, simple is that the stone broken into powder. The quartz powder is relatively coarse, below 325 mesh, the silica fume is relatively fine, more than 325 mesh. Whiteness, whiteness and hue are different because of impurities, and the purity is more than 99%.
Microsilica, a by-product of industry, is a mixture of sio2 and si. We are also called silica fume. Basically black or gray. The particle size is relatively small, and sio2 is also amorphous.
According to these essential differences, the use of these products is also not same.
Quartz powder and micro-silica powder, silicon micro-powder, mainly differ in thickness and application.
More silica fume specification: http://www.microsilica-fume.com/shop