Production of silica fume
Microsilica powder or silica fume is a gray powder that is a byproduct of electric arc furnaces during the production of ferrosilicon alloys. Microsilica powder or silica fume contains 94 to 96% silicon dioxide. size of microsilica powder is in the range of 0.05 to 0.15 microns and compared to cement particles, it is 100 times finer and softer. Silica has a very high reactive level due to its fine grain.
Microsilica powder or silica fume is added to concrete to increase some properties and characteristics of concrete. The addition of microsilica powder or silica fume to the concrete mixture causes the reaction of silicon dioxide with the free calcium hydroxide solution in the pores of the concrete and in this way produces insoluble calcium silicate crystals and finally causes the compaction of the cement paste structure and ultimately increases the compressive strength of concrete. Microsilica powder will increase the density of concrete and also increase the adhesion quality of concrete components. Microsilica powder will increase the erosion resistance of concrete and also reduce the alkaline reaction potential of aggregates, and hence the life of concrete will also increase.