Silica fume

Silica fume on the other hand, is a very fine pozzolanic, amorphous material, a by-product of the production of elemental silicon or ferrosilicon alloys in electric arc furnaces.

With the implementation of tougher environmental laws during the mid-1970s, silicon smelters began to collect the silica fume and search for its applications.

The early work done in Norway received most of the attention, since it had shown that Portland cement-based-concretes containing silica fumes had very high strengths and low porosities.

Since then the research and development of silica fume made it one of the world's most valuable and versatile admixtures for concrete and cementitious products.

[5] Silica fume is a byproduct in the carbothermic reduction of high-purity quartz with carbonaceous materials like coal, coke, wood-chips, in electric arc furnaces in the production of silicon and ferrosilicon alloys.

Silica fume can be used for a primary placement of grout as a hydraulic seal in the well bore, or secondary applications such as remedial operations including leak repairs, splits, and closing of depleted zones.