Micro silica, also known as silica fume, is an ultrafine powder produced as a by-product during the manufacturing of silicon and ferrosilicon alloys. It is primarily used as a pozzolanic material in high-performance concrete, enhancing its durability and strength. When added to concrete, micro silica fills gaps in the wet mixture and chemically reacts with Portland cement, resulting in a hardened, compact concrete with improved strength and durability. The production of micro silica involves heating high-purity quartz and coal to over 2000°C, consuming significant electrical power. Micro silica's applications in concrete include increasing corrosion resistance, sulphate resistance, and abrasion resistance, as well as reducing heat generation and permeability. Despite its higher cost and potential for increased shrinkage and reduced workability, micro silica contributes to sustainable building development by improving concrete properties and reducing environmental impact.