Limestone has a diversified use in today's Industrial world. As a raw material it is used in the following industries and construction projects Glass Industry: Limestone is used in the purification of molten glass. Most glass is made by fusing a mixture of silica sand and soda ash, limestone dolomite and other material. Generally very high purity (CaCO3 98.5 % or CaO 55.2) is required for this application. Iron Industry: Limestone is used to remove impurities from molten iron. Limestone or lime is used as a flux to assist melting. The lime reacts with silica and alumina impurities in the ore and forms a slag which floats on the surface of the Melt Steel Industry: Limestone is also used as a flux in the steel industry and is required to remove silica and phosphorus from pig iron. The limestone required should be of high purity with low silica (5 to 2%) and sulphur of less than 0.1%.