Lime is a versatile compound. Various forms of lime are used in environmental, metallurgical, construction, and chemical/industrial applications etc. The largest single use of lime is in steel manufacturing, where it serves as a flux for removing impurities (silica, phosphorus, and sulphur) during refining of steel. The fastest growing use of lime is in environmental applications, where lime is used for treatment of flue gases, wastewater, solid waste, and drinking water.
Lime is a white crystalline solid with a melting point of 2572 deg C. It is a basic oxide and is used to react with the acidic oxides (e.g. silica) in various smelting operations. With water it makes milk of lime used for neutralizing acidic waste water. It is also being known as quick lime, lime flux, unslaked lime, and fluxing lime. Lime having some percentage of MgO (usually 2 % to 4 %) is also known as dolomitic lime. Lime is a hygroscopic material and absorbs moisture from the air. With the absorption of moisture it loses its reactivity and gets hydrated.
Calcined dolomite is also known as dolime or doloma. When dolomite is heated at a high temperature then it loses its reactivity and the product is known as burnt dolomite. Burnt dolomite is a refractory material and is used in the manufacture of basic refractories.
Various uses of lime and dolomitic lime in the steel plant include its use in the production of basic sinter, as a desulphurizing agent, as a slag forming material to remove impurities in basic oxygen furnace (BOF) and in electric arc furnace (EAF), in secondary steel making, neutralizing of waste acid liquors, and in the treatment of water. A growing use of lime is in the treatment of stack (flue) gases. Lime absorbs and neutralizes sulphur oxides of these gases.