Production of DRI with Coke Oven Gas as Reductant Jul05

Production of DRI with Coke Oven Gas as Reductant...

Production of DRI with Coke Oven Gas as Reductant  Direct reduced iron (DRI) is technically defined as iron ore which has been reduced to metal without melting it. A DRI production process is one in which the solid metallic iron is obtained directly from solid iron ore without subjecting the ore or the metal to fusion. Major DRI production processes are either gas based or coal based. Feed material in a DRI process is either iron ore sized to 10 to 30 mm or iron ore pellets produced in an iron ore pellet plant. In the gas based plant the reactor, where the reduction reaction takes place, is a shaft furnace.  The shaft furnace works on counter current principle where the iron bearing feed material moves downward in the furnace by gravity and gets reduced by the up flowing reducing gases. In a gas based process gaseous fuels are used. These fuels should be able to reform or crack to produce a mixture of H2 (hydrogen) and CO (carbon monoxide) gas. High methane containing natural gas is the most commonly used gas. Natural gas is reformed to enrich with H2 and CO mixture and this enriched and reformed gas mixture is preheated. Coke oven gas (COG) is a byproduct of the coke making process in byproduct coke oven battery. COG consists of a complex mixture of various gases. Its composition typically consists of 55 % H2, 6 % CO, 25 % CH4 (methane), plus small percentages of CO2 (Carbon dioxide), H2O (moisture), heavy tars, volatile hydrocarbons and sulphur impurities. It also contains some N2 (nitrogen). COG is typically used as fuel gas for various heating applications within the steel plant, and surplus COG is used to produce steam, electrical power or is flared. Use...