Study of Gas Fuel or Liquid Fuel Injection Technology in Iron Ore Sintering Process

Traditionally, solid-fuel such as coke or anthracite has been used in the sintering process in the past. Solid-fuel is mixed with iron ores and limestone, after that its combustion heat promotes sinter reaction. As the quality of sintered ore can be ascribed to the mineral structure and constituents, the heat control in the sintering bed is a significant technique to yield the high quality sintered ore. Temperature control in the sintering bed was studied for ordinary sintering method with solid-fuel. For example, the high mixing ratio of solid –fuel increases the temperature in the sintering bed, and the size of fuel can control solid-fuel segregation in the bed height direction. On the other hand, JFE Steel Corporation has studied the new heat control technique by gas-fuel or liquid-fuel with different combustion behavior from solid-fuel. As the results, JFE Steel Corporation developed a new technology for injection of hydrocarbon gas fuel in sintering machines, gSuper-SINTER (Secondary-fuel Injection Technology for Energy Reduction)h. It was successfully applied to several commercial sinter plants for the first time in the world. With gSuper-SINTERh technology, it is possible to extend the optimum temperature zone by injecting a hydrocarbon gas fuel from the upper side of the charged raw materials as a partial substitute for coke breeze. As a result, the energy efficiency of the sintering process was greatly improved, and it has been achieved to reduce a significant amount of CO2 emissions.