7TH EUROPEAN COKE AND IRONMAKING CONGRESS - ECIC 2016

JFE Steel Corporation developed a technology for injection of hydrogen-based gas fuel in sintering machines, “Super-SINTERTM (Secondary-fuel Injection Technology for Energy Reduction)”, which makes it possible to greatly reduce CO2 emissions in the sintering process, and successfully applied this technology to a commercial sinter plant for the first time in the world. In ordinary sintering process, after coke breeze is mixed with iron ore and limestone, raw materials are charged and sintered in sintering machine. To produce high strength and high reducibility sintered ore, it is necessary to keep the sintering temperature between 1,200 °C and 1,400 °C during sintering. In the temperature zone below 1,200 °C, the strength of sintered ore decreases because raw materials don’t melt enough. In the temperature zone over 1,400 °C, the strength and reducibility decrease by increasing glassy silicate. With “Super-SINTERTM” technology, it is possible to extend the period in the optimum temperature by injecting a hydrogen-based gas fuel from the upper side of the charged raw materials as a partial substitute for coke breeze. As the result, the energy efficiency of the sintering process is greatly improved, and it has been achieved to reduce CO2 emissions. Moreover, combined injection technology of hydrogen-based gas fuel and oxygen is developing as the improvement technology of Super-SINTERTM. This technology can extend the period in the optimum temperature extends longer than Super-SINTERTM and increase sintering speed by increase of combustion rate of hydrogen-based gas and coke breeze by oxygen enrichment. As the results, sinter productivity was improved greatly.