Experimental Study of Gaseous Fuel Injection Method for Controlling Heat Pattern of Melting Zone in Iron Ore Sintering

In recent years, seeking for green and clean alternative fuels has become an urgent issue in the iron and steel industry as a countermeasure against global warming. However, it is widely reported that sinter strength would be weakened due to the damaged heat condition at high replacement ratio of biomass. In this paper, the gaseous fuel injection method was experimentally investigated with the aim at solving this problem. Methane concentrations of 0.0% and 0.5% are tested, keeping the total calorific heat input unchanged. A newly generated secondary combustion zone in the upstream was used to control the heat pattern of melting zone. The eight thermocouples data indicated that duration time of melting temperature increased by employing the methane injection method. With the rise of methane injection concentration, the oxygen concentration in the waste gas increased, indicating the improvement of combustion condition. Experimental results showed that it was promising to strengthen the heat pattern in sintering bed at high charcoal proportion with the secondary fuel injection method. The recommended methane injection concentration was 0.4%~0.5% in iron-ore sintering process.