Model of an iron ore sinter plant with selective waste gas recirculation

Abstract

The use of sinter influences hot metal production substantially and significantly affects an integrated steel mill's total emissions. Sintering of iron ores is an enormous energy-intensive and resources consuming process. Introducing a selective waste gas recirculation (SWGR) to the sintering process reduces the energy consumption, stack gas volume flow, and sulfur dioxide emissions of an iron sinter production. Simulating this complex process in flowsheet simulations of integrated iron and steelworks is a fast and cost-effective opportunity to validate new operation settings. The implementation of a sinter plant in gPROMS ModelBuilder®characterizes the sintering processes by three main sub-models. A burner model describes the gas combustion, a black-box model consider the main sintering processes, and a wind box model divides the total off-gas into a recycle gas and a stack gas. A specific temperature polynomial represents the temperature distribution across the wind boxes to allow detailed investigations on SWGR in complex flowsheet simulations. Implementing SWGR to the sintering process, the model shows a reduction of coke consumption, stack gas flow rate, and sulfur dioxide emissions by 11%, 27%, and 27%, respectively. In the SWGR scenario, the utilization rate of carbon monoxide increases and less coke is consumed. The chlorine emissions of the sintering process differ with and without SWGR insignificantly.