A novel gas-solid suspension ironmaking process with much less energy consumption and carbon dioxide emissions than the current blast furnace technology is under development at the University of Utah. The proposed process is based on flash reduction of iron ore concentrate with a gaseous reagent, such as hydrogen, syngas and/or natural gas. This Part 3 deals with economic feasibility analysis of a commercial scale novel ironmaking process based on natural gas, the flowsheet and process simulation of which are described in Parts 1 and 2. To evaluate economic feasibility, the net present value for 15 year operation was calculated for each process, using capital and operating costs estimated from available open references. The sensitivity of the estimated net present value to the variation in item costs was also analysed.