Decarbonising the steel industry will involve rolling out new steel processing and iron making techniques – such as feeding electric arc furnaces with either direct reduced iron (DRI) or recycled steel – as well as significantly increasing the efficiency of traditional blast furnace and basic oxygen furnace (BF-BOF) processes.
As part of a decarbonisation memorandum of understanding (MoU) with one of our high-efficiency-BF customers, we are exploring the potential to produce and use Kumba Iron Ore’s DR Lump as a suitable direct charge for a high-efficiency BF operation. Studies show that replacing typical mainstream lump with 10% DR Lump could reduce greenhouse gas intensity by 11 kg of CO2/tonne of steel.
To assess the feasibility of realising these emissions reductions, we are running a project that comprises three sets of activities:–
- Producing DR Lump: a direct reduction screening (DRS) plant at Sishen is located between the Quaternary Screening Plant and the lump ore load-out stations at our Dense Media Separation (DMS) plant. A chute diverts Premium Lump from the final product stockyard, conveys the lump ore onto the DRS feeding conveyor, and feeds this into the screen plant, where DR Lump is produced by narrowing down its size from -31.5+6.3 mm to -20+8 mm.
- DR Lump laboratory characterisation: we have completed laboratory characterisations that confirmed that Kumba’s DR Lump is a good feed for a high-efficiency BF operation. This is due to various characteristics: the smaller, even particle size helped improve the ore’s reducibility; the narrow size distribution and uniform particle size increased burden permeability and BF operational stability; the high physical strength reduced fines generation at handling; and the high shock resistance and low disintegration reduced fines generation inside the blast furnace.
- DR Lump blast furnace plant trial: we tested the use of the Kumba’s DR Lump in a trial carried out at two large blast furnaces, where we evaluated key metrics, including lump reducibility, solid fuel consumption (coke rate) and gas permeability. The trial confirmed the laboratory characterisations and concluded that Kumba’s DR Lump is a good direct charge for high-efficiency BF operations.
We will also be testing the use of Kumba’s DR Lump in a DRI pilot furnace.
