Overview
Direct reduction of iron ore, particularly with green hydrogen, is a key pathway to decarbonisation of the iron and steel industry. This project aimed to document countermeasures to any adverse ferrous materials behaviour during and after direct reduction, which is critical to de-risking these technologies for use with Australian iron ores. It commenced with a review of global ferrous feedstocks, documenting literature and industry experience with DRI sticking in shaft furnace and fluidised bed processes, and the transport and handling of reduced products.
Project Details
Sticking behaviour during production of direct reduced iron (DRI) is a serious issue encountered in industrial production of DRI from various iron ore sources. Literature covering industrial experience and scientific research was reviewed. Key information on the controlling variables and potential countermeasures are summarised.
Whilst much is known about the physical and metallurgical properties of pellets prepared from magnetite concentrates, little is known about Australian pellet and lump properties during direct reduction in a shaft furnace or materials handling properties after reduction. The literature related to iron ore type, pellet production and sticking and clustering in shaft furnaces was reviewed.
In addition, the transport and handling of DRI was reviewed and the need for hot briquetted iron discussed.
Research Areas
Low-carbon iron exports from Pilbara ores / Decarbonise production of green iron products from magnetite ores
Outcomes
This project established potential root causes and elimination research options for preventing:
- sticking and clustering of pellets in shaft furnaces;
- sticking behaviour of iron ore fines in fluidised beds, and;
- transport, storage and handling issues for DRI (HBI, pellet & lump).
It showed the causes of sticking are common in both shaft and fluidised bed processes. Sticking behaviour of pellets in shaft furnaces is potentially controllable through adjustment of pellet composition, the use of inert additives and coatings, and temperature control. Similarly, the range of operating temperature and the use of various anti-sticking additives in fluidised bed DRI production were identified. It also delivered a set of research recommendations and directions for subsequent investigation in future collaborative research.
As a part of this project, engagement was established with global DRI/HBI industries such as Midrex, Tenova, Primetals, Metso-Outotec, and Calix for the industry experience with DRI sticking issue, as well as reduction behaviour of lump, pellets and fines.
Next Steps
This result has led to a new 3-year research project: Prevention of Sticking in H2 fluidised bed DRI production.
Published Scientific Papers
- Purohit S, Pownceby MI, Guiraud A. Sticking and Swelling of Iron Ore Pellets: Mechanisms and Controlling Factors. J. Sustain. Metall. 11, 67–87 (2025)
- Wang R, Purohit S, Paymooni K, Honeyands T. Sticking in Shaft Furnace and Fluidized Bed Ironmaking Processes: A Comprehensive Review Focusing on the Effect of Coating Materials. Metall Mater Trans B. 2024; 55, 2977–3006.