Overview
The hydrogen direct reduced iron (H2DRI) process is emerging as a key technology for decarbonising steel production. While current DRI production relies on high-grade iron ore, the anticipated growth in DRI usage means that lower-grade ores, which contain more gangue (non-metallic minerals), will also need to be processed.
Existing electric arc furnace (EAF) technology struggles with high-gangue DRI, prompting the need for an intermediate solution such as electric smelting furnaces (ESFs). ESFs can separate gangue into slag while producing liquid iron for steelmaking. Additionally, the slag generated could serve as a feedstock for cement production, adding value to the process. However, the ESF route requires further evaluation to address challenges related to productivity, energy efficiency, and operational costs.
Currently, ESF technology has been commercialised for relatively low tonnages of iron production (less than 1 million tonnes per year) and the scientific basis of these processes are not well understood. For example, it is not clear how different levels of gangue (undesirable mineral matter found with iron ore) in DRI effect the rate of smelting or influence productivity gains achieved through hot feeding of the DRI.
Using advanced modelling, laboratory experiments and industrial data, this project will provide insights into the technoeconomic viability of processing Australian iron ores through the H2DRI-ESF route. The research will build on findings from HILT CRC projects RP1.004 and RP1.005 and offer recommendations for optimising ESF technology to support a sustainable steel industry in Australia.
Project Details
This project aims to de-risk ESF technology by understanding how key factors – such as gangue content ores, the physical properties of DRI, operating temperatures and carbon levels – affect productivity, energy consumption, metal quality and slag usability. It will also assess the feasibility of incorporating waste materials, such as scrap and waste oxides, into the process.
The project aims to quantify and evaluate:
- The effect of gangue content in different Australian iron ores on ESFs in terms of productivity, energy usage, metal chemistry (particularly silicon, manganese and phosphorus content) and the suitability of the slag produced as a feedstock for cement production.
- How the form of the DRI (e.g. density and shape), the level of carbon in the bath and operating temperature of the ESF affect the productivity, energy usage, and metal and slag chemistry of the process.
- How the addition of waste oxides and scrap into the ESF process affects productivity, energy usage, and metal and slag chemistry.
- The key variables associated with Australian iron ores on the technoeconomics of processing them through an H2DRI-ESF route.
HILT CRC Milestones
- 1.2 Producing green iron products from hematite/goethite ores
Research Areas
- Low-carbon iron exports from direct shipping ores
- Alternative low-carbon ironmaking
- Decarbonising production of green iron products from magnetite ores
Project Outcomes
The project will deliver:
- A comprehensive thermodynamic model of the ESF process for evaluating key energy and chemistry issues.
- A practical heat transfer model for evaluating the smelting behaviour of different forms of DRI over a range of different operating conditions in an ESF.
- A practical technoeconomic model for evaluating the performance of Australia Iron ores in the H2DRI-ESF route.
Project Benefits
- Specific information on the impact of ore quality on the performance of DRIs generated from these ores in an ESF
- Greater confidence in how the suitability or otherwise of processing these ores through a H2DRI-ESF route.
- De-risked implementation of the H2DRI-ESF route through:
- Addressing the key issues around energy, productivity, metal chemistry and the slag produced
- Thorough analysis of the key technoeconomic issues.
- Rigorous assessment of the major technical issues of ESF technology, providing support for industry in assessing investment potential.
Download the Project Summary
RP1.014 De-risking electric smelting furnaces for Australian ores