Tech could reduce iron ore grade needed for DRI: IEEFA

New technologies could enable the usage of poorer quality iron ores in low-carbon steelmaking, according to the Institute for Energy Economics and Financial Analysis (IEEFA).

Direct reduced iron (DRI)-based production is seen as one of the main technologies for cutting carbon emissions in the steelmaking process, and it is proven — DRI currently accounts for around 5pc of global steel production, according to consultancy McKinsey. DRI is also easier to convert to hydrogen or to retrofit with carbon capture, utilisation and storage technologies, than other methods.

However, existing DRI production requires low-impurity iron ore with an Fe content of 67pc or above. For this reason, leading iron ore mining firm BHP suggests most of the world's steel will still be produced in blast furnaces in 2050, as there is insufficient high-grade iron ore to allow the expansion of DRI-based output to sate global steel demand. DR-grades account for just 4pc of global iron ore exports, according to the IEEFA.

But some companies are examining new technologies that can enable use of lower-grade ores in DRI production. German producer Thyssenkrupp is planning to install a submerged arc furnace (SAF) that melts DRI produced material, before sending it to an existing basic oxygen furnace (BOF). The BOF can handle material with more impurities than an electric arc furnace, allowing the company to use blast furnace grade iron ore in its DRI modules. ArcelorMittal is also examining the use of SAF technology to decarbonise its Dunkirk works in France, where it intends to use hydrogen as the reductant.

Another technology that enables the use of more abundantly available iron ore fines in the DRI process is hydrogen-based fluidised bed reduction, according to the IEEFA. Here, fines can be reduced in a series of reactors to produce iron without any pelletising or agglomeration, meaning it is cost-competitive versus DRI production fed with more expensive pellets.

Among others, South Korea's Posco is examining the use of this through its HyREX initiative.

Such technologies challenge the idea that a lack of DR-grade ores will limit the transition from blast furnace production to DRI, the IEEFA said.

By Colin Richardson