The upgrading of iron ore for DRI production using products from seawater

The Challenge

DRI production is set to grow from 8% to 24% pf iron production by 2050 (the MRIWA green steel report 2023). To make this production economic higher grade iron ores will be required. An increasing proportion of mined iron ore in Western Australia will not be of suitable grade for DRI.

Key Findings

Use of renewable energy and reagents from seawater desalination brines to upgrade treated and leached lower grade wasted iron ores. Removing impurities effecting steel quality such as phosphorus and gangue will allow lower cost steel production. The results obtained were from this study showed that Silica and Alumina could be reduced by over 60% and Phosphorus by up to 70%. Bi products including Calcium- Alumina-Silicates produced in these trials may also assist in the economics of the process. It was also found that preheating of ores can lead to improved results and the combined processes could improve iron recoveries.

Benefits to WA

The process if commercialised will allow Western Australian ores to be increasing used for DRI production by increasing iron grades. It will produce large amounts of potable water as a bi-product which is valuable considering the iron ore resources are in the driest parts of Western Australia. Recovery of brines will greatly reduce the amount of brine for ocean disposal. The project outputs were used to progress with project M10522 which will use the findings to design a potential pilot plant for a new brine process. Funding has been approved my ARENA and MRIWA and is progressing with a commercial concept.