Australian iron ore miner Rio Tinto has proven the effectiveness of its low-carbon iron-making process using ores from its mines in Australia in a small-scale pilot plant in Germany, and is now planning the development of a larger-scale pilot plant to further assess its potential to help decarbonize the steel value chain. BioIron’s potential was confirmed in a comprehensive and independent technical review by Hatch, the global engineering, project management and professional services firm. Hatch noted the thorough work completed by the team and BioIron’s capacity to reduce greenhouse gas emissions while converting Pilbara iron ore into iron and steel.The BioIron process will now be tested on a larger scale, at a specially designed continuous pilot plant with a capacity of one tonne per hour. The design of the pilot plant is underway and Rio Tinto is considering suitable locations for its construction.The process, known as BioIron, uses raw biomass instead of metallurgical coal as reductant and microwave energy to convert Pilbara iron ore to metallic iron in the steelmaking process. The BioIron process works using lignocellulosic biomass including agricultural by-products (e.g. wheat straw, canola stalks, barley straw, and sugar cane bagasse) or purpose-grown crops. The biomass is blended with iron ore and heated by a combination of combusting gases released by the biomass and high-efficiency microwaves that can be powered by renewable energy. BioIron has the potential to support near-zero CO2 steel-making, and can result in net negative emissions if linked with carbon capture and storage.Over the past 18 months, the process has been tested extensively in Germany by a project team from Rio Tinto, sustainable technology company Metso Outotec, and the University of Nottingham’s Microwave Process Engineering Group. Development work was conducted in a small-scale pilot plant using batches of 1,000 golf ball-sized iron ore and biomass briquettes.