Scientists from the Federal Institute for Materials Research and Testing of the Rhenish-Westphalian Technical University Aachen (RWTU) and Fraunhofer Institute for Surface Engineering and Thin Films (IST) have carried out the first industrial pilot project on iron production with the use of hydrogen. In the course of trials they converted more than 80 tons of Australian iron ore into direct reduced iron (DRI) in the electrically-operated rotary hydrogen furnace.
The rotary furnace built specifically for this project on the Oschivelo site in Namibia uses hydrogen as reducing substance to remove oxygen from the iron ore.
The furnace is a horizontal or inclined rotary cylinder to which the ore and hydrogen are fed. The gas in the cylinder is heated to very high temperatures. While this occurs, the cylinder itself is rotating thus providing the ore mixing and uniform contact with hydrogen. During hydrogen heating water is released which is then removed from the furnace.
It is essentially important that the researchers managed to use the ore with reduced iron content – about 56%. Earlier it was believed that ‘green’ metallurgy should only use high quality raw materials with iron content about 70%. Therefore, the new technology extends the available resource base and reduces the requirements for the initial raw material.
The trials took place on the installation belonging to HyIron Green Technologies in Namibia. The iron ore was supplied by Fortescue, while the development and construction of the hydrogen rotary furnace were conducted by TS Elino GmbH. Iron received is to be sent to Germany to assess the possibilities of its use in steel production, including automotive industry.
Practical significance of such developments goes far beyond the boundaries of metallurgy. In the European Union, requirements for the reduction of the carbon footprint become part of the industrial policy: when discussing the easing of restrictions on the sale of automobiles fitted with the internal combustion engines in the post-2035 period one of the key conditions now is the use of climatically neutral fuels and materials, including steel with minimal carbon footprint.
