Primetals develops technology for carbon-free direct reduction for iron ore fines

Primetals Technologies has developed the world´s first direct reduction process for iron ore concentrates from ore beneficiation not requiring any preprocessing like sintering or pelletizing. Primetals can resort to the comprehensive experience from the earlier Finmet development and plant installations. The new technology can be applied to all types of beneficiated ore and particle sizes of 100% smaller than 0.15 mm. As primary reduction agent, the new process uses H2 from renewable energy or alternatively H2 rich gases from conventional steam reformers or H2 rich waste gases. This results in a low or even a zero CO2 footprint. The direct reduction plant comes in a modular design with a rated capacity of 250,000 tons per year and module, making it available for all sizes of steel plants. A pilot plant for testing purposes will be set up at voestalpine Stahl Donawitz, Austria and is due to be commissioned in the second quarter of 2020.

The use of DRI/HBI is expected to continue to grow due to the need to reduce greenhouse gas emissions and the growing number of electric arc furnaces in service worldwide. Currently, all available technologies require agglomeration, like pelletizing to produce DRI or HBI. An additional challenge steel producers face, is the reduced quality of iron ore, resulting in the need to beneficiate the iron ores. In order to progress to a CO2-free steel production, a process using mainly H2 is most desirable. The solution developed by Primetals Technologies takes care of all the above considerations.

The pilot plant will consist of three parts: a preheating-oxidation unit, a gas treatment plant and the actual reduction unit. In the preheating-oxidation unit, fine ore concentrate is heated to approx. 900 °C and fed to the reduction unit. The reduction gas H2 is supplied over the fence from a gas supplier. A waste heat recovery system from the off-gas ensures optimal energy use and a dry dedusting system takes care of dust emissions from the processes involved. The hot direct reduced iron (HDRI) leaves the reduction unit at a temperature of approx. 600 °C, which can be subsequently used in an electric arc furnace or to produce Hot Briquetted Iron. The aim of the pilot plant is to verify the break-through process and to serve as a testing facility to provide the data basis for setting up an industrial scale size plant at a later date.