Today’s steel production is mainly based on blast furnace – basic oxygen furnace route (worldwide about 75% of total steel production). It is a process route, which was optimized over decades to ameliorate the consumption of input material (ore and coal), decrease energy consumption and valorise many of the byproducts and energy streams (slags, thermal energy, gases, chemical products).

This process route is also producing a large amount of the greenhouse gas CO2, whose effects on climate change are well known and acknowledged. To achieve the worldwide necessary reduction of CO2-emissions, the steel industry will leave the established route of steelmaking and will replace it by a less emissive route, H2-based direct reduction (DR) combined with electric melting furnaces. These technologies can decrease CO2 very effectively from about 1850 kg CO2/t of crude steel to almost zero. The direct reduction based on natural gas combined with an electric arc furnace is state of the art and well established outside Europe but still depending on fossil fuels. However, the upcoming use of hydrogen in the direct reduction is still a challenge.

It is essential to learn more about the DR-Process using hydrogen and the properties of the new hydrogen reduced DRI and its behaviour in melting aggregates.

Saarstahl cooperates with the BFI in EU funded project InSGeP. The slags and the slag generation are investigated in the project. It includes evaluating the reduction behaviour of different iron ore-based pellets under gas atmospheres with different amount of hydrogen. Afterwards the melting behaviour of the DRI in the electric melting furnaces will be evaluated for a better understanding of the processes, as well as the slag properties with respect to the slag valorisation options. The goal of the work is to optimize the operation of the new facilities, to integrate these processes in the existing integrated steel plant and to reduce CO2-emissions while keeping the existing high levels of efficiency and further usage and valorisation of valuable by-products (esp. slags).