The idea of using hydrogen instead of carbon as a reducing agent for steel production dates back to the 1970s. Starting with experiments with molecular hydrogen, work was also continued with hydrogen plasma. In cooperation with the Montanuniversität Leoben and voestalpine, K1-MET has set itself the task of advancing the process for the reduction of iron ore by plasma smelting with hydrogen and argon. Currently research questions arise in the area of hydrogen utilization, electrode consumption, complete continuous operation and the substitution of the process gas argon.
- The highest possible proportion of hydrogen should serve for the ore reduction
- Cost savings by using inexpensive nitrogen instead of expensive argon to stabilize the plasma jet
- Specification of a feedstock mixture with an optimum reducibility
- Concept for continuous operation of an HPSR system instead of batch operation
- Concept for an upscaling of the hydrogen plasma smelting reduction plant to the pilot scale
With the use of thermodynamic simulations (FactSage, etc.), basic data will be created to increase the use of hydrogen. This should then be checked on a laboratory scale and later used in the integrated Miniplant.
The calculations will already consider whether cheaper process gases such as nitrogen can substitute argon, and which effects this exchange has on the process.
In addition to increasing gas utilization, it is also very important to minimize the wear of the electrode. For this purpose, different process parameters are to be tested and the optimal working point has to be found.
In the course of increasing gas utilization, it is also necessary to adapt and optimize the raw material mix. For this purpose, the input material is tested for differences in behavior during the reduction.
In order to drive the process towards an industrial application, a continuous tapping concept for the reactor is required. This has to be designed theoretically and a concept for the expansion of the integrated Miniplant has to be delivered.
With all the evaluated parameters, a basic flow sheet for the pilot plant has to be created. This will give the basics to pre-engineer a pilot plant.
It is important to determine the best degree of hydrogen utilization under various conditions and thus the minimum hydrogen consumption for the reduction of iron ores (economy and conservation of resources). In addition, the efficiency has to be increased by separating the unused hydrogen from the exhaust gas and returning it to the process.
It is also important to find the optimal process parameters to achieve the highest possible electrode durability. This could e.g. be reached with the help of alternative electrode materials.
Different variations like the use of nitrogen instead of argon, a different fine ore mix and a concept for continuous operation will make the entire process more economically attractive.
A basic flow sheet for the pilot plant including mass and energy balance can be used for the specification of production.