Resource efficient metal extraction
Metallurgical industry and not the least Swedish metallurgical industry are facing a number of large challenges; to be able to produce metals with minimum emissions of greenhouse gases, ores and scrap become increasingly complex and the metal content of scrap from consumer goods changes quickly over time.
Given the above challenges for the metallurgical industry the research is organized into three different areas:
- Raw material efficiency
- Alternative reductants
- Recycling and residue utilisation
Raw material efficiency
Holistic modelling of combined scrap and ore processing. To optimize the extraction of minor components into suitable material streams, a holistic view on combined scrap and ore processing has to be developed based on fundamental thermodynamic and kinetic data included in models combining knowledge about all unit processes in the processing chain. As a first step impurity elimination in roasting operations are studied through laboratory experiments. A joint project between Ore Geology and Process Metallurgy.
Fundamental understanding of unit processes. To understand the impact of different raw materials on the unit processes a more fundamental knowledge about the behaviour of different elements in the unit processes is needed. The activity is for the moment focused on the alkali circulation in a Blast Furnace, part of an ongoing European research project.
Research within this area is mainly concerned with the use of biocoal in blast furnace ironmaking, the efficiency when introducing biocoal and the recycling of carbon containing residues and waste fractions. Several of the activities are also partly carried out within European and Swedish industry supported projects.
Flexibility in coke making. By developing methods for using e.g. biocoal, thermal coal, pet coke, etc. in the cokemaking the dependence on coking coals can be reduced. Fundamental studies are carried out in lab and pilot scale.
Improved coal combustion and efficiency of injected materials. Improved coal combustion efficiency under various BF conditions and with various new carbon containing materials is studied. The reaction kinetics are determined in lab scale, the kinetic data then used in CFD modelling giving input to modification of equipment.
Use of bio-coal for injection and in agglomerates. Large forest areas in Sweden gives possibilities to use forest residues or even stem wood to produce bio based reductants. Different types of bio coal, charcoal or torrefied, are tested in lab scale and in full scale plant trials.
The Use of waste plastic as reductant for reduction of metal oxides in slag in base metals production have been studied both in lab scale and in a full scale plant trial. A process concept on how to maximise the internal recycling of coal containing residues, e.g. blast furnace sludge, within iron- and steelmaking have been tested in full scale. Implementation is in both cases evaluated by the industry partners.
Recycling and residue utilisation
Slag utilization. Research projects are carried out to increase the utilization of both steelmaking slag and slag from base metals production. For both type of slags the research is based on the unique properties of the slags due to their mineralogical composition.