| Energy and reductant supply:
Less use of fossil-based heating and fossil reductants since they
are the main cause of the massive greenhouse gas emissions in the
metallurgical sector; transition to carbon-free reductants; efficiency
improvement |
| Feedstock types: Improved
methods for the use of scrap instead of/mixed with ores as feedstock;
fluidized bed reactor with power oxides instead of sintered pellets;
use of low-purity feedstock types |
| By-products: Less production
of dust, fume and off-gas: less use of sulfuric acid, arsenic fumes,
NOx, dioxin, CO2
|
| Hazardous by-products:
Several
purification processes create by-products containing arsenic, cadmium,
mercury, lead and zinc; loss of valuable resources; one method’s
waste is another method’s feedstock |
| Non-fossil reductants: Changes
in free energy balance upon change in chemical composition of reactants;
competition in reaction for use of mixed reductants (e.g., use of
methane and hydrogen) |
| Mineral feedstock: Energy
balance for low-grade, chemically less pure mineral feedstock (example:
reduction of banded Fe-Si-oxides); transport coefficients as a function
of chemical composition of reactants; mobility of reactants in high-component
oxides and sulfides; nucleation mechanisms in phase transformations
under redox conditions; transport vs nucleation limitation |
| Thermodynamics of slag:
Equilibrium relations between melt and slag |
| Elemental partitioning coefficients:
Partitioning between melt, slag and reductant atmosphere, i.e. which
elements partition into slag, vapor and melt |
| Modeling: Scale bridging
modeling of direct reduction (shaft reactor and fluid bed reactor)
and plasma-based reduction; multiphysics models that account not only
for the chemical reactions but also for mechanics, transport limitations
and defects |
| Kinetics: Diffusion mechanisms
during oxidation and reduction |
| Impurities: Influence of
gangue-, scrap-, reductant- or process-related tramp elements on kinetics |
| Artificial intelligence:
Machine learning and text mining in pyrometallurgy method development |
