Speaker
Description
Fly-ash–based casting fluxes have been widely applied in ingot casting due to their advantageous physical properties such as low bulk density, good thermal insulation, and favorable flowability. However, current market and regulatory developments are increasingly challenging the availability and consistency of fly ash, creating significant impacts on flux formulation and casting performance. High carbon fly ash, formerly produced by older, less efficient coal-fired power plants, is becoming scarce as modern plants generate ash with considerably lower residual carbon contents (<5%). At the same time, political decisions and the progressing coal phase-out across Europe drastically reduce overall fly ash supply, leading to rising costs and stronger fluctuations in composition.
Compensating the missing residual carbon solely by adding pure carbon carriers affects combustion behavior, resulting in accelerated burning, increased consumption, reduced insulation, higher slag viscosity, and impaired lubrication—effects that can directly influence surface quality and inclusion pick-up behavior during casting. In addition, material segregation and transport-induced consolidation pose further risks for mixture homogeneity, emphasizing the need for adapted handling procedures.
To address these challenges, several strategic pathways are emerging. The qualification of granulated casting powders helps stabilize physical properties such as flowability and homogeneity. Moreover, semi-synthetic fluxes—which limit fly ash content and compensate chemical and physical fluctuations by targeted raw materials—provide more consistent performance. Fully synthetic fluxes, formulated without fly ash and based on controlled oxides and mineral raw materials, minimize property variations and reduce the need for frequent recipe adjustments. These approaches mirror earlier developments in continuous casting and represent robust solutions for ensuring process reliability and casting quality under changing raw material conditions.
| Speaker Company/University | INTOCAST AG |
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