Completed: Valorisation of Metallurgical Wastes through Chemically Bonded Ceramics (VMW-CBC)

In collaboration with Luxfer MEL Technologies

In a circular economy, by-products retain some value since they may feed into other production processes but feasibility of their use hinges on the availability of symbiotic manufacturing sectors as well as cost effective repurposing strategies. These do not exist for most by-products from the Foundation Industries and waste streams are often mixed.

This project explored thermal and chemical repurposing methods for magnesium-rich by-products with the aim to produce reactive magnesia for ceramics for repair applications. Optimal treatment was attained at 500 oC at which point reactive magnesia formed. Above this temperature, compounds crystallised to the less reactive, periclase MgO phase. The magnesium-rich sludge did not react upon exposure to enforced CO2, which limited the scope for cost effective chemical valorisation. The reactivity of the thermally treated MgO and the resulting mechanical properties of the ceramics were compared with a conventional raw material, referred to as burnt magnesia. Impurities in unsegregated waste streams modified the reaction and products formed but mixing with alloying oxides such as ZrO2 improved ceramic quality.

This project has therefore demonstrated the feasibility of using metallurgical wastes for ceramics for repairs and has provided valorisation protocols and identified the role of constituents from other waste-streams that may be used to enhance performance.

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Dr Sam Adu-Amankwah

Aston University (formerly University of Leeds)

s.adu-amankwah@aston.ac.uk