Characterization of hybrid silicate materials based on ceramic glazes and waste London underground dust

In “London Underground” stations, a high concentration of dust particles containing organic and inorganic matter of varying chemical composition. “London underground dust” is created from train wheels and brakes grinding against steel tracks and collected in filtration systems. The experiment will focus on using “London Underground Dust” to colour the ceramic facing tiles intended for re-use in newly built London Underground stations. The phase composition, particle size distribution surface area, morphology, and thermal behavior of collected dust were studied by XRD, XRF, SEM-EDS, BET, heating microscopy, STA-MS, UV–VIS spectroscopy. The substrate tiles for glazing experiments were prepared from local London clay. The mixtures of glazes and collected or milled dust were sprayed on the substrate tile's surface, dried and finally fired at 1060 °C. The influence of used materials weight ratio and dust milling time were shown as crucial parameters to obtain optimal final glaze colour. • Novel utilization of waste “London Underground Dust” (LUD) as a source of dyes. • Comprehensive characterization of the LUD containing colouring oxides. • Optimization of glazing procedures with original and milled LUD. • Tuning the final colour of ceramic facing tiles using colorimetry analysis.