The Influence of Processed Steel Slag Additive on Brick-Making Clay

Authors

Mojca Loncnar
Acroni (Slovenia) image/svg+xml
Sara Tominc
Slovenian National Building and Civil Engineering Institute image/svg+xml
https://orcid.org/0000-0003-3956-9109
Lea Žibret
Slovenian National Building and Civil Engineering Institute image/svg+xml
Maruša Mrak
Slovenian National Building and Civil Engineering Institute image/svg+xml
Vilma Ducman
Slovenian National Building and Civil Engineering Institute image/svg+xml
DOI: https://doi.org/10.18690/um.fkkt.1.2026.5

Synopsis

As clay deposits become scarce, the brick industry is increasingly seeking additives or substitutes. This study investigates a high-plasticity clay that requires an opening agent, for which was used 10 wt.% of processed steel slag Ekominit S1. Ceramic-technological tests were performed to determine the compressive strength, density and porosity. The addition of Ekominit S1 increased the total porosity by 5% in samples fired at 950 °C, and by 4% in samples fired at 1050 °C, while the compressive strength decreased by 36% in the samples fired at 950 °C and by 38% in those fired at 1050 °C compared to the reference material. Although the mechanical properties were lower than those of the reference, the benefit is reduced shrinkage. The processed steel slag could be incorporated successfully into bricks, which would also reduce the environmental impact of this sector by using secondary products instead of virgin materials.

Author Biographies

Mojca Loncnar, Acroni (Slovenia)

Jesenice, Slovenia. E-mail: mojca.loncnar@acroni.si

Sara Tominc, Slovenian National Building and Civil Engineering Institute

Sara Tominc, PhD, is a researcher at the Department of Materials, in the Laboratory for Cements, Mortars and Ceramics, at the Slovenian National Building and Civil Engineering Institute. Her research focuses on traditional ceramics, and on the beneficial use of waste materials in the construction industry. She obtained her BSc in Chemistry and Chemical Engineering at the University of Maribor and her PhD at the Jožef Stefan Institute, where she investigated the influence of pentavalent dopants on twinning and microstructure development in SnO₂ ceramics for high-performance varistors and dielectrics. She specialises in electron microscopy, thermal analysis and waste characterisation. Recently, she has been investigating accelerated mineral carbonation, aiming to understand the mechanisms and kinetics of CO₂ sequestration and to optimise carbonation conditions.

Ljubljana, Slovenia. E-mail: sara.tominc@zag.si

Lea Žibret, Slovenian National Building and Civil Engineering Institute

Ljubljana, Slovenia. E-mail: lea.zibret@zag.si

Maruša Mrak, Slovenian National Building and Civil Engineering Institute

Ljubljana, Slovenia. E-mail: marusa.mrak@zag.si

Vilma Ducman, Slovenian National Building and Civil Engineering Institute

Ljubljana, Slovenia. E-mail: vilma.ducman@zag.si

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Volume

8th International Conference on Technologies & Business Models for Circular Economy: Conference Proceedings

Pages

54-68

Published

April 21, 2026

Series

Technologies & Business Models for Circular Economy

Categories

Copyright (c) 2026 University of Maribor

License

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

How to Cite

Loncnar, M., Tominc, S., Žibret, L., Mrak, M., & Ducman, V. (2026). The Influence of Processed Steel Slag Additive on Brick-Making Clay. In S. Potrč, M. B. Miloš Bogataj, Z. K. Zdravko Kravanja, & Z. Novak Pintarič (Eds.), & (Ed.), 8th International Conference on Technologies & Business Models for Circular Economy: Conference Proceedings (Vols. 8., pp. 54-68). University of Maribor Press. https://doi.org/10.18690/um.fkkt.1.2026.5