Mining waste provides strong boost to concrete construction

Flinders University researchers are turning mining waste into a powerful tool for sustainable construction — proving that superior construction materials can be developed from unlikely sources.

Dr Aliakbar Gholampour from Flinders University’s College of Science and Engineering has uncovered promising applications for a rare earth by-product in concrete production.

The study focuses on Delithiated β-spodumene (DβS), a by-product of lithium refining, which exhibits pozzolanic properties — meaning it reacts chemically to enhance the strength and durability of concrete. The research shows that when used in geopolymer binders, DβS can improve mechanical performance and long-term resilience.

“By examining the microstructural behaviour of DβS-based geopolymers under varying alkaline activator ratios, we’ve gained critical insights into its suitability as a sustainable concrete ingredient,” Gholampour said.

Conventional concrete is the most widely used and made construction material, with 25 billion tonnes used every year — but it consumes about 30% of non-renewable natural resources, emitting about 8% of atmospheric greenhouse gases and comprising up to 50% of landfill.

The findings of the new studies by Gholampour and his team provide insight into the effective incorporation of DβS as an alternative ingredient to fly ash (a coal combustion by-product) in the creation of geopolymer binders. It also identifies the optimal alkaline ratio range for use in geopolymer.

“This approach not only enhances mechanical properties and durability of geopolymer concrete, but also addresses a growing environmental concern by diverting DβS from landfill,” Gholampour said. “With lithium refining responsible for generating increased volumes of DβS, the capability to reuse this in construction offers a sustainable solution that will reduce industrial waste, prevent potential soil and groundwater contamination, and support circular economic practices in the mining and building sectors.”

The findings — ‘Advanced characterization of ambient-cured geopolymer paste with delithiated β-Spodumene: effect of Na2SiO3–to–NaOH ratio on performance and microstructure’ and ‘Reactions, phase evolution, and microstructure of ambient-cured geopolymer with delithiated β-spodumene’ — have been published in Materials and Structures journal and Journal of Materials in Civil Engineering.

This builds on a series of research papers published by Gholampour’s research team — from testing alternative compositions of improved construction materials to the more effective use of 3D printing of concrete.

“These findings not only contribute to reducing environmental impact and resource consumption but also enhance the performance, predictability and adaptability of next-generation concrete systems,” Gholampour said.

Image caption: Delithiated beta spodumene material and concrete cylinder made from the by-product. People in image (left to right): Mohammad Valizadeh Kiamahalleh and Dr Aliakbar Gholampour. Credit: Traci Klarenbeek