A team of researchers from Flinders University have found an innovative way to repurpose mining waste and use it in the production of concrete.
Dr Aliakbar Gholampour from Flinders University’s College of Science and Engineering found that Delithiated β-spodumene (DβS), a rare earth by-product of lithium refining, exhibited pozzolanic properties.
That property means that the material reacts chemically to enhance the strength and durability of concrete.
The research demonstrates an effective way to incorporate 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 the geopolymer.
“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,” says Dr Gholampour.
“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.”
About 25 billion tonnes of conventional concrete is used every year, and it consumes about 30 percent of non-renewable natural resources, emitting about eight percent of atmospheric greenhouse gases and comprising up to 50 percent of landfill.
Other research teams across Australia have also been investigating ways to make construction materials more sustainable. Earlier this year, engineers at RMIT University discovered a new way to convert low-grade clay into high-performance cement. The team demonstrated that cheaper and more abundant illite clay can be mixed with low-grade kaolinite clay to make stronger, more sustainable concrete.
Separately, a team from RMIT University also developed an ingenious decarbonising solution for the built environment that strengthens concrete by 30 percent by using biochar made from recycled coffee grounds.
Read more: Australia set to rack up $64 billion construction waste bill
