KalClay: Leading an Eco-Cement Revolution
Curtin University Research Associate, Dr Nadia Bustos Salgado, from the Mining Rock Mechanics Group in the WA School of Mines (WASM), is undertaking groundbreaking research in the heart of Australia’s mining sector at Curtin’s Kalgoorlie campus, alongside leading Professor Ernesto Villaescusa with funding support from the Resources Technology and Critical Minerals Trailblazer.
In the future, it is likely most mines will face increased costs associated with cement-based products as they continue to be consumed in larger quantities. Due to the high energy requirements of cement manufacturing, an increase in the carbon footprint of most mining operations is expected to occur, severely impacting the environment. As a result, there is a demand for initiatives that can minimise the use of cement whilst maintaining safety and reducing overall costs.
The introduction of calcinated clay as proportional replacement of cement has the potential to reduce costs and importantly, reduce CO2 emissions in the order of 30-40% in a number of concrete products heavily used in the mining industry. As an early career researcher, Nadia has helped to develop a low cost, sustainable cement product, called KalClay, using an Aluminium silicate non-expanding clay base in cable-bolt grouts, shotcrete, and backfill. Additionally, the spraying of KalClay also reduces the exclusion time post spraying by 2 hours. Thus, this new and innovative cement replacement technology offers many advantages, from cost reductions to reduced carbon footprint and improved technical performance.
The project aligns with the Trailblazer’s aim to build capability and capacity in WA’s mining sector with funding from the program being used to acquire additional equipment and recruit key researchers, which will lead to the development of new intellectual property on mix formulation optimisation which has the potential to increase research income for Curtin University.
Industry partners such as IGO Ltd, Goldfields, Evolution Mining, Geobrugg, mining3, Ambrose Mining, and Barminco, have contributed AUD$1.7 million towards Nadia and her team’s exciting research.
IGO Ltd General Manager Operations Support Marco Orunesu Preiata said IGO invested in the research project because it aligned with their purpose of Making a Difference and commitment to a net zero emission target for their direct operations and activities by 2035.
“The key characteristic of the KalClay project is its lower carbon footprint in comparison with the traditional cement used in the mining industry. This lower carbon footprint is achieved with a more sustainable production process with inherent lower emissions (clay calcination against cement furnaces), and a lower transport footprint considering its local nature in proximity to IGO’s operations. All these characteristics can potentially translate to lower costs in a win-win scenario for IGO, the environment and local communities,” Marco said.
Goldfields Vice President for Geotechnical and Backfill Peter Andrews added that the project’s ability to reduce cost’s has had a significant impact on their business operations.
“The partial substitution of OPC with KalClay is relevant, from a Gold Fields perspective, in a potentially significant cost reduction in shotcrete, but more importantly in pastefill, which on our 4 underground mines in the Eastern Goldfields region, is the biggest consumer of cement. This potential reduced cost in backfill, will reduce the mining cost and may allow for the economic extraction of lower grade material. In addition to this the lowered CO2 from the KalClay product are assisting Gold Fields in meeting future ESG targets.”
Mining3 also supported the project by renewing the leading Professor Ernesto Villaescusa’s role as Chair in Mining Rock Mechanics in 2024 because of his involvement in this leading cutting-edge research alongside Nadia.
Through this collaboration with key industry partners, Nadia and her team have de-risked the application of this new technology for the mining sector, a core objective of the Trailblazer program.
Along with KalClay, Nadia has also developed an Integrated Geotechnical Data platform (IGD), that has been successfully implemented within a number of operating mines across Australia, Chile, and Peru. IGD allows mining operations to analyse contributing geotechnical parameters within a region of interest, whilst combining rock mass characterisation, blasting, seismic response, and numerical modelling data, for an all-inclusive analysis.