SOURCE: Quarry | July 29, 2026
Researchers may have found a new pathway towards greener cement production, using more sustainable ingredients such as basalt.
Across the globe, researchers and manufacturers are trialling alternative fuels, recycled materials, carbon capture systems, and low-emission production methods to reduce the environmental footprint of one of construction’s most essential materials.
Cement production remains heavily reliant on a small group of raw materials, including limestone and clay or shale, which are heated to high temperatures to form clinker. This clinker is then finely ground with gypsum to produce Ordinary Portland Cement (OPC), with silica sand and iron ore often added to meet specific chemical standards.
Researchers from the University of California believe they may have identified another pathway towards greener cement production, one that could significantly reduce both emissions and energy demand by replacing limestone altogether.
Researchers Jeff Prancevic and Cody Finke claim calcium-rich silicate rocks such as basalt could potentially substitute limestone in Portland cement production. Their findings suggest the switch could reduce carbon dioxide emissions by more than 80 per cent while utilising existing cement manufacturing infrastructure.
Unlike limestone, basalt does not release significant amounts of carbon dioxide during heating because it lacks large concentrations of carbonate minerals. This means producers could avoid the emissions generated during calcination while still producing the calcium compounds required for clinker production.
The researchers also suggest basalt-based cement production may require substantially less energy than conventional methods. According to their study, producing Portland cement from basalt could use less than 60 per cent of the energy required when manufacturing cement from limestone.
Prancevic and Finke estimated the energy requirements and carbon dioxide emissions of cement production using silicate rocks and discovered the theoretical minimum energy requirement is more than 40 per cent lower than that of limestone. Using natural gas as a power source, the minimum carbon dioxide emissions per tonne of cement produced decreased from 609kg using limestone to 43–59kg, depending on the specific type of silicate rock used. The implications for the quarrying industry could be substantial. Basalt is one of the most abundant volcanic rocks on Earth and is already widely quarried for construction aggregates, road base, and rail ballast. In regions with established basalt quarries, producers could integrate extraction and processing into existing operations.
However, cement manufacturing is governed by strict performance and chemical standards, meaning any alternative feedstock would require extensive testing before large-scale commercial use. Durability, consistency, kiln performance, and compatibility with existing supply chains would all need to be assessed.
There are also logistical considerations. While limestone deposits are typically located close to existing cement plants, transporting basalt over long distances could offset some environmental benefits if supply chains are not carefully managed. Despite these challenges, the research highlights the growing role geology could play in the decarbonisation of construction materials. Traditionally viewed primarily as an aggregate resource, basalt may emerge as a strategic material in the push to lower emissions.
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