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Quarrying to a net-zero future

Are quarries the key to the construction industry achieving net-zero carbon emissions by 2050? Kayasand believes so, and the secret is in the sand.

The Australian Government legislated greenhouse gas emission reduction targets in 2022. As part of the global push to fight climate change, it plans to reach net-zero emissions by 2050.

Cement production plays an important role in this endeavour. According to Beyond Zero Emissions, an independent think tank, cement production is the world’s single biggest industrial cause of carbon pollution, amounting to about eight per cent of total global emissions.

Bram Smith, general manager at Kayasand, told Quarry that Australian quarries can help cut down on these emissions using a common byproduct in the industry – crusher dust.

“Once processed into manufactured sand, it can be widely used as a substitute for natural sand in concrete. The trouble is natural sand is becoming more difficult to access and more variable in quality,” Smith said.

“Historically, the problem with using manufactured sand in concrete is that it’s often poorly shaped, badly graded, inconsistent and often contaminated with clays and silts. As such, it’s considered an inferior product to natural sand.”

“Getting it right requires precise shaping, good particle size distribution, contamination controls and quality consistency. It’s  about engineering the sand not just processing it, and the final product has many advantages over natural sand.”

“A good quality engineered sand will make stronger concrete with less cement and lower emissions than natural sand. It often outperforms natural sand in the mix.”

Engineered sand is designed to have extremely consistent properties. Image: Kayasand

Kayasand’s innovative technology enables quarries to process crusher dust into precisely engineered concrete sand.

Concrete trials have shown a cement reduction in concrete of at least 10 per cent is achievable without any impact in strength. This means substantial emissions reductions.

The ability to process crusher dust into a high value product also enables quarries to better balance their inventory and minimise waste generation and to optimise yields, aligning with sustainable development principles and carbon reduction reporting requirements.

The United Nation’s Sustainable Development Goals requires large enterprise, regional and local government agencies to report on the sustainability of business practices and products in their supply chain.

“Using Kayasand’s V7 equipment and technology helps quarries meet this requirement,” Smith said.

“Not only that, but they add new revenue streams and help support the construction industry with high quality materials.”

Engineered sand is designed to have extremely consistent properties, allowing for more precise and optimised concrete mix designs. It leads to reduced material wastage during construction and a reduction in the overall carbon footprint of a project.

Processing crusher dust into a high value product enables quarries to better balance their inventory and minimise waste.Image: Kayasand

It is also often produced in quarries closer to construction sites. This reduces the need for long-distance transportation and emissions due to fuel consumption.

Smith said public concern about the environmental impact of natural sand mining is making it harder and more expensive to access natural sand resources. By using engineered sand instead of natural sand in construction projects, the growing restrictions on sand supply can be mitigated.

“The environmental and sustainability impact is even more meaningful when a quarry uses technology like Kayasand’s V7 sand plant to engineer its concrete sand. The process is dust-free, low-noise and uses no water for washing. Quarries could substantially scale back their sediment ponds and water tailings,” Smith said.

“It also helps conserve natural resources by reducing the demand for riverbed and coastal sand. Preserving these ecosystems can help mitigate carbon emissions associated with habitat destruction and loss of carbon sinks.”

Engineered sand doesn’t just have to be about quarrying by-products and crusher dust. Kayasand technology can recycle glass and concrete back into premium concrete sand and create cement substitutes from limestone filler and slag.

Smith said quarries that sell engineered sand will be an important part of the construction industry’s push to achieving net-zero emissions.

“The environmental benefits, lower carbon footprint, consistent quality, and circular economic potential make it a viable antidote for a constrained supply chain,” he said.

“By embracing good quality engineered sand, the construction industry can build their way to a more sustainable future.”•

For more information, visit kayasand.com

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