CIRCULAR ECONOMY FOR
CONSTRUCTION MATERIALS A BY-PRODUCT FROM THE PRODUCTION OF NICKEL IS BEING USED AS AN AGGREGATE IN CONCRETE APPLICATIONS AND COULD SOON BE APPROVED TO AUSTRALIAN STANDARDS AS A SUPPLEMENTARY CEMENTITIOUS MATERIAL. SLN AUSTRALIA EXPLAINS.
B
eyond Zero Emissions, an internationally recognised Australian think-tank, estimated the production of Portland cement (the most common cement product) is responsible for around 7.4 million tonnes of emissions in Australia. This equates to 1.3 per cent of national emissions. In its ‘Rethinking Cement’ report released in 2017, it states clinker substitution is one of the ways cement production emissions can be reduced. This will require increasing the level of supplementary cementitious materials (SCM), which reduces the amount of limestone that needs to be calcined but upkeeps the quality of cement. Further into the process at concrete batching plants cement is then mixed with SCM’s, sand aggregates and water to create the concrete product. Use of SCM’s at this stage can also reduce emissions. While fly ash and slag are common clinker substitutions, SLN Australia has introduced a new product that can be produced as either a fine aggregate used in concrete, a supplementary cementitious material
(SCM) for both cement and concrete applications or an addition for granular road building materials. The product, Le Sland, is a by-product from SLN’s nickel smelter facility in New Caledonia. Currently around 20 million tonnes of the product is ready to be transported for use in Australia. There is also a 10,000 tonne stockpile available for sale at Port Kembla. Le Sland can be used in general concrete, precast concrete or concrete blocks, road base, land reclaim and sand blasting applications. Le Sland can also be used in Australia as a coarse sand substitute for use with other sand materials that complies with Australian Standard 2758.1, aggregates and rock for engineering purposes.
“ROAD BASES ARE BOUND BY PLASTICITY INDEX OR AGGREGATE INTERLOCK SO WITH HIGH PLASTIC MATERIALS OUT THERE THE ADDITION OF THIS MATERIAL COULD BRING THE PLASTIC INDEX DOWN TO AN ACCEPTABLE RANGE.”
Le Sland is a by-product from SLN’s nickel smelter facility in New Caledonia.
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Yves Veran, Business Development Manager for SLN Australia, says Le Sland contributes to a reduction in the carbon footprint when used in its raw form or when ground to be used as a supplementary cementitious material. SLN Australia has a commitment to circular economy principles in all its practices and Mr. Veran says this led the company to explore avenues for an alternative product to be used in the construction sector. Michael van Koeverden (CQT Services Pty Ltd) is an independent technical expert that has been working with SLN Australia to evaluate the properties of Le Sland as both an aggregate and supplementary cementitious material. “Because the SLN aggregate material is
