Independent testing on Zeotech’s (ASX:ZEO) AusPozz™ confirms that the metakaolin product can replace 20% of cement in underground mining paste backfill and reduce total binder consumption, thereby cutting costs while maintaining operational performance.
The study by Sustainable Future by Design evaluated AusPozz™ as a supplementary cementitious material in cemented paste backfill applications. Results were independently replicated on-site by a major global underground mine operator.
Testing demonstrated that all plug mixes containing AusPozz™ achieved the early age strength requirement of 100 kilopascals within 24–30 hours, enabling continuous backfilling operations.
Plug mix is a critical component of underground mining, providing structural support and enhancing safety and mine cycle efficiency.
Body mixes incorporating AusPozz™ almost doubled in compressive strength at seven and 28 days compared to standard cement formulations. The product delivered comparable or higher strength results at 10–20% lower total binder levels.
CEO James Marsh says the results confirm AusPozz™ can deliver immediate operational value in underground mining applications, “particularly in cemented paste backfill, where cost, performance, and reliability are critical”.
“The ability to reduce cement usage while maintaining early strength and enhancing long-term performance highlights a clear pathway to cost and sustainability benefits,” Marsh says.
“Combining this with the demonstrated improvements to flow and pumpability presents a very compelling proposition to the underground mining sector.
“This work supports the potential for a blended cement product incorporating AusPozz™ to provide a practical, scalable solution for one of Australia’s largest consumers of cementitious materials.”
Testing also demonstrated improved workability with increased slump flow and no evidence of segregation or instability. Zeotech describes the enhanced pumpability as an important performance requirement for underground mining operations.
Cemented paste backfill involves the placement of a cemented slurry comprising tailings, water, and cementitious binder to provide ground support and control dilution. Binder systems can account for up to 75% of cemented paste backfill costs, and backfilling can contribute up to 20% of total underground operating costs.
A life cycle assessment indicated that optimised mixes reduce carbon dioxide equivalent by up to 25–40% per cubic metre, depending on binder optimisation and transport assumptions.
AusPozz™ also delivers performance and cost advantages in fibre-crete and cable bolt grout applications. In fibre-crete applications, 20% replacement of general purpose cement with AusPozz™ delivers a 10% reduction in total binder content and reduces accelerator requirements by at least 50%.
Zeotech will continue engaging with industry participants to advance commercial adoption of AusPozz™ across underground mining applications.
The company will be attending the Noosa Mining Investor Conference, held from 22–24 July, at Peppers Noosa Resort, Noosa Heads, Queensland.
Mining.com.au is an official media partner of this year’s conference.
Write to Maddison Elliott at Mining.com.au
Images: Zeotech
