Solutions that enable the cost-effective recovery of secondary minerals from mining waste can unlock valuable critical and strategic mineral resources and may offset the costs of mine rehabilitation activities.

Recognising the potential value of these assets, Geoscience Australia recently launched an online Atlas of Mine Waste to provide information about mine tailings, waste rock, and other mining waste stockpiles in Australia.56

Cost-effective solutions that support secondary mineral extraction from waste streams such as tailings, wastewater, and waste rock stockpiles present an opportunity to improve closure outcomes. Consultations have noted that economic recovery opportunities are present in legacy sites where less efficient extractive processes have left high concentrations of target minerals in waste.

Mine rehabilitation is the return of disturbed land to a safe, stable, non-polluting condition that supports a post-mining land use (PMLU). In Queensland, grazing and native ecosystems are the most commonly proposed PMLUs for rehabilitated land. However, there are a range of other PMLUs, as well as post-rehabilitation opportunities for future landholders, that could be explored to maximise social, economic and environmental outcomes from rehabilitation in Queensland.

Repurposing mineral waste may reduce the burden of waste management and generate cost-effective products. Converted waste products can support mine rehabilitation processes. For example, a common practice of waste repurposing is the co-disposal of tailings and waste rock to create physically stable mixtures to backfill mining voids.

Converted waste products can also support other industries, such as agriculture, construction, and manufacturing. Technical solutions can convert mineral waste into neutral and stable products depending on mineralogy.

Ideally, solutions will align with circular economy principles and generate waste-derived products to meet local demand such as the production of construction materials for local infrastructure.

Australia’s only primary tungsten producer, EQ Resources, is processing waste from an historic Far North Queensland mine to produce the critical mineral in increasing demand around the world, while creating good job jobs for the local community.

Mt Morgan is located in Queensland and was the largest gold mine in the world at its peak in the early 1900s. Over its lifespan, the mine yielded approximately 262 metric tons of gold, 37 metric tons of silver and 387,000 metric tons of copper.

The recovery of gold and copper from tailings will help meet increasing demand for the resources required for the clean energy transition, while also improving environmental outcomes for the region and industry.