New step in mineral processing could help prevent a sand sustainability crisis

15 November 2021

A step-change in mineral processing could help the world avoid a sand sustainability crisis.

Researchers from The University of Queensland’s Sustainable Minerals Institute’s (SMI) and the University of Geneva (UNIGE) are investigating whether ore-sand (o-sand), an alternative construction material produced from mineral ores, could become a sustainable source of sand while significantly reducing the volume of waste produced by mining.

Sand is the most exploited natural resource after water, with applications ranging from concrete and asphalt to glass making and manufacturing of silicon chips for electronic devices. Over the past two decades demand has tripled primarily due to urbanisation and population growth in Asia and Africa.

SMI’s Development Minerals Program Leader Professor Daniel Franks said his team’s research presents an opportunity to address two global sustainability challenges simultaneously.

“Sand is one of the world’s most exploited natural resources and its extraction from rivers and nearshore environments poses a sustainability problem that will only get worse.

“At the same time, the world’s largest stream of waste – mineral waste from the mining of metal ores – might provide a solution to this challenge with the majority often comprised of sand-like materials.

“Separating and repurposing these sand-like materials before they are added to the waste stream would not only significantly reduce the volume of waste being generated but could also create a responsible source of sand.

“There are known options for adjusting mining and processing operations to recover o-sand, and new innovations, such as coarse particle flotation, may widen the possibilities supported by incentives for uptake.”

A map showing mine sites (red) and areas where there is significant demand for aggregates (blue).

The 12-month project is specifically investigating sand produced from iron ore mining, pioneered by Vale in Brazil and independently sampled by the research team.

UNIGE’s Professor Pascal Peduzzi said the project was an important step towards a circular economy.

“Developing countries have fewer options for using recycled aggregate materials, given their more recent infrastructure. However, many of these countries have mining operations which can generate o-sand as a by-product,” he said.

Early results have been announced in the Interim Report. The Final Report and findings from the project are expected early next year and will be shared with the Constituencies of the 5th United Nations Environment Assembly as well as broader community.

You can watch an overview of the project here.

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