WorldWide Drilling Resource

15 DECEMBER 2022 WorldWide Drilling Resource® Ore-Sand: Reducing Waste and Supplying a Demand Adapted from Information by the University of Geneva Sand has many applications, including concrete, asphalt, glass, and electronic chips. Composed of small mineral particles, this granular material comes from sensitive dynamic environments such as seas, beaches, lakes, and rivers; or from static land-based environments such as ancient river deposits and rock quarries. Approximately 50 billion tons of sand are used each year. Demand has tripled over the past two decades primarily due to urbanization and population growth, a trend which is expected to continue and contribute to aggregates use increasing each year by 2030. In addition to risks of local shortages, extraction of such a volume of sand has environmental and societal consequences. For example, it is leading to erosion in river banks, which significantly increases flooding risks. Researchers from the University of Geneva (UNIGE) and from the Sustainable Minerals Institute (SMI) at the University of Queensland (UQ), Australia, have researched a potentially viable alternative to naturally occurring sand. This material has been coined ‘‘ore-sand’’. UNIGE’s Adjunct Professor at Department F.-A. Forel for environmental and aquatic sciences, Pascal Peduzzi said, “oresand has the largest potential in volume for reducing the amount of sand taken in the natural environment. By using what has been so far considered as ‘left over’ material, the project gives an important impetus towards a more circular economy.” Professor Daniel Franks, program leader at SMI said ore-sand has the potential to address two global sustainability challenges simultaneously. “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.” The 12-month study independently sampled and investigated sand produced from iron ore mining, pioneered by Vale S.A in Brazil, which has previously experienced tailings dam failures. Researchers demonstrated part of the material stream which would otherwise end up as mining residues could be used as a substitute for construction and industrial sand. “By mapping mining locations worldwide and modelling global sand consumption, we discovered that almost a third of mine sites can find at least some demand for ore-sand within a [31-mile] range. This could contribute to at least 10% reduction in the volume of tailings generation at each site. Simultaneously, almost half of the global sand market (by volume) could find a local source of ore-sand. For example, ore-sand could potentially substitute [more than one billion] tons of sand demand in China,” explained Franks. Based on the Vale case, the life cycle assessment of ore-sand also shows substituting naturally sourced sand with oresand could potentially lead to net reductions in carbon emissions during sand production. “Considering the coproduction of oresand is a significant advantage for mining companies. It reduces the large tailings which hinder operational mining activities, while at the same time can generate additional revenues. Ore-sand is a step towards a ‘no tailings mine’,” explained Peduzzi. “Developing countries have fewer options for using recycled aggregate materials, given their more recent infrastructure. However, many have mining operations that can generate ore-sand as a by-product.” Some of the next steps are to collaborate with aggregate market players to demonstrate this substitute material’s ease-of-use, performance, and sourcing process. Findings from the study were presented at the Fifth United Nations Environment Assembly. ENV Groundwater Week Booth 239