Representatives from mining companies, academia and specialists from the Sustainable Minerals Institute met in Antofagasta and Santiago to discuss the capabilities for a circular economy innovation to produce by-products, reduce mineral waste and improve the global sustainability of sand.
The work sessions were held first at Universidad Católica del Norte (UCN) and then at SMI-ICE-Chile’s headquarters. They sought to promote discussion and collaboration among key stakeholders in the mining innovation ecosystem regarding the possibilities for the technological development OreSand, especially the potential impact of how large-scale tailings are handled. Given the topic’s current relevance, these workshops were attended by technical representatives from tailings management, innovation and circular economy areas at companies like Codelco, BHP and Anglo American, as well as experts from Universidad Católica del Norte (UCN), Universidad de Antofagasta, Universidad de Chile, and CIMS (Centre for Innovation in Sustainable Mining), among others.
OreSand is a solution that addresses the so-called «sand challenge», on which researchers at the Global Centre for Mineral Security—a centre of the Sustainable Minerals Institute at The University of Queensland—have been working intensively in recent years to reduce mineral waste at source by incorporating additional processing steps to generate value-added co-products or by-products as a sustainable alternative to the supply of sand.
After water, aggregates—sand, gravel and crushed rock—are the second most exploited natural resource in the world. Demand for this material is growing exponentially around the world with urbanisation, development, population growth and sea-level rise. Yet, extraction of sand and gravel from rivers and the nearshore environment is already an environmental and resource problem.
Currently, large volumes of silicate ores are produced in the crushing and separation stages of ore to extract metals. These minerals, common in aggregates, are disposed of as part of mining waste and tailings under the «linear» mining paradigm. An estimated 30 to 60 billion tons of mining waste are generated each year, the largest waste stream on the planet, an order of magnitude greater than all urban waste. The increasing value of sand, the costs of storing mining waste and the possibility of optimizing mineral processing circuits—for both primary products and by-products—offer an opportunity for circular economy innovations such as OreSand.
Workshops were organized and led by Dr. Juliana Segura-Salazar, professor Leigh Staines and Dr. Louise Gallagher, with the support of professor Daniel Franks, director of the Global Centre for Mineral Security. These workshops were also supported by Pontificia Universidad Católica de Chile, Imperial College London, Dr. Mary Valdés (UCN), and Dr. Doug Aitken and Dr. Dennis Vega from SMI-ICE-Chile.
According to Professor Franks, «OreSand represents a paradigm shift in the process of operating the mine site, harnessing the processing of copper or iron, among other elements, to also generate a by-product called OreSand. The whole process means fewer tailings, more sustainable management of mining operations and a contribution to the sustainability challenges faced by the aggregates industry.»
»The mining industry should look at a deposit like a butcher looks at a cow; everything from the nose to the tail of the animal can be used,» he says. «Instead of just mining the deposit to get the fillet, the industry should also be making sausage, and OreSand is a great opportunity to do just that. I believe that the mining industry should work more in this direction: innovating to take advantage of minerals for the benefit of society and, in turn, reducing the impacts of mining waste on the environment.»
«But this technology is not a recipe for transforming tailings waste into other materials,» he clarifies. «It is a paradigm shift whereby mineral processing stages are added to the process to extract by-products and, in this way, reduce tailings for more sustainable management.»
The OreSand initiative has been successfully implemented with companies such as Vale in Brazil and is currently being validated Newmont in Australia.
Since 2020 Brazilian mining company Vale has been operating the Pico Block Factory, the first pilot plant using OreSand as the main raw material for civil construction products. At the end of March 2022, the company inaugurated the first road in Brazil using OreSand in all four pavement layers.
The properties of the sand produced by the Vale mining company are backed by analyses carried out by scholars from the Sustainable Minerals Institute at The University of Queensland (Australia) and Université de Genève (Switzerland). These researchers studied the feasibility of producing alternative construction materials from minerals, converting these by-products into a sustainable source of sand while significantly reducing the volume of waste produced by mining. They introduced the term OreSand for sand processed as a co-product or by-product of minerals.
The full scope of this development is detailed in a final report from The University of Queensland and Université de Genève, entitled: «Ore-sand: A potential new solution to the mine tailings and global sand sustainability crises«.
The findings of this report were also presented at the Fifth United Nations Environment Assembly, held in March 2022, in Nairobi, Kenya.
Juliana Segura-Salazar, an associate researcher at the Global Centre for Mineral Security and the Julius Kruttschnitt Mineral Research Centre (JKRMC) at the Sustainable Minerals Institute, is leading a research project with Newmont, which is helping drive implementation of this development in copper mining. The project is funded by Newmont and the Australian government, through the Ministry of Education.
«Our goal is to test whether this material works to produce concrete and concrete applications and then develop a sales and marketing model,» says Juliana Segura-Salazar. «At this stage, another critical element of this project has been our alliances with other partners, such as the School of Civil Engineering at The University of Queensland, where we are working with Professor Rebecca Gravina, Dr. Mehdi Serati and Professor Vinh Dao and other JKMRC researchers like Dr. Christian Antonio and Dr. Lulit Habte.”
