How can the mining industry meet an increasing global demand for minerals while preserving the planet for future generations?
Associate Professor Glen Corder from The University of Queensland’s Sustainable Minerals Institute (SMI) believes the mining industry needs to explore different ways of thinking if they are to meet the challenge of juggling economic viability, social performance and environmental responsibility.
“With declining ore grades and increasing waste, the mining industry needs to be creative in its approach to resources and waste use,” Dr Corder says.
There will be strong demand for metals far into the future, particularly for renewable energy technologies, but society won’t accept that industry should meet demand at any environmental and/or social cost.
SMI is at the forefront of research into how the mining industry can continue to provide essential materials while reducing environmental and social impacts.
“Modelling business practices around a circular economy will see the industry become more sustainable, reduce costs to the environment, and enable companies to manage the cradle-to-grave operations,” he says.
But what is the circular economy?
Traditionally, mining operations follow a linear process of digging up ore, processing minerals and metals, producing the final product and disposing of any waste. This kind of economic model is known as take, make, dispose.
Plant operator inspecting froth in a flotation cell at a mineral processing plant
In the circular economy, ore is mined and processed, but opportunities are explored for waste to be processed to create by-products that could be used by the mining industry itself or by other industries. This creates a circular economic model of take, make, use, recycle/reuse.
The circular economy is gaining ground in Europe, where it is seen as a vital response to resource security concerns. The European Resource Efficiency Platform (EREP) manifesto adopted by the EU in 2012 calls for Europe to “promote resource efficiency and move to a circular economy.”
The British Standards Institute has even created a standards-based framework to help organisations adopt the circular economy model – BS 8001:2017.
Close-up of a gold grain
To ensure the availability of resources in the future, current patterns and volumes of production and consumption need to change dramatically so that they are brought back within planetary boundaries. To do this while continuing to thrive as a society, a complete re‑think of how things are done is needed. Transitioning to a circular economy could offer a significant contribution to solving the emerging resource and climate problems and create opportunities for shared value.
The mining sector can embrace the concept of a circular economy by looking both inside and outside the sector to identify opportunities to repurpose, reuse or recycle.
Dr Corder says waste is a critical issue along the whole metals value chain.
“This extends from mining waste and tailings, to end-of-life products such as scrap steel, demolition waste, and the growing problem of electronic waste.
Rethinking and redesigning the processes along the value chain and between supply networks promotes opportunities to improve economic viability while reducing environmental liability."
Dr Corder believes there are several ways that would help the mining industry find innovative solutions to many current social and political issues.
Two examples are upcycling and industrial symbiosis.
Upcycling transforms by-products, waste and unwanted products from the production process into new materials or products, such as using mining waste as a soil additive, or for road construction.
Industrial symbiosis has the waste from the mining process being diverted into the processes of another company or companies. These companies could be within the mining industry or be in a completely different industrial sector.
Dr Corder said that cobalt a by-product from copper mining that can also be found in copper tailings, presents a great example of this potential for symbiosis.
“The by-product and tailings could be ignored if cobalt is not core business, but with a different focus from the mining company and possibly in collaboration with a third party, the material could be reprocessed to extract cobalt and possibly other metals,” Dr Corder says.
Cobalt is of interest because of its use in batteries and the rise in the use of electric vehicles alone could see a significant increase in demand for cobalt. The majority of the world’s cobalt comes from the Democratic Republic of Congo (DRC) which, according to the 2017 US Geological Society Survey, has about 50 per cent of the world’s reserves.
“There are countless other opportunities which could be exploited by mining and associated upstream and downstream industries.” Dr Corder says
Mining in the broader economy could benefit from the recycling of mobile phones and other electronic waste known as WEEE (waste electrical and electronic equipment). WEEE contains a wide range of metals. Efficient collection programs to recover the metals from WEEE are contributing to resource efficiencies, and essentially extending the life of current primary ore reserves.
Australia is well placed to become a leader in the circular economy within the mining sector. Dr Corder believes that designing waste out of the mining process will go a long way toward securing a sustainable future for mining in Australia, not only from an environmental perspective but also from an economic perspective. The knowledge and expertise that Australia develops from designing out waste from mining could then be exported to the rest of the mining world which is facing similar challenges.
“We need to look at developing new business and regulatory models that seize the opportunities that exist along the current linear value chain,” he says.
“Having the proper regulatory models in place will send the right signals for industry to transition effectively to the circular economy. This thinking will help reduce the negative impacts of the industry while maintaining the positive outcomes mining delivers for modern society. Importantly, it will also help the mining industry enhance its contribution to the Sustainable Development Goals.”
Synchrotron images of hyperaccumulator plants
New discoveries by institutions such as SMI will provide scaffolding for a new circular economy.
“Work on hyperaccumulator plants is just one of the areas that holds a lot of promise in extracting more value from mining waste,” Dr Corder says.
These plants accumulate particular metals, or metalloids, in their living tissues to levels that may be far greater than is normal for most plants growing on similar soils. There is potential for these plants to then be harvested and the metals extracted in a more environmentally friendly fashion.
A close-up of seawater neutralized red mud with salt flakes on surface.
Other exciting work includes development of a mineral gel technology for effective, low cost, rapid management of caustic red mud from alumina refineries. The gel links mineral grains into stable and benign soil-like structures so the red mud can sustain plant root systems. This will give not only aid in land rehabilitation but also help with seepage management.
On the social side, SMI has created a multi-party research consortium to look at the social aspects of mine closure. This will enable the development of a knowledge base to support improved policy and practice, with globally transferable outcomes.
Flowers growing on mine site in Chile.
So what’s the next step? For Dr Corder, it is to lodge the concept of the circular economy on the national agenda, a key outcome from the collaborative multi-university three-year Wealth from Waste project that SMI was involved in. This project focussed on 'mining' above ground resources - that is, the metals contained in WEEE and other urban waste, as well as in rejects from mining and industrial processes.
“We need to stay in touch with global trends, and that requires a national conversation between our policy makers and business leaders to look at what a circular economy means to Australia,” he says.
Member states of the European Union will, by 2019, be collecting 65 per cent of electrical and electronic waste for proper reuse, recycling, resource recovery or disposal.
“While the EU looks at the end-of-life products, we should be starting with the upstream processing and make inroads into all resource collection, usage and recycling,” Dr Corder says.
“The mining sector is well placed to lead the way within the circular economy to give resource security while protecting the world for generations to come.”