While the transition to a circular economy is underway, the recovery of metals and minerals from existing and future ‘above-ground’ resources or waste materials forms a key part of the economic opportunity presented in this new framework.
Once considered of little or no value, these materials are now becoming accessible and valuable, stimulating the growing global capacity and innovation in recycling and closed-loop supply chains (World Economic Forum, 2014).
Australia is an economy with rich stocks of mineral resources, which have been the source of national wealth and competitive advantage, enabling Australia to be one of the global resources leaders internationally. While there is no doubt that mineral resources will continue to be imported, about seven million tonnes of metals leave the economy through waste streams every year, creating enormous potential for Australia to turn its extensive expertise and know-how in primary mining towards the recovery of metals and minerals from ‘above-ground’ resources.
In particular, research has identified the possibility for the country to adapt established expertise in extraction, recovery and processing of metals from secondary sources to make a major contribution to smarter technologies and approaches for metals recycling. In fact, the reuse, recycling and recovery of metals from end-of-life products or industrial waste is an area that Australia is well-positioned to influence globally, and take advantage of economically.
There is a significant business opportunity in the mining equipment, technology and services (METS) sector to tap into new openings in the market, both in the areas of mining sustainability and in deriving wealth from waste. This could be from mine waste or from above-ground stocks of resources contained in waste products and infrastructure from cities. Given this potential, the opportunity to bridge mining know-how into sectors from mine waste to recovering metals from electronic waste should be embraced. For example, in 2014 worldwide over 40 million tonnes of e-waste were generated containing approximately USD 60 billion worth of resources (48 billion EUR) (Baldé et al., 2015).
Fast-growing, developed economies such as Australia often have a higher level of urban metal stocks, as well as greater waste generation and therefore potential to establish valuable material loops. The benefits that this could offer are fairly well-known, such as reduced energy requirements and emissions, which are typically 50% to 99% lower for recycled metals compared with primary produced metals. Yet, on a global basis, current estimations indicate that the recycling rates are above 50% for 18 metals and between 11% and 50% for another six metals (refer to Figure 1) while many other metals mostly end up in landfills (Graedel et al., 2011).
But the challenge with recycling of metals it is often complex, requiring several main stages such as collection, sorting, shredding, physical separation, hydrometallurgical treatment, and smelting, and involving numerous companies at different stages. Added to this, the number and amount of recovered metals significantly depends on the complexity of waste stream mineralogy and the ability of the technology to handle the complexity.
Based on reports from UNEP (UNEP, 2013) and USGS (USGS 2014), the work of the Wealth from Waste Cluster estimates that the annual waste metal generation level in Australia could account for 50-60% of the current consumption (taking into account the average period of metal use within the economy, metal consumption and population growth over the last few decades). Using our estimated current consumption of 520 kg per person, this results in about 300 kg per person or seven million tonnes in total for metals in waste streams per year based on the Australian population of 23 million (ABS, 2014).
At this consumption rate, the estimated potential value of metals from waste in Australia is of the order of AUD2 billion (USD1.4bn) a year. This is broken down into metals lost to landfill and lost opportunities in domestic processing of collected metal scrap – refer to Figure 2. Currently, only about half of collected waste metal is processed in Australia, partly due to a lack of domestic facilities for separation and smelting non-ferrous scrap (apart from any remaining secondary aluminium and secondary lead production). As a consequence, most of it this metal shipped to and processed in Asia. The only well-established metal recycling system in the country is for iron and steel scrap, and this is part of the conventional iron smelting technology. Changes are occurring though, with Outotec agreeing to provide Nyrtsart Port Pirie Smelter site (SA), as part of its redevelopment, with Outotec smelting technology which can treat a wider range of raw materials allowing for multi-metal recycling (5AU ABC, 2014).
If we build on the outcomes above using a macro level model, we can estimate the flows of metals into and out of an economy. This model starts with the flow of metal from mineral extraction, through several stages of transformation (such as processing, refining, fabrication, and manufacturing), including product use in the economy (consumption), and ending with product disposal, or recycling of metal for the next cycle – see Figure 3.
About 300 million tonnes of metals are accumulated in in-use stocks in Australia, and these are growing with 1.5-2% annual rate. Currently, the metals are predominantly utilised in buildings and infrastructure (50-70%), while the rest are in vehicles, machinery and consumer products (Golev and Corder, 2014). About seven million tonnes of metals leave the economy with waste streams a year, out of which about five million tonnes are collected for recovery, including 2.5 million tonnes of scrap metal exported overseas. Potentially, Australia could be recycling much of these metals if favourable technology and economic conditions.
The need for a paradigm shift in metals recovery and re-processing of ‘above ground’ resources is paramount to efficient and effective management of the growing waste volumes. Upstream chemical and metallurgical engineering approaches have not been fully applied to the sorting, separation and recovery of metals and other materials in end-of-life products or industrial waste. In a conventional mining sense, there is a strong grade driver for metal containing wastes such as e-waste, which contains metals (for instance gold) in concentrations or grades that of the order of 10 to 100 times higher than that of typical ore bodies. While ‘urban mine’ ore bodies might be more complex, the rewards for recovering metals from wastes are higher and also prevent potential environmental legacies. Such factors point towards the urgent need to develop and adapt transformative technologies that will harness this value from ‘above ground’ metal resources.
5AU ABC, 2014. Oututec to provide Smelter Tech.
ABS, 2014. 3101.0 – Australian Demographic Statistics, Mar 2014
Baldé, C.P., Wang, F., Kuehr, R., Huisman, J., 2015. The global e-waste monitor – 2014. United Nations University, IAS – SCYCLE, Bonn, Germany.
Golev, A., Corder, G.D., 2014. Global systems for industrial ecology and recycling of metals in Australia: Research report. Prepared for Wealth from Waste Cluster, by the Centre for Social Responsibility in Mining, Sustainable Minerals Institute, The University of Queensland. Brisbane, Australia. – ONLINE.
Graedel, T.E., Allwood, J., Birat, J.-P., Buchert, M., Hagelüken, C., Reck, B.K., Sibley, S.F., Sonnemann, G., 2011. What Do We Know About Metal Recycling Rates? Journal of Industrial Ecology 15, 355-366.
Trading Economics, 2014. Australia GDP Growth Rate.
UNEP, 2011. Recycling Rates of Metals – A Status Report. A Report of the Working Group on the Global Metal Flows to the International Resource Panel. Graedel, T.E.; Allwood, J.; Birat, J.-P.; Reck, B.K.; Sibley, S.F.; Sonnemann, G.; Buchert, M.; Hagelüken, C.
UNEP, 2013. Metal Recycling: Opportunities, Limits, Infrastructure. A Report of the Working Group on the Global Metal Flows to the International Resource Panel. Reuter, M. A.; Hudson, C.; van Schaik, A.; Heiskanen, K.; Meskers, C.; Hagelüken, C.
World Economic Forum, 2014. Towards the Circular Economy: Accelerating the scale-up across global supply chains, Geneva, Switzerland, 2014.
The work presented in this article has been conducted in the Wealth from Waste Cluster, an Australian initiative to identify viable options to ‘mine’ metals contained in discarded manufactured products and consumer goods or end-of-life products. Further information on the Cluster is available at www.wealthfromwaste.net, and a more detailed analysis of the material presented in this article is available in Golev and Corder (2014).
Lead image: David Hawkins-Weeks/Flickr CC by 2.0