Xianlai Zeng, Saleem H. Ali, Jinping Tian & Jinhui Li
Nature Communications volume 11, Article number: 1544 (2020)
While ‘natural’ or ‘true’ minerals comprise the majority of the approximately 5,000 known minerals on earth, we now know of at least 200 human-made minerals – some of which have been created deliberately, while others are by-products, for example from mining or smelting.
Man-made, or Anthropogenic Minerals (AM), offer enormous potential in the face of a growing population, and a growing global middle class, generating ever greater demand for technology.
Just as your recycled newspaper may become an insulation panel, or your plastic bottle could be reconstituted as a bicycle helmet, there is a growing movement to ensure metals and minerals are not discarded and are put to good use once more.
In their recent paper, Zeng et al consider anthropogenic mineral generation and its implications for achieving a circular economy.
While their paper focuses exclusively on China, it is certainly not a bad place to start given China now leads in the production of 220 of 500 global industrial products. Simultaneously, China has long- established itself as a leader in global recycling, and indeed triggered headaches for policymakers across many western nations having banned the import of several types of waste in 2018.
Rather than this previously low-margin undertaking, the focus is now on higher value materials, including the rare minerals which are essential for a range of modern technologies, from smart phones to solar panels.
As well as economic and environmental benefits, harvesting anthropogenic mineral could be essential for us to sustain our modern way of life. As their paper notes, natural mineral extraction is encountering tremendous challenges, with current global underground reserves able to sustain future consumption for less than 40 years.
A GROWING RESOURCE
The total weight of anthropogenic mineral in China reached 39 Mt in 2010 and will double by 2022, before quadrupling in 2045. Stocks of precious metals and rare earths will increase faster than most base materials. The total economic potential generated by anthropogenic mineral is anticipated to grow markedly from 100 billion US$ annually in 2020 to 400 billion US$ in 2050.
The paper notes that the recent rapid expansion of high-tech industries, along with manufacturing innovations and consumer demand, have revolutionised societal investments in infrastructure for networking and for the rapid expansion of international commerce. However, the shortening useful life expectancy of the product, driven by rapid innovation, miniaturization and affordability, and an increasingly anthropogenic metabolism have led to a major increase in the accumulation of product waste, which could potentially be classified as anthropogenic mineral.
Zeng et al identify three core waste categories: waste electrical and electronic equipment (WEEE), end-of-life vehicles (ELV), and waste wire and cable (WWC). The authors suggest these are identified as the core scope of AM not only in China, but also in many industrial nations.
Central to their paper is the notion that to meet future resource consumption, mining from AM has become a global concern and further popularised the concept of a circular economy.
However, measuring the quantity of AM generation and its role in future resource supply is still a crucial scientific challenge. Basic AM information—including generation, composition, and resource flow are identified as imperative to formulating effective policy for the recycling industry.
The generation and quantity of AM are subject to urban metabolism affected by a variety of regulations, resultant policy, and technological change. However, due to challenges in tracking and recording, the accurate estimation of AM remains difficult to obtain. In this paper, the authors collect all the available data and initially create the mathematical models of AM recycling and meeting potential.
GENERATING ANTHROPOGENIC MINERAL
Taking ELV as an example, China has become the largest generator and seller of vehicles since 2009. The total ELV reached 11.01 Mt in 2010, and a three-fold rise will occur in 2017. Later, it will reach around 61.37 Mt in 2030 and 97.10 Mt in 2050. The paper notes that more than any other waste category, ELV may impose the most stress and tension for governments and industry.
Moreover, the amount of cobalt and columbite will lead in the increasing rate among all the base materials given the dramatic and continuing boom of batteries and vehicles. From an economic perspective, the large amount of valuable resources accumulated in AM is also enhancing the recycling potential. Despite the wide range imposed by market price of resource, the average economic potential from urban mining has evolved from roughly 74 billion US$ in 2010, to an anticipated 170 billion US$ in 2030 and 428 billion US$ by 2050.
MEETING DEMAND THROUGH AM SUPPLY?
With the dramatic rise of AM generation and the gradual saturation of material consumption, the potential supply from AM is set to overtake the resource consumption rate for several product groups.
The authors suggest that while we are currently still far from a closed-loop society for the majority of products owing to low recycling rates, a rapid advancement is arising for the required regulations, policy, and technology to support a circular economy and urban mining.
Looking to the future, the highly efficient collection of cutting-edge recycling technologies should significantly enhance recycling rates. Thus, if substantial recycling occurs, the authors predict that by 2050, eighteen materials could provide over two-fold consumption levels through AM.
Although several vital minerals including Cu, Al, and Co cannot meet their potential consumption levels by 2050, the disparity gap between their consumption and AM will be greatly reduced in the following decades. Consequently, AM supply has a growing potential to meet their future resource consumption.
The study concludes that further efforts in regulation and more targeted technologies related to the circular economy and zero waste have the potential to ameliorate the current situation. Secondly, investment in research and infrastructure to allow for AM mining represents an effective approach to relieve the current resource shortage bottleneck. In the meantime, the increase in the amount of AM, as shown by their data, suggests more economic viability in harnessing this reserve.
Lastly, the authors argue that the environmental and social risks associated with harnessing AM should be fully considered. With appropriate policy impetus and precautions, the role of AM in achieving the targets set forth in the United Nations Sustainable Development Goal 12 (Responsible Production and Consumption) are far more likely to be achievable for China, and indeed for other rapidly growing economies.