A key factor in reducing the impact of mining on the environment is by implementing circular approaches to mine site waste materials, particularly metal scraps and equipment or machinery.
Recycling scrap metals plays an increasingly important role in reducing demand for virgin materials and new mines, which can help to reduce effects on ecosystems such as deforestation and pollution. With the appropriate infrastructure and supply chains, it is estimated recycling can supply up to 15 to 20 per cent of metal production, enabling more efficient energy use and a speedier transition to low-carbon production.
Each stage of mining – from early exploration to post-mine closure – produces varying types and 72 amounts of waste, necessitating recycling strategies that consider these nuances. Full-site deconstructions are an effective way of preventing debris and waste products from affecting the environment and enabling the efficient repurposing of viable scrap metal materials.
With an effective recycling program, miners not only reduce waste disposal costs and generate revenue from selling recycled materials, but they further push the industry to adopt more environmentally responsible methods.
All manner of mine site infrastructure can be recycled, as well as slags, tailings, drill cores and cuttings from mining processes, while even mine water can be used in local agriculture and aquaculture.
A report by the International Council on Mining and Metals (ICMM) highlighted the link between mining as a process and as a product, noting that both the way materials were produced and used needed to be considered to be truly circular.
It said: “By looking at both process and product circularity in tandem, mines can deliver value to communities and nature at site level, while the materials they produce become resources that can be used again and again.
“In the case of mining, this means having operations that have a net positive contribution to the environment and society, and working with the wider metals supply chain to promote the responsible use and recovery of metals after they enter markets.”
Pointing out that circularity was not new to the mining and metals industry, ICMM said the industry had been integrating circular principles at the site level for many years, in part to reduce the negative impact of extraction but also because it made good business sense.
ICMM added: “Reducing waste and tailings, optimising water usage, regenerating closed mine sites, valorising and recycling other waste such as tyres and focussing on efficiency is already at the heart of strategy in the industry.”
Mining majors have increasingly factored scrap recycling into their business decisions, with Rio Tinto last year investing US$700 million for a 50 per cent stake in Canadian recycled aluminium producer Matalco, to supplement its production of primary aluminium.
Rio Tinto Chief Executive Officer Jakob Stausholm said the company had the lowest carbon-contained primary aluminium in the world but was missing something [without] a recycled product.
He added that with the purchase of a stake in Matalco, Rio Tinto now had that recycled option.
Rio Tinto projects that demand for recycled aluminium in the United States will increase by more than 70 per cent from 2022 to 2032.
Recycling aluminium, along with environmental and financial benefits, can help make energy use more efficient, as it takes 95 per cent less energy to recycle aluminium than to produce new metal from raw materials.
Stausholm said: “Recycling will continue to increase and that means that there will be more growth in secondary aluminium than primary aluminium — we want to be part of the growth as well.
“There are some customers who don’t necessarily need the performance from the primary aluminium and therefore want to entirely use recyclable.
“The way I see it is that it will strengthen our ties with existing customers and open up new customers.”
This notion was also shared by BHP head Mike Henry, who said the private sector must turn recycling into a meaningful source of metals for the world, as it would reduce the need for fresh metal and therefore the amount of mining required.
Though it has yet to make a move comparable to Rio Tinto, BHP has explored the potential of recycling battery scrap and used batteries at its Nickel West operation into nickel-bearing products, as well as working with a US copper cable manufacturer to track how metals flow through downstream supply chains.
The hesitancy to move into metals recycling as a business on BHP’s part may be because, as Glencore Head of Recycling Kunal Sinha noted, the risks involved in running a mining operation were very different than those with running a recycling business.
He said: “As a mining company, you actually know how much copper or nickel is in the ground – you have done your tests, so you have a high degree of confidence in how much metal is in the ground.
“In the recycling business, you don’t own the resource, you are tapping into the urban mine or this massive ecosystem of waste collection [and] you are not sure what you are getting.”
Glencore has for many years developed its metals recycling capability, having recovered 32,000 tonnes of copper, 107,000 ounces of gold, 1.35 million ounces of silver, 6,200 tonnes of nickel, and 1,500 tonnes of cobalt in 2022.
Over the last three years, about US$200 million to US$250 million of annual earnings were generated by Glencore’s recycling business, though this makes up less than 1 per cent of its total earnings.