Mining for materials

19 Apr 2018 |

The volume of electrified vehicles on our roads, both hybrid and battery-electric, is forecast to rise sharply in the coming decade. That increase will place new demands on the supply chain for battery packs and electric drive motors, with lithium-ion cells and permanent-magnet drive technologies likely to dominate for years to come.

According to Frances Wall, Professor in Applied Mineralogy at the University of Exeter’s Camborne School of Mines (CSM), the increased future demand for raw materials like nickel, cobalt and neodymium will have an impact on mining that is felt more widely than simply in higher production requirements. In fact, that perceived future demand is already having an effect.

“We’ll need more of all kinds of specialist metals, including the 15 rare earths that are only mined in small quantities,” she says. “This expected rise in demand is already having an effect in buoying up the exploration companies, who are finding it easier to raise money to go and explore for new deposits.”

Lithium exploration has come into particular focus for investors of late, partly for the simple reason that it features in the name of the widely used battery chemistry. There’s even an exploration project by a company hoping to extract the metal from hot springs in Cornwall.

There are, Wall says, more than enough mineral deposits in the earth for all the materials we need. The challenge lies in extracting them at a price that manufacturers want to pay, and in an environmentally and socially acceptable way.

Take the long view The volume of electrified vehicles on our roads, both hybrid and battery-electric, is forecast to rise sharply in the coming decade. That increase will place new demands on the supply chain for battery packs and electric drive motors, with lithium-ion cells and permanent-magnet drive technologies likely to dominate for years to come. Mining is a complex, long-term business, in which it currently takes an average of ten years to develop a new mine. As a result, there may be bumps in the road ahead for raw material prices as the mining industry adjusts to increased demand from new technologies in EV batteries and motors. “We’d like the exploration industry to become faster-reacting, to be able to switch on deposits much faster than currently, and that’s something we’re working on at CSM,” says Wall. “Researchers are also looking at methods that require lower capital investment. Especially for a small company, it’s a very slow process to prove to investors at every stage that it’s a promising project. You might need hundreds of permits and permissions to open a mine, and you then have to raise the money to do it. Anything we can do on the technology side to improve people’s knowledge of deposits, so that they can target the best ones and make the processing easier, cheaper and more environmentally friendly, is all good.”

According to 2016 figures from the US Geological Survey, some 83% of the world’s rare earth mine production is in China, primarily at the giant Bayan Obo mine in Inner Mongolia. The only other country with more than 10% of the market is Australia thanks to the Mt Weld mine that opened in 2011 – more than 20 years after the original exploration was done.

It was only the price spike in the 2000s, caused by an export restriction on critical metals from China, that finally cemented the economic case to begin mining at Mt Weld. “They managed to open up because they’d done a lot of the groundwork already,” Wall observes. “It’s important that the data and samples from the first exploration work isn’t wasted, that it’s held until the time is right. Being prepared to put that investment in, being ready to go when the opportunity’s right, is important. It’s highly likely we’ll need these resources in the future.” She believes that the automotive industry can help by talking to people on the raw materials side at an early stage when considering new technologies. They can then be advised on the use of high-technology metals and if necessary, plans can be made to start mining new deposits.

A force for good

Apart from increasing demand, the automotive industry could impact upon mining in another, positive way: by advocating responsible sourcing. This involves ensuring that mining for rare metals has no negative impact on the local population, economy and environment of the area in which the mine is located.

“It’s one thing to open a mine, but to mine those deposits in a responsible way is another challenge,” says Wall. “It’s something that as consumers on the end of long supply chains we know very little about. But we do know for example, that because almost all rare earths come from China, we’re party to the environmental problems that have been caused [by mining] in that country.

“High brand-profile manufacturers are probably the key people who are beginning to think more carefully about where their materials are coming from,” she continues. “It would be something really neat, and something I would certainly welcome, if the car manufacturers, as they change to electric vehicles and use new technologies, would check their supply chains back to the source and make sure there are responsible mines at the beginning.”

Well-publicised associations with environmental damage and ‘conflict minerals’ are topics that any image-conscious global brand will want to avoid. Instead, automotive companies could help to accelerate positive changes that are already being made in the mining and other industries.

Mobile phones are one area where responsible sourcing has become a hot topic. Apple was targeted by conflict mineral campaigners after using tantalum in capacitors for mobile phones. Tantalum is one of several minerals that has fuelled conflicts, notably in the Democratic Republic of Congo.

“Apple subsequently became one of the leaders in the responsible sourcing of those minerals and avoiding conflict minerals,” notes Wall. “In 2017, it announced its intention to make products only from recycled materials and end its reliance on mining altogether. But that’s impractical at the moment due to increasing global demand – we simply don’t have enough material in circulation to be able to recycle everything. Responsible mining will therefore remain an important topic for some time to come.”

The mining industry – led by the biggest companies such as Rio Tinto, Anglo American and BHP – has already taken steps to clean up its act in the past two decades. Wall says that after poor corporate reputations had started to prevent them from doing business and opening new mines, the companies set up the International Council on Mining and Metals (ICMM) to improve the industry’s environmental and social performance. Best practice has been developed, published and widely shared.

Other developments include the Initiative for Responsible Mining Assurance (IRMA), which in 2017 is beta testing an independently verifiable certification system. The organisation says that the new system will also give purchasers a chance to connect with leading mines through their supply chains.

In China, too, the situation is slowly improving. “China realised that its environmental performance with respect to rare earths was poor,” says Wall. “They’re working to improve their environmental performance but the job’s not done yet, I would say.”

Worldwide, the level of investment required for new mines means that there is indirect control from the financial industry, too. Consultants representing reputation-conscious international banks conduct checks and the Equator Principles, a risk-management framework for social and environmental issues, are applied to major investments.

No easy answers

Aside from potential pollution from the mine itself, the environmental impact of extracting a rare earth element extends to the energy expended in the mining and processing of its oxide into a usable resource. Heavy rare earths – those with the highest atomic numbers – tend to be in the lowest absolute abundance so typically require the most chemicals to extract them from the mined minerals.

They can be difficult and energy-intensive to process, with their use resulting in higher greenhouse gas (GHG) emissions.

It’s possible that in the future, new sources could lower the environmental cost of extracting some rare earth elements. CSM is conducting a research project into whether rare-earth deposits at new mines could get the extraction-GHG figures typical of Bayan Obo down by using more environmentally friendly and more efficient processing techniques.

But as Wall explains, energy-intensive extraction is only one factor to consider when looking at potential material choices for new technologies. If, for example, employing a heavy rare earth element were to greatly reduce energy consumption in the end product – as is the case with low-energy light bulbs – then it could still be the right option. As well as examining the overall lifecycle of a product, social considerations can play a role in material choices, too.

“There are very sophisticated ways of doing lifecycle assessments by looking at embodied energy, and simpler ways of looking at a material’s sources and deciding whether that’s a good thing,” she says. “We mustn’t forget that lots of developing countries rely on their natural resources for their economic development so it can be important to them [for technology] to use those raw materials. There might be ways you can help sustainable development in a country by putting a certain material into a component or battery, for example.

“Responsible sourcing is a complicated issue,” she concludes. “Things are improving, albeit slowly, and maybe for the car manufacturers, there’s everything to play for. They are very powerful, very high-profile purchasers. I think that if they really started to take an interest, then they could make a big difference.”

The potential to extract lithium from Cornwall was recognised in early 2016 by Jeremy Wrathall the CEO and founder of Cornish Lithium. The fact that Cornwall hosts mineralised waters which contain lithium has been recognised since 1864 but advances in technology now make the extraction of this lithium a possibility. The rapid increase in demand for lithium has already seen its price triple since 2016 and this has given rise to a flurry of exploration activity worldwide.

Cornish Lithium has identified a large area where it believes lithium in mineralised brine could occur given the unique geology of Cornwall. The company has successfully negotiated rights to explore for, and to extract, lithium from mineralised brines over an area exceeding 300km2 and the company has now embarked upon what it believes to be the largest exploration effort Cornwall has ever seen.

Given that the lithium in Cornwall is contained in geothermal brine the company believes that extraction will be environmentally benign. The mineralised water will be extracted via a drill hole similar to a water well or a geothermal well. Once the water has been brought to surface new developments in extraction technology should enable the lithium to be extracted using a small processing plant similar in size to a small supermarket. This plant will produce battery grade lithium carbonate or hydroxide for sale to the battery manufacturers and may also produce heat for use in domestic heating schemes.

Wrathall is confident that the dramatic rise in demand for lithium-ion batteries used to power electric vehicles and to store power from renewable sources will result in a significant increase in demand for lithium and other battery materials such as cobalt and graphite. “If Cornish Lithium is successful with its exploration efforts a domestic source of lithium can be expected to materially assist the UK to become a significant player in the supply of lithium-ion batteries” says Wrathall.