Turning mine waste from risk into opportunity

“If you’re writing about waste valorisation and circularity you must to speak to Karen Chovan. I can introduce you…”

That’s how the conversation went with a mutual acquaintance. And so, in late February, when it was still possible to meet in person, Karen and I sat down at the SME Conference in Phoenix to talk about the challenges and opportunities that waste presents for companies in the mining sector.

But first, some background: Chovan is a consultant based in Saskatchewan, Canada. She was a key facilitator in the environmental leadership team at Cameco before founding Enviro Integration Strategies, a company that supports businesses in the extractive sector to find and implement environmental strategies, tools and techniques that improve performance and outcomes of their projects and operations.

Chovan provides training to support teams on sustainability and the elimination of risks, focusing on systems thinking, collaboration, and team engagement. She is also chair of the Environmental and Social Responsibility Society for the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) which is currently hosting a virtual Tailings Risk Management Workshop, typically held in person at annual CIM Conventions.

I could go on, but what I’m trying to say is: my acquaintance was not exaggerating; Chovan knows her stuff.

Where we’re at and where we’re going

We began by talking about circularity in the context of mining, where we’re at and where we could realistically be in ten year’s time.

“We’re starting to see companies think more about circularity,” Chovan said. “There are a few companies that have, or are working to create closed-loop systems, for instance by processing waste scrap to turn it back into product, but it’s not often part of their regular business.

“In battery metals, lithium in particular, I’ve seen recent movement; talks from various companies about partnering with battery producers to not only take in waste batteries as feed, but also the by-products that the manufacturing production lines create, and turning that back into a useable resource.

“We need to start looking more at how mining can support the circular economy, and how we can turn waste into new products.”

There are two aspects to consider: firstly, addressing current mining processes and practices to minimise the production of waste, or what we think of as waste. And second, dealing with the materials that are already sitting in dumps and in tailings dams around the globe.

“We need a two-sided approach,” Chovan agreed. “How can we support the world by taking in scrap or waste materials and turning them back into useable products? We’re starting to see companies deal with electronic waste, and they’re looking at separating very specific mixes of metals. Could we work together using e-waste processes and mining processes to find efficient and sustainable solutions?”

ICMM member, JX Nippon Mining & Metals, is an example of this in action.

The company recycles and re-purposes various materials, including end-of-life mobile phones. ICMM stated that, of the total volume of waste materials the group generated in 2015, 83% was re-used internally, while, in its copper recycling system, around 26% of its total scrap production was recovered.

Glencore also has a recycling arm. The company is one of the world’s largest recyclers of electronics and a major recycler of secondary copper, gold, silver, platinum and palladium. It accepts materials from over 18 countries and approximately 15% of the raw material feed for its smelting operation comes from recyclable materials

Adding value with ‘waste’

“We also need to reduce the production of mine waste and look at existing mine wastes, or rather residuals, to see what other value lies within them,” explained Chovan.

“Right now, most major companies consider all metals within their polymetallic deposits, and they will recover metals other than the target ones that are present within their by-products. However, this was not always the case for historic operations, nor is it for smaller operators now.

“There could be a lot of value in those residual minerals, particularly if the operation is in a remote area that needs development. Non-metals may not be worth a great deal, but companies are spending money to retain that waste and manage their associated risks over time. Those containment infrastructures will have to be closed in the long-term and managed indefinitely to make sure that they don’t impact the environment or society.

“If you can turn even half of those stored materials into something that can be used for development of infrastructure or for alternate products, that could be beneficial,” she added.

Swedish mining company LKAB is thinking along these lines for its ReeMAP project.

The company is testing the production of apatite (phosphorous) concentrate from the waste generated by its iron-ore operations. The material also contains rare earth elements (REEs) which are vital in the production of electronics.

Currently, 95% of REE supplies come from China, but LKAB hopes to use this material to create a supply closer to home. Reprocessing waste material will not only help LKAB to manage its footprint and costs in the long term, it will also secure a new stream of revenue for the miner and support European manufacturing activities.

The benefits of diversification

US coal company, CONSOL Energy, is looking to implement filtration and dry stacking technologies for its tailings and, in order to help justify the expense, the company is exploring selling some of its by-products for other uses.

“In doing that they’re having to look for new markets and test new processes,” commented Chovan. “But it does help pay for the stabilisation of the wastes that companies need to permanently store.”

Of course, this approach not only helps to de-risk a company’s tailings storage facilities, it also diversifies the business and reduces its exposure to changes in the markets which can only be a good thing long term.

Chovan agreed: “Yes. I think one of the biggest hurdles is getting companies to diversify. Many have a fixed mindset: they’re a mining company with one or two commodities and that’s all they want to produce.

“But the only options to reduce waste volumes and convert the residuals into products are to alter their extraction circuits and diversify, or to collaborate and partner with other companies that want those other products, and have the technologies to do so.

“There’s a lot of opportunity. People still have the set view of ‘who’s going to want all this waste?’ We need to start looking at waste differently. There’s a lot of demand for some of the materials we have.”

Redefining waste

Chovan made a good point; part of changing people’s mindset lies in the way we define waste. If there is demand for a material, inside or outside of the mining industry, then it is in fact not waste at all. It is simply a by-product and, by assigning materials that term, we’re acknowledging that they have purpose and value to someone somewhere.

“The way I like to think about it is, a lot of it’s just inert sand and gravel,” said Chovan. “Sand and gravel are one of the highest volume traded commodities out there. While you’re putting them in a pile somewhere, somebody else who wants and needs them is going to find somewhere they can dig them up.

“They’re creating another quarry or mine, they’re doing studies to find where that resource is, they’re permitting the development, doing investigations and environmental assessments. It’s a huge cost and disturbance that could be offset just by using wastes that are sitting there instead.

“The other argument that might come up is that there’s a lot of waste that is contaminated. But, from my understanding, on average 80% of the materials that are in tailings are inert and they could be used for many things.

“In many extraction processes, metals are separated and potential contaminants precipitated out. Those precipitates tend to be finer grained, more like slimes, they’re harder to settle out. So, for ease of management and storage, they’re usually mixed with the coarser tailings material before being sent to a tailings storage facility.

“It makes sense operationally to store all your fine wastes in one place, but if you could keep those materials separate, one, 80% of your waste volume could potentially be used for something else locally, and the other 20%, maybe that’s got other value in it? Or you could store it for the future when reprocessing technology costs come down.”

Tailings in the long term

I asked Chovan what she thought of dry stack methods for tailings storage. The technology has the potential to transform the way mining companies handle and store waste, but it won’t be the silver bullet many are hoping for.

Are we putting too many eggs into one basket? Should the industry be spending more time and money researching alternative avenues too?

“With the volume, I’d say that dry stacking is one of the best options right now,” she said. “The thing with filter stacking is there can still be stability issues; you have to do it right – design for it, build in lifts, compact, ensure drainage at the base. You need the right climatic and site conditions to support it. There are lots of elements that need to be thought through, and it might not work everywhere.

“But technologies have advanced to the point where they’re much lower cost than they used to be. And they’re being more widely applied, so there are more positive success stories. It’s easier for vendors to show how much dry stacking could benefit companies but, as with any process, you still need to test it and see whether it’ll work with your by-products.”

Chovan is hopeful that dry stacking will eventually eliminate the need for large tailings dams, and that more mining companies will start to make tailings management a core part of their businesses; something we are already seeing steps towards.

“If we have to store residual materials, I’d like to see them built into a solid and stable landform that fits with the natural landscape with reclamation progressing alongside mining activities,” she told me. “And from the waste side, I’d like to see companies minimising that volume by creating multiple products and supporting the region around them to do so.

“If producers can get to the point where they’re creating end value and value-add products, that would be ideal for everyone. There’s a lot more development in technology needed to get there, and we need to invite more people in with different knowledge and experience.

“The keyword is ‘collaboration’. Why not work with other mining companies and share the costs and intellectual property? Let’s develop solutions together to benefit everyone, because you’re not going to do it on your own unless you want spend a lot of money.”

Thinking outside the box

At the moment, METS companies in particular are pushing hard to create more circularity in their production processes, to extend the life of their products, offer recycling opportunities, and to produce technologies that help mining companies deal with their own waste.

Sandvik Group, for example, has been working on the circularity of its products and processes since the 1990s. The company is aiming for 90% circularity by 2030.

I asked Chovan if there’s a similar trend amongst mining companies?

“There’s definitely a lot more awareness around the topic now,” she said. “But manufacturing is very different to mining. Manufacturing is very controlled; the inputs and outputs are generally consistent.

“Mining inputs are completely variable and dependent upon the geology, and that can change throughout the life of mine. We are getting better exploration and modelling technologies and, as those move forward, we may be able to work out variability in advance. That’s especially important if companies are thinking ahead to how they can create other products.”

In terms of miners that are thinking holistically, Chovan pointed to Avalon Advanced Materials, a junior company headquartered in Toronto, as a good example of what is possible.

Avalon has three advanced stage projects where it will produce a range of metals including lithium, tin and indium, as well as REEs, tantalum, niobium and zirconium.

The company also plans to produce by-products including silica, rubidium and cesium. Lithium feldspar from the pegmatites found at its Separation Rapids property in Ontario will be sold for use in glass and ceramics, as will calcium feldspar from the deposit at its Warren Township property near Timmins.

Calcium feldspar has the ability to lower the melting temperature and energy demand of the glass batch, thereby reducing energy intensity and carbon footprint.

Keeping up with metal demand

Lepidico is another lithium producer that is thinking outside of the box.

The company has developed its L-Max hydrometallurgical process to extract lithium carbonate from lithium mica and phosphate minerals, like lepidolite, which are often overlooked by mainstream producers.

The company will utilise the technology at its own mining projects and will also take lepidolite concentrate (which might otherwise go to waste) from Avalon’s Separation Rapids project to further extract valuable minerals.

The processing of lithium micas will also allow Lepidico to produce potassium, REEs and silicate containing by-products, which it said will significantly offset the operating costs of lithium carbonate production.

Business models and technologies like these will be particularly valuable going forward as demand for metal demand surges in line with electric vehicle and green energy technology production.

A recent report from the World Bank, Minerals for Climate Action: the Mineral Intensity of the Clean Energy Transition, found that the production of minerals, such as graphite, lithium and cobalt, could increase by nearly 500% by 2050. It estimates that over 3 billion tons of minerals and metals will be needed to deploy wind, solar and geothermal power, as well as energy storage.

If we produce those using traditional methods and models… well, it could equal an awful lot of waste.

New materials, new markets

And then there are companies outside of the mining sector that are helping to inspire or drive circularity within it.

“Lafarge is a great example,” said Chovan. “They have an entire arm called Geocycle that looks at industrial waste management and how to turn those wastes back into products. They’ve done quite a bit of work on industrial symbiosis and closed loop production.

“And you must have followed Apple and Tiffany on their Salmon Gold project? They’re aiming to clean up salmon lands in the Yukon that are impacted by gold tailings and create a product from the waste.

“I was super excited when I saw that. We need more companies who buy end products to be looking into sustainability and circularity in metal production.”

Mining by-products could also be used in new materials development, for example for 3-D printing.

“There is a lot of research that could be done to find new purposes for residual mining materials,” said Chovan. “It’s really up to the companies producing the waste to figure that out and then look for partners and markets if they’re serious about it.

“With 3-D printing, metals or materials could be sent direct to the manufacturer in powder form. Sandvik’s Additive Manufacturing arm is using diamond composites in 3-D printing, and there’s a company called Markforged Industries which is 3-D printing pump components; they’re working on a variety of products that use various metals.”

The 3-D printing of parts using new materials (created from mining by-products) feeds back into lean manufacturing methods which could help METS companies reduce the number of manufacturing steps, and amount of waste generated in the production of new mining equipment.

And there, ladies and gentleman, is an example of circularity; not just within one company but a whole supply chain.

Redefining mining

“I think the missing piece of the puzzle is that we haven’t been looking outside of our industrial or commodity silos to see what other material demands and technologies could support new business models and streams of revenue,” said Chovan.

“There’s probably a lot being done out there that we could easily apply. Maybe we don’t know which worlds to look to? We definitely need to look broader than our own circles and start more dialogue on the topic.”

The biggest takeaway I left with, and that I hope you too will glean from this article, is that waste valorisation is not just a clean-up exercise; it’s a whole new business opportunity if companies are willing to pivot their businesses and explore different markets. An open mind is all that’s needed.

Perhaps we don’t just need to redefine waste; perhaps, going forward, we need to redefine what it means to be a mining company…?

If you would like to learn more about future mining business models, Karen Chovan will be speaking in the CIM 2020 Technical Program Series on June 23, 2020. The session is free to attend. Learn more here