Story by John Burfitt
Photography by Jessie Casson

In the area of sustainable metal recovery, the world is watching New Zealand’s Mint Innovation, as it leads the charge in extracting green metals from waste to accelerate a circular economy.

The Auckland-based company is the first in the world to use natural biomass and smart chemistry to extract green metals from e-waste, producing lower carbon emissions in the process. Each year, more than US$80 billion of valuable metals are discarded in consumer and industrial waste.

The processes Mint uses can save up to 90% of the carbon produced in recovering metals, such as gold and copper. The work of Mint, founded in 2016, was recognised at the InnovationAus 2023 Awards for Excellence, in the categories of Energy & Renewables and Manufacturing Innovation.

In 2022, Mint expanded its operations across the Tasman Sea with a commercial biorefinery in Sydney. Now the business is looking to expand to the US and other major manufacturing nations.

Colum Rice CA, Mint’s CFO and head of strategy, spoke to Acuity about Mint’s impact on the environment, economies and the plans for global expansion.

Why did you join Mint in 2022?

You don’t get too many businesses in our part of the world that have developed world-leading technology which is looking to solve a global problem. The business seemed to be at the right stage to take that solution to the world and that made the timing too exciting to walk away from.

Has care for the environment always been high on your agenda?

My last role at PwC was leading ESG [environmental, social and governance] across Asia Pacific and I had trended in that direction over the 20 years I was a partner at PwC. Mint was an opportunity to get more directly involved in a business trying to make a direct impact.

What is the background story of Mint?

The inspiration came from the founders’ vision. Our CEO and co-founder Will Barker had previously been involved with successful biotech businesses in New Zealand and saw the opportunity of using similar technology to create solutions for the issue of e-waste. He was looking for a trash-to-treasure opportunity that would have a real sustainability impact.

Have you been surprised by the rapid evolution of the processes?

The inspiration comes more from how wide the impact of the recycling technology can be. To decarbonise means to electrify, which is heavily dependent on the electrification elements and the demand is going through the roof. But supply takes an awful lot longer. Mint can make a real contribution by increasing the supply of low-carbon metals and directing those metals back into electrification and decarbonisation infrastructure.

Where does the e-waste come from?

Almost everyone has that drawer which has 20 years’ worth of devices, phones, laptops and cords that have been discarded. Those devices are our core feedstock. But with how computing has changed, now with most processing happening in the cloud, our feedstock is moving to data centres because they are a massive collection of circuit boards that get changed out pretty frequently.

How does the biorefinery process work?

First, we grind up the circuit boards to a sand-like consistency. We then use smart chemistry to get the material into a solution. Then, we use a biomass to bind to the gold and filter out the gold using a filter press. After that, chemistry and more traditional processes are used to concentrate the other metals. There are often 30-plus metals on a circuit board, so it is a complex challenge.

What are the main metals Mint extracts in this process?

The two most important are copper and gold. Copper is the most abundant and it’s a critical metal on most government lists due to looming supply shortages. A single Mint plant can recover enough copper to construct four Statues of Liberty a year. And the gold we recover is critical because its value enables us to unlock the rest of the processes we work with.

“A single Mint plant can recover enough copper to construct four Statues of Liberty a year.”

Once the metals are extracted, how are they used?

These metals go back into electrification to contribute to decarbonisation. So, it becomes a properly utilised circular existence. Ideally, those metals will go back into the supply chain for the original equipment manufacturers and, when they reach the end of that existence, those items can come back to the Mint plant a second and third time. Maybe more.

How has the process changed in recent years?

The process didn’t exist seven years ago so it’s been created in that short time frame. What is always happening is continuing to improve the process, like being about to extract more of the 30 or 40 kinds of metals in a circuit board and use them, too.

How much do you think it will change in the future?

When you think about increasing sustainability that usually means using less resources, that’s good from a financial as well as environmental impact. So, it is about trying to find ways of using less energy, fewer chemicals, and achieving greater purity of metal and extracting more individual metals without spiralling the costs.

How does Mint fit into the circular economy?

We can only be a part of a broader process to capture and recover these critical metals and get them back into the economy. We need companies and individuals to capture their e-waste and direct it into the right parts of the supply chain, so it ends being processed through a low-carbon solution. This is where there’s a real opportunity for businesses to take responsibility for the e-waste they create and ensure it’s not just recycled but is going to low-carbon, sustainable and circular processors.

There is a plant in Auckland and in Sydney – what’s next for Mint?

A plant in the US is our next priority. We are looking to scale rapidly in the US but also looking at other countries because we can deploy our technology anywhere there is feedstock. Countries across Europe and Asia have also identified the urgent need to secure the supply of green metals.

What can corporate Australia and New Zealand do to operate more sustainably?

It’s working out what’s the biggest impact and how to move the dial on that quickly. For many CFOs, that lines up nicely from a financial point because it’s about using less to be able to deliver more. So, just being able to decrease your consumption of anything – whether it’s energy, consumables or travel – that’s a positive impact, because everything your business consumes comes with a carbon load. E-waste is getting greater attention, as people understand its life cycle and the serious environmental impact when it’s not processed appropriately.

Is there better understanding in the market of the value of the work Mint is doing?

We are getting a lot of approaches now directly from OEMs [original equipment manufacturers] and well-known brands. Once these businesses understand how our technology can contribute to them achieving their sustainability commitments, they are keen to work with us.

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Four things CAs should know about the circular economy

Mint Innovation CFO and head of strategy Colum Rice CA explains the value of working within the circular economy and reusing materials as a means of continuing production in a sustainable way.

1. It’s the economy of the future. The take-use-dispose economy has a limited horizon. This shift to a circular model requires rethinking traditional approaches to creating value and it will add value to your business because you’re futureproofing the business.

2. There’s value in the savings from reduced waste or reduced consumption. Being more sustainable is good for the bottom line and COVID showed us that often what businesses thought could not change can change rapidly when it is a priority. Many businesses once said they needed to fly to every meeting, then remote communication completely changed our practices.

3. Better disposal of waste can lead to operational savings. Taking a waste stream and then finding a home for it, which is useful for somebody else, can be a far cheaper point of disposal for your business.

4. It’s where the big brands are heading. A lot of OEMs [original equipment manufacturers] are making commitments around only using recycled inputs, which sets a benchmark that a lot of other industries, and competitors, will move forward on.

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