An unintended consequence of the net zero drive towards a safer, more sustainable planet is a rise in demand for critical minerals such as lithium, nickel, cobalt, copper and platinum group metals. These materials are essential for clean technologies such as electric vehicles (EV), wind turbines, solar photovoltaic (PV) panels and electricity networks. According to the International Energy Agency (IEA), to reach the goals set out by the Paris Agreement, the mineral input for clean technologies will need to quadruple by 2040.

The renewable energy sector is fast becoming a leading driver behind the global mineral market, meaning there is increasing pressure on primary extraction to meet demand. This poses several problems.

Not only are critical minerals expensive to extract from primary sources, but they may come with a high human or ethical price tag. Metal extraction has been associated with issues including human rights violations, child labour, geopolitical tensions, water stress and biodiversity loss. For example, cobalt, a primary material used in lithium-ion rechargeable batteries for EVs, has been linked to modern slavery in the Democratic Republic of Congo, where three-quarters of the world’s cobalt mining takes place.

Primary extraction also involves processing large volumes of extraneous ore to achieve a relatively small amount of the required materials.  

Losing critical minerals in waste 
While demand for critical minerals is rising, at the same time, every day we throw away vast volumes of critical resources – precious metals, minerals and chemicals.

Electronic household waste such as PCs, laptops, mobile phones and batteries, and industrial waste like automotive catalysts are crammed with precious metals. However, inefficient waste management, consumer behaviour and a lack of awareness mean that some of these materials are only used once, when they could be recovered and their value put back into the economy.

While the equipment and products may be reaching the end of their initial use, the materials themselves have plenty of life in them, and their disposal in landfill can be hazardous.

One solution to meeting growing critical mineral demand is to scale-up the recovery of critical minerals from end-of-life products.

A solution in plasma technology 
The good news is that there is a way to extract critical materials from spent devices and equipment, prevent hazardous waste reaching landfill, and create a beneficial by-product. And the answer lies in plasma technology.

Just as critical materials are initially mined from the earth, recovering materials from waste is a process in itself. If we follow a PC’s journey past its usable life, for example, its responsible owner takes it to the municipal household recycling centre or puts it in an e-waste dumpster. Initial processing at a waste management centre strips and shreds the plastics and isolates key materials for extraction. The critical materials are concentrated in the remaining printed circuit boards (PCBs) and can go through a controlled process, where plasma technology is applied and the precious metals are recovered. Any spent materials are converted into substances that are benign to the environment.

The good news is that there is a way to extract critical materials from spent devices and equipment, prevent hazardous waste reaching landfill, and create a beneficial by-product.

Why plasma? Plasma is an electrically charged – or ionised – gas. It’s sometimes described as the fourth state of matter and occurs naturally in the environment in lightning, sparks from static electricity and the aurora borealis. Plasma is used in television screens, fluorescent lighting and even arc welding.

Recovering critical metals from electronic equipment via plasma technology involves introducing the materials in the PCB feedstock into a sealed furnace and using a plasma arc to apply intense heat and ultra-violet light in a controlled environment. The chemistry separates and recovers the valuable metals, minerals and other materials from the feedstock. The process destroys any hazardous elements and leaves behind a non-hazardous glass-like material. Because it is powered by electricity rather than fossil fuels, plasma technology can be one of the cleanest thermal processing technologies available.

Using plasma technology to recover precious metals can help drive a circular economy, returning significant environmental and economic benefits. With Statista claiming a global average of more than 50mn tonnes of e-waste produced yearly, the unlocked value in the volume of recoverable resources is astonishing.

Plus, as we transition to a clean energy system, new waste streams will emerge as clean technologies start to reach their end of operational life. For example, the first wave of end-of-life EV batteries is estimated to produce 1.7mn tonnes of battery waste in 2030. This represents a huge opportunity for critical mineral recovery and the metals can be used again in clean technologies needed for the energy transition.

Using plasma technology, we can make the most of the critical minerals that already exist in waste and avoid some of the risks associated with primary extraction, while facilitating a truly circular economy.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.