recycling

In a circular economy, recycling is a preferred option after reuse, repair, remanufacture and refurbishment. In recycling, an obsolete product is processed to recover and produce new materials (e.g. technology metals).

Recycling offers both environmental and energy benefits. For example, if electronic waste (e-waste) is landfilled, heavy metals and hazardous chemicals could be released and they may cause negative impact on human health and the environment.

Compared to mining, metal recycling uses less energy and saves resources. To produce one tonne of lithium carbonate, 300 tonnes of rock must be processed and around 370 tonnes of gross brine. To produce the same amount of lithium, it is enough to recycle 28 tonnes of lithium-ion batteries from electric vehicles.

However, recycling suffers from insufficient collection. In the case of technology metals, their recycling rates are very low. This is due to their use in small amounts in a miriad of products and often in complex configurations. Recycling of technology metals requires therefore new and innovative technologies. 'Design for recycling' is of fundamental importance to ensure that the efficiency of recycling increases, as well as improvements in collection and segregation processes.

Recycling metals

Recycling offers the opportunity to recover metals that are essential for the decarbonisation of the economy, such as copper, lithium, nickel, etc. These metals are found in various quantities in everyday objects such as electrical and electronic waste, vehicles, industrial equipment, packaging, as well as in industrial processes that derive metal waste. Recycling may vary substantial depending on the end-of-life product or waste stream characteristics. For example, e-waste recycling involves dealing with complex waste composed of three different layers: metals, organic materials (plastics, etc.) and inorganic materials (ceramics, glass).

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recycling Processes

Current recycling processes involve:

Physical methods shred the materials to reduce their size and free the metals from any casing. Inorganic materials, metals and organic materials are then separated according to their different physical properties (magnetism, density, electrical conductivity, etc.). However, a fraction of the metals is lost during the process and hazardous dusts are likely to be produced.
Pyrometallurgical processes subject the waste to very high temperatures, allowing the metals to be concentrated in an ingot. Organic materials are used as fuel for the process, but their incineration releases hazardous gases and chemicals. Inorganic materials produce slag in which some metals are lost.
Hydrometallurgical processes use strong chemicals (acids, bases, oxidants) to dissolve metals in aqueous solutions. This method consumes large quantities of chemicals and produces hazardous liquid wastes. The limitations of current processes must be addressed by developing innovative and sustainable processes for metal recovery. Very often, recycling processes use a combination of physical, pyrometallurgical and hydrometallurgical methods to recover high purity metals.

A new era for metal recycling

Until now, metal recycling has focused on IT equipment and e-waste (smartphones, refrigerators, televisions, etc.), which contain small amounts of technology metals. The collection of this type of waste is difficult because the items are scattered among different households.

But in the near future, new sources of waste will appear and make recycling more favourable. These items will contain large quantities of metals (lithium-ion batteries from electric vehicles, magnets from wind turbines, etc.). They will be easier to collect because large quantities are in one place (solar and wind farms) and their life span is predictable. The value of the metals contained is also higher, giving rise to greater economic incentives for recycling (platinum group metals in catalysts for hydrogen production, etc).

Better processes

Innovative methods are emerging to improve metal recycling. These methods would improve the collection of dispersed tech waste through the use of digital product passports. They would improve the sorting and separation of different wastes through the use of artificial intelligence (computer vision).

Current processes involve shredding, burning or dissolving inorganic, organic and metallic phases without distinction. A better approach to recycling would be to use tools specifically designed to target weaknesses at the interface between these different layers. Such tools include ultrasound to selectively remove brittle inorganic layers, chemical approaches to selectively dissolve organic layers, selective dissolution of metals using sustainable solvents, hydrogen embrittlement for the recovery of lanthanide elements in magnets...

Legal and regulatory:

Recycling targets vary for different products, and generally do not focus on component materials. Currently, recycling targets for products rich in critical minerals such as EV batteries are somewhat crudely defined in terms of setting a target by overall weight of product (e.g. for vehicles, just overall target 85%-95% by weight- this crude overall target does not necessarily help recover the most valuable material). More targeted legislation is needed to recover materials of greatest value
potential disadvantage of widespread reuse- will have negative impacts on recycling industry
transportation: costs and safety risks of transporting hazardous material for recycling
EPR regs only apply to specific product streams e.g. WEEE, automobiles, batteries
need to design for recycling: ensure ease of dismantling and disassembly to facilitate recycling
incentives and better awareness for consumers
policy incentives for recycling
smarter collection mechanisms that reduce cost and effort for consumer to recycle e.g. portable batteries
Permitting mechanisms to facilitate recycling e.g. metal recovery conditions targeted to CMs

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