Every year about 400,000 tons of waste printed circuit boards (PCBs, see Figure 1 for an example) are collected in Europe representing a large resource of precious, critical and other metals such as gold, platinum, palladium, copper and solder; often in concentrations significantly higher when compared with their ores i.e. copper (0.5–1% copper), gold (1–10 g/ton gold).
PCBs are used to mechanically support and electrically connect electronic components. They are used in almost all electronic equipment such as televisions, computers or mobile phones.
Waste PCB are difficult to recycle as tyres are designed to be durable and tough. This durability and toughness of tyres is a result of their composite nature made of resin, glass fibre, copper clad boards, solder and electronic components.
Composite Recycling Ltd (CRL) developed a patented PCB recycling process, which uses molten salt at temperatures of 350-400°C. The technology uses whole PCBs, significantly reducing capital and operational costs compared to other processes, who shred the PCBs and while doing so loose precious and other metals. Moreover, the PCBs are recycled within 15 minutes. Combined these two advantages result in an economic process.
Composite Recycling Ltd’s PCB recycling technology (PCBRec) offers many significant advantages over current technologies, which is also the unique selling proposition (USP):
1. Yields: over 95% recycling rate of copper, steel and solder [1, 2] greatly exceeding the recovery rates of current technologies of 70-80% [4].
1. PCBRec boosts the recycling yields of technology metals (indium, tantalum, etc.) to 50-80%. Moreover, aluminium, solder and steel is separated and recovered in metallic form rather than incomplete as by typical metallurgical processes.
2. Critical and special metals: for the first time, metals such as indium and tantalum will be recyclable.
3. All types of PCBs: high value (motherboards; high gold content) and low value (TVs; low gold content) PCBs.
4. No shredding: energy efficient process - no prior opening of lithium batteries or mobile phones resulting in cost savings.
5. Simple process from established industries: no moving parts, low capital cost. Easy to operate.
6. Continuous process: large throughputs are possible.
7. Scalability: Easy scale up: doubling the salt volume, doubles throughput. Modular technology, allowing further capacity increases in a systematic fashion.
The main objective of the study, establishing the technical, environmental and the economic feasibility of the PCBRec process on a commercial scale has been achieved.
