The number of printed circuit boards that are manufactured each year is growing at a rate of nearly 9%. Two of the world’s biggest producers, Taiwan and China, are alone producing more than 200 million square metres in a twelve-month period.
These boards then make their way into electronic devices, from data sensors to mobile phones and everything in between. But what happens when these products are discarded?
In many instances, electrical goods can be recycled in an environmentally friendly way, especially here in the United Kingdom and other countries that form the European Union.
Yet despite having strict laws, the methods used to recover valuable metals present on populated PCBs can release toxic fumes. And that only covers the goods that are sent off for recycling – many consumer items are still thrown away with general household waste.
This means that the substances used in electronic manufacturing, often heavy metals and dioxins, can leak out and pollute the earth due to their toxic nature.
However, researchers at Shanghai’s Jiao Tong University believe that they have discovered and environmentally friendly way of recycling and disposing of PCBs. The technique that the Chinese team have developed involves grinding the plates down and then using a high voltage electric field to separate the metallic and non-metallic products.
The metals – such as gold and copper – are then recovered by a process known as vacuum fractional distillation. The non-metal components can be compressed and used in the construction industry.
The Jiao Tong University team tested this technique with 400 kilogrammes of PCBs, collected from a variety of electronic workshops and household waste centres.
This process is yet to be rolled out or indeed tested on a wider scale anywhere else. But Derek Fray, a researcher in the field of material recycling at Cambridge University, believes that this breakthrough is an important one.
“This is an interesting technique that can be part of a portfolio of technologies to treat printed circuit boards,” he said.