It’s hard to grasp how fast electronics have transformed the world, and one of the most startling changes is the way technology has changed resource use. Meeting the demand for new electronic devices has been a massive boost for several mining industries, with a third of all copper and silver that’s extracted now being used for technology manufacturing. Even more striking is the fact that 80 percent of all extraction or rare earth and platinum group metals took place in the last 30 years. The problem is that this rate of extraction is putting resources under huge pressure. More rare earth metals have been sent to landfills in scrap electronics than exist in all known reserves.
This is obviously a serious concern, because as our reliance on technology increases the materials needed to manufacture it are becoming very scarce. It’s also an environmental problem – over two-thirds of the toxic metal dumped in US landfill is in scrap electronics and as the waste corrodes this leaches out into the soil and often the groundwater. Proper processing of electronic scrap could remove a major source of pollution as well as recovering valuable resources and saving huge amounts of energy – recycling rare earth metals from scrap needs a tenth the energy of mining fresh supplies.
Unfortunately landfill is still the most common way of disposing of electronic waste. Currently less than 15 percent is recycled globally, and for rare earth metals that drops to less than one percent. A large part of the recycling that does take place is outsourced to China; the global capital of e-waste recycling is Guiyu. Unfortunately environmental standards are low and Guiyu now has the highest levels of toxic dioxins ever recorded anywhere. There are also some creative recycling schemes in operation, such as refurbishing older-model cellphones for reuse, but manufacturers often object to these phones being unlocked and put back into circulation.
Now BlueOak Resources is aiming to set up an electronics recycling plant at Osceala, Arkansas, that will be capable of processing 7,500 tons of electronic scrap every year – and will have the potential for rapid expansion. The aim is to salvage valuable materials, and eliminate possible sources of pollution, using an advanced recovery process based around plasma arc technology. The plasma jet equipment will be licensed from Tetronics International, who specialize in metallic waste recovery.
Plasma waste processing uses a high-voltage electric arc to convert a stream of inert gas into an extremely hot jet of ionized plasma. This can have a temperature of up to 25,000°F, which is hot enough to break down chemical bonds within the waste. The result is that any complex organic molecules are broken down and converted to carbon monoxide, which can be reused as a fuel to generate some of the power required by the plasma jets. Other solids are converted to slag. Any metals in the slag can then be recovered using chemical or physical processed and what remains is sold to the construction industry.
Plasma arc reprocessing is a very clean way to eliminate potentially toxic waste that would otherwise have gone to landfill. It also allows for a very high recovery rate of valuable metals. Hopefully BlueOak will make a success of their Arkansas plant and substantially increase the recycling rate for electronic scrap.