Recovering gold, copper and other metals from electronic waste – a practice called “urban mining” – is not only more environmentally friendly than extracting virgin materials, but can also be more cost effective. Newly published research shows that the revenue from selling metals recovered through recycling television sets far outweighs the recyclers’ expenses. With these offsets, it costs 13 times more to obtain these metals from ore than from urban mining.
About 50 million tons of e-waste will be discarded around the world in 2018, according to the United Nations’ Global E-waste Monitor report. This waste contains over $50 billion worth of metals. For example, a typical cathode-ray tube (CRT) TV contains almost a pound of copper and more than half a pound of aluminum, though it only holds about 0.02 ounces of gold.
Researchers Xianlai Zeng and Jinhui Li of Tsinghua University in Beijing and John A. Mathews of Macquarie University in Sydney sought to determine whether recycled CRT TV sets were a viable alternative to mining ores. Published in the American Chemical Society’s journal Environmental Science & Technology, their study found that urban mining is not only cheaper than virgin mining, but is becoming more affordable every year.
The researchers obtained data from eight recycling companies in China to calculate the cost for extracting copper and gold from e-waste. Expenses included the costs for waste collection, labor, energy, material and transportation, as well as capital costs for the recyclers’ equipment and buildings. The urban mining costs for one-kg ingots of metal were found to decrease from $6.697/kg in 2010 to $1.684/kg in 2015 for copper, and from $8438/kg in 2010 to $1591/kg in 2015 for gold. By comparison, they estimate virgin mining to cost between $0.8-0.9/kg or $1.4-1.6/kg for copper (depending on the method used for extraction) and an average of $33,404.626/kg ($1039/oz) for gold.
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Once government subsidies and the revenue from selling recovered materials and components are considered, the total treatment costs for obtaining copper and gold from recycled CRT TVs was estimated to be 13 times less than from virgin mining. As such, the researchers see implications for the economic prospects of urban mining as a circular economy alternative to virgin mining of ores.
“Our results are confined to the cases of copper and gold extracted and processed from e-waste streams made up of recycled TV sets, but these results indicate a trend and potential if applied across a broader range of e-waste sources and metals extracted,” the abstract reads. “If these results can be extended to other metals and countries, they promise to have positive impact on waste disposal and mining activities globally, as the circular economy comes to displace linear economic pathways.”