Two high value metals in discarded printed circuit boards Metal Tech News – Nov. 11, 2020
EnviroLeach Technologies Inc. has taken additional steps toward its goal of developing an environmentally friendly process for recovering the roughly US$4,000 of gold, copper, tin, palladium, and silver contained in every metric ton of printed circuit boards from outdated computers, last generation smartphones, and the numerous other electronics becoming obsolete with the forward march of technology.
While each type of circuit board has its own special blend of metals, it is estimated that the average metric ton of these electron superhighways at the heart of nearly every electronic device contain roughly US$1,800 worth of gold, US$1,300 of copper, US$400 of tin, US$350 of palladium, and US$300 of silver.
At these rates, there is somewhere around US$639 million of metal in the approximately 166,000 metric tons of outmoded circuit boards in old electronics that are stuffed into desk drawers, sent to recycling centers, or simply thrown into landfills each month.
Currently, the circuit boards that make it to recycling centers are shredded and sent to smelters that melt down the components to recover the gold, copper, and some of the other metals. While effective, this heat intensive method is not efficient and sends large quantities of carbon dioxide into the atmosphere.
In an effort to develop a more environmentally sound process for recycling electronic waste metals back into the economy, EnviroLeach has developed a method that uses five ingredients that are FDA approved for human consumption to dissolve the metals in recycled electronics and a diamond-based electrochemical process to ultimately recover them.
EnviroLeach says its process offers an almost zero environmental footprint – no atmospheric emissions, water discharges, or special storage for solid waste material.
"We are setting a new paradigm for sustainable and economic metals processing," said EnviroLeach Technologies President and CEO Duane Nelson. "EnviroLeach is clearly establishing itself as a market leader with a best-in-class technology solution."
A year of extensive laboratory testing has demonstrated the EnviroLeach process capable of recovering high purity copper and 92.6% of the tin from circuit boards.
"The last 12 months of extensive research and laboratory tests have confirmed the viability of the tin-copper recovery process," said EnviroLeach Technologies Vice President Ish Grewal. "The potential high mass reduction delivers multiple benefits such as the higher concentration of residual precious metals, the reduction of smelting and shipping costs, and of course the reduction of carbon dioxide equivalent emissions associated with the current smelting of whole PCBs (printed circuit boards)."
EnviroLeach's non-toxic formula has already proven highly effective at dissolving and recovering gold, silver, and palladium at its 3,600-metric-ton-per-year printed circuit board processing facility in Vancouver, British Columbia.
This western Canada plant includes state-of-the-art grinding and separation circuits, as well as a leach circuit that uses EnviroLeach's patented and reusable formulation.
Earlier this month, EnviroLeach announced an initial purchase of 42.5 metric tons of end-of-life printed circuit board assemblies from an established Middle Eastern e-waste supplier. The company said the 15 metric tons of high-grade and 27.5 metric tons of low-grade circuit boards purchased will provide feedstock at its processing facility.
With the Middle East and North Africa seen to be an important supplier of e-waste for its recycling process, EnviroLeach Technologies Chief Technical Officer Hanif Jafari has visited the region in order to foster relationships with e-waste suppliers in the region. He is also investigating the viability of starting up a sorting and primary processing facility somewhere in the Middle East or North Africa.
EnviroLeach is also a co-owner of Group 11 Technologies Inc., a US-based company that is developing a means of in-situ mining of gold, silver and potentially other metals using the EnviroLeach formula.
Additional information on Group 11 can be read at Group 11 intends to disrupt gold mining in the Sept. 2 edition of Metal Tech News.
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