Many of those informal recyclers use caustic and toxic cyanide solutions to strip gold, silver and platinum from circuit boards and other obsolete electronic items. Taiwan-based UWin Nanotech Co. Ltd. has created a non-cyanide-based alternative chemical that it says can alleviate many of the hazards at these operations.
UWin’s Kenny Hsu says a bath of the UWin solution attracts gold particles to two stainless steel cathode plates on either side of a tank. After the gold is collected, the solution can be filtered and recycled for reuse, said Hsu.
Tin also can be recovered with the system, said Hsu, with one metric ton of treated cell phones yielding 400 grams (14.1 ounces) of gold and 80 kilograms (176 pounds) of tin.
The UWin chemical process is in use on a large-scale at the Wistron Corp. precious metals refinery in Texas, said Hsu. Systems can be designed at many different scales and sizes, he added. “This can change your impression of gold recovery completely,” Hsu stated.
Electronics Recycling Asia was organized by Switzerland-based ICM Ag and held at the Shangri-La Hotel Singapore Nov. 11-14.
|
.JPG)
.JPG)
