Circuit boards inside electronic devices use a small amount of gold on key connections because of its conductivity and other properties. While many circuit boards are simply discarded, some companies--and even individuals--have turned to gold reclamation to strip circuit boards of their small quantities of gold.
Cleaning the Circuit Board
When a circuit board is first pulled out of a computer for gold reclamation, it is covered in miscellaneous circuitry and devices that have no gold in them. They must be stripped from the board before the gold can be recovered. This process is performed either by hand or machines, and involves removing any non-gold materials from the board, including integrated circuits, screws and batteries. Once these extra pieces have been removed and safely discarded, the actual gold reclamation process can begin.
Removing the Gold
Gold can be removed from circuit boards in a variety of ways. It can be scraped off of the boards by hand, which is time consuming, but yields excellent results. The gold can also be removed via a process known as reverse electroplating, where a chemical solution and electricity are used to draw the gold off of the circuit board. Finally, gold can be removed by dissolving it in a harsh chemical bath, then drained and purified. Chemical baths are some of the most common form of gold reclamation, and while dangerous for individuals to perform, provide the best results.
Purifying the Gold
Once gold has been scraped or dissolved from a circuit board, it must be purified and melted down before it can be sold. The purification process depends largely on the removal process that was used. If electroplating was used, the gold can be scraped off of the electrode used to draw the gold off of the circuit board. If the gold was scraped off of the circuit boards by hand, it can be filtered for any non-gold particulates and melted down. If, however, the gold was removed in a chemical bath, a lengthy filtration process is required before the gold is pure enough to melt down. This purification process involves running the gold through a series of chemical baths and filtration systems, which separate the gold from other metals that may have been dissolved from the circuit board.