There are various methods to remove these minute traces of gold from printed circuit boards, processors, and other peripherals. First requirement is milling of the PCB to expose the gold in the chips. Various methods can be used to break or mill the printed circuit board. The easiest and cheapest way of extracting gold from Printed Circuit Boards would be to mechanically cut off the tops of the microchips and carry out forging to melt all the metal that is present inside the chip. Gold has a higher molecular weight which makes it denser and heavier than other metals. Hence, any of the traditional methods of separation such as skimming, draining lighter metals or settling tank for heavier metals can be used.
There's another method for extracting gold from printed circuit boards in which, the Printed circuit board scrap is treated with one part concentrated nitric acid and two parts water at 70-80°C for 1 hour, which dissolves the base metals. As a result, it liberates the chips from the PCB.
Note: We will refer printed circuit boards as PCB in short hereafter.
Coming back to the process, after solid and liquid components are separated, the chips along with some metallic residue and Ti02 precipitate are mechanically crushed. This liberates the base and gold metal present within the protective plastic or ceramic chip.
The base metals in this pulverized product are further dissolved by leaching with the same composition of nitric acid and water. The remaining solid residues, crushed chips and resin and solid particles of gold are treated with aqua regia by leaching process at varying and suitable times and temperatures. Gold is then precipitated from the leaching product with ferrous sulphate.
There are plethora of options to extract gold from processors, PCBs, and other similar things. For extracting gold from printed circuit boards even in minute quantities, you may require a large number of PCBs. A metric ton would approximately have 80 to 1600 grams of gold. With evolving technology and development in PCB design, the amount of gold used for fabrication and creation of components is reduced. Moreover, before extraction you need to figure out the potential earnings involved with the amount of gold available on these PCBs, so that the cost of retrieving the gold does not exceed the cost of the gold obtained.
More so, there are many more things to be considered, before you try anything of this sort, and try to gain handsome profits out of all your hard work. Hence, before extracting Gold from Printed Circuit Boards, you need to do an economic assessment on the value of the recoverable gold to make the process worthwhile.
Various chemicals have the ability to remove and refine gold such as sodium cyanide and sodium meta nitro benzene sulphonate. Sodium cyanide is the cheapest available unless you can find calcium cyanide. However, the overall methodology is fairly complex in comparison to the other conventional ways. There are other ways of even using chemicals for Extracting Gold from Printed Circuit Boards. Looking for the Cheapest Way of Extracting Gold from Printed Circuit Boards - follow the link in resource box.