Gold is a precious metal in extremely short supply on our planet. In fact, only about 190,040 tons of gold have ever been mined in recorded history, which equates to about 4 swimming pools. And the majority of that gold was extracted from ore taken from gold mines.
Gold ore includes platinum, silver and other precious metals apart from gold. The process of separating the gold begins by crushing the gold ore into a fine powder. Chemicals are then used to extract a solution of gold and other valuable components. The solution (pregnant solution) is placed in an electrolytic bath where difficult-to-ionize gold, platinum, silver and other elements are deposited out of the solution. The extract is then melted down in a high-temperature oven, where high specific gravity gold settles to the bottom and can be separated. At this point, the gold is 98% pure.
After repeated refining, the purity of the gold increases to 99.99% and that is what is used to manufacture gold bullion ingots.
China once had its share of gold mines with high concentrations of gold, but with not enough gold remaining to make mining profitable any more, the majority of those mines are now closed.
In China, instead of gold mining, Urban Mining is currently attracting a lot of interest. In fact, there is a vein of gold running through towns and cities that carries much more gold than that left in gold mines. That gold is in our computers, cell phones, digital cameras, game machines and other devices. Of the precious metals, gold is the least susceptible to corrosion and degradation, and because it can be stretched into fine filaments or thin leaf and is highly conductive of electricity, it is also an essential part of precision manufactured products. Only a very little gold is used in a single product, but when all collected together it rivals that collected from a huge mine, so we call this recovery process Urban Mining.
DKS Technology is able to recover precious metals from Urban Mining in Japan, from which it refines high purity gold. This recycling process is explained below.
