Gold Refinery Procedures
In the past when gold exists in heavy black sand concentrates or when it is crushed from quartz rock miners have used cyanide and mercury to dissolve the gold and separate it from the ore. Because of the exclusive properties of gold it dissolves in very few materials and unfortunately they are all toxic.
The New Zealand Crown Mines Company at Karangahake was the first company in the world to use cyanide for large scale commercial mining. The cyanide was mixed with the quartz ore after crushing and enabled a major breakthrough in gold recovery rates for 1889. They were able to recover a staggering 90% of gold and 50% of silver from the crushed concentrates. The success was such that they were able to profitably rework old tailings (previously processed material).
For the recreational prospector or small scale gold miner there much safer alternatives to the toxic chemical solutions. Modern applied science has been fined tuned to enable gold to be cleaned with a near 100% recovery rate without chemicals. Today we can use centrifugal force and water reticulation to safely extract all the gold from your concentrates with The Gold Lab.