Published: December 14, 2011
REVISEd: November 22, 2015
Gold fingers or the edge connectors that provide the electro-mechanical connections between daughter, which include memory modules, to a computer'smother board provides the most value-rich resource of gold in e-scrap computers.
Not all edge connectors are gold plated. Most modern printed circuit board manufacturing processes bond a type of tin foil to the board to provide the electronic channels. High quality boards used in older computers and for some telecommunications and military applications may use gold plating rather than tin. Other boards are manufactured with a gold plate applied to the fingers and those gold fingers form the basis for what the author wrote about here.
The easiest way to identify gold fingers is the color. Gold fingers in fact look like gold, such as the edge connectors in the photo included here, which shows a RAM stick. If the edge connectors look silver then those connectors are not gold fingers.
To process gold fingers, the recycler cuts the part of the circuit board containing the gold plated connector from the rest of the board. The remainder of the board is then set aside to determine if that portion of the board contains any other valuable components, such as processor chips, monolithic ceramic capacitors, or CPU's.
When reclaiming the gold from gold fingers, a processor should expect a yield of about 1.0 to 3 grams of gold per pound of gold fingers. If the recycler calculates the yield using the low end of the averages then result of gold recovery should be higher than the estimated yield.
There are approximately 31.1 grams to a troy ounce so the estimated value of a pound of gold fingers would roughly translate to the market price for an ounce of gold divided by 31.1. Therefore, if gold were selling at $1700 per ounce, a pound of gold fingers would be worth at least $54.66 or $1700 divided by 31.1. If you could buy a pound of gold fingers for $40 and arrange for processing at a cost of $10, then you would just about break even, less the amount paid for shipping unless the gold fingers yielded more gold than the low ball average, in which case the recycler may make a profit .
An alternative would be to collect the gold fingers and sell them to a home chemist for about $40 per pound. The home chemist would gamble on a higher gold yield than the low end average and would extract the gold from the gold fingers. The home chemist would then either stockpile the gold or sell the reclaimed gold to a gold dealer.
One place to sell the gold fingers is on e-Bay. There are always listings on e-Bay for scrap circuit boards for gold recovery. Gold fingers are a type of clean scrap because there are no mounted components to decrease the yield of gold. On e-Bay, the buyer and seller agree to a fair price through an auction process.
Another alternative for the recycler is to set up a lab and act as a home chemist to reclaim the gold. This is a very hazardous activity because most methods for reclaiming the gold from circuit boards involve the use of various combinations of acid solutions and electrolytic processes. The acids are hazardous and the fumes are toxic and corrosive. This activity must be performed in a well-ventilated area; preferably using a vented hood that incorporates a method to remove the toxic gases. No home chemist wants the EPA showing up and shutting down the operation. Once again, check on any local regulations before setting up such a lab.
Gold dealers buy gold according to the purity of the gold and the purest gold drives the spot price. When the commodities market specifies the spot prices for precious metals those prices reflect the prices paid for the purest precious metals. The purity rating for gold is the karat and the purest gold is 24k gold or 99.9% pure gold. Therefore if gold is selling for $1700 per ounce and a dealer buys an ounce of 24k gold, the dealer pays $1700 for the material.
Lower purity gold commands a lower price and much of the gold recovered from escrap is not 24k gold so the actual amount paid for this gold would be lower than the spot price and would be determined by the weight and purity. Aside from 24k gold some other common purity ratings are 18k, 10k, and in some markets purity may be specified to values ranging all the way to 1k.
So how is the purity of the gold determined?
Various tests help the buyer determine the purity of gold. Some tests involve the use of stannous chloride or other chemicals. An assay performed on the gold using an approved test method determines the purity and value of the gold. The assay procedure normally includes a charge. For very small quantities of gold, the assay fee may be higher than the value of the gold under assay.
The point is that an inexperienced home chemist may run into extreme difficulty when trying to sell the recovered gold because the buyer does not really know what the home chemist is selling. For beginning recyclers, the best bet may be to collect the gold escrap and sell the escrap as-is to a refiner. The refiner then pays the recycler up front for the scrap material and bases the amount paid to the recycler according to the grade of escrap sold.
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Really... on July 23, 2014:
you're an idiot.
cyberbot on November 02, 2013:
buddy, precious metals are troy ounces, 31.1 grams,
not regular ounces at 28grams.
throws the calculations out of whack.
Dizzious on July 16, 2012:
"There are approximately 28.35 grams to an ounce so the estimated value of a pound of gold fingers would roughly translate to the market price for an ounce of gold divided by 28.35. "
That's actually wrong. While there are ~28.35 grams in an ounce; Gold is not measured in standard ounces. All precious metals are measured Troy Ounces, and a Troy ounce is 31.1 grams.
It would be a good idea for the author to update this article with the correct information; as the use of oz t is considered basic knowledge in the precious metals trade.
@Bob Wortham - no, you cannot simply melt down gold-plated items to recover the gold. You generally would need to get some chemistry equipment and dissolve the items in strong acid. The correct type of acid will dissolve everything except for the gold; and then you can filter out the gold particles and either melt them down from there or refine them further.
This Old Guy (author) from Somewhere in Ohio on March 27, 2012:
You would want to separate the metals before you melt them. Although different metals have different melting points, controlling the temperature could be problematic.
I hope this helps.
Bob Wortham on March 24, 2012:
HI.I have separated some gold off of computer sticks or memory sticks. I also got some plactic and maybe a little silver, copper and alum mixed with it. I have it all in crucible if I melted it would each item separate from the gold and not mix in the gold. Thanks