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"To make gold, start with gold"


Regarding electronic scrap, let's run some numbers. Suppose you have a pile of circuit boards. Sell the CPUs (468, Pentium etc.) on ebay. You'll get between $1.00 and $2.00 each as of this writing. The only other enticement in your hoard might be the plated edge contacts, also called "fingers". Assume that you have diligently clipped off 100 fingers and each one is 10 cm long and 1 cm wide. Each finger has a surface area of 10 cm2 and the area of the total batch is 1000 cm2. With me? Plating thickness varies and it is way less than you think. Let's use 0.5 micron plating thickness (an average value), or 0.00005 cm. Our volume, then, is 0.05 cm3 of plated gold on top of base metal. The density of gold is 19.3 g/cm3, so we have 0.965 g of gold in our batch of 100 fingers. Today, gold is selling for $420 tr oz or $13.50 per gram, so our theoretical yield is $13.

In summary,

100 fingers 10 cm long should yield about 1 gram of gold that is worth the gold spot price per gram on any given day. Right? NOT REALLY... read on, young Jedi!

What if the karat weight of the gold plating is less than 24K? If so, then expect between $7 to $10 worth of gold per 100 fingers.

AND...... what if the plating thickness is smaller than 0.5 micron? If so, then expect about $5 per 100 fingers.

AND AGAIN.... what if your refining process and/or skill level is only capable of recovering 70% of the values in solution? Now you are down to $3.50 for every batch of 100 fingers. Does that cover your expenses? Is it worth your time & trouble? You must decide.

After a few hundred years of toil, the alchemists finally gave up. Now, clipped PCB fingers are selling on eBay for $20 per pound (on average). Why? Gold fever!

Dave Catherman
former alchemist - Connecticut, USA


Darn it! I guess I'd better keep my day job.

Trent Kaufman
Trent Kaufman
   electroplater - Galva, Illinois

2005 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

I have several hundred gold plated nuts, I would like to reclaim the gold from. What process could I use to accomplish this?

Gary Thompson
- Rancho Cucamonga


Hey Dave,

That was a helluva good reply you did. I couldn't do that !
But as an alchemist, do you ever read the ALCHEMISTS DIGEST?

Back in the 60's I go to this lab in Montreal and they're making gold.

One goes through a special door with a security wallah who looks at me very suspiciously .... and there, on the floor, is a HUGE pile of gold dust. I always wanted to lift up some gold dust in my hands ... which I did ... but the guard has an itchy trigger finger so regretfully I put it back again.

freeman newton portrait
Freeman Newton [dec]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).


Ed. note: The Alchemist's Digest is the newsletter of the SMA and CMA. It is published three times a year and is included with membership. For a copy of the most recent issue contact: customerservice@sma-online.org

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