Gold Content of Scrap Items Series: 3COM ISA Network Cards

lazersteve · Jun 22, 2007

All,

I decided to start a new series of posts detailing the yields of harvesting various scrap items.

The first installment in this series will be the yield data on network cards like this one:

I determined this information based upon two hundred and fourteen 3Com 3c509TP Etherlink III ISA ethernet network cards with RJ45 and AUI connectors.

Here's the box of the 214 cards after the fingers and AUI pins were removed:

Here's an overview of the before and after shots:

Now for the yield information:

The 214 cards yielded 600 grams of fingers and 125 grams of gold plated pin tips from the 16 pin AUI connectors. The fingers are in the large bag in the photo above and the AUI gold tips are in the quart sized bag. The small bag contains the unplated portions of the AUI pins and weighs 64 grams.

Every 5 cards weighed 15.8 ounces (~1 LB) and yielded 14 grams of clean cut fingers.

28 grams (1 ounce) of fingers (10 cards worth) produced the foils seen in the jar in the upper right corner of the photo above. Here's a closeup of the foils:

I haven't melted and weighed the foils yet, but I will update this post with a photo of the gold BB they form and a weight for the BB.

Additionally, I'll be filming portions of the processing of the fingers pictured here to demonstrate the process in detail for everyone.

My next installment will show yield data for slotted processors.

Steve

aflacglobal · Jun 23, 2007

You are a fine gentlemen. I cannot believe the extent that you go thru sometimes to educate us. Thanks again steve.

Ralph

:wink: :wink: :wink:

lazersteve · Jun 23, 2007

Ralph,

I'm glad someone appreciates my hard work. :lol:

It's a labor of love. I've been clipping fingers and plucking pins for several days now on and off. Ultimately we will all have the knowledge required to accurately determine the gold yields from specific types of scrap and therefore it's value based upon the gold content.

This first installment is not complete. I'll add the gold yield data after I purify and melt all the foils from the 214 cards.

My plan is to do a long series of these yield data posts and then make a master post that will have links to the various scrap types. What do you think of that idea?

Steve

Paige · Jun 29, 2007

Steve,

I apologize for not posting; you have my most sincere appreciation for what you go thru to educate me and to the extent others need it, for them as well.

You are a very fine gentleman.

Paige

Noxx · Jun 29, 2007

This is a VERY VERY good idea. This kind of informations is very essential.

Will you only test the resulting gold from 10 cards or you will process larger batches ?

Thanks

lazersteve · Jun 30, 2007

Noxx,

I'll be processing the 600 grams of fingers to get the yield for the entire lot of 214 cards. This will give a good average. Besides the foils from the 10 cards is too light to register on my scales.

Steve

Noxx · Jun 30, 2007

Yea, that what I taught. Good luck !

firedan525 · Jul 7, 2007

Wow Steve, we definatly appreciate your level of dedication to the hobby and to our learning. We are all young jedi, teach us the force. It is stong with you. Thanks Dan

lazersteve · Aug 3, 2007

I'm finally getting around to posting the yield data for the ISA network cards.

The 214 above mentioned ISA Cards produced the following button:

The final yield data works out as follows:

600 grams of fully plated, double sided, ISA fingers yields 2.5 grams.

So for per pound of fingers yield data we have:

(454 * 2.5) / 600 = 1.89 grams Au per pound of fingers.

For per card we have:

2.5 / 214 = 0.012 grams Au per double sided fully plated ISA card.

I'll post the data for the pins as time permits.

Steve

mike.fortin · Aug 3, 2007

Lazersteve--nice work!! I gots a question. I want to practice catfish and GSP math exampls against your real purdy buton. Can you give me the L & W of the short strip? The Long strip? Gold today makes per card about 26c in finger foiles. Right? Mike.

lazersteve · Aug 3, 2007

Mike.Fortin said:
Can you give me the L & W of the short strip? The Long strip?

Each foil contact is 2 mm x 5 mm.

The short finger strips have 18 foils per side.

The long finger strips have 31 foils per side.

Let us know what you come up with.

Steve

mike.fortin · Aug 4, 2007

Lazersteve--thanks. I guess I need to do this with everone looking in. I start with the 2mmx5mm at 10sqare mm per foil pad x 36 bothside pads on short ones. That be 360sqare mm foil per shortstrip. 214 short strips x 360sqare mm foil = 77040sqare mm on short ones. How am I doin so far? And how do I figure out how thick this gold is. Thats somthing GSP and catfish can guess at and I have no clue. Long strips will be 2mmx5mm@10sqare mm per foil pad x 62pads on longones. That will be 620sqqare mm foil per long stirp. 214 long strips x 620sqare mm = 132680sqare mm on long ones. This metric messess with my mind. So I add 132680sqare mm longs and 77040sqare mm shorts for total 209720sqare mm area. I still dont know how thick the gold and I dont know what todo next. Help? Mike.

lazersteve · Aug 4, 2007

I believe the estimated foil thickness is 30 mils according to Catfish and GSP.

Steve

catfish · Aug 4, 2007

Hey Mike:

Let me see if I can weigh in on this.

One pad is 2mm x 5mm+10 sq mm

10sqmm = .0155 sq in. per pad.

Each board has a total of 49 pads on each side for a total of 98 pads per bd.

.0155sq in x 98= 1.519 sq in per bd.

Today’s price of gold is 672.70 per oz.

.672 x 1.519 x.30=.306 or roughly 31 cents per bd.

214 bds x .31= 66.34/21.63 per oz of gold = 3.06 grams gold per Silverpros method.

My method is as follows:

10mm=.0155sqin X 98=1.519sq in per bd

214 bds x 1.519=325.066sq in at 30 u in thick would be .00975 cu in of gold

.00975 sq in = .1598 cc
19.3 grams per 1 cc= 19.3x.1596=3.08 grams of gold if the pads was 30 micro inches thick

If they were 20 micro inches then the expected gold yield would be 2.05 grams

It appears the gold thickness is about 25 micro inches

Catfish

lazersteve · Aug 4, 2007

Catfish,

Thanks for doing the math. The thickness may indeed be 30 mils as my scale accuracy is +/- 0.5 grams so the button could actually be slightly over 3 grams. I used the value as read from the scales for my example. I really need to get my +/- 0.01 gram Ohaus electronic scales fixed (they read only 1/2 of the actual weight). I've tracked the problem to a precision resistor on the board, but haven't found the correct resistor yet.

Steve

lazersteve · Aug 4, 2007

This is a test. This thread is giving me errors when accessed.

mike.fortin · Aug 4, 2007

catfish said:
Hey Mike:

Let me see if I can weigh in on this.

One pad is 2mm x 5mm+10 sq mm

10sqmm = .0155 sq in. per pad.

Each board has a total of 49 pads on each side for a total of 98 pads per bd.

.0155sq in x 98= 1.519 sq in per bd.

Today’s price of gold is 672.70 per oz.

.672 x 1.519 x.30=.306 or roughly 31 cents per bd.

214 bds x .31= 66.34/21.63 per oz of gold = 3.06 grams gold per Silverpros method.

My method is as follows:

10mm=.0155sqin X 98=1.519sq in per bd

214 bds x 1.519=325.066sq in at 30 u in thick would be .00975 cu in of gold

.00975 sq in = .1598 cc
19.3 grams per 1 cc= 19.3x.1596=3.08 grams of gold if the pads was 30 micro inches thick

If they were 20 micro inches then the expected gold yield would be 2.05 grams

It appears the gold thickness is about 25 micro inches

Catfish

Catfish--thanks for the help. I am still confused in a coupl places. Math is just not my best subject as you can tell. One place I dont understand is where GSP moved the point on gold price left 3 places. Do you know why? One yours I got messed up where you changed.00975 cu in to .00975sq in when you was turning into cc. And is the 1cc = 19.3 grams becasue that is the denseness of gold? Sorry to bother you. Im just rying to learn. Mike.

goldsilverpro · Aug 4, 2007

I've changed my formula a little bit. I now move the decimal place 4 places or, divide by 100,000 - same thing. I covered it in detail, here:

https://goldrefiningforum.com/threa...mount-of-gold-in-electronics-and-jewelry.809/
Here's the bottom line:

Dollar value of gold plating = Spot price divided by 100,000 X thickness in micro" X area in square inches.

Example: The gold spot is $650. You have 9.58 square inches of gold plate that you estimate to be 30 micro" thick.
650 divided by 100,000 X 9.58 X 30 = $1.87.

There is no answer to "why" this works. I was playing around with the math one day and just happened to notice the similarity between the two. Pure coincidence. Actually, there is a mathematical answer but, it's not worth worrying about. The method is about 98.5% accurate. Plenty accurate for what we're doing. The accuracy for the thickness estimate is far worse.

NOTE: I originally made an error in this post. Instead of dividing the spot by 100,000, I divided by 10,000. The correct number is 100,000. I have edited this post to the correct value.

catfish · Aug 5, 2007

Hi Mike:

I am glad that you are trying to learn how to determine the value of scrap and how to make an educated guess on the approximate value.

Mike on the issue of confusion where I changed the cubic inch figure to cubic centimeters; Wikipedia http://en.wikipedia.org/wiki/Gold sez that the density of gold (at near room temperature) is 19.3 grams per cubic centimeter. This makes the quantity of gold much easier to determine that using cubic inches.

I found that it is much simpler to convert your final cubic inch number to cubic centimeters and then multiply that number times the density of one cubic centimeter’s density of gold. Example .1598 cc times 19.3 = 3.0841 grams of expected gold.

Mike, the following web site http://www.sciencemadesimple.net/conversions.html is an excellent tool in number conversions and I have found it to be very accurate. I always use 4 decimal places in any scientific computations.

I hope this clears up the confusion.

Catfish

Edited to add the following:

I am still at a loss on how Goldsilverpro's formula comes out so close to the actual computation of the cubic volume of gold. When I get some time, I am going to do some serious number crunching on this problem. I am confused, if the value of gold changes dramatically, how would the formula track.

All I know for sure, it works and is certainly close enough for our purposes and definitely a lot simplier

Tom

aflacglobal · Aug 5, 2007

I got messed up where you changed.00975 cu in to .00975sq in when you was turning into cc. And is the 1cc = 19.3 grams becasue that is the denseness of gold?

This would make a good poster for the wall. Theirs that confusion ctafish. :wink:

i was wondering if it was just me. Luckly i am good at math so i understand it.

Gold Content of Scrap Items Series: 3COM ISA Network Cards

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