# 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


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## 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:


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## 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


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## 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


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## 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


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## 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


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## Noxx (Jun 30, 2007)

Yea, that what I taught. Good luck !


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## 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


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## 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


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## 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.


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## 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


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## 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 [email protected] 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.


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## lazersteve (Aug 4, 2007)

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

Steve


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## 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


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## 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


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## lazersteve (Aug 4, 2007)

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


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## mike.fortin (Aug 4, 2007)

catfish said:


> Hey Mike:
> 
> Let me see if I can weigh in on this.
> 
> ...



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.


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## 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:

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=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.


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## 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


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## 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.


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## catfish (Aug 5, 2007)

Hey Aflac:

Us old farts get confused some times and our fingers and “other extremities” don’t always follow our brain. I think I lost him when I made a typo on .00975square inches instead of .00975 cubic inches.

Just always remember “old age and treachery will always prevail over youth and enthusiasm”. :x 

Keep the posts coming; I look forward each day to see what you are going to think up next. :lol: :lol: 

Catfish


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## mike.fortin (Aug 6, 2007)

Catfish--GSP---thanks for the replys. Ill just keep trying. Those URLs were shure helpful. Mike.


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## aflacglobal (Aug 6, 2007)

Auhhhhh !!! The duck. What’s he up to now. I have spent the last two days learning about RF waves. Or more deeply, magnetic flux. Basically that's all that energy is. From the atom, to the volt, to the magnet, radio waves, microwaves, light, matter, energy, you get the idea. Their is more to cover that one would think. People don't realize the role it plays in every day life. If you have something electronic, it is based on some magnetic Principal . Ever wonder how them chips get that coating of gold on the wafer. Plasma fields. 

One particular point of interest is crystal growing. :idea: 
Water can be acted upon by magnetic waves to create forces on the atomic level that are just crushing in effect and pressure. You think ultra Sonics is something. Send a magnetic wave ( not sound, magnet flux density ) thru a solution at a few MHZ or GHZ and the whole show changes. Physics is not just about controlling chemical processes with chemicals. As variables and parameters change, suddenly the impossible become the possible. At least more likely. lol

Just a report.


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## lmills148 (Aug 22, 2007)

lazersteve said:


> 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.
> 
> ...


Steve

this is great information, thanx a few questions tho:

1) the 15.8 lbs per 5 boards is that with foreign attachments, specifically the steel "things" at the end of the board that attach them to the housing?

2) have you processed the pins yet? what kind of yeild do you expect? 

3) do you bother with the rj45 jacks?

4) was there anything else that you harvested such as flat packs or mono.cap. that could contribute to the overall value of scrap.

from what I see so far it seems a good *"scrap value"* would be around 40cents per lb (allowing for cost of recovery refining and @50% margin).


.
Lloyd


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## lmills148 (Aug 22, 2007)

goldsilverpro said:


> There is no answer to "why" this works.



GSP
I applied this to a memory stick I had sitting around and it looks like this ...
1.05sq in.x.066x 20u = $1.38 does this sound right? 
I hope so I have about a thousand of these.
I didn't think the yeild was that hi.

.
Lloyd


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## goldsilverpro (Aug 22, 2007)

NOTE: Totally ignore this post. I used the wrong assumptions and the wrong math. I should have used 100,000, instead of 10,000. Everything about this post is wrong.

What is the 20u? Is this the number of individual fingers or the estimated thickness? In the following, I assume it is the thickness - 20 microinches?

You forgot to multiply times the gold spot and divide by 10000.

Dollar value of gold plating = Spot price divided by 10000 X thickness in micro" X area in square inches.

1.05 X .066 X 20 = 1.386. Now, multiply this times 659 (gold spot) and divide by 10000.

1.386 X 659, divided by 10000 = $.09


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## lmills148 (Aug 22, 2007)

goldsilverpro said:


> What is the 20u? Is this the number of individual fingers or the estimated thickness? In the following, I assume it is the thickness - 20 microinches?
> 
> yes thickness 20 microns
> 
> ...



sorry I wasn't clear this is what I did

*1.05sq in.(area)x $.066(spot price/10000) x 20 microns(estimated thickness)*

Lloyd


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## lazersteve (Aug 22, 2007)

Lloyd said:


> 1) the 15.8 lbs per 5 boards is that with foreign attachments, specifically the steel "things" at the end of the board that attach them to the housing?
> 
> 2) have you processed the pins yet? what kind of yeild do you expect?
> 
> ...




 The 15.8 *Ounces* per 5 boards is for complete boards, just as they come out of the pc.

 No. I expect between 0.5 - 1.0 grams per pound.

 When I run out of high and mid grade scrap I'll look into the low grade stuff. These particular RJ45 jacks are the type that are only partially plated. If they were fully plated I would process them as mid grade scrap.

 See part one of answer #3.

Steve


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## goldsilverpro (Aug 23, 2007)

I really screwed up, mathwise. If you have used my NEW method, you have been evaluating the gold plating at 10 times too high. I made a decimal point error. I hope I didn't cost anyone any money. What can I say?



> FROM lmills148: ....sorry I wasn't clear this is what I did
> 
> *1.05sq in.(area)x $.066(spot price/10000) x 20 microns(estimated thickness)*


 You calculated this to be worth $1.38, using my formula, exactly. 

I looked at the gold area, of about 1 sq.in., and a thickness of 20 micro", and I knew it couldn't be worth $1.38. Here's the right formula:

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

lmills148, back to your material. The calculation would be:

$660/100000 X 1.05 sq.in. X 20 micro" = $.138.

I have only given my NEW, FANCY method in 1 other place. I will edit all of my posts that contain this error and will add to each post a note, in blue, explaining what I did. Give me a couple of days days. Sorry, again.


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## aflacglobal (Aug 23, 2007)

1.05sq in.(area of my home)x $.066(spot price/10000)( My yearly salary) x 20 microns(estimated thickness of the IRS agents head doing my Audit)

Hey, think i will try that formula on my taxes this year.


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## lmills148 (Aug 25, 2007)

goldsilverpro said:


> *The Correct Formula*
> *Dollar value of gold plating = Spot price divided by 100,000 X thickness in micro" X area in square inches.*
> 
> lmills148, back to your material. The calculation would be:
> ...




I made a mistake as well I was using microns instead of micro inches.


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## Anonymous (Jun 17, 2008)

Hi everybody  ,



catfish said:


> Hey Mike:
> 
> Let me see if I can weigh in on this.
> 
> ...




19.3 grams per 1 cc
0.00193 grams per 1 micro metar on sq centimetar
http://en.wikipedia.org/wiki/Micrometre

If they were 20 micro metar


a. 20 (micro metar) x 0.00193 (grams per 1 micro metar / sq centimetar) x 9.8 (sq centimetar per bd) = 0.3782 (grams per bd) = 
0.3782 (grams per bd) x 214 ( bd) = 80.95 grams (grams per 214 bd) NICE but WRONG why :?: 

b. 2.5 (grams per 214 bd) / 214 = 0.01168 (grams per 1 bd) / 9.8 ( sq centimetar on 1 bd) = 
0.001192 (grams per 1sq centimetar on 1 bd) / 0.00193 ( grams of gold per 1 micro metar on sq centimetar) = *0.6176 microns of foil on the bd* WRONG or... :?:
http://en.wikipedia.org/wiki/Gold_plating#Electronics


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## catfish (Jun 17, 2008)

Hi Bonzo:

I am not sure I understand just what your point or question is! 

You may want to refer back to the site you posted as reference;

http://en.wikipedia.org/wiki/Gold_plating#Electronics

Please note that the reference states that: Quote;

(The resulting layer is typically only 97% pure and thin, typically (0.5-0.75 µm)).

Then if you will refer to;
http://www.sciencemadesimple.net/length.php

You will note that .5um or microns equal .000020 inches or 20 micro inches.
.75um or microns equals .000030 inches or 30 micro inches.

You will find that most consumer electronics equipment manufactured in the past 10 years, the gold plating will be within that range. Note there are still some exceptions though, some more and some less.

I think where you are getting confused is the difference between microns (micro meters) and micro inches. There is a big difference. All Federal Trade Commissions (FTC) standards for gold plate thickness are in micro inches or either microns. 

I believe if you will go back and refigure the problem by using either .000020 to .000030 micro inches or either using .5 micro meters (Microns) to .75 micro meters (microns) you will come up the same answer I did. Please remember that this is only one part of the equation. Thickness times the squared area should equal the cubic volume. Then apply the rule of 19.3 grams of gold equals 1 cubic centimeter or 1cc

By the way, GSP’s method is accurate enough for an estimate on the gold quantity in a circuit board or etc. with a flat surface and even if the surface is round, you can still figure the square surface area and come up with the same numbers. His way is much simpler and easier to use than my method.

If you will go back on the forum and read some of the earlier posts last year, you will find that several of the members made several test cases on how to determine the quantity of gold versus the actual amount of gold recover from the items. They came out very close. 

Hope this helps,

Catfish 


PS If you would like to discuss this futher, we need to move this discussion to a different thread on another subject, other that assaying.


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## Anonymous (Jun 18, 2008)

Thanks catfish,

yes, yes I was confused with micro inches and microns. :shock: 

This help very much to me.


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