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As to why the stannous chloride test revealed a black precipitate it is possible the result was silver chloride which darkened on light exposure:

Intel Package Datasheet said:
A silver filled epoxy adhesive is applied to the package substrate at die attach. Dice are picked
from the wafer and placed on the adhesive. The adhesive is then cured.

The solder for the microPGA cpu lists the solder content as :

Intel Package Datasheet said:
After the pins are fixtured, 95% Sn 5% Sb solder is used to reflow the pins into the interposer.

Which is 95% tin and 5% antimony, this does not confirm the content of the solder for the PPGA heat slug which is listed as "high temperature solder" by the same datasheet. A preliminary google search also reveals a lead free substitute high temperature solder as SAC (Sn, Ag, Cu).

Lastly a search of the Intel Package Datasheet for Palladium reveals no results whereas a search for gold and other metals reveals several results.

Steve
 
I had used a magnet from a disassembled lab stirrer - not the most powerful magnet but not a very week magnet either.

There was no response but then again I did not disassemble the chip either.

I've not yet had the opportunity to dig out my muriatic and peroxide I've been disassembling an old frequency controller all morning and am unwrapping potentiometer coils at this moment thanks to the great info found here and on lasesteve's site.

Lots of pretty gold on these old electronics.

Somewhere I have some magnets out of a hard disk drive I will give them a shot if they show up.

I obtained these chips from Y-12 - the atom bomb plant here in oak ridge - sometimes they purchased special versions of what were otherwise common items - however I expect that you are quite correct these back plates are mostly nickel.

This thread has been a great deal of help and I am quite appreciative.

thanks
 
Thanks Steve.

Any idea on how I can consult that data sheet or similar data sheets?

Thanks again.
 
Aristo said:
Any idea on how I can consult that data sheet or similar data sheets?

I have it posted on my website. It's a portion of a larger document from Intel. I can provide links if anyone is interested.

Steve
 
DMG will turn bright yellow (precipitate) in the presence of palladium, on the acid side. On the ammonia(cal) side, nickel turns bright red.
 
goldsilverpro said:
DMG will turn bright yellow (precipitate) in the presence of palladium, on the acid side. On the ammonia(cal) side, nickel turns bright red.

I'm surprised DMG isn't used more by these guys. It was, to me, one of the most used test solutions, second only to stannous chloride.

Harold
 
Harold,

I think there are a couple of reasons, at least for me:

  1. Expensive
  2. Unknown until recently (for me)
  3. Hard to find

I would also guess that it may have been made harder to come by the powers that be like a lot of chemical reagents have become now days.

If I had some, I would use it, but I don't and the places where I know to get it from want an arm and a leg for very small amounts.

Steve
 
A gram of DMG is about a lifetime supply. One gram makes a 100 mL. of solution. One mL is about 20-25 eyedropper drops. It only takes one drop. That's 2000-2500 tests per gram.

Fisher Scientific, on the net, has 100 grams for $116. You could probably find it cheaper. You could spread the costs among, say, 15, or more, people and have someone get it, divide it up, and mail it out. Or, someone could buy it and sell it by the gram for a few bucks. Let him make a few bucks for the effort. It is harmless to ship, I think. Just use a small ziplock baggie inside of a pill bottle.

Fisher Scientific - DMG
 
Great information Chris, I had no idea the required amount was so small. I just purchased a 25 gram supply.

Steve
 
If you make the mistake of using this for refining Pd (it expands about 100 fold, at least), it would take a lot. For testing, a drop. You could sell 1 gram packages. It's the cat's meow (to get Ralph involved) for palladium and nickel testing, when the metal is in solution form.
 
goldsilverpro said:
If you make the mistake of using this for refining Pd (it expands about 100 fold, at least), it would take a lot. For testing, a drop. You could sell 1 gram packages. It's the cat's meow (to get Ralph involved) for palladium and nickel testing, when the metal is in solution form.

Yep! What GSP said! :)

Some of you may recall our dear friend that was banned from the board, who's name escapes me at the moment. Perhaps Steve will do a search and post a link to a post of his in which he actually provided some useful information on making the DMG testing solution. I wish I'd have known that when I was refining. I don't recall the details, but he alluded to what I'll say below.

DMG does not dissolve well in water. It requires extensive boiling, and even then the outcome isn't great. He suggested that it will dissolve readily in alcohol. That being the case, it's entirely possible it can be so dissolved, then water added. It is worth the effort to learn.

By the way, while I don't recall the price of DMG, it wasn't cheap even back in the 70's, when I purchased the small amount I needed. I never again needed to buy a second amount, and I used it regularly. Great stuff!

As Chris says, and I've mentioned on more than one occasion-----you'd have to be a complete moron to use it for recovering palladium----the volume of the salt is overwhelming, and it's very difficult to handle. Perhaps this evening I'll be able to find time to take a picture of various palladium salts, samples of which I kept from my refining years. Don't hold your breath---it may not happen as hoped, but it will happen eventually. I'm spread quite thin of late.

Harold
 
I think I remember that 1% DMG will dissolve, in distilled water, in about 2 days. Make in up in a dropper bottle and shake it occasionally.

DMG dissolves immediately in alcohol. I usually used grain alcohol (ethyl) - Everclear in a liquor store. Or, I might use denatured alcohol (pharmacy), which I think is ethyl with a little bit of methyl, just to make you blind if you drink it. I don't use rubbing alcohol, which is 30% water and 70% isopropyl alcohol. When it said alcohol, I used alcohol.

DMG in water or alcohol seem to do the same thing. Make both up at 1% - 1 gram per 100 mL of solution.
 
I was able to purchase some DMG solution locally. It was about $10 for 1 oz. I was in an alcohol solution and the kid that sold it to me thought it was 5%.

Tomorrow I am going there again, and will see if he has a ready supply of it. He was out of the chrystal form and didn't know when or if he was going to get more.

But if Steve bought a bunch, he'll probably make it available.

In the picture is the test The green solution is nitric acid with unknown metals in it. I poured some into the small beaker and added household ammonia to it. It forms a white, cloudy precipitate. Like silver chloride. Upon adding more ammonia it turns the pretty blue, which indicates copper.

Then I took a drop of the blue solution on the piece of tile, and added a drop of DMG. It turns red instantly. If you don't use enough ammonia to neutralize the acid, the DMG won't work.

On nickel metal, I scuff it with sandpaper add a drop of ammonia, then a drop of DMG and the metal shows a faint red color. But the ammonia has to be used again, or it won't work. Don't know why.
 

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I got my DMG today! 8)

I'll mix up some up and test it out. I'll post some dropper bottles of DMG test solution for sale on my website if anyone is interested.

Steve
 
All,

I did my first test with DMG today. After a few drops of my solution and about 45 seconds here's what I got:

[img:754:774]http://www.goldrecovery.us/images/pd_dmg.jpg[/img]


Looks like I have some Palladium to precipitate :p

Thanks Harold and Chris for suggesting the DMG purchase!

Steve
 
All,

I filmed my first run at precipitating Palladium using ammonium chloride and sodium chlorate. Needless to say I learned a lot. I kept Hokes book close at hand. Following Hokes lead I was able to precipitate this red salt from 50 mL of my Palladium Chloride solution:

pd_naclo.jpg


I'll edit the video down in due time and post it to my website soon.

The main thing I learned is that dropping Pd is very different than dropping gold. You need to have a lot of patience and good observation skills to do it correctly. I'm sure it will get easier as time goes on. The whole reaction took over thirty minutes of tiny additions and heating. It's not something you want to do on a small scale like I did in this test run.

Rinsing is involved also since you need to use ammonium chloride instead of water.

The second most important thing I learned is that the precipitation is a balance of the ammonium chloride concentration and the sodium chlorate concentration. It is very important to concentrate the mother liquor as much as possible before beginning due to the water solubility of the resultant red salt (Palladium Ammonium Chloride). I figured out that if you add too much sodium chlorate the red salt will redissolve into the solution. A small addition of ammonium chloride will reprecipitate the red salt. I suppose this is also a side effect of the solubility of the red salt and concentrating my solution may solve this problem.

Any pointers the members can give me on this one would be great before I do the final cut on the video.

Steve
 
I'm not convinced that you know any less than I do, Steve. As you alluded, the precipitation of palladium appears to be a fine balance of almost everything. When conditions are perfect, it happens almost immediately, and completely, but a full precipitation is more a rarity. I often still had traces in solution, which were recovered in the stock pot rather than mess with such a small amount.

Looks really good, Steve. The color is outstanding. I took note that if my solution was somewhat contaminated, the color shifted towards a darker red---bordering on maroon in some cases.

Harold
 
I am just getting to that part of Hokes book after starting in the back and reading up on smelting before I got into the beginning and started to read front to back..... so as I read Steve's post I picked up Hokes book and turned 4 pages over and found the procedure..... I now completely understand why this book is so valuable to the hobbyist refiner and even the full time shops to have on hand, the material to reference is outstanding! and written so an old hillbilly can understand it even [ok so I may not be a hillbilly, but they would accept me as one of them.... after awhile] I do have to curb the urge to set up a lab that would rival that of a ful time chemist just to do the testing that is suggested in the book, although making solutions and putting such on a shelf for use as needed in varying strengths might not be a bad idea as I get into this hobby..... er uh business.

Those pictures are amazingly clear too btw.

William
 

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