Safe recovery of a big mess

[wildbill_hickup]

Hi folks, it has been some time since I have been on the board. Health issues as well as other things have kept me from this interest. However I am back and ready to start again. For right now I have a special interest and I hope that someone can gat me pointed in the right direction. For the last several days I have been refreshing this old brain on some of the things I had learned the first time around here. I have recovered some gold using the AP solution on gold foils. What fun, til my wife threw the coffee filters out that I had them stored in, bummer, she's my exwife now. :lol: While doing so I have been looking for a situation similar to mine to no avail. Here it is.

I have a friend with a solid block (approx 3 lbs) of an amalgum of elements. It is the product of burning off PC boards. I know I allready gave the guy a piece of my mind for that, but here I am and this is what I've got. I imagine that the majority of the content is copper and lead however there must also be PM's as well. Is this an item I should attempt to take apart or is it hopeless at this point. Even if I took a small sample just to show him what he's got. I intend to undertake this process completely outside this spring how ever in the meantime I would like to do my reseach. Can anyone here point me to a link(s) that would get me started. If I can't do this with a resonable margine of safety then I will tell him he must go to a professional smelter, but I would really like to give him an idea of weather it is worth his investment to do so.

Thanks Wildbill

 

[dtectr]

hey wildbill
I'm new at this, too so just have a couple of questions:
Is it completely free of combustibles? and
Is it in an ingot or a cow manure pile?
I guess 3 questions - Is it a finely consolidated mess, or are there various globs fused together?

We'll have fun figuring out how to process this, if nothing else.

good luck!
dtectr

 

[Barren Realms 007]

Take a drill and drill it in a few places top and bottom to get you about 1/8-1/4 oz of material and run it in some nitric and see what is left after the base metals dissolve. Check your solution when you are finished to make sure you don't have PM's in it. Then process the powder that is left if there is any.

 

[wildbill_hickup]

Thanks guys, information has just been clarified as to the source of the brick. It actualy comes from pins only. It is solid, all metal. I will be recieving about a gram of shavings soon for testing. From what I am tols it is the reduction of two shopping bags full of pins. The brick itself wieghs just over 3 lbs. There were two of them produced, one for each man. I know there is no exact formular for calculating the amount of gold but if anyone has any guesses I'd like to hear them.

 

[qst42know]

Search pin yield and this is one of the threads.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=53&t=193&p=2369&hilit=pin+yields#p2369

 

[Fournines]

Probably in the range of 0.25% to 0.50% percent gold (one quarter to one half of a percent).

Approx 3.4 to 6.8 grams of gold (if I have my math correct)

 

[wildbill_hickup]

UPDATE: I started with 3g of the subject amalgum being discussed in the form of hacksaw filings. I added 20ml HLC to that I added 10ml H2O2 and processed as per instructions at Lasersteves site. Approx result I was left with a grayish/black sediment(no foils as there were none to begin with) of about 2/3's the origional volume. After 2 washings in HLC I wound up with approx 1/2 the origional voIume. I then proceeded to produce AuCl3 using 20ml HCL and starting with about 5ml of Clorox adding 3ml additional. I imeadiatly got the reactions that are mentioned in Lasersteve's video. After approx 15 min I have my nice golden yellow AuCl3 however reaction has stopped and there is, what appears to be some of the sediment as well as some salts in the bottom of the container.

My question is, do I need more AC solution, more heat, or just to let it sit longer? I have been providing heat to such a point that is quite warm to the touch.

So far so good(I think) :|
Any help would be appreceated.

 

[wildbill_hickup]

UPDATE UPDATE: My AuCl3 seems to be turning green. Hopefully there is a pic attached. Also the seems to be salts forming although most of the sediment previously mentioned have disolved. What is left is more gray than black. What-I-Do Wrong? Help!!!!!!!! It was doing so well!!!!!

 

[Emmjae]

Hi Wildbill,

I’m still quite a noob at this but I believe you still have a lot of base metals present.

First thing is to check solution with stannous to make sure you have any gold. A 3g sample is pretty small to work with. Also, don’t heat up your HCL/Clorox until after your done dissolving you sample. You want to apply the heat (not boil) to rid the solution of any excess Clorox before your filter and drop your gold.

I have found when working with HCL/Clorox it seems to dissolve the gold first and then cement itself back onto any remaining base metals. Then the HCL keeps attacking the base metals and turning your solution green. The remaining sediment is probably your gold.

I’m sure the guys here will correct me if I’m wrong. I’m still learning too. :lol:

 

[Harold_V]

I’m sure the guys here will correct me if I’m wrong. I’m still learning too. :lol:

No correction required.

Harold

 

[wildbill_hickup]

Stannous, positive for gold though a mild reaction(slight purple stain on filter paper). I guess I got my hopes up when the instant yellowing of the acid/Clorox mix happened. I assumed (wrong) that the gold content was fairly strong. The end of the AP process resulted in clear HCL wash and clear water rince. Removing sediment to a clean coffee filter showed no colored stain. (All as per Lazersteve's videos) A that point I figured I had all or at least most of the base metals removed. I then proceeded to the Acid/ Clorox procedure. It reacted just as in the video, til the green showed up that is.
So now can I save this mess or should I just start a new bigger batch. I still have several grams of the material however it is in a more solid form (chunks). I can grind them into more powder. I have had no experiance with AR or nitric (though I do now have the materials to make either). Would it be better to proceed that way or grind and process in AP then Acid/Clorox. I don't mind the extra labor of grinding or the new experiace using nitric. So which is the best way to go?

 

[lazersteve]

Bill,

Try a small sample of the shavings in Modified Poorman's AR and see what kind of reaction you get.

Iron in solution is golden yellow-orange.

Steve

 

[wildbill_hickup]

Hi Steve, I was kinda hopein you woould chime in. I'll try that today. I'll have to go look up MPMAR as I've never worked with anything other than AP, AC. There's something about nitric, I don't know. Anyway I got some Rooto the other day so I'll keep you posted. Do you think it's worth keeping this solution till I (we) figure out what I did wrong? Everything was going so well. Guess I patted myself on the back a little to soon. Not sure if this might have any bearing on the subject but my shop is a not so well heated garage. 'Room temp' is 50ish. Could temp variance have these kinds of affects.

Thanks again to all for your help.

 

[dtectr]

This is a problem that we don't talk about much here, namely tin contamination. Some posts suggest that if you get rid of any solder, you won't have tin problems, and depending on the process, that isn't necessarily the case.

The result is common from pins, edge card connectors, anything with a phosphor bronze base, which is most of these. If the connector needed "spring" or was crimped or otherwise manipulated when placed in its plastic connector, the phosphor is what allows for these without stressing or cracking the base metal.

Kovar, which we talk about more often, is used for something that needs to be tough, but "springiness" to withstand repeated insertions or stamping to form the connector is not necessary. is used for "legs"-type pins, such as cpus.

The tin content of phosphor bronze is fairly high, 3-10%, (the balance copper minus 1% phosphor) & it reacts with nitric, even the nitric made in Poor Man's to form metastannic acid,
From Hoke:

"Second: Try the effect of hot strong nitric acid, first on a scrap of
tin, then (in a clean test tube or beaker) on lead. . . The effect is
quite different. In both cases the acid goes to work at once, giving
of f the usual brown fumes. . . The tin goes to pieces, and in its
place appears a white pasty or slimy substance. We call this tin
paste. The chemists call it meta stannic acid. If you add some
water the tin paste will thin out, like jelly, but it will not dissolve.
This tin paste, which forms when nitric acid acts on tin (and at
other times as well) is the main reason why tin is troublesome in
refining.

"Because of these facts, we dissolve lead metal in diluted nitric
acid. But when it comes to tin we see that, while nitric acid acts
on it, it does not really dissolve it, but merely converts it into that
troublesome tin paste.

"... If you still have some tin paste, left over from an earlier experiment, try
the effect of sulphuric acid upon it. . . It dissolves it, whether dilute
or concentrated.

"... Repeat the nitric treatment if necessary, then wash
the residue well, but do not let it dry. The residue is gold, plus tin
paste, plus such base metals as were not reached by the nitric acid.
Next, mix up a little sulphuric acid and water, half and half (pour
the acid into the water, slowly, and stir all the time) and cover
your residue with this solution. Warm gently. This dissolves the
tin paste, dissolves any remaining tin metal that the acid can reach,
and changes any remaining lead into white insoluble lead sulphate.


So, if you add water to the salts & they dissolve, they're likely lead or sodium salts. If not, see above. I am, in fact, doing some of this this morning - If the sun comes out, I'll try to take some photos.

Good luck

 

[wildbill_hickup]

Just so everyone knows I AM reading. Guess I don't need the Rooto. I'll be back when I try Steve Modified Poormans AR.

Dtectr Are you refering to the salts in my solution. If your are I assume then that I should hang on to it for further testing, yes? I, for right now am going to give Steve's suggestion a try on a new batch. I have to go back and read the post again that discribes it, so I'm gonna be awhile.

This is very frustrating, but it's a ton of fun and I'm learning a whole bunch of good stuff. Thanks guys.

 

[dtectr]

Just so everyone knows I AM reading. Guess I don't need the Rooto. I'll be back when I try Steve Modified Poormans AR.

Dtectr Are you refering to the salts in my solution. If your are I assume then that I should hang on to it for further testing, yes? I, for right now am going to give Steve's suggestion a try on a new batch. I have to go back and read the post again that discribes it, so I'm gonna be awhile.

This is very frustrating, but it's a ton of fun and I'm learning a whole bunch of good stuff. Thanks guys.

Wild Bill
Don't feel bad. I'm sure you're reading - The only reason I could find that reference that quick is that I've been reading up on it the last 2 days! In fact file just stays up on my monitor. The tin has been my nemesis on this current project. Approx 40+ lbs of Elco edge connectors, 44 & 56 pin, manufacturer's waste, never installed, both budget & top end. I've felt like a dog chasing his own tail - it IS frustrating. But you're right, hang on to it for now, maybe by then we'll have come up with something more concrete.
BTW - the Rooto is the sulfuric - if you decide to do the dilute sulfuric wash.

Let us know how that other turns out, too. We'll beat this thing yet!

 

[goldsilverpro]

Kovar, which we talk about more often, is used for something that needs to be tough, but "springiness" to withstand repeated insertions or stamping to form the connector is not necessary. is used for "legs"-type pins, such as cpus.

I think, originally, the Kovar was chosen because it's coefficient of expansion was about the same as the insulating glass attached to it. This prevents leakage at the glass-to-metal seal. It is tough but I don't remember it being too springy. I once had a couple of girls doing nothing but straightening Kovar legs on side-braze packages (about 50,000/week) with tweezers. As I remember, the legs bent easy and had almost zero memory after bending.

 

[dtectr]

My poor composition skills, GSP.
Should have been:
"Kovar, which we talk about more often, is used for something that needs to be tough, (but "springiness" to withstand repeated insertions or stamping to form the connector is not necessary) is used for "legs"-type pins, such as cpus."

Parenthetical expressions have always been my downfall. I meant to contrast the "springy" characteristics of Phosphor Bronze with the "tough" characteristics of Kovar.

BTW: Tried Hoke's advice on tin oxide, and found out that, as I cited previously, in another post, "Metastannic acid is white crystalline insoluble in water and in nitric acid. It takes up hydrochloric or sulphuric acid without dissolving in it." A dictionary of chemistry and the allied branches of other sciences, Volume 5 By Henry Watts

Sulfuric breaks up the sticky nature of the paste, allowing for easier filtering, but if you dump it into several times its volume of water, as Hoke recommended, the paste precipitates out again & you get caught in a daisy chain of diluting & filtering.

I finally wound up going with a fiberglass insulation plug in a funnel, which did better than anything thus far.

"Metastannic Acid, I hate you!"

G**, I feel better now.

 

[Harold_V]

Sulfuric breaks up the sticky nature of the paste, allowing for easier filtering, but if you dump it into several times its volume of water, as Hoke recommended, the paste precipitates out again & you get caught in a daisy chain of diluting & filtering.

I finally wound up going with a fiberglass insulation plug in a funnel, which did better than anything thus far.

"Metastannic Acid, I hate you!"

G**, I feel better now.

It was my repeated experience that if I had metastannic acid involved, incineration, followed by a wash in hot HCl solved the riddle time and again. If nothing else, it yielded a solution that would filter. Magic bullet is incineration and a wash in HCl---for a cure of many ills. Incineration should be carried out to the point of dull redness, to insure that everything is well oxidized.

Harold

 

[dtectr]

Sulfuric breaks up the sticky nature of the paste, allowing for easier filtering, but if you dump it into several times its volume of water, as Hoke recommended, the paste precipitates out again & you get caught in a daisy chain of diluting & filtering.

I finally wound up going with a fiberglass insulation plug in a funnel, which did better than anything thus far.

"Metastannic Acid, I hate you!"

G**, I feel better now.

It was my repeated experience that if I had metastannic acid involved, incineration, followed by a wash in hot HCl solved the riddle time and again. If nothing else, it yielded a solution that would filter. Magic bullet is incineration and a wash in HCl---for a cure of many ills. Incineration should be carried out to the point of dull redness, to insure that everything is well oxidized.

Harold

Harold,
You read my mind! I was trying to decide where to post the question - "Has anyone tried incineration on foils?" According to references, red heat converts metastannic acid (which I becomes SO voluminous, I feel like the Sorcerer's Apprentice!)to anhydrous tin oxide, which is soluble in concentrated acids, as I understand it. I was worried about how the foils would stand up.

I will attempt that on my next batch.
Thanks for the input.
dtectr