Depopulating Cell Phone Boards .. what is the best method ?

[Anonymous]

Ben the process of dissolving gold into HCl with the air from pouring the jug as an oxidiser isn't a rapid one. I don't think you have a real problem there in the context you're using it.

Just remember lads- until you pour it away you've still got it. Whether you stockpot that wash liquid, or use it for your next dissolve you're literally "golden" 8) 8)

I'm glad things like this get brought up.

Jon

 

[UncleBenBen]

Ben the process of dissolving gold into HCl with the air from pouring the jug as an oxidiser isn't a rapid one. I don't think you have a real problem there in the context you're using it.

Just remember lads- until you pour it away you've still got it. Whether you stockpot that wash liquid, or use it for your next dissolve you're literally "golden" 8) 8)

I'm glad things like this get brought up.

Jon

You are correct, Jon. It really isn't a problem, especially with the religious use of stannous. Just kicking it around out of curiosity more than anything.

That and to get Topher riled up!! :mrgreen:

 

[Topher_osAUrus]

Ben the process of dissolving gold into HCl with the air from pouring the jug as an oxidiser isn't a rapid one. I don't think you have a real problem there in the context you're using it.

Just remember lads- until you pour it away you've still got it. Whether you stockpot that wash liquid, or use it for your next dissolve you're literally "golden" 8) 8)

I'm glad things like this get brought up.

Jon

You are correct, Jon. It really isn't a problem, especially with the religious use of stannous. Just kicking it around out of curiosity more than anything.

That and to get Topher riled up!! :mrgreen:

Haha!
It doesnt take much to get my cogs upstairs a cranking around (eventually filling my head and house with smoke)

But, i too, am glad the little things like this get discussed.
Will it ever be something that is *needed* to know?
-probably not.. But, I'd rather know and not need it, than need it and not know.

But, besides the small nuances and idiosyncrasies of this little tid-bit...

Who here *really* doesnt use stannous?
Yes, the new guys think its just a *suggestion*...but, for those in the know...we all *know* it is something to live by.

Or we should anyways...right? :roll: :mrgreen:

 

[Geo]

I have managed to put gold powder back in solution with just HCl washes 3 or 4 times so far. One of the times it wasn't even heated.

It's hard to remove nitrates with just rinses. Even sodium hypochlorite is hard to destroy and solutions must be brought to a boil to decompose it completely (214 °F). Sodium nitrate decomposes at 716 °F which is a very big difference. Unless you neutralize the acids, you will always dissolve some values using hot HCl washes. To neutralize the acids, you can use a base which leaves a byproduct that is soluble in water. You can also incinerate. Incineration is recommended. Generally speaking, if you can't roast the precipitated gold powder for whatever reason, that reason should also exclude you from dissolving it in the first place.

 

[Anonymous]

Incinerate powder before washing it? Never. Bad advice Geo. I agree with so much that you say and respect you a great deal but that's just garbage.

Most guys on here have a gramme or two at a time. Incineration just adds to the losses at that point.

Jon

 

[Geo]

When you can't incinerate, neutralize the acid with a base. That's why I gave two options. I use sodium bicarbonate. Follow the base with several water rinses before moving to any other step.

 

[Geo]

Incinerate powder before washing it? Never. Bad advice Geo. I agree with so much that you say and respect you a great deal but that's just garbage.

There are many proponents of incinerating gold powder before rinsing on the forum. It's the way I was taught to do it. When I was first starting out, I worked with small amounts. Now, when I work on small amounts of gold powder, I add the small amounts together and refine a larger amount at once. It takes the same amount of time and effort and the losses seem to be less. Incinerate foils and powders to save in headaches later on in the process.

 

[Topher_osAUrus]

Incinerate powder before washing it? Never. Bad advice Geo. I agree with so much that you say and respect you a great deal but that's just garbage.

Most guys on here have a gramme or two at a time. Incineration just adds to the losses at that point.

Jon

I have never incinerated my ppt'd powders.
But, i have only dealt with a max of 20g at a time, while i finish getting my feet wet, so to speak.

It's sketchy enough trying to incinerate foils, or filters.

Roasting my powders :shock:
I may lose sleep over that.

Not to say it shouldn't be done at times. I believe i read harold(maybe harold, maybe another founding guru - not that i dont consider you a guru Geo, -as i have watched a great many of your videos, and have "creeped" your posts for wisdom and insight- )

I just kind of fear incinerating period.
-no, fire doesn't scare me-
Losses because i dont have a filtered fume hood for incineration.

Ahh, the nightmare...the horror :evil:

-on a more seriois side-

*Neutralizing the powder.*
Would this be acceptable/are there any that do this?-
*precipitate gold
*hot water wash
*ammonia wash
*hot water wash
*HCl wash
*hot water wash
***borax water wash
*melt barely damp in borax coated/already seasoned melt dish

I know some use ammonia *after* their hcl wash/water washes for remaining AgCl and copper. But would it be beneficial to do such *before* the initial HCl wash of powder gold.

***I read a thread where GSP actuslly washed his silver cement with borax water (and i think also nitrate water), which made the silver "melt like butter"...Would this be a good practice for gold too? Especially if one (me) is using the borax from wally-world where it *PopCorns* up under heat until it decomposes and loses some water?

I always feel i lose gold when it begins to popcorn...but, I am using a cruddy MAPP gas torch and I don't have a good melting tip for it, or a good fire brick set-up to retain the heat (Ive been using corning ware dishes stuffed with fiberglass insulation)

But, then again, ever since i found this forum, i have believed i have lost gold *everywhere* at *everyturn*... My mind is more at ease now after learning a thing or three, but still.. I was curious if this is done by anyone?

-toph

 

[Geo]

The best way to avoid excess nitrates is to not use an excess to begin with. If you consecutively dissolve values when you do HCl washes, it is a problem of pre-treatment or the lack thereof. You will need to include a way to neutralize the excess oxidizer before the wash. Ammonia is a base but using ammonia with nitrates is not recommended for beginners (at least by me). Ammonium nitrate is formed by adding nitrates to ammonia. The dry crystals is a strong oxidizer. It forces organics to decompose at a high rate of speed (with light and heat) under the right circumstances. There's little chance of forming an explosive compound as long as you study and understand what is happening. Ionized gold can be very, VERY unstable under the right circumstances. It's more explosive than silver. Silver was used in the primers of bullets until it was deemed too unstable. There are chemicals that seem benign enough and are normally, but when reacted upon can be very dangerous.

 

[Topher_osAUrus]

So remaining (stubborn) nitrates that stick around after precipitation is the reason that ammonia isn't used after a few hot water washes on precipitated gold powder?

I thought i read on here from Lou or 4metals, that once gold is precipitated, the nitrates in the powder have effectively been ridden away, otherwise gold would redissolve in solution right there (leaving the red fumes in its wake - im going to look for that thread in a second)

I was just more curious as to if that order would be acceptable, i, in no way, was trying to belittle or diminish your statement Geo. And, in my list above i forgot number of times. Which could be important i.e.

*precipitate gold*
*decant
*rinse hot water x3
**rinse in warm ammonia
*rinse in hot water x3
*rinse in HCl
*rinse in hot water x3
*#*#*rinse in borax water
*melt

The **'s is what i was curious about, if that would be an acceptable practice which could aide in neutralizing the clingy NOCl/NO3/Cl/O whatever is left and taking up gold in the HCl wash?

The *#*#* is what I'm really *really* curious about.?.
Is it something that could be done for gold?(of course it can *be* done, but would it aide melting?)
I really just hate the laundry borax with my torch setup.
With my family's oxy/acetylene torch, its no big deal, but this crummy MAPP with its even crummy-er tip, just literally makes the stuff *pop*... Even if the dish is red hot, the heat from the top just sucks (for lack of better word..)

-topher

 

[Geo]

It can be done the way you describe. I am saying that if you are dissolving gold with the HCl rinses, you need to change what you are doing. I don't like following HCl with ammonia or the other way around because of the ammonium chloride smoke created. I neutralize the acid before adding the ammonia or I acidify the ammonia with vinegar before washing with HCl.
There should not be a set number of rinses and washes. The main thing is to repeat the rinse or wash until the rinse or wash stays clear. Any color change means you still have more to do. It may be on the first rinse or the tenth, but when the rinse stays clear, move to the next step.

 

[Anonymous]

Topher

Why would you rinse in Ammonia as a standard procedure if there's no silver present? It's only present in certain recoveries from ewaste. I have never used it as a wash apart from experimentation. Yes in inquarting it's more of an issue however there are other methods of removing it.

Geo whilst your comment regarding incineration and amalgamating multiple recovery drops may have merit I can assure you that regardless of whether you may have been taught that method originally, it is not required. Regardless of whether your drop is 1g or 100g if you neutralise the Nitric correctly, the dissolved gold should be negligible. The only issue arises when people haven't removed the vast majority of the Nitric, and the people who don't are more likely to be those who both recover very small amounts, and don't understand the processes.

We're talking to people here who don't get that bit wrong, and yes I agree that using less Nitric is something that comes with experience but Sulphamic acid and an 85 degree cook should remove it to an almost insignificant level. It's that insgnificant level that I am referring to, not an overly abundant excess in the powder.

I trust that clarifies what I meant.

Jon

 

[Topher_osAUrus]

I have only used ammonia 1 times in my powder wash procedure. And that was because i had AgCl troubles my first couple of melts.

Patience (and dilution) cured that problem so i no longer use it.

It was more of a curiosity, that if it (ammonia wash, pre HCl), would be a decent candidate for a two-for-one process, -stop the small dissolution of gold- and -remove other impurities like copper and silver-

Not something i plan on doing anytime soon.
Really i just wanted to know if it was a viable option should the circumstance arise.

I like to use sulfamic acid at times just because it serves multiple purposes in one fell-swoop

-topher

 

[Anonymous]

Thanks for clarifying Topher 8)

Jon

 

[Topher_osAUrus]

Thanks for clarifying Topher 8)

Jon

No worries.

Many a times, my mind works a million times faster than my fingers (most people's brains do-as neurons fire around 280mph, -we also emit around 80-120watts of power-which could effectively be picked up by the new James Webb space telescope..from very...very..far away)
And when i finally am able to peck my way through a thought, several have passed that i wanted to put, but got omitted by accident.

I need to get my laptop out of my kids room and use it... The 130 words per minute i can type on it, is much better than the msybe 50 on my phone... Sure isnt 280mph, but, every little bit helps lol.

 

[UncleBenBen]

I have managed to put gold powder back in solution with just HCl washes 3 or 4 times so far. One of the times it wasn't even heated.

It's hard to remove nitrates with just rinses. Even sodium hypochlorite is hard to destroy and solutions must be brought to a boil to decompose it completely (214 °F). Sodium nitrate decomposes at 716 °solutionis a very big difference. Unless you neutralize the acids, you will always dissolve some values using hot HCl washes. To neutralize the acids, you can use a base which leaves a byproduct that is soluble in water. You can also incinerate. Incineration is recommended.

As I said earlier in the thread, there were no nitrates involved. I only recently made some cold nitric to help with testing material. The hypochlorite I was using as an oxidizer should have been destroyed as you said, as it was after several boils of the powder in water before washes in HCl. And then it was usually on the 2nd or 3rd wash that gold would go back in solution.

Another example of why I suspect it was that almost empty jug of HCl was when processing almost powder fine gold foils in several filters, along with all the filters, paper towels, Q-tips, etc, that were in my filter bucket. Incinerated, crushed and placed in a beaker. I poured in the last of the HCl from that old jug and sat it aside as I was setting up my hotplate and catchpan and what not.

I remember going in the house for about 30 minutes to help the wife. When I got back outside I noticed the HCl in the beaker had a familiar yellow tint to it. Tested with stannous and sure enough it was positive for gold. The picture is after stirring it for a few minutes with a piece of 8awg copper wire.



Once it all cemented out I decanted and continued with a new jug of HCl and didn't have any more problems. That's why I figured the HCl had to have absorbed THAT much oxygen, or was contaminated from the start. Also, most of the accidental dissolving happened around the same time, just within 2 or 3 weeks time. Didn't have any trouble with it before or since, but I think my filter bucket was one of the last things I processed before I put it all on hold.

Generally speaking, if you can't roast the precipitated gold powder for whatever reason, that reason should also exclude you from dissolving it in the first place.

My studies here have taught me that unless there is a need to incinerate, like powders mixed with a tin mess, then precipitated gold never leaves the beaker until it's ready to melt. But I do agree that I don't have any business dissolving gold. Which is why I packed it all away months ago until I can get a lab put together with a working fume hood.

I'm still keeping my test tubes and tiny beakers busy though. I love testing new materials for PMs!! :mrgreen:

I was going to use ammonia once back around October. It was some Au powder that came from gold clad over silver relay contacts and I just couldn't bring myself to do it. I don't think I could even with a hood. Ever since my 'ammonia incident', as my wife calls it, last July when I accidentally drank some thinking it was vinegar, I can't take the slightest of a smell of ammonia now without instantly vomiting. Made for one heck of a scary night in the ER.

Remember kids, just because all your friends are doing it, drinking ammonia won't make you cool!!!

 

[Topher_osAUrus]

Hello Ben,

Ive been thinking of you! -and your theory!(mainly the theory)

So, Lou said that heat can/will decompose HCl.

Whats the weather like in your neck-of-the-woods?

Had any really hit days that your jug has been subjected to? Or direct sunlight?

Im wondering if the O2 in the atmosphere has aided this dissolution, or if the HCl has decomposed a bit giving some Cl in solution thats free to oxidize the powder easily?

Just a thought, about the only one ive had.

-topher, the thinker-er-err

 

[UncleBenBen]

Hi Topher,

There is no telling what the jug may have been through before I bought it. The Lowe's I by it from seems to run through their stock pretty quickly. I probably bought that one around the beginning of October. I was down to the last of it by mid November, which was around the time I was redissolving gold so easily.

So while I had it the hottest days were in the 70s. The jugs are white. They stay in the basement in an old refrigerator with the gasket still on the door. And I get sunburned looking out the window, so when I was outside refining it was dark or I was in the shade.

I thought about what you and Geo discussed about traces of oxidizer on a stir sticks. I used a sturdy plastic one for a while which could explain it. But when I found the picture I posted last post, I had already bought new beakers which meant I had new glass stirrers too. I was pretty meticulous about keeping my glass clean.

I might just have to chalk it up as just one of those things. Unless it starts happening again when I get back to processing. If nothing else it was definitely a good lesson in the importance of testing!

 

[Geo]

HCl alone, whether heated or not, should not oxidize gold. I know that things happens that can't be explained easily but from a purely scientific standpoint, you have assume that there was an oxidizer introduced somehow. It was either on the glass, in the HCl or in the material itself.

 

[UncleBenBen]

HCl alone, whether heated or not, should not oxidize gold. I know that things happens that can't be explained easily but from a purely scientific standpoint, you have assume that there was an oxidizer introduced somehow. It was either on the glass, in the HCl or in the material itself.

EDIT: Hahaha! I'm sorry Geo. I just now saw that the reply I had typed didn't make it to the post! :roll:

I think what I had written was along the lines of I agree with that whole paragraph. Y'all gave me some good ideas as far as possible reasons for the problem.

I'm almost certain my HCl had gotten contaminated somehow. I haven't had a problem since with accidentally dissolving gold in all the small tests I've done. Even though I was working with tiny amounts of powder at a time. Hopefully it will never be a problem again.

I was saving all those tiny amounts of powder in a 50ml beaker for months. It was usually barely enough to even see when I would wash it from the test tube. But it all added up to my latest button!!



I didn't try to weigh it. I heated the dish back up and let it get stuck in some borax so I wouldn't lose it.