# What to use to remove tin from foils?



## Agold2019 (Oct 17, 2019)

Would a lye solution work to remove the tin from the foils? The options that I see would be to use muriatic or lye. Muriatic is hard if not impossible for me to buy so I was wondering if lye is an option. Are there any tricks to clean the foils? I also do not want to lose any silver if there is any involved. After I ran them through nitric again I do not think that any of it is silver.


----------



## Lino1406 (Oct 17, 2019)

If you expect gold/silver take a sample and use muriatic acid. Just for worth estimation


----------



## Agold2019 (Oct 18, 2019)

Hi Lino thank you for the response. These are foils that came from pins and fingers and other gold plated copper nickel components from cell phone boards. There was also left a slimey grey residue which I think is tin. In my country it is hard if not impossible to get muriatic. I was wondering if lye could work? If not I will work on getting some muriatic and doing the test that way.


----------



## niks neims (Oct 18, 2019)

Agold2019 said:


> Hi Lino thank you for the response. These are foils that came from pins and fingers and other gold plated copper nickel components from cell phone boards. There was also left a slimey grey residue which I think is tin. In my country it is hard if not impossible to get muriatic. I was wondering if lye could work? If not I will work on getting some muriatic and doing the test that way.



But it was no problem getting the nitric to make metastannic acid with?  Oh the USA with it's elusive muriatic acid....By the way what is it's chemical formula?... you could try substituting it with hydrochloric acid...., it still won't work on metastannic without incineration, though...

also hit the books buddy, hard


----------



## Martijn (Oct 18, 2019)

Hi Agold, have you created another batch with tin and gold foils in 2 day's since your first post: "e waste mixed hi grade Mystery Metal"? 
You were given some sound advice in that post, and it became an unplesant post to read for you maybe, but stick to the advice given and don't make a big thing out of other people's comments. It will lead nowhere. 

You will have to study more and if you keep asking questions that most of us here can see right through, you will, by doing so, tell them you haven't put in the effort learning the basics and still want a quick fix. That will not be appreciated here, and some harsh comments WILL follow. Or complete radio silence as a reaction to your ignorance...your decision. 

Tin paste /metastannic acid> incineration followed by HCL leaching is the best solution a far as i understood from other members comments in other posts. Without incineration the tin paste will not dissolve. (not as fast or at all?.. not sure) 
Prevention of tin in your mix is the best option. How to incinerate without losing any values: search button.

But understand what you're doing, experiment with small amounts in a glass test tube. watch, observe and learn. Then come back with better questions. questions wil never cease to arise in this field of fun stuff. 
You don't have to become a master scientist to perform the steps neccesary, but follow the steps given and understand the basics will help alot. Others have figured out methods by research or improved the methods and explained them in great detail, often, over and over. there is a ton of info here, it just needs some reading. it took me about 4 years to start to get a grip on some processes. 

Stick to one post, don't start over in another. we'll know :roll: 

good luck, keep it simple and enjoy the ride! 
Martijn. 

I will also do my best to divide in paragraphs better than i usually do :wink: 
Its a learning curve for all of us.


----------



## niks neims (Oct 18, 2019)

Martijn said:


> Without incineration the tin paste will not dissolve. (not as fast or at all?.. not sure)



First time I recovered gold from e-scrap, I just threw some fingers in nitric, and encountered same metastannic problem, I actually went straight to AR, metastannic and all, it didn't dissolve, I just had to filter AR and wash out the metastannic goo with some water, seemed to work, but I wouldn't suggest it, very messy...


----------



## butcher (Oct 18, 2019)

Martijn said:


> Hi Agold, have you created another batch with tin and gold foils in 2 days since your first post: "e-waste mixed hi-grade Mystery Metal"?
> You were given some sound advice in that post, and it became an unpleasant post to read for you maybe, but stick to the advice given and don't make a big thing out of other people's comments. It will lead nowhere.
> 
> You will have to study more and if you keep asking questions that most of us here can see right through, you will, by doing so, tell them you haven't put in the effort learning the basics and still want a quick fix. That will not be appreciated here, and some harsh comments WILL follow. Or complete radio silence as a reaction to your ignorance...your decision.
> ...




The best advice I have heard all day.


----------



## Agold2019 (Oct 18, 2019)

niks neims said:


> Agold2019 said:
> 
> 
> > Hi Lino thank you for the response. These are foils that came from pins and fingers and other gold plated copper nickel components from cell phone boards. There was also left a slimey grey residue which I think is tin. In my country it is hard if not impossible to get muriatic. I was wondering if lye could work? If not I will work on getting some muriatic and doing the test that way.
> ...



It was no problem buying the nitric. But, like I said muriatic also known as hydrocloric is. I guess that you are assuming that I’m from the USA because I said I was e waste scrapping in New York? I don’t live in New York anymore. I saved my money and live and work in South America now I find it a much more relaxing place to be. 

I found a great resource for e waste here, I can buy old clean boards and all e scrap at not so bad pricing. I think I can buy sweepings from all the jewelry stores also if I learn this trade as I am now learning it is an easier way to learn and start. There are no refinery’s close for at least 1000 miles as far as I am aware. I’m thinking to do this to make money but also more hoard gold for myself and start as a hobby if until it develops. It’s a much safer investment than paper. 

I have been reading everyday. I am interested in learning. Could you elaborate please on incineration? I was worried about mixing the two metals to make a bigger mess. I know about using fluxes but I’m not sure what happens when those two alloy or if it only burns off? I don’t see any information on if or when this happens.


----------



## Agold2019 (Oct 18, 2019)

Martijn said:


> Hi Agold, have you created another batch with tin and gold foils in 2 day's since your first post: "e waste mixed hi grade Mystery Metal"?
> You were given some sound advice in that post, and it became an unplesant post to read for you maybe, but stick to the advice given and don't make a big thing out of other people's comments. It will lead nowhere.
> 
> You will have to study more and if you keep asking questions that most of us here can see right through, you will, by doing so, tell them you haven't put in the effort learning the basics and still want a quick fix. That will not be appreciated here, and some harsh comments WILL follow. Or complete radio silence as a reaction to your ignorance...your decision.
> ...



Thank you I should have read this first. This was the answer I was looking for. And no it was the same batch that I cleaned it all up if you can call it that. Where I live I may not be able to get HCL. Maybe I can, but looking for other options if possible. That’s why I asked about lye.

Once again thank you.


----------



## g_axelsson (Oct 18, 2019)

I think we all assumed you were from USA as it's stated in your profile that shows up with every post you make.

If you add your correct location on the globe you might get better advice to where to find supplies, material and buyers.

Göran


----------



## Agold2019 (Oct 18, 2019)

g_axelsson said:


> I think we all assumed you were from USA as it's stated in your profile that shows up with every post you make.
> 
> If you add your correct location on the globe you might get better advice to where to find supplies, material and buyers.
> 
> Göran



I did not know that. Well, I am from the USA  8) :lol:


----------



## g_axelsson (Oct 18, 2019)

You could also add your location to the profile.
That way you can have both origin and location.
http://goldrefiningforum.com/phpBB3/ucp.php?i=ucp_profile&mode=profile_info

Göran


----------



## Agold2019 (Oct 18, 2019)

g_axelsson said:


> You could also add your location to the profile.
> That way you can have both origin and location.
> http://goldrefiningforum.com/phpBB3/ucp.php?i=ucp_profile&mode=profile_info
> 
> Göran



I see now. Updated. Thanks and sorry about confusion.


----------



## Jmk88 (Oct 25, 2019)

I have had a similar issue with a batch of jewellery; I have got to the bottom of the issue with help from Butcher who gave me enough information for me to work things out.

I love the way Butcher plants clues/hints as it discourages laziness and encourages study.

I believe Hoke (I think on pages 75-85) discusses this in detail. There is a two stage recovery required if I understand correctly, which requires two hcl boils, two water boils, a caustic wash and then a final water for good measure after your initial bulk recovery. The foils must be put through this process. Harold emphasises the importance too.

Hoke states this is sufficient to remove solder paste. What Hoke doesn’t advise is the durations in which the foils should be left in these processes.

Perhaps one of the Jedis can shed light.


----------



## anachronism (Oct 25, 2019)

Do you mean a real Jedi or one of the sickly politically correct Disney Jedis? 

:lol: :lol: :lol: :lol: :lol: 

Jon


----------



## Jmk88 (Oct 25, 2019)

The Jedis;

Butcher
Frugal
Harold 
Geo 
Lasersteve 
Ka driver

Then you got the dark side...

Dr. Poe (Vader)


----------



## anachronism (Oct 25, 2019)

OK! Will let them help you then 8) 8)


----------



## rickzeien (Oct 25, 2019)

Turn from the dark side...May the farce be with you...refine you must!






Sent from my SM-G950U using Tapatalk


----------



## butcher (Oct 25, 2019)

Roaming in the woods and blindly picking up mushrooms and making you some mushroom soup, before you even learn which mushrooms make good soup with, is one way to learn, but is a hard way to learn, you may be able to figure out which mushrooms were not very good to eat.


----------



## Jmk88 (Oct 25, 2019)

Sorry Jon.

I’m sure you’re just as good! Stop being sensitive....

I would welcome you’re views too.

Yep!! Win or learn. It’s never ever a loss.


----------



## butcher (Oct 25, 2019)

Jmk88,
I can think of ways you could clean the foils without HCl, but I do not think that would help you much at this point, because it would only bring up a thousand more questions with very few answers.

If you are going to learn to recover and refine gold, you will need HCl, muriatic acid, hydrochloric acid, Clorhydric acid, or spirits of salt, common concrete etch or pool cleaner grade will do just fine.

Put up your acid and chemicals away, spend some time looking for muriatic or HCl while you are studying.

Study to gain an understanding before making a mess.

Before making another mess:
I would deal with the last two (study dealing with waste).
Save and dry any powders or solids store them in a safe place.
study the safety section gain an understanding of the dangers and how to do the chemistry safely.
set up a safe small lab.
Use Hoke's book to do the getting acquainted experiments.
Begin your study with a simple recovery process like using cupric chloride to recover gold from memory.
and then further your study of a simple refining process like using HCl and hypochlorite to refine the gold.
study everything you can find about it, before even thinking of opening a bottle of acid.
Study all of the problems that can and will be involved with a process before you open a bottle of acid.
Study all you can find about the acid and the metals before you open the bottle.

Study, and do the research of which mushrooms are good to eat before you make the toxic soup to eat.

Basically stop and study for now.

I would expect any further questions from you would be regarding the safety aspects and dealing with the toxic waste from these last two failed recovery attempts of making a mess before we even think about answering questions concerning how to get a few flakes of gold from some toxic trash.

Or you could just keep throwing mushrooms into a pot of acidic water solutions and see if they taste like soup and then maybe you can figure out which ones are poisonous, or ask the jedi why your tummy hurts.


----------



## Jmk88 (Oct 25, 2019)

AGold,

The section in Hokes book is pages 69-73.

I wouldn’t advise tasting the washings though. 

Definitely need Jedi input after that.

Sulphuric acid is recommended after recovery. I use AP for recovery due to silly U.K. restrictions. 

Can anyone suggest an alternative to Sulphuric? Caustic will remove lead nitrates but I don’t think the tin paste.

Can someone help!? 

Thanks all.


----------



## Jmk88 (Oct 25, 2019)

Thanks Butcher.

I’ve been studying and studying.... and studying and studying.

I believe your assistance has allowed me to I’d the issue which is tin paste. Probably a common beginners mistake. 

Where Hoke advises on Sulphuric, is there an alternative? I understand caustic will remove nitrates but not the paste. 

Someone has advised me acetone (a jeweller) will completely remove tin paste. Is this correct and would there be any adverse affects?


----------



## butcher (Oct 25, 2019)

Jmk88,
Can anyone suggest an alternative to Sulphuric? Caustic will remove lead nitrates but I don’t think the tin paste.


It is hard for us to keep up with what all your doing, and sometimes what you are talking about or working on, it might be easier if you kept all of your discussion in one topic or forum thread.

I do not know what you are talking about now, are you talking about removing lead nitrates powders from the gold foils?

lead nitrates are soluble, caustic can be used to make a more insoluble lead hydroxide, in a salt of sodium nitrate in solution, although you can lower the solubility of the lead in solution to about 10 milligrams per liter at around a pH of 10, adding more caustic and the amphoteric lead dissolves more into solution.

Pb(NO3)2 + NaOH --> Pb(OH)2 + NaNO3 




Sodium bisulfate is often used as an alternative to sulfuric acid, but then again I do not know what you're doing, and aparantly neither do you at this point.

Your statements or descriptions are also not easy to follow, one time you speak of working with 18K gold then we find out it is gold filled trash full of base metal, which could have been costume jewelry of pewter brass bronze and any other gold plated junk alloys for all we know...

And another time you speak of using the acid peroxide method (cupric chloride etch) to recover foils from junk jewelry and electronic trash, but you cannot find HCl in your country to wash the foils??? 

I am beginning to feel more lost and confused than you are on these questions.


----------



## Jmk88 (Oct 25, 2019)

Butcher,

I have 50 litres of 33% hcl. I have nitrates (sodium and potassium). I have 15% hypochlorite. I have sodium hydroxide. 

It’s sulphuric and nitric we cant get. And above 11% peroxide.

I only work with rolled jewellery. Because of the profit margin.

I think, with the greatest respect, what I am asking is straight forward. And relative to this post.

What can you use to dissolve tin/solder paste. Hoke says sulphuric. As above, we can’t get this.

So what would we use as an alternative? That’s all I’m asking, and I believe that’s all the original post was asking.

I understand the lead will be fine. However, the solder paste is what is causing me, and the original poster an issue.

Hoke doesn’t touch upon sulphuric alternative so I was asking someone (yourself) who would know. Which you answered. 

So my next question would be does bisulphate need any further process or can I/we simply replace the sulphuric with it? 

Regards


----------



## anachronism (Oct 25, 2019)

Jmk88 said:


> Sorry Jon.
> 
> I’m sure you’re just as good! Stop being sensitive....
> 
> ...



Haha I'm joshing with ya. 8) 8)


----------



## Jmk88 (Oct 25, 2019)

What’s your thoughts on the above Jon?


----------



## butcher (Oct 25, 2019)

Jmk88,
I think you have already got the questions answered, but I do not believe you understand the answers.

In another thread, You had gold foils with chloride salts
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=28093&p=296348#p296348

In this thread, your concern is nitrate salts and metastannic acid.



niks neims said:


> Agold2019 said:
> 
> 
> > Hi Lino thank you for the response. These are foils that came from pins and fingers and other gold plated copper nickel components from cell phone boards. There was also left a slimey grey residue which I think is tin. In my country it is hard if not impossible to get muriatic. I was wondering if lye could work? If not I will work on getting some muriatic and doing the test that way.
> ...



Some confusion may come from you not knowing what the different acids are called.
you have HCl but you cannot get muriatic acid...


----------



## Jmk88 (Oct 25, 2019)

Butcher,

I am not AGold!  

I think you’re confusing the two of us.

I am fully aware that sulphuric will dissolve the tin paste. I understand that. 

My question comes down to “can I substitute sulphuric for something?” 

If I can with Sodium bisulphate (and yes I know the difference between sulphite) how do I do that? Do I mix with hcl and water?


----------



## Jmk88 (Oct 25, 2019)

Basically...

This is the answer. I think?

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?t=25624


----------



## butcher (Oct 25, 2019)

I am really confused now. why do want to use sulfuric acid to remove tin, what is the salt of tin a chloride or a nitrate?

What are you working on with what and how...
Please keep the questions in one thread so maybe we can follow...

Tin in HCl Tin will make a soluble stannous chloride, which can hydrolyze to stannic chloride.
This is not a problem unless gold was dissolved in solution with the stannous...


Tin and nitric will form a gelatinous metastannic acid.
If this metastannic acid paste was also mixed with gold foils, and we used HCl, we would also dissolve some of the gold locking gold up in solution as colloids.
We can incinerate the metastannic salts to form tin oxides that will dissolve in HCl without dissolving the gold.

Tin is one of the amphoteric metals it forms insoluble hydroxides that with more or an excess of alkalis will begin to dissolve again.

Sodium bisulfate could be used in a fusion process, as a substitute for sulfuric acid, but without knowing the details of what you are doing, which question, which member is asking, or which tin salt we are talking about, or why you need to use sulfuric acid, I cannot go further into this confusion...


----------



## kurtak (Oct 26, 2019)

Agold2019 said:


> Where I live I may not be able to get HCL. Maybe I can,




Per the underlined --- I have a hard time believing you can't get HCl where you live - HCl is a "common" acid used all around the world - it is used (commonly) as a concrete cleaner as well as a cleaner for swimming pools as well as for Ph adjustment in swimming pools

So you should be able to find it in most hardware stores (usually in there paint department) &/or building supply stores &/or masonry supply stores &/or swimming pool supply stores 

You NEED to find it because without it you can not/will not be able to "effectively" recover &/or refine the precious metals from circuit board --- HCL is an essential acid "required" for the recovery & refining of PMs from CBs 

go find it - or - forget the idea of trying to recover/refine Pms from CBs --- try to do so without HCl will do nothing but cause you problems

Kurt


----------



## kurtak (Oct 26, 2019)

Jmk88 said:


> Basically...
> 
> This is the answer. I think?
> 
> http://www.goldrefiningforum.com/phpBB3/viewtopic.php?t=25624



Jmk88

Yes - the thread you linked is "in part" the answer to the question

in my first reply in that thread - did you follow the link I provided there

if not - here it is - & it will provide you with the rest of the answer

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=15324&p=155859&hilit=tin+oxide#p155859

read the "whole" thread

in that thread you will notice my user name changed from kurt (in 2012) to kurtak (in 2015)

Kurt


----------



## butcher (Oct 26, 2019)

You do not want or need to incinerate the tin chlorides especially if there is gold involved, the gold can go up in smoke in the fusion.

stannous chloride in solution will reduce gold and other metals or salts of metals in solution---itself being oxidized to a higher state converting the stannous to stannic chloride in solution.

Just a little about some of the more common tin salts.

SnCl2, tin (II) chloride, stannous chloride, solubility 84g/100ml H2O @ 0 deg C.

SnCl4, tin(IV) chloride, stannic chloride, Hydrolysis in water, pentahydrate very soluble. 

SnSO4, Tin (II) sulfate, stannous sulfate, solubility 33g/100ml @ 25deg C, melting point 378 deg C (712 deg F).

SnO, tin (II) oxide, can be two different colors blue/black more stable than the red metastable, insoluble in water, amphoteric will dissolve in strong acid or base.

SnO2, tin (!V) oxide, stannic oxide, cassiterite ore, insoluble in water, amphoteric dissolves in strong acid or base, can be reduced to elemental tin in a reduction with carbon in the reverberatory furnace, stannic acid hydrate is also called stannic hydroxide.

Sn(OH)2, tin (II) hydroxide, stannous hydroxide, in air stannous hydroxide Sn(OH)2 is oxidized into stannic oxide SnO2.


H2SnO3, mettastannic acid, this is the tin that forms a gelatinous goo with nitric acid, amphoteric insoluble in alkalis but with excess can form mettastannate which is soluble in water but not soluble in the alkalis.

As far as using H2SO4 sulfuric acid to dissolve the tin oxides or tin chloride salts to form a soluble tin sulfate salt, I cannot see any reason you would want to do this, because the tin chloride is more soluble than the tin sulfates are...
lead chloride is not very soluble in cold water but much more soluble in hot water.
lead sulfates are insoluble.


----------



## Agold2019 (Oct 26, 2019)

butcher said:


> You do not want or need to incinerate the tin chlorides especially if there is gold involved, the gold can go up in smoke in the fusion.
> 
> stannous chloride in solution will reduce gold and other metals or salts of metals in solution---itself being oxidized to a higher state converting the stannous to stannic chloride in solution.
> 
> ...



So much to learn


----------



## Agold2019 (Oct 26, 2019)

kurtak said:


> Agold2019 said:
> 
> 
> > Where I live I may not be able to get HCL. Maybe I can,
> ...



Best believe it. It is controlled and you need a license.


----------



## Jmk88 (Oct 28, 2019)

Thank you Kurt - very much appreciated. 

Thank you Butcher.


----------



## butcher (Oct 28, 2019)

some revision of the notes above:

View attachment gold Tin.rtf


----------



## Jmk88 (Oct 29, 2019)

Thank you again Butcher.

I now know what’s needed.


----------



## Lino1406 (Oct 29, 2019)

Here is an additional formulation to dissolve tin dioxide
SnO2 + 4HCl + Zn = SnCl2 + ZnCl2 + 2H2O


----------



## Jmk88 (Oct 29, 2019)

Butcher.... you really are a legend.


----------



## butcher (Oct 29, 2019)

Nope, I just spent some my time looking for information to try and answer to some of my questions, and I found more answers than I was looking for, which always leaves me looking for more, and provides me with more questions...

Lino,
I like it! 
(similar to silver conversion)...


----------



## g_axelsson (Oct 29, 2019)

Lino1406 said:


> Here is an additional formulation to dissolve tin dioxide
> SnO2 + 4HCl + Zn = SnCl2 + ZnCl2 + 2H2O



Does that work with metastannic acid too?

Göran


----------



## butcher (Oct 29, 2019)

I cannot see why it would not work.

Meta- stannic acid is structurally identical to SnO2 with more or less absorbed water.


B stannic acid (meta stannic acid) is formed with concentrated nitric acid and tin, In diluted nitric acid solutions, the tin will form stannous nitrate salts.

Meta stannic acid or B stannic acid the formula has been represented by several different formulas, such as H2SnO3, (H2Sn5O11 . H2O), or (SnO2 . H2O)5.
so with this we can write the reaction:
3Sn + 4HNO3 + XH20 --> 3(H2SnO3) + 4NO
or
3Sn + 4HNO3 + XH2O --> 3(SnO2 . H2O) + 4NO

B metastannic acid is insoluble in sulfuric acid even concentrated.
B meta stannic acid is very sparingly soluble in water


----------



## Jmk88 (Oct 30, 2019)

A 4 hour boil in water removed almost every trace of the goo.

It was lead: not tin. 

I added fresh boiled water every 45 minutes to keep approximately 800ml volume. 

I’m not sure how much lead chloride I had as it was wet and hard to measure. Appreciate this isn’t answering the immediate questions on stannic, but I believe the original post should try the same.

I strongly, strongly, strongly advise reading Burchers posts “word for word” and especially his paper that’s downloadable.


----------



## Jmk88 (Nov 6, 2019)

Kurt,

You are also a legend.

I have been running tests with the black goo.

Sodium Hydroxide and incineration.

I would be spending any more money on hydroxide. 

Thank you for your comments!


----------



## Jmk88 (Nov 6, 2019)

*wont be


----------



## Jmk88 (Nov 7, 2019)

AGold,

I’m not sure what material you’re using but the key is to basically remove anything like this before you even go near hcl recovery. 

Bit disappointed that no one has really explained how easy this is to do... as well as the importance. I believe Harold emphasises this, via incineration.

Having spent two days in London’s diamond district, Hatton Garden, I have been lucky to witness how the biggest U.K. refinery does this. 

It’s extremely straight forward.

Bathe what you have in lye for 48 hours prior to starting any process. Within 60 seconds you’ll see the solder start to rise; as this is solder, it breaks the lead and the tin away. You do not need to worry about separation; simply pour off the solution. You will note any scrap gold as being oil free and as clean as you can chemically get.

Then you begin your recovery. You can use AP or nitric for this; your AP should be highly charged with copper to ensure no precipitation when steel goes into solution. Although still not an issue of this occurs as you’ll find copper is dissolvable is warm hcl or cold with a bubbler.

Nitric is obviously the best but very hard now days to obtain: even in the US. 

Remember, the best joiner in the world is unlikely to match their skill with arbocultural knowledge. They don’t need to know how trees grow to apply their skill. 

I think sometimes the chemistry and refinery processes are a bit convoluted in the sense that too much chemistry information is given. 

That’s not saying you should ignore it; if anything you need to understand for safety.

If you obtain less than 37% hcl, the hazards are drastically reduced in the sense of vapour. It will still burn if you spill on skin but you will have enough time to water it and shouldn’t be an issue. Above 37% is not the case and is difficult to work with even with PPE. The fumes alone are not removed by hoods entirely. You should always be outside if using that or nitric in my opinion. 

The answer to your question, simply put, is bathe in sodium hydroxide before doing anything.


----------



## Jmk88 (Nov 7, 2019)

Also, use Harolds cleaning process and Kurts instructions once you have removed the gold. 

Incinerate and wash twice in water and hcl. Don’t need to boil the hcl, 40-50 degrees is more than enough. 

This will ensure you 99.99% purity.


----------



## anachronism (Nov 7, 2019)

Jmk88 said:


> AGold,
> 
> I’m not sure what material you’re using but the key is to basically remove anything like this before you even go near hcl recovery.
> 
> ...



That advice cannot be given blindly. You mention in your post that people pay too much attention to the chemistry but if you did, you'd know why you can't say what you just said. 

Fair?


----------



## Jmk88 (Nov 7, 2019)

In part.

I’m going on the basis of scrap gold jewellery. As I stated.


----------



## Jmk88 (Nov 7, 2019)

Although I’m struggling to think of what gold scrap the average person can obtain that contains solder contaminants this wouldn’t work on.


----------



## butcher (Nov 7, 2019)

It is all about chemistry or the movement of electrons.

You do not have to understand the chemistry, or about how electrons of atoms react with other atoms, as long as you understand what is going on with the metals, the acids, or the electrolytic reactions...

C.M. Hoke in her book shows the layman jeweler the chemistry involved in recovery or refining without going into any scientific detail or using the chemist lingo which she was surely well versed in, explaining the reactions without using chemical equations or explaining how the metals and acid react on an atomic level, so the laymen jeweler could recover and refine his gold.

You do not have to understand much about how a car engine runs to change a starter or to do a tune-up or to get one running with a mechanical problem. (Just google it, or search your youtube channels if all else fails).

But going beyond being the neighborhood shade tree mechanic, you would want to understand everything you could about how the engine runs and why down to the atomic level if necessary.

Understanding chemistry is going to another level of understanding that gives us more insight into the reactions and what could happen or what might have happened and helps us to get a better understanding of the mechanics.

You do not need to understand chemistry, geology, engineering or mineralogy as well as many other disciplines to be a prospector or miner, or to find gold, but to any good miner worth his salt would want to understand all of these disciplines and how gold reacts down to the atomic level...


----------



## Jmk88 (Nov 7, 2019)

Yes that’s what I was trying to say.

I think the chemistry side of things helps with safety too. I was rather enlightened this week and think it was the best 16 hours I could have given. 

I was amazed at how easily solder is actually removed, yet how many people, myself included, fail to do so in their initial recovery stages.

The guy I was shadowing has a background in chemistry but says that once you understand the actual processes and have the safety in place, it’s a case of practicing over and over to become better and better. He kept stressing that trying to understand the chemistry beyond safety requirements initially will cause most people to go wrong through misunderstanding.

I think what he was trying to say is chemistry is for gifted minds where as anyone can pick up refining with safety and practice.


----------



## butcher (Nov 7, 2019)

We can always start off learning to become a good shade tree mechanic and work on learning more in the field of work, improving our skill and gaining more of an understanding...

I do not think that to work to gain a better understanding of the chemistry around us is beyond anyone's mind or their abilities.

An understanding only improves our ability's, and thus our minds to be able to understand even more...

Heck, you can teach monkeys to recover and refine gold, but getting the monkeys to understand what is going on or when things do not go as planned maybe a bit harder, or when something about the chemical reaction is different... When the monkey sees and the monkey does, but the procedure or experiment does not go the way monkey was taught, or something was different...


----------



## anachronism (Nov 7, 2019)

butcher said:


> We can always start off learning to become a good shade tree mechanic and work on learning more in the field of work, improving our skill and gaining more of an understanding...
> 
> I do not think that to work to gain a better understanding of the chemistry around us is beyond anyone's mind or their abilities.
> 
> ...



Well worded. Put another way - if you cannot understand why something happens how can you understand how to put something right when the recipe doesn't work?


----------



## butcher (Nov 7, 2019)

Anyone could plant and grow some tomatoes, even if a few plants get lost along the way, but the farmer who has some understanding of the chemistry of his soil will be able to grow better tomatoes, and if he understands something about pest control may even have some for his table...

A good farmer also understands the importance of safety around the farm, the animals and the farming equipment and how dangerous his work can be, and how he can protect himself and his family...


----------



## Buckly (Jan 2, 2020)

Hey, good day all.
I'm new to the forum and noticed this post of yours so I wanted to ask you a few questions, please?
I have successfully collected gold flake from fingers and recently attempted a recovery from CPU pins. That was challenging as I tried to soak in HCl first to remove the solder (as I thought I had to do prior to treatment with Nitric to remove the base metals) and noticed this issue - There was a precipitate (some tin compound?) that fell out WITH some gold and I had a lot of trouble trying to separate/filter them. Also, it appeared that something (the Tin compound?) was plating on the pins and the more HCl I added would just add more plating and fine gold particles that settled out. I eventually just treated it all with HNO3 and did end up with Au foils, but I'm sure I lost some yield in the process.
Any assistance would be appreciated.
Thx,
Buckly


----------



## butcher (Jan 2, 2020)

attempted the recovery of gold from CPU pins. 
I tried to soak in HCl first to remove the solder 
(as I thought I had to do prior to treatment with Nitric to remove the base metals) 
HCl will attack lead/tin solder.


https://en.wikipedia.org/wiki/Reactivity_series

Tin and lead are more reactive than hydrogen in the reactivity series of metals, as well as many other metals like nickel, iron which can also be attacked and can be alloys or plating onto the pins...

HCl alone will not attack metals below hydrogen in the reactivity series of metals, like copper, but if we have air or oxygen or some other oxidizing agent we can attack the copper or even gold metal.

noticed this issue -
There was a precipitate (some tin compound?) that fell out WITH some gold and I had a lot of trouble trying to separate/filter them. 
Also, it appeared that something (the Tin compound?) was plating on the pins and the more HCl I added would just add more plating and fine gold particles that settled out. 

Metal ions dissolved in a chloride solution can be displaced from the solution as the solution attacks a more reactive metal.

iron which is more reactive than copper, iron metal will give up electrons to copper ions in solution, displacing the copper from solution, or cementing or plating the copper out of solution as the copper gains electrons from the iron which now has lost an electron from its atom to become a chloride ion, in a displacement reaction the copper will tend to plate onto the iron as the electrons are exchanged and cement the copper from solution as a metal powder as the solution become saturated as an iron chloride.
one metal in a solution can be displaced by another more reactive metal...

The tin will dissolve into HCl as soluble stannous chloride SnCl2, which can hydrolyze into stannic chloride SnCl4.
Tin being so reactive it probably was not the metal you have seen plating out on the pins or which was being displaced from the chloride solution...
The lead will form a fairly insoluble PbCl2 salt...

I eventually just treated it all with HNO3 and did end up with Au foils, but I'm sure I lost some yield in the process.

Any time you have gold involved and you have previously used HCl, and are planning to move on to use HNO3 in a later step and do not wish to dissolve any gold, you need to remove any chloride salts through washing, heating to drive off chlorides, and incinerating the material to form metal oxides...


----------



## Xsvfan1 (Dec 12, 2021)

butcher said:


> some revision of the notes above:
> 
> View attachment 42519


good stuff man. learned alot from this. will be saving for future refrence


----------



## Geo (Dec 12, 2021)

Hydrated tin oxide (metastannic acid) can be removed completely in a short period of time. 
First, add hydroxide to convert the tin hydrate to tin oxide. Very important, rinse well and dry the mass. Do not over heat or burn the salt. Dry on low heat. Once the salt is dry, add it to a beaker and add acetic acid. The tin oxide will dissolve instantly creating tin acetate. Any foils or solids should be rinsed well before processing further. The process only works if the salt is dry. It will not work on wet material. 
I have used ammonia after drying the salts and it dissolves the salt but then you have to neutralize the solution.


----------



## Jado (Dec 12, 2021)

Jmk88 said:


> AGold,
> 
> The section in Hokes book is pages 69-73.
> 
> ...


Is the restriction regarding possession or just sales? Magnesium Sulphate should be accessible if possession isn’t the issue.


----------

