# Hcl to dissolve tin



## Williamjf77 (Nov 9, 2019)

I have a quick question about using Hcl to depopulate and dissolve tin, is it better to dilute 31%hcl when dissolving tin?

I may be wrong but doesn’t Hcl especially when hot just fume off Hcl vapor until it is 20%. Does the water play any roll in dissolving tin?


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## Jmk88 (Nov 9, 2019)

Don’t use hcl.

Use sodium hydroxide. Solder is the problem which is lead and tin.

Make sure you understand the safety of working with it but it will remove all solder rapidly.


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## anachronism (Nov 9, 2019)

Jmk88 said:


> Don’t use hcl.
> 
> Use sodium hydroxide. Solder is the problem which is lead and tin.
> 
> Make sure you understand the safety of working with it but it will remove all solder rapidly.



OK please explain the chemistry of using lye rather than HCl. .


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## Jmk88 (Nov 9, 2019)

Do you ever have anything positive to contribute? 

I don’t need to explain the chemistry. It works. 

You explain why hcl is better.


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## butcher (Nov 9, 2019)

You do not have to write equations to explain a chemical reaction or why you believe sodium hydroxide is better than using Hydrochloric acid to remove solder lead and tin...

you are the one telling everyone not to use HCl to remove lead or tin solder, but that they should use NaOH, so a member asked you why and asking you to give an explanation of your statement...


Hoping that you had something to contribute.


Basically back up your statement with something besides just words ...

Now I am also wondering why should I not use HCl and use NaOH... Hoping you have something to contribute.


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## nickvc (Nov 10, 2019)

Given the choice I think I’d rather use HCl rather than lye as the dangers are far less, i class lye with concentrated sulphuric and use only with extreme caution.


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## Jmk88 (Nov 10, 2019)

Here comes the multitude of chemistry equations....

Because it breaks away the solder where as hcl will react slow with it.

Butcher with all due respect I have asked you that question 3 times and you didn’t once answer me; I spent an hour with a professional refiner and he was a bit bamboozled at your posts too. From a refining POV.

Tell me why you wouldn’t use lye?


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## Jmk88 (Nov 10, 2019)

I use a tinned drink for example.

If a child asks you how to open a tin, you simply explain that you please your thumb under the ring and pull up.

Why would you explain that the ring is a cantilevered system that relies on the density differences between two of the same components in order to excerpt excessive compressive strength on the bottom component via the top.

The kid would look at you like you have 9 heads.

Very similar to how you gus are bamboozling people that want to know the practicality of things, not the chemistry. 

Hoke clearly states it’s unnecessary and I have confidence that Baird and co refiners know what they’re talking about. Particularly the man I shadow who I would humbly suggest is more advanced in chemistry than your average man.

The approach doesn’t make sense. If anything, can you explain the rate of dissolution of lead in hcl? Any material quantity’s of decent size will have shit loads of lead; the chap posting seems to think it’s just tin. Hcl will not dissolve lead efficiently at all. You well know this.

The fact he’s discussing hcl suggests he has no nitric so how do you justify using hcl (way more hazardous) than hydroxide? You need to use far more material and spend more time. 

That’s how you make money... spend more time and materials than the man next to you. Not.


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## anachronism (Nov 10, 2019)

Jmk88 said:


> Here comes the multitude of chemistry equations....
> 
> Because it breaks away the solder where as hcl will react slow with it.
> 
> ...



I'll happily answer that for you when you've answered my question. Answering a question with a question ends up in a never ending loop.


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## Jmk88 (Nov 10, 2019)

I know the answer.

With all due respect sir, I’m not too worried about any information from you.

You seem more concerned talking to me or trying to catch me out rather than helping the chap asking a question.

Your intent is clear to me and I would kindly ask you don’t reply to my posts unless I have given incorrect advice.

I’m here to learn and pass on my experience to others; not offer theoretical education.

All the best.


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## anachronism (Nov 10, 2019)

Wow how patronising. Where do we find people like you.


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## Jmk88 (Nov 10, 2019)

Jon,

Again, with all respect, I’ve not witnessed one positive post you’ve made to one member here.

Yet you expect the same respect as people such as Butcher etc. Doesn’t really work that way, neither does life.

As I say, unless it’s to point out misinformation or contribute something to answer the questions people are asking, I kindly suggest we stick to our own paths.

Cheers,


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## butcher (Nov 10, 2019)

If I tried to explain why I would not use caustic soda it would confuse your refiner, I might use equations or terms he does not understand related to the chemistry he is doing...

Sorry, I wasted my time trying to help answer your questions.

Give my apology to your refiner, tell him if he wishes to learn the chemistry involved, or for me to explain the equations or my post, he is welcome to join the forum, he may find the information very helpful to his business if he learns to understand the chemistry, and the answers I provided you within that post ...

And I am sorry you feel I have wasted your time.

I think I can explain how to open a soda can to any kid (monkey see monkey doo)...

But explaining recovery and refining to someone who knows very little about it, well that is harder for me to do, it is not like I can just show the monkey and the monkey doo, the monkey would have to learn and gain an understanding of the language and terms used, basically he might have to study some gain a better understanding.

Seriously I thought I was trying to help, and I thought I was answering your questions to the best of my ability and my intention is not to confuse or baffle anyone.

Whenever you study a field or are learning any skill you are going to run into things like equations you do not understand. or someone may use those equations in an explanation of a question that you have.

That is where we educate ourselves to be able to understand those equations or explanations during our study of that field of work...
Ask the person answering the question too dumb down his answer where any monkey can understand it, or find another source of information to answer your questions that speaks more in a language we understand.


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## Jmk88 (Nov 10, 2019)

Butcher,

I’m not having a pop. I was simply passing on what I was told. Which is kind of reinforced by Hoke.

A great teacher will always understand that minds work differently; whilst you clearly have a gifted mind for chemistry, others simply don’t.

I grew up in a very excluded education system where unless you’re an A* chemistry and maths student, you’re told you’ll never go far. 

I just wish I had the confidence I have as an adult to challenge that. 

The chemistry is needed on a basic level; for people predominantly with a basic understanding. 

I simply can’t understand why you would bathe in hcl instead. I literally witnessed the tin and leaf removal start occurring in 60 seconds. I even saw soldered components completely separate from 2 kilos of jewellery by the end of my first day.

And the comments given regarding your chemistry were actually the opposite; that they are rather advanced and you clearly know what you’re talking. They was not belittling your knowledge; rather criticising your method of teach. That’s all.


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## butcher (Nov 10, 2019)

If this goes on much farther, we should take it to debates and discussions.

I cannot see where this discussion is helping anyone learn the complicated reactions of tin.

I can smell trouble in the air, gentlemen we should settle between ourselves without disturbing those wishing to learn about tin.

I cannot see where this discussion will lead forward to help anyone.


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## Jmk88 (Nov 10, 2019)

Agreed.

I’ll Pm.


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## butcher (Nov 10, 2019)

I did not understand the chemistry when I joined the forum, it took time for me to begin to understand it.
You do not need to understand the equations although you will find them extremely useful if you do.


I know it may seem over your head, but believe it or not, that is how I learned.

I spent 12 years in school and could not read after graduation, I taught myself how to read after I was an adult mainly by studying technical manuals related to the different fields of work I was involved in.

I knew almost nothing about electronics, but I wanted to learn.

I could not read schematics, I could not do the complicated math formulas, heck I did not even understand the language, but I ordered a subscription to a couple of magazines, popular mechanics and electronics now along with any other electronic book I could find anything 

When I began reading there was almost nothing I read that I understood, but I would struggle past that until I found myself finding something I did understand, as I read and studied I began to understand more and more of the language, I began learning how to read schematics, design, and repair most anything electronic...


I can easily try and dumb down my answer and leave out the equations I was trying to use to help explain it, but I do not think that would be fair to you or me, or the other members reading our discussions, you would not be exposed to it, or some of the other very helpful information you may pick up from it, and I would not be helping you or others to the best of my ability.






I


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## nickvc (Nov 10, 2019)

Jmk88 said:


> The fact he’s discussing hcl suggests he has no nitric so how do you justify using hcl (way more hazardous) than hydroxide? You need to use far more material and spend more time.


Sorry but this is complete rubbish lye is extremely dangerous, if you splash a little HCl on you it will do little damage to your skin or even eyes that is permanent I really wouldn’t want to do the same with lye....
The lye may well be faster but I wouldn’t feel happy suggesting that to everyone especially those with little understanding of the dangers involved.


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## g_axelsson (Nov 10, 2019)

Jmk88 said:


> I simply can’t understand why you would bathe in hcl instead. I literally witnessed the tin and lead removal start occurring in 60 seconds. I even saw soldered components completely separate from 2 kilos of jewellery by the end of my first day.



Are you talking about electronic components or jewellery? It's two totally different feed stocks.

Putting safety issues apart, what concentration of lye do you recommend?

Just telling people to use lye adds a lot of ambiguity as lye often comes as a solid and you have to mix it yourself. It is well known that lye reacts different with components than hydrochloric does, even the circuit board reacts with lye.

Göran


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## snoman701 (Nov 10, 2019)

This whole thread is a bit disappointing. Quit bickering please. 

Tin and lead are both amphoteric. They will react with acid or base. 

With base, forming sodium stannate or sodium plumbate and hydrogen gas.


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## kurtak (Nov 10, 2019)

Williamjf77 said:


> I have a quick question about using Hcl to depopulate and dissolve tin, is it better to dilute 31%hcl when dissolving tin?
> 
> I may be wrong but doesn’t Hcl especially when hot just fume off Hcl vapor until it is 20%. Does the water play any roll in dissolving tin?



Getting back to the original question of this thread --- NO - it is not better to dilute HCl when dissolving tin - it will slow down the reaction AND if made to dilute it will actually cause the tin to precipitate out as stannic tin (the white paste)

if anything - when using heat (which is not needed when dissolving tin) which can/will vapor off HCl you would want to add "more" HCl to keep the HCl from becoming dilute

You "only" need to use hot HCl for dissolving solder IF the solder is an alloy of tin & lead --- that's because cold HCl does not react well with lead - but when lead is alloyed with tin the lead will dissolve along with the tin when the HCl is heated

Then - when the solution (tin/lead dissolved in hot HCl) is cooled - the lead will precipitate out as lead chloride crystals - which dissolve again when heated

Therefore - if the solder is tin solder (most if not all newer electronic scrap) - (mid 90s & newer) use HCl without heat & don't dilute it

older electronic (70s into early 90s) it is more likely the solder is lead/tin alloy therefore heat MAY need to be applied to dissolve the solder 
Kurt


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## butcher (Nov 10, 2019)

Thanks, Kurt, you explained that so very well.

Saying it another way.

HCl will only fume off if the concentration of the acid is above its azeotrope of around 20%.

Metals less reactive than hydrogen in the reactivity series like copper will not really react with HCl.

Now, the fact above can change if the copper has any copper oxidation, as the HCl would attack the oxidation products of the copper, making some cupric chloride in solution, which with oxygen absorbed from the air into the can also make the HCl more reactive towards copper metal, different metals ... but that is just nit-picking, HCl lone basically will not attack copper.

Base metals that are more reactive than hydrogen in the reactivity series like tin or lead will react or dissolve In HCl without the addition of an oxidizer.
In the reaction of HCl acid with these metals, we will have gases of that will evolve from the reaction, while HCl gas and its products may be carried off in the fumes of the other gases of the reaction it is not the HCl fuming off because of its azeotrope, or because of its concentration, as much as it is that some HCl fumes just getting carried along for the ride with the other gases evolving from the reaction such as hydrogen and the evolution of water vapors...

The HCl does not gas out of solution with the base metals it reacts with them to evolve hydrogen

solid Tin (Sn) metal or solid lead metal dissolves in hydrochloric acid (HCl) produces hydrogen gas (H2), it is the hydrogen gas that evolves from the reaction (and thus may carry some HCl fumes along for a ride) as the HCl is reduced to a chloride ion (Cl-), and the tin is oxidized to stannous chloride, or a lead chloride solution.

Sn(S) + HCl(aq) --> SnCl2(aq) +H2(g)
Pb(S) + 2HCl(aq) --PbCl2(aq) + H2(g)

Stannous chloride SnCl2 reacts ( or hydrolysis in the dilute solution) with water to form an insoluble basic salt called hydroxotin (II) Chloride Sn(OH)Cl(S) and hydrochloric acid in solution HCl(aq).

SnCl2(aq) + H2O(l) --> Sn(OH)Cl(s) + HCl(aq)

stannous chloride SnCl2and water H2O with oxygen O2 (oxygen absorbed into the solution from exposure to air...), we get a product of hydrolyzed stannic chloride SNCl4(aq) in solution and the insoluble salt called hydroxotin (II) Chloride Sn(OH)Cl(S).

6SnCl2(aq) + 2 H2O(l) + O2(g) --> 2SnCl4(aq) + 4Sn(OH)Cl(s)
6SnCl2(aq) + H2O + O2 --> Sn(OH)Cl + SnCl4


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## kurtak (Nov 10, 2019)

Jmk88 said:


> You explain why hcl is better.



Because HCL has been the STANDARD method for removing solder (tin &/or tin/lead solder) by refiners (MAJOR refiners) around the world

Using NaOH is NOT the standard used by refiners

Does NaOH work --- yes

but there is a (good) reason why "experienced" refiners DON"T use it

Seems to me - as a NEW member here - you should be listening to them (the experienced refiners) instead of being combative with telling them how much wiser you are in your total lack of real knowledge &/or experience

Your experience - likely watching some "ill informed" you tube videos before joining this forum a few months ago with 44 post

The experience of those trying to help you ------

Butcher - member since 2008 with 8866 post - nickvc member since 2009 with 4343 post - Goran member since 2007 with 5007 post - Jon member since 2016 (under current user name) with 2743 post (was a member under another user name with MANY more post) - me member since 2014 (under current user name) with 1836 post (was a member under another user name with MANY more post)

Concerning "your" problem with Jon (& it is YOUR problem - because you don't like what &/or how he is telling you about refining) --- I recently just spent a week in his refining lab - Jon refines more gold "in one day" then you are likely to see in your life time (with your current attitude) --- on the other hand - if you gave him the "respect he deserves" as a "professional" refiner - you to may "someday" achieve the kilos of gold he refines

For what its worth (& as someone that has been at this for years) your "pushing" this idea of using NaOH to dissolve solder is a fools errand & continuing to "push it" you will soon rise to the level of being an idiot --- IMO 
Kurt


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## snoman701 (Nov 10, 2019)

kurtak said:


> ...but there is a (good) reason why "experienced" refiners DON"T use it



I understand that 95% of the reactions discussed on this forum are acid dissolutions...call it a hammer for your nail. But sometimes you need a screw, and I personally prefer screwing. :lol: :lol: 

So what IS the reason experienced refiners don't use caustic? 

Are there any, outside of the assumption that they are more accustomed to hammering instead of screwing?


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## Shark (Nov 10, 2019)

To quote Kurt from this post...

Depopulated board in oil



> And - don't forget - the FINE black powder from dissolving the tin away contains "gold" (and antimony) as well - so let that fine black powder from you HCl decant & the water washes settle out for processing as well
> 
> Kurt




Goods enough for me when I gain gold, even a tiny bit. 

How would that tiny bit be gained using NaOH? Convince me it is better.


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## Williamjf77 (Nov 10, 2019)

I’m going to stick with the hcl, I didn’t try it without heat though. That would be good if it still strips tin solder without heat. I’ll keep it full strength.


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## Jmk88 (Nov 10, 2019)

Kurt,

That simply isn’t true. Refiners commonly use caustic. Particularly with jewellery.

Even Hoke mentions caustic.

And I don’t think I’ve once said I’m more experienced than others or know more; if anything I’ve repeatedly asked for input.

I believe I’ve expressed my gratitude for the people you’ve mentioned having input, as well as yourself. 

The point is you don’t need to dissolve solder. You can simply remove it. Is that right or wrong? I believe right.

Why go to the trouble of dissolving when you can remove? That doesn’t make sense.


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## Williamjf77 (Nov 10, 2019)

I’m perfectly comfortable working with lye or acids, the precautions should be the same as far as respecting both. I get that some things are worse than others. 

I’m just looking for practical means. I see now why some say the best way is to not process e scrap. Complete PITA compared to gold filled. 

The education I got so far is invaluable though and the chemistry of it all is a huge learning curve but well worth learning.


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## Jmk88 (Nov 11, 2019)

Basically Kurts point was spot on; if you’re using modern e scrap yes, hcl.

If you’re using anything vintage, e scrap or jewellery I would definitely go with lye.

It’s a lot easier to remove in bulk on vintage things prior to removing any gold and lye will achieve this quite nicely.

But yes, if non lead containing solder (modern material) then I wouldn’t apply the same advice.


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## kurtak (Nov 11, 2019)

Jmk88 said:


> Kurt,
> 
> (Point 1) --- That simply isn’t true. Refiners commonly use caustic. Particularly with jewellery.
> 
> ...



Point 1; - that simply is not true - there may be some you tube hobby "hacks" out there that commonly use NaOH to remove solder --- but not pro refiners - pro refiners ether use acid to "eliminate" solder - or in the case karat jewelry they simply melt it - pour it to shot - dissolve it in AR - Add a "bit" of sulfuric to precipitate the lead as lead sulfate - filter out any stannic tin &/or lead sulfate - precipitate the gold - put the gold through the proper washes - melt the gold

Point 2; - Hoke only mentions using NaOH in the final precipitated gold powder wash if you suspect "lead sulfate" followed your gold drop (page 73) --- other then that Hoke gives VERY CLEAR instruction to use hot HCl to "eliminate" tin/lead solder before taking the gold to AR (starting on page 70)

Point 3; - HCl "eliminate" the VAST majority of the solder when it "dissolves" the solder --- NaOH may "remove" much of the solder - but it's NOT going to eliminate all of it like acid does --- that means you are going to have more lead & tin follow you in the rest of your refining process. --- that is a fact & a period at the end of what I just said

Point 4 --- Because of what I just said above --- soooo - stop pushing what amounts to "misinformation" - you are coming very close to crossing the line of MANY that have come before you pushing such B.S. - & the don't last long here

Kurt


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## Jmk88 (Nov 11, 2019)

Kurt,

How is that misinformation?

Point 4 would be exactly the same as your point 1. If you remove the solder from vintage jewellery with lye, you would be able to dissolve the minor bits left and as you say, precipitate with sulphuric (or sulphamic). 

There is nothing I have said factually incorrect; you may disagree with my opinion that lye is more effective on jewellery which is fine, you stick to you and I’ll do me.

I haven’t given any misinformation at all, I have simply pointed out another way of removing solder. 

Why would someone be banned for expressing opinion? That’s not helpful to anyone, even if they are wrong there is enough people here that would point that out, which would result in valuable information.

I accept that you and others may not apply my approach, but to say it doesn’t work is not correct. Whether it’s better than hcl or not, I wouldn’t comment. I’ll just say I’ll stick to me.

Regards,


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## Jmk88 (Nov 11, 2019)

Kurt,

Another point, is that I don’t disagree hcl will dissolve solder. However, if you look at some posts here with the issue and I have had it myself, is that the rate of reaction across say 2kg of gold jewellery, would be tremendously slow, if simply placed in hcl and heated. You will also have other metals reacting with the hcl, particularly if heated.

You would be waiting a long time to have solder free gold. Even when incinerated, plus the amounts of solder (such as a 2k batch) would require a hell of a lot of hcl.

I think you need to calm down and stop attacking every point I make because I think its a debate worth having. Doesn’t need to become an argument.

My opinion, and it’s my opinion, is economically and environmentally you would be 1000 times better removing solder prior to gold recovery, IF APPLYING TO JEWELLERY.

This is the type of conversation that would benefit people looking to refine seriously.


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## Lou (Nov 11, 2019)

snoman701 said:


> kurtak said:
> 
> 
> > ...but there is a (good) reason why "experienced" refiners DON"T use it
> ...



Maybe not caustic baths...but experienced refiners (i.e. places doing a truck load every 20 min...we all know who they are) do something similar. Moreover, caustic gets the masking and the tin and without fume. Is it more dangerous than muriatic acid? Absolutely. Is the waste somewhat more involved? Absolutely. Is it better? In my opinion, depends on the tin content. Stannate de-tinning is well established and used on loads of tinned copper since time immemorial. Higher tin, the better. 

On the blister copper that contains the PMs poured from the converter/ shaft furnace, the slag contains hydroxide...which one I cannot say, but believe me, 'tis everything but the squeal and there's plenty of money in processing tin based solders. That tin slag also contains the Ta and Nb from caps. It also sucks to process :twisted: 

Metallic Resources, really close by to us here in Ohio, has a process where they do very very large quantities of solder.


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## Jmk88 (Nov 11, 2019)

Lou,

That’s essentially all I was trying to say.

https://www.bairdmint.com

This is what I witnessed one of their refiners do last week (with my jewellery).

His advice was big batches are not economically viable if you are talking solely about solder removal (bit wordy) unless you have extreme patience and are not aiming to make money. 

I have tried both and unless I’m placing the jewellery in hcl incorrectly, even with boiling and the horrendous fumes it generates, the results were not really comparable. That’s my personal experience and was reinforced by the chap at the above.

He said you just simply wouldn’t keep up with serious refiners, plus would generate fumes, a lot of acid and money expenditure. 

I know butcher had provided the capacity of hcl for lead/tin but can’t find it. I believe it was around 82g per litre off the top of my head, which is a hell of a lot of acid consumption, in my opinion. 

I’m beginning to fear saying anything out of not wanting to be publicly attacked and threatened with banning, so if any of the above is not right please do let me know. It will be hugely appreciated.

Kindest Regards,


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## butcher (Nov 11, 2019)

Jmk88,
We do not ban members because they have a different opinion, we do expect them to keep any disagreement civil polite and without attacking the other member, or disrupting the forum...

Disagreements can be a good thing as long as we learn something from them and we all can come to some kind of agreement together if nothing else to agree to disagree with each other as gentlemen and ladies...

As far as stirring up a hornet nest and getting a lot of members to disagree with you on your first arrival to the forum, well sorry you are on your own on that one,

Looks like your holding your own and being a gentleman and putting your argument over effectively, so who knows you may survive the debate and maybe we will all learn something from it.


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## Jmk88 (Nov 11, 2019)

Thank you Butcher, very much appreciated.

Kindest Regards,


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## snoman701 (Nov 11, 2019)

It would also be helpful to note that those whose name is in green are moderators. 

They have proven time and time again to be consistently level headed, well spoken, and value added assets to the community. 

Everyone else is just a minion with an opinion. 

Most of the problems in refining have more than one right answer...which answer is right for you depends on your individual situation, your education and your experience.


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## anachronism (Nov 11, 2019)

snoman701 said:


> It would also be helpful to note that those whose name is in green are moderators.
> 
> They have proven time and time again to be consistently level headed, well spoken, and value added assets to the community.
> 
> ...



Hehe


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## AuPure (Nov 11, 2019)

I just wanted to say as a new member with little experience with recovery and refining, I have found this debate quite interesting. I like to learn about all the different processes. 

I can say that personally I have just started doing very small batches < 10 lb. Of ceramic ICs with some solder still on the pins and holding the tiny capacitors on the top. For batches this small using hot HCL has worked great for me. But I do this as a hobby and can let the parts soak in hot HCL for hours a day for multiple days if needed. I'm not doing this for a living, or for the $. I just like the whole chemistry/ mad scientist aspect of it. :lol: And having a beautiful little button of gold for my efforts at the end is just a good bonus. 

Thank you all again for sharing this info freely.


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## Williamjf77 (Nov 11, 2019)

I agree, I love the heated debates. It ends up bringing out a lot of great info that is probably already somewhere on the forum but gives it a bump.

I was the OP. Guess I’m the instigator.  

Back on to the hcl, I just put 4lbs of mixed cpus to remove pins in hcl. It’s 60 something degrees here in CT. 

I want to see how long it takes without adding heat. If it goes over 24 hours I will abandon it and heat it. It is supposed to go down to like 15 tonight so we’ll see.


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## Jmk88 (Nov 11, 2019)

Just be careful with the fumes Sir, above 50 degrees (c) and it starts to get quite heavy! 

Don’t have any of your metal equipment in close distance either... 

Good luck! 

:wink:


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## Williamjf77 (Nov 11, 2019)

That’s 60degrees F but yeah the hcl fumes is what started this whole thread really. Honestly I was just trying to avoid leaving the fume hood blower going all night. Actually I better go turn it on now.


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## Williamjf77 (Nov 11, 2019)

Ok just checked the solution. It is reacting nicely at room temp.
I knew most of what I read says hot hcl but if it can be done reasonably without heat that’s great for me. I didn’t like the thought of venting fumes in the summer when everyone is outside so I collected my materials during the warm months and am processing now. Plus I had to put a new roof on the garage.

I do have a makeshift exhaust out the window top. It works good. I can’t bring myself to cut into the beautiful roof I just put on. Eventually I will and do the whole scrubber setup. I scored a nice 2500 something cfm squirrel cage blower, when I install that I’ll do a proper roof exhaust. 

But thanks for the safety warnings. One can never be reminded enough times about the hazards we deal with, be it a first timer or an old timer,


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## butcher (Nov 11, 2019)

Williamjf77 said:


> But thanks for the safety warnings. One can never be reminded enough times about the hazards we deal with, be it a first-timer or an old-timer,



How true, old=timers may know better but they can easily become too relaxed or careless in their practices, or neglect to continue their study in the safety aspects...


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## Shark (Nov 11, 2019)

Could someone explain how heat and cold affect the solutions? I know they slow down when cold and usually speed up when hot, but what is actually going on that causes the effect? Thought I would ask here as it seems to follow along pretty well.


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## FrugalRefiner (Nov 11, 2019)

Energy. When we warm something, we add energy. When we cool it, we remove energy. In a warmer solution, all the ions are more energetic, so they bang into each other more often and with more force. If you toss a baseball gently at a piece of drywall it will probably just bounce off. If you throw it as hard as you can, you may put a hole in the drywall.

Göran can probably provide a much more elegant explanation.  

Dave


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## butcher (Nov 11, 2019)

I can not explain it but I can guess that adding heat energy would have a lot to do with speeding the reactions, with an increase in rate or number of high energy collisions,the physical reaction of an increase in molecular movement and the action in the solution, the production of the gases increase, solubility change, the concentration of the solution which also concentrates the remaining unreacted acid or base or other reactants in the reaction.

Or just because it is like this old man, it just works better in warm weather than cold.


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## Shark (Nov 11, 2019)

butcher said:


> Or just because it is like this old man, it just works better in warm weather than cold.



Now that I can understand,


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## anachronism (Nov 12, 2019)

If you imagine a big jug of water with a load of table tennis balls (or similar in it) at room temperature- those balls are pretty much sitting there. Now heat the water to boiling and look at the balls. 8) 8) 

That's pretty much what happens with reactions. The atoms are smashing against each other much more frequently like the balls in boiling water.


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## Williamjf77 (Nov 12, 2019)

Well it was taking too long without heat but I believe it would have done the job if the temp stayed @60-70f .

I think tomorrow after it is done I will distill off the HCL and save the stannous Chrystal’s


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## Williamjf77 (Nov 12, 2019)

Here is another safety tip from this newbie

Safety labels 
Cheap from Amazon now a days and it makes my space look less like a meth lab. Or at least a safety conscious one.




Edit: I tried to rotate the pic but couldn’t


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## butcher (Nov 12, 2019)

Williamjf77,
Excellent advice, you should also keep a book of the MSDS sheets for all of your reagents...


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## Williamjf77 (Nov 12, 2019)

I find I’m more likely to label stuff properly if the labels are pre made and right there. I think I paid 6$ for the roll.


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## Jmk88 (Nov 13, 2019)

William, (and anyone interested)

Here is what sodium hydroxide does. 

Pic 1. Gold jewellery in boiled water

Pic 2. 3 minutes in 

Pic 3. 15 minutes in 

Pic 4. 20 minutes in

After an hour I will remove this and place it in fresh water after rinsing it off with a hose (whilst wearing goggles - very important after being in lye).

I will then add approximately 50 grams of hydroxide again and boil for another hour. You will notice the water stays almost clear on the second wash indicating the removal of all solder.

The brown in pics 2 - 4 is tin and lead precipitation, mainly lead as this is vintage material. Now I will not need to worry about hcl use, fumes, separation, incineration etc. I simply pour off solution, place my material in my choice of removal acid and proceed. This will leave you with almost completely clean foils. 

Lye will remove any organic oils as well as most synthetic contamination (if any). So the brown you see is mainly lead precipitation. 

Hope this was helpful.

Clarity 

Pic 1 - bottom 

Pic 2 - 2nd from top

Pic 3 - 2nd from bottom 

Pic 4 - top pic


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## Williamjf77 (Nov 13, 2019)

That’s interesting. I may give it a try on the gold filled I have to refine. The last batch I did I incinerated then nitric and I had problems with what looks to me like tin and lead and then the silver content was more than 10% of the batch.

What does lye do to silver?


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## Jmk88 (Nov 13, 2019)

Yes silver will react with sodium hydroxide; gold will not. Silver oxide will be formed. Not enough to worry about so pour away with the solder.

The second wash in caustic will not produce much solder at all but still let it go for an hour. You’ll notice a muddy colour looking water by the end of the second.

But most is taken off by the first within 30 minutes.

Gold filled is normally set on copper or stainless steel. Occasionally silver but mainly these two. 

Kind regards,


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## FrugalRefiner (Nov 13, 2019)

Why did you put an entire watch including the movement in there?

Dave


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## Jmk88 (Nov 13, 2019)

Because it’s easier than hammering it apart.

You remove that and all the glass is removed too. You will lose a bit of gold where the solder breaks away but it’s better than having a huge mess.

Regards,


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## Jmk88 (Nov 13, 2019)

I have about 12 watches in there, 25 bangles, 15 chains, 7-10 rings, bracelets.

In total I have 4kg which I hope to get 80-120 grams of pure gold from. That in the picture is approximately 200grams of jewellery and you can see the water is literally black after half an hour. I placed 10 grams of dried solder (previously incinerated) which was mixed with gold flakes from a previous batch in hcl Sunday night. 

Not even a third has dissolved. 

See my point?


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## Shark (Nov 13, 2019)

A whole watch? What karat is it?


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## Jmk88 (Nov 13, 2019)

18k gold filled. 

There is about 12 or 13 watches in total if my
Memory is correct.

Thos was just a sample to show people how caustic removes the solder which I hope is apparent from the pics.

Here is another one that shows the removal after half an hour of the first clean. You can see the lead and tin.


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## FrugalRefiner (Nov 13, 2019)

Jmk88 said:


> In total I have 4kg which I hope to get 80-120 grams of pure gold from.


Best of luck with that.  4 kg of scrap, including watch movement, watch bands with all the stainless steel parts of the bands that touch the arm, the springs, the watch backs, etc. NONE of that is gold filled. The gold filled weight only refers to the caps of the bands on the outside, and the exterior of the cases. All the gold on gold filled jewelry is on the outside surface, which is subject to wear, with the gold filled layer wearing away first. You never achieve anywhere close to the theoretical yield.



> See my point?


No. I spent twenty years in the jewelry business, dealing with everything from gold filled, to karat, to platinum alloys. About the only time I encountered tin or lead based alloys was if a "handyman" used a soldering iron or torch to repair a piece with plumbing solder.

I think you're going to be disappointed with your result

Dave


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## Jmk88 (Nov 13, 2019)

well I’ll keep you posted with my disappointment! 

:wink: 

I can only comment on my experience; 3 days to dissolve 4 grams of solder isn’t what I call efficient.

But we’ve gone over that!


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## butcher (Nov 13, 2019)

I am also interested in this thread and following it with interest (as long as no one gets harmed), I cannot see how this is going to work without a lot more problems, the material is low yield and troublesome, especially for a beginner...


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## Jmk88 (Nov 13, 2019)

18k of gold fill:

4kg/100 * 5 = 200

200/100= 2

2 * 75 = 150grams 

Allow for wear (I know the condition and it’s tip top)

At worst half of that 75 grams. For a 400£ outlay isn’t too bad. At best 150 grams means you turn 400£ to either £2,800 or £5,700. 

I can buy this like I can buy a pint of milk.

The solder is removed as you can see in the pic. Copper chloride will do the rest. 

I’m a beginner but I am being guided! It’s not being done for me but I do have guidance as well as all the amazing information here.


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## butcher (Nov 13, 2019)

I can not follow the math without some type of explanation of what the numbers actually represent.

I am not sure of what other guidence you have available, hopefully, it is helping you to understand the dangers involved and pointing you in a safe you in at least a safe direction.

I still fail to see how you are going to pull this off without a lot of trouble. Can it be done that way, yes, but why go through all of the trouble?


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## Jmk88 (Nov 13, 2019)

Because without the use of nitric there isn’t any other way.

And I’m unable currently to use nitric.


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## Jmk88 (Nov 13, 2019)

Gold filled here means a minimum of 5 % of the overall item weight is the karat it’s stamped with. 

So you take 5% of 4kg at 18k.

I trust that now makes sense.


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## butcher (Nov 13, 2019)

It helps to know what the numbers represent, I will let some others check your math of the possible gold content, at least now I can follow your figures, 

I see more problems with the way you are preparing your scrap for recovery, I do not see that using the hydroxide is much of a problem (be sure to wear your eye protection, lye makes soap with oils from your skin and make slippery in your hands...

I still fail to see what benefit has here over HCl, with the type of materials involved.

Either way, I would spend more time preparing your scrap, the less trash in, the less trouble, and trash out.


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## Williamjf77 (Nov 13, 2019)

I may be wrong here but when an item is stamped gold filled case the 5% means of the case and when it says gf tops it means 5% of the weight of the band.

That’s why necklaces say 1/20 12kt gf because the whole piece is gold clad. But when you get to watches it usually says gf tops on the band and something like GF case, SS back or whatever it tends to be


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## FrugalRefiner (Nov 13, 2019)

Did you bother to read the post I made above? The gold filled parts of a watch are just the case. The movement inside is part of your 4 kg, but it's not gold filled. The same applies to any stainless steel watch backs and the spring bars. And the same applies to the watchbands. Only the caps of the watchband are gold filled. The bottoms, springs, etc. are not gold filled, but they are a large part of your 4 kg.

I'm not even going to argue the use of lye to dissolve solder you believe is there. I'm just talking about the starting weight of your material vs. the yield you're expecting.

But don't listen to those of us who have done this before. I'll wait for your results.

Dave


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## Williamjf77 (Nov 13, 2019)

Jmk88 said:


> Gold filled here means a minimum of 5 % of the overall item weight is the karat it’s stamped with.
> 
> So you take 5% of 4kg at 18k.
> 
> I trust that now makes sense.






You should take out the movements and crystals and weigh one and then do your math, and even that would probably be too high of an estimate.


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## FrugalRefiner (Nov 13, 2019)

Williamjf77 said:


> I may be wrong here but when an item is stamped gold filled case the 5% means of the case and when it says gf tops it means 5% of the weight of the band.


Yes, you're wrong about the bands. If the band says gold filled TOPS, it means the TOPS only, not the entire weight of the band. The bottoms, springs, etc. are not part of the gold filled weight.



> That’s why necklaces say 1/20 12kt gf because the whole piece is gold clad. But when you get to watches it usually says gf tops on the band and something like GF case, SS back or whatever it tends to be


Correct.

Dave


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## snoman701 (Nov 13, 2019)

We really need the popcorn emoji.

I don't think you understand the difference between solder in electronics (which can be dissolved with lye) and solder in jewelry (which can't)

You are just making a mess. 

Gold filled weight percentages only refer to metal with a copper/brass/silver alloy base. Stainless is specifically excluded from weight in the gold filled legal descriptions. 

4kg of mens gold filled watches with gold filled bands with zero wear MAY get you an ounce or a tiny bit more.


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## snoman701 (Nov 13, 2019)

Williamjf77 said:


> Jmk88 said:
> 
> 
> > Gold filled here means a minimum of 5 % of the overall item weight is the karat it’s stamped with.
> ...



Much too high.


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## Williamjf77 (Nov 13, 2019)

I wasn’t sure about the bands. I know that watches are pretty specific on labeling where the gold is on gold fill pieces.

Not to burst his bubble but there is probably a good reason why he can get so much of it. Watches take tedious work to disassemble. That would be a great profit margin though. On eBay I have a hard time finding GF for 80% of gold value. He’s paying what 5% Can’t be right.


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## Shark (Nov 13, 2019)

Most women's watches I have dealt with, when complete, are only about 1/3 of that weight broken down. (Example not exact numbers)...A whole watch that weighed 100 grams, when stripped down to the gold filled averages about 30 grams. Most men's watches have been even worse. There are many watch's out there that do better, but *assuming* all of yours is better is a serious mistake. I have took in 1000 grams of material and ended up with less than 700 when cleaned and stripped several times, some were even worse than that. Examining your pictures leads me to think also that much of what you see is the dead skin and sweat from the jewelry having been worn a lot, ground into the cracks and crevices and being ate away the same as boiling in hot water would do. 

This reminds of the people who dump whole boards into acid and can't figure out where they went wrong.


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## Williamjf77 (Nov 13, 2019)

Now that we know you can’t get nitric , I would think you should have used HCL and peroxide after you stripped the watches.


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## Bertho (Nov 13, 2019)

With all the knowledge on dissolving solder (lead/tin) in this thread hopefully someone can help me with the reverse problem: 
How can I dissolve the lead chloride & stannus chloride from the leaching process?
I got tiny specks of gold mixed with it that I am trying to filter out and recover.


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## butcher (Nov 13, 2019)

Lead chloride is somewhat soluble in cold water 
0.67 grams of lead (II) chloride PbCl2 is soluble in water at 0 degrees C.
0.98g/100g H2O @ 20 deg C.
1.08g/100g H2O @ 25 deg C.
1.19g/100g H2O @ 30 deg C.
1.32g/100g H2O @35 deg C.
1.78g/100g H2O @ 50 deg C.
2.13g/100g H2O @ 65 deg C.
2,62g/100g H2O @ 80 deg C.
3,25g/100g H2O @ 100 deg C.

So with very hot water (soaking wash), we can dissolve a couple of grams of lead chloride--decanting the solution while hot (with all of the silver chloride settled), letting this wastewater cool to lower the solubility of the lead chloride, when cool return the water (leaving most of the lead salt behind) to pick up more lead chloride from your reaction vessel with a reheat, repeat this until you no longer get the needle-like PbCl2 crystals in the cooled wash water. 

Silver chloride is white and fluffy or milky can be hard to settle it likes to move around easily in solution. So you may have to lower heat from a rolling or bubbling and give the silver salt some time to settle when you remove lead chloride...
Silver chloride is insoluble in cold or hot water or in acid.

Tin (is just a problem ), some of the soluble tin salts will be washed out with the lead and the hot water washes above, the hot water washes can also promote further oxidation of the tin salts that and exposure to air or other conditions you could have a variety of tin salts or oxides involved.
SnCl2 is soluble in water, about 98g SnCl2/100g H2O @ 20 deg C. and stannous chloride is very soluble in HCl acid.
SnCl4 stannic chloride (hydrolyzes in water) soluble in concentrated. 20% HCl.
but you are more likely to have other oxides of tin such as;
SnO2 tin (IV) oxide stannic insoluble in water, soluble in concentrated HCl (hydrolyzes to goo in dilute of cold solutions)
Sn(OH)2 stannous hydroxides insoluble in water, but soluble in concentrated 20% HCl.
Sn(OH)3 stannite (Normally made from SnO or some other tin salt or tin oxide reacted with a strong base), soluble in strong HCl...

Tin chloride salts in a warmer more concentrated acid solution will form a little less of the jelly-like goo, tin chloride salts in dilute solution or water hydrolyze to give more trouble in filtering...

Water washes after acid washes will remove more salts and in some cases make the salts easier to oxidize, lowering the acid involved...

Many of the other base metal chlorides will also be soluble in the hot water washes or in the HCl washes...

We can go different ways from this point to get the silver (through a complex) as an ammonium complex in which there is a danger of making an explosive compound if not carefully performed properly, (acidified to recover silver and make safer), there is also thiosulfate which can dissolve silver...

Because of the chloride salts involved, we would not want to go straight to nitric acid at this point (unless our goal was to put gold into solution), the silver chloride insoluble in the acid.


Silver chloride salts, along with the other base metal chloride salts, would put some gold into solution as the base metal chloride reformed HCl in solution with the gold and nitric acid...

With fine gold or foils, we can dissolve the gold in a chloride solution without using nitric, we can use hypochlorites or H2O2...

Silver chloride is insoluble in aqua regia where the gold is soluble...
Or in a gold chloride solution made sodium hypochlorite or H2O2 or some other suitable oxidizer... 

Or 

We can wash the insoluble silver and base metals salts in a solution of NaOH this will lower some of the acidity, help oxidize some of the base metals (may dissolve some of the more amphoteric base metals along the way), and help us to convert base metal chlorides to sodium chloride salt (table salt) that can be washed with water, drying these salts they can be fused ( to further drive off acids and convert to oxides, and then roasted in a red heat fine powders stirred well and well exposed to oxygen or atmospheric air to complete the conversion of base metals ready for most any acid like nitric...

Edited to add a little info and grammar corrections as best I could.


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## butcher (Nov 13, 2019)

How can I dissolve the lead chloride & stannous chloride from the leaching process?
I got tiny specks of gold mixed with it that I am trying to filter out and recover.

Is this a filtering problem?
Or
Are you talking about salts in solution or the gold mixed with an insoluble powder and scum?
it is hard to help without knowing what you have done or what you are doing or planning to do, or what we have...

without seeing or knowing what all is happening it is difficult to answer some of these questions...


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## Jmk88 (Nov 14, 2019)

https://www.assayoffice.co.uk/assets/uploads/Final%20Guidance%20Notes%20Oct%2016.pdf

Not sure what rolled gold you’re getting, but I assure you in London, particularly where I trade, you will not get away with selling rolled gold legally if it has much less than the original 5% weight of gold.

If it is worn you are required to explicitly state it’s wrong.

Why would you use peroxide? What and then cement out your gold? Lol.

Where is the sense? You’d have a mess not dissimilar to failing to remove solder. Peroxide is an oxidiser not a recovery agent. 

It can be used to substitute nitrates, nitric or hypochlorite so William, not sure what you’re getting at there but not advisable. Peroxide much above 6% will dissolve your gold too.


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## Jmk88 (Nov 14, 2019)

https://m.youtube.com/watch?v=Q9cLykpdFnc&t=858s

19 grams from 400grams.

Not sure where you guys are doing your maths or the material you think I’m using.

I would say, as before, mine was very conservative (humble) as if you pro rata this example to 4kg of scrap you’ll find my estimations are accurate.

I’m fact, you’ll find they were heavily dropped to enable discussion on the matter. 

I think focusing on watch bands is probably irrelevant; I have 12 watches, as you can see the one in the pic doesn’t have bands. It’s set on stainless steel. I have ten like that and one small women’s watch with a band. 

The majority are bangles, rings, bracelets and pocket watches. All of which have been vetted and checked in Hatton Garden for condition, stamps and weight. 

You may not want to accept someone has the opportunity to obtain and make that sort of money, but it’s a reality. 

I encourage more focus on the process I am adopting as opposed to the profitability. 

Kindest Regards,


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## Jmk88 (Nov 14, 2019)

Shark said:


> Most women's watches I have dealt with, when complete, are only about 1/3 of that weight broken down. (Example not exact numbers)...A whole watch that weighed 100 grams, when stripped down to the gold filled averages about 30 grams. Most men's watches have been even worse. There are many watch's out there that do better, but *assuming* all of yours is better is a serious mistake. I have took in 1000 grams of material and ended up with less than 700 when cleaned and stripped several times, some were even worse than that. Examining your pictures leads me to think also that much of what you see is the dead skin and sweat from the jewelry having been worn a lot, ground into the cracks and crevices and being ate away the same as boiling in hot water would do.
> 
> This reminds of the people who dump whole boards into acid and can't figure out where they went wrong.



I advise you to split 100 grams and boil 50 in water for 3 hours. Upon completion, use my hydroxide method on the remaining 50. Maybe then you’ll believe your own eyes. It’s non comparable. 

And I assure you it’s not oils, they were removed via incineration and then 3 boiled carbonate washes followed by a third and thorough propane incineration. The lye will not show oils or anything organic as precipitate; it will dissolve a 300 pound human body very quick if the concentrate is high enough. Don’t believe me do your own research. Oils and organic material would not be visible. So please, through order of elimination, what else you think it might be that reacts with hydroxide to break away and form black precipitate? 

Copper? Silver? Steel? Or maybe gold? Or do you think it’s that solder stuff? 

I’m going to shoot and go with the solder.

Copper will oxidise also but the rate of reaction with 50grams of caustic is so slow that the reaction is barely able to start after an hour, so this isn’t an issue. You can also identify and copper precipitate as it’s distinctly different colour.


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## butcher (Nov 14, 2019)

Several metals or their salts are amphoteric or have amphoteric properties, and will dissolve in an acid or a base, the dark color of the solution is not much of an indication.

In some conditions, even gold and silver and their salts show up with some amphoteric properties.

Jmk88, 
it seems like you just want to see things the way you believe them to be, or wish them to be, without considering what others are saying, and then you seem also to be misunderstanding what others are saying...

Something we all do at times, but it is not very helpful.


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## Jmk88 (Nov 14, 2019)

On the numbers or the process? 

I’m more than open to suggestion, but in a bowl of only gold, copper, stainless and solder, I don’t really see the objective or logical point.

Oils and fats simply won’t show. Copper will be a blue precipitate. Gold will be gold. Stainless won’t react. I’m fact anyone that’s done this will verify you get a minor surface precipitate of copper on the worn sections of your material. Very minor. 

I’m more than open. However it needs to be logical and objective, not “you’re wrong because you’re wrong”. I stopped paying attention to that philosophy years ago.

You can’t simply say “you’re wrong”. Which seems to be the over arching conclusion I’m taking. If hcl will do it better, which I’ve tried multiple times, against the advice of who does guide me, please post pics or time frames as to why it’s better. I made a complete mess before which I needed a professional to resolve. The link I’ve attached shows how much jewellery solder there is. It’s not hard to review the rate of tin/lead dissolution which will give you an indication of the unnecessary time you must then add to your process.

My numbers are more than accurate. But I’m really not interested in that side of things.


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## Jmk88 (Nov 14, 2019)

The dark is precipitate not a dissolved solution.

The hydroxide does enough to remove it all, I’m not interested in dissolving it all. I don’t need to.


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## anachronism (Nov 14, 2019)

Look I'm reaching out here, so take it as such regardless of what you've said to me already. 

You have a number of experienced guys here telling you that:

1. Your calculations are wrong. Yet you tell everyone that they are wrong and you are right.
2. That the solder you have isn't what you think it is, and therefore the lye approach isn't doing what you believe it is. Again everyone is wrong and you are right.
3. That you're not interested in hearing the chemistry. Again the chemistry tells you the best way to do it and you're only just beginning to see that having refused to listen to others.

There's a pattern here. Why don't you step out of that comfort zone and listen. I mean really listen and inwardly digest what you're being given on a plate here. I can't help you with gold filled, but there are some really good guys here offering up their time for nothing to try and get you onto the right path. Don't look a gift horse in the mouth. 

Jon


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## nickvc (Nov 14, 2019)

I have never seen very much 18 k gold filled or rolled gold in the UK and I was in the business for over 30 years, the only exception was perhaps the odd large pocket watch case, all the chains and rings etc were 9 k, I have seen plenty of 18 k plated material, which refers to the colour as all plating is high purity.
As gold filled is the cheap alternative to full karat items why would they use 18 k ?


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## Jmk88 (Nov 14, 2019)

Jon,

Please do provide the chemistry as to why hcl is better. I will read and read and read. I promise.

So please proceed; what is the expected dissolution rate of solder from jewellery in hcl?

What time frame could you expect this to be completed on 4kg of material? 

Please correct my numbers in that case. We can then discuss that.

Are you saying caustic doesn’t react with tin and lead!!?? 

More than happy to be wrong, but please do show how that’s the case. Fairly straight forward to prove if it is, in my opinion.

Nick - apologies, are you effectively questioning that 18k gold filled jewellery exists? 

Kindest Regards,


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## nickvc (Nov 14, 2019)

I worked for JM who supplied gold fill to the few jewellers who still used it and it was all 9 k that I can recall, it was some years ago, 18 k may exist elsewhere where low karat is not allowed but you said you purchased this in London.
I’d trim my expectations of the yield as I know of no gold dealers or refiners who willingly give away that much gold , I may be wrong but I doubt you will get an ounce of fine and if you get that you have a good source at a reasonable return, doubling your money plus is not common in this business.


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## Jmk88 (Nov 14, 2019)

Nick,

With all due respect and I thoroughly mean that, that’s not a discussion I’m prepared to spend energy on.

I suggest you read the link I posted.

All the best.


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## Jmk88 (Nov 14, 2019)

https://www.assayoffice.co.uk/assets/uploads/Final%20Guidance%20Notes%20Oct%2016.pdf

https://hrcak.srce.hr/file/215595

https://en.m.wikipedia.org/wiki/Gold-filled_jewelry

https://www.gldn.com/blog/2017/3/2/what-is-14k-gold-fill-vs-gold-plated


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## butcher (Nov 14, 2019)

Cheers, that is nice of you anachronism.





Jmk88, 

My friend your still not listening, You are a smart man I can tell, but your plowing so far ahead it is hard for me to tell where in the field you are.
Slow down and listen, take it easy, you may find the information and people you are plowing by so fast somewhat helpful, there may be other, or even "Better" or faster ways, but it may not be the best way to get the field plowed before winter.
If you slow down some you might see another way or something you did not see when you were flying by so fast with the mule, if nothing else you may see something that might help you slow that mule down before he pulls you over a cliff with him.

You may find the information wrong or find a better way later or learn different later or prove us all wrong, but you will not know another way, or maybe even something you do not know now if you do not listen or open your mind a little.

Consider somewhat at least that we may have some idea about what we are talking about when it comes to gold recovery and refining, and listen to at least a little bit, (even if you do not agree at first).

I would consider Jon's gracious offer to help you with the gold fill...
Any time Nickvc talks about jewelry or gold I am all ears.


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## nickvc (Nov 14, 2019)

I forgot to tell but you I also worked at the Birmingham Assay Office and rolled gold or gold filled is not required to be hallmarked and there is no legislation to cover exactly what you get, it’s down to the manufacturers honesty to mark their goods correctly and as pointed out the only part that is gold is the surface which is what wears and where it’s polished before been sold.

If your expectations aren’t achieved I’m pointing out why, how you process this material is your choice but I would advise listening to those who have been there and done that.


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## Jmk88 (Nov 14, 2019)

I’m super open to any help. But it needs to be logical
and practical; it’s a generic offer which isn’t supported with how or why it will help.

I’ve absolutely no issue with being wrong; I welcome being wrong as that’s when you learn. I’m a win or learn man. I never consider loss unless it’s associated with something living.

I still don’t understand what it is I’m “wrong” about. I have posted various supporting information to my comments and it isn’t hard to establish what major refineries do regarding caustic and jewellery.


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## Jmk88 (Nov 14, 2019)

Nick,

We are both UK based and I have an office in Birmingham. Also one in Finsbury Square.

I will pm you; I’m happy to discuss on phone or even arrange a joint process with you. 

I work for myself so am fairly available. Would love to speak in person and make a U.K. connection from here.

Would you like me to send my personal contact details? 

Kindest Regards,


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## butcher (Nov 14, 2019)

It may not be: what is fastest, what works the best, how much, a certain amount, a certain formula, a certain method...

The real chemistry is not always as neat and tidy as the chemistry books...
Chemistry is not black and white.
Recovery and refining is not black and white.
There may be more than one way.

Most of the chemistry we do is not written in your college chemistry books, although we do use that chemistry found in those college books to help explain, help us understand the chemistry of what we do, the college chemistry books can help us figure some things out, and understand different ways to go, or not, provide us with very helpful and useful information,,,


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## Jmk88 (Nov 14, 2019)

Yes and please don’t think ignorance is a demon that I entertain... it really isn’t.

The information I find here is second to none; it’s the practicality of when the theoretical doesn’t work. And the reality is, I ignored professional advice and went with hcl the first time and it just created an absolute mess which nearly lost me my guidance. 

I then had to humbly plead for the professional to clean my mess up; as a man, having other people clean your mess up is not very encouraging or where I personally want to be.


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## butcher (Nov 14, 2019)

My wife had a knocking noise inside her engine, she went to a professional mechanic.
She said she wanted to learn to fix it herself.

He gave her a lesson on how to fix her car, explaining the repairs and tools needed in every detail...


I will leave the results to your imagination after she starts stripping all of those nuts and bolts...

Now she may go to another professional mechanic and he may give her somewhat different advice about how he does the repairs and explains how she should fix her car explaining every detail.

Well then, now she not only has a pile of stripped bolts half of her car tore apart, but she is now is even more confused, and frustrated.
some simple things are not really as simple as they seem.

One mechanic said to pull apart the top half of the engine to get to the problem.
The other mechanic told her to pull off the bottom half of the engine, using different tools.
Without a background or at least a little bit of mechanical experience, it is just not that simple.

Even if she followed instructions to a tee, not everything that is mechanical will follow the rule book or work like it is supposed to just like plumbing, any time you work on it it is going to work to give you problems to solve...


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## Jmk88 (Nov 14, 2019)

Thanks Butcher and I fully get where you’re coming from.

I’ll keep you posted of my process. Each step of the way. This will include all hurdles and things that go wrong, I’m not here for glory I’m here to become the best I can.


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## Williamjf77 (Nov 14, 2019)

I see other posts on here of people who can’t get nitric using Copper Chloride to do gold filled. That’s why I said use hcl peroxide after the material was cleaned. It seemed to have worked for some on here, maybe not the fastest or most effective but I believe it will strip everything won’t it?


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## Jmk88 (Nov 14, 2019)

Thanks William.

I think what you’re referring to is the minor addition of peroxide when dissolving copper to form copper chloride which yes, is advisable if no gold is in with it.

It will speed up the dissolving of copper and leave you with copper chloride.


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## Jmk88 (Nov 14, 2019)

I prefer an air bubbler. Cheaper and no risk of dissolved and cemented gold.


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## Williamjf77 (Nov 14, 2019)

How do you plan to strip the base metals after the NaOH? I would think without nitric it would have to be Cooper Chloride or Ferric Chloride? That’s why I thought you could skip the solder removal and go straight to the acid.


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## Williamjf77 (Nov 14, 2019)

Also the whole debate on the quantity of material seemed only based on watches, but as you said only some of the material is watches. I think you threw everyone a curveball by showing the whole watch in the solution when most would just put the band, at least that’s where I would think any solder would be.

I know the last gold filled I did had some kind of solder or just real crap material to begin with.


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## Jmk88 (Nov 14, 2019)

William,

I weigh everything in terms of time and cost. Both are infinitely linked.

The time it takes to remove all those components isn’t worth doing. My process will cause all screens and faces to detach and float. 

It would take me a day or half to remove all of them manually. 

Yes the watches make up under 10% of my material. But I still haven’t seen anyone offer realistic numbers despite criticising mine.


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## anachronism (Nov 14, 2019)

Jmk88 said:


> Yes and please don’t think ignorance is a demon that I entertain... it really isn’t.
> 
> The information I find here is second to none; it’s the practicality of when the theoretical doesn’t work. And the reality is, I ignored professional advice and went with hcl the first time and it just created an absolute mess which nearly lost me my guidance.
> 
> *I then had to humbly plead for the professional to clean my mess up; as a man, having other people clean your mess up is not very encouraging or where I personally want to be.*



If your professional is that good-why are you even here? You're certainly not listening to anyone on the forum.


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## Jmk88 (Nov 14, 2019)

Jon,

I do believe I’ve kindly asked you to refrain from negative comments.

Why would anyone want to learn from a professional? I’m gonna have a stab at that one, I reckon it might, just possibly be, that they would like to also become a professional.

It’s a bit like the frequent “you watched a YouTube video and think you can” comments you make to everyone.

It’s crazy to think that Lebron James saw Michael Jordan doing his thing on TV and thought “I can do that”. How did he ever have the nerve? 

It’s called inspiration Jon, something you haven’t yet shown me.


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## Williamjf77 (Nov 14, 2019)

Jmk88 said:


> William,
> 
> I weigh everything in terms of time and cost. Both are infinitely linked.
> 
> ...



I still don’t see what you are trying to accomplish with watches in NaOH, the crystal and the movement come out easily and the watch bands are all mechanical connections which will be springs and pins or something that aren’t gold filled and most likely steel . I don’t see how anything but dissolving the whole case away is going to liberate the movement.


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## Jmk88 (Nov 14, 2019)

William,

Lead in strong alkali forms a salt, also known as plumbites. This happens when lead is hydrated (hydroxide) and forms brown precipitate (salts). Alkalis that are concentrated (I use 99% - obtained from soap makers) will do this. 

I suggest looking up lead plumbates which you’ll find is consistent with the pictures I’ve posted. Then add lead or solder prior and you will be on the right path.

If it’s pure lead, it will be a red dust. If mixed or an alloy, it will be dark brown as my pics. 

I suggest reading, and some more. Not just you.

I’ve given you enough information to learn it and make your own mind up. I can’t connect the dots for you.

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

https://onlinelibrary.wiley.com/doi/10.1002/9783527656189.ch14


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## anachronism (Nov 14, 2019)

Jmk88 said:


> Jon,
> 
> I do believe I’ve kindly asked you to refrain from negative comments.
> 
> ...



Haha priceless. Who on earth do you think you are with your self important opinionated and entitled attitude? 

You come here into OUR forum, and start telling people who they can talk to and what they can and cannot say. You know absolutely nothing about me or what I do, but I've tried my best to be polite and now I'm fed up to the back teeth with your holier than thou attitude and lack of respect for all the help people are trying to give you. Frankly your level of knowledge sucks but you seem to feel you have something to offer. That's delusion.

If you are going to nay say everyone in favour of your professional then I really don't see the point of any of it. 

Have a lovely day- I am going to the gym. Over and out. :lol: :lol: :lol:


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## Jmk88 (Nov 14, 2019)

Thanks Jon,

Enjoy the gym and have a lovely day.

I have no issues with you not giving me advice at all. I wish you well.

Take care,


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## Jmk88 (Nov 14, 2019)

William,

You may also find it interesting that the work plumber derived from Latin (which I have a great knowledge of) and essentially means “a man that works with lead”.

The original was Plumbarius (plumber) and Plumbum means lead.

Regards,


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## Williamjf77 (Nov 14, 2019)

Jmk88 said:


> William,
> 
> Lead in strong alkali forms a salt, also known as plumbites. This happens when lead is hydrated (hydroxide) and forms brown precipitate (salts). Alkalis that are concentrated (I use 99% - obtained from soap makers) will do this.
> 
> ...



I get the tin removal but how does the NaOH Help in separating the watch movement and crystal. Removal of the crystal and movement is the easiest part. I don’t get it unless your watch bands are held together by lead and tin and the movement is soldered in. That’s what doesn’t make sense. 

So basically in English translated from Latin , how does removing solder help separating a connection that isn’t soldered together.


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## Jmk88 (Nov 14, 2019)

William,

It doesn’t. You then dissolve your base with your acid of choice; nitric or other means.

Regards,


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## butcher (Nov 14, 2019)

Some metals are very reactive, some will just sit there and look at you with passivation on its face...

The very first part of any recovery process normally begins by separating the values from the gangue and other trash or metals.

Trying to process the whole mountain in a leach for a little valuable metals normally does not go well, it is simpler to remover the ore, separate and concentrate the values, remove as much of the valuable metal from the mountain, and process that for a recovery of the metal, and then take that metal and purify it further through refining...

It appears to us at this point, your trying to dissolve the whole mountain.


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## Williamjf77 (Nov 14, 2019)

That was kind of my point, removing tin and lead first before treating with nitric makes sense because of the metastatic acid. But copper chloride would just dissolve the tin lead and copper and steel wouldn’t it?


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## Shark (Nov 14, 2019)

For over a year I processed foils from gold filled that had been ran in copper chloride. These foils were bought already processed and the buyer needed someone to finish them up. In that year plus, lead was never an issue, nor was tin. The guy could have left them in the copper chloride a bit longer to reduce the amount of copper, but wasn't much a problem either. I have run gold filled that way myself as well as used nitric, even ran it in nitric made in the same beaker as my gold filled. There are many ways to do it, and each will have it's own set of complications to deal with. The biggest difference between copper chloride and nitric is the time involved, so long as you know how to deal with the differences each pose.


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## Jmk88 (Nov 14, 2019)

William,

No it’s back to the debate of dissolution rate. Place some lead in hcl and cc and you wait three weeks. Just do 50 grams. You’ll see my point.

Like Shark said, he is spot on, nitric and cc comes down to time. Cc will take a lot longer. Nitric you’d be done in less than 8 hours.

Kind Regards,


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## butcher (Nov 14, 2019)

But copper chloride would just dissolve the tin, lead, and copper and steel wouldn’t it?

Yes but not without problems or conditions.

Removing the bulk of the unwanted metals mechanically will remove many of the problems.

Tin even any acid is trouble, it is somewhat easier to deal with in a chloride solution, it still can cause trouble filtering reacting with other metals... it is best to remove it mechanically or by some other means if possible...

While you can deal with the iron, stainless, lead and tin, and other base metals in a cupric chloride leach it is best to keep them limited or out of the solution as much as possible.

Tin in a chloride solution hydrolyzes become hard to filter, its salts are amphoteric and react with other metals and their salts and the solution with its own red-ox reactions, and is a well-known thief of gold in solution...
stainless is made to make iron resist acids or oxidation... 
Iron in volume in a solution converts a copper cupric chloride leach into a ferric chloride leach...


The more trash in solution --> the more trash out.
The more trash in solution -->the harder to get values out.


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## Jmk88 (Nov 14, 2019)

What Butcher said.


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## snoman701 (Nov 14, 2019)

Nobody is disputing dissolution rate other than you. You seem to be having a circular argument trying to prove you are doing something worthwhile, you are not. 

I run gold filled straight in nitric, then refine the foils with AR....I cannot imagine doing it any other way with my current capacity. 

Most mid tier "refiners" do not refine gold filled at all, just assay for gold and silver and sell it on, usually melted in to their karat so they get better rates for it. 

Personally, I've done enough with nitric. I can do a few kg load in a day, but it creates a lot of waste. I'll very likely switch to electrolytic copper in the near future, but that's not a conversation for this thread. 

Miller chlorination or electrolytic copper cell is going to be the next most utilized method...but nobody that I know of is putting jewelery in lye.


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## Williamjf77 (Nov 14, 2019)

It’s also hard to compare dissolution rates unless you are using the same Molarity and Particle size. A solid nugget of tin is going to take a while to dissolve even in any solution compared to powder or film.

I think hcl works good for e waste solder because it can get access on most sides. A solder joint in jewelry is probably more of a very thin film by capillary action.


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## Shark (Nov 14, 2019)

snoman701 said:


> I run gold filled straight in nitric, then refine the foils with AR....I cannot imagine doing it any other way with my current capacity.
> 
> Most mid tier "refiners" do not refine gold filled at all, just assay for gold and silver and sell it on, usually melted in to their karat so they get better rates for it.





Where is that thumbs up emojii?


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## Williamjf77 (Nov 14, 2019)

Not being able to get nitric must be a pain. Is that a UK thing or is it just real hard to find, or real expensive?


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## Bertho (Nov 14, 2019)

I Wrote: How can I dissolve the lead chloride & stannous chloride from the leaching process?
I got tiny specks of gold mixed with it that I am trying to filter out and recover.

Butcher wrote:
Is this a filtering problem?
Or
Are you talking about salts in solution or the gold mixed with an insoluble powder and scum?
it is hard to help without knowing what you have done or what you are doing or planning to do, or what we have... without seeing or knowing what all is happening it is difficult to answer some of these questions...
-------------------
Thank you so much Butcher for a very detailed answer.
A quick summary: I was solder leaching old HP PCBs with gold plating in HCl. The thermostat failed and the PCBs were in boiling HCl for a day. Some gold actually came off as tiny specks and is now mixed with the lead & tin sludge. Presumably also some dissolved copper. There is no silver in the mix. The PCBs were free from components.
Net result: I am trying to recover the gold flakes mixed with the sludge. If I could dissolve the sludge I then could filter it. Maybe I should be thinking about it the opposite way: How to properly dissolve the gold while mixed with the sludge?


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## butcher (Nov 14, 2019)

Many times a choice would depend on conditions...

Have you tried putting the salts back into solution with HCl? Most of the metals that were soluble before should redissolve.


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## g_axelsson (Nov 15, 2019)

If you have something that is hard to dissolve then the solution might be to dissolve the gold and filter / decant off the gold chloride solution.

A trick Harold often advocated is to incinerate the material before dissolving the gold. It made it a lot faster to filter afterwards.

You might lose some gold, but at some point you have to decide how much time and money are you going to spend to get that last part of gold. 

Göran


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## Jmk88 (Nov 15, 2019)

This is interesting and I will be reading about it all night. Very rock and roll for a Friday... for a 30 year old.

Lead-tin solders readily dissolve gold plating and form brittle intermetallics.[9] 60/40 Sn-Pb solder oxidizes on the surface, forming a complex 4-layer structure: tin(IV) oxide on the surface, below it a layer of tin(II) oxide with finely dispersed lead, followed by a layer of tin(II) oxide with finely dispersed tin and lead, and the solder alloy itself underneath.

I think Butcher May know whether this layered structure maintains its integrity when aiming to remove. If so, it may explain why so many people have issues with it? I have a whole filter paper full of tin/lead contaminants and am planning to place in strong acetic acid. I will post the results. May not be for a week or two.


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## Jmk88 (Nov 15, 2019)

I believe today was also a massive learning experience. 

I understand why my comments may have stirred up some controversy and criticism. I believe the key to the difference in opinion comes down to discussing hard or soft solders. 

I now understand why soft solder would not be best processed the way I discussed; and thus I apologise to anyone that may have upset.

It was shown to me today that hard solder is broken down to silver chloride when processed in Copper Chloride with the higher reacting alloyes such as zinc and cadmium dissolving along with the base metals. 

I understand that what I was perceiving as Lead was silver chloride. 

However, we did play around with soft solder and hydroxide as well as hcl and I still reserve and opinion which I’m hesitant to express and reignite discussion on that.

I wanted to acknowledge publicly the above and hopefully show I’m learning and a good rate. Again, I apologise for anyone that took what I said as being ignorant and can see why that may have occurred. 

Thank you to anyone who had input into this discussion, it has led me to here.

Kindest Regards,


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## Shark (Nov 15, 2019)

British Dictionary definitions for ignorant

ignorant / (ˈɪɡnərənt) /

adjective

1. lacking in knowledge or education; unenlightened
2. (postpositive often foll by _of)_ lacking in awareness or knowledge (of)ignorant of the law
3. resulting from or showing lack of knowledge or awareness: an ignorant remark

I think we have all been there, but we come here to educate ourselves and (hopefully) not be as ignorant as we once were. A good many of us, myself for one, have no where else to learn about refining but from the internet and spend many hours here in the hopes of making up for not having a real person (in person) to study under. Often it is hard to put into words what we have in our minds as well. 

"The journey of a thousand miles begins with one step" but is sure does leave many more steps to reach that destination......... Welcome to refining.....


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## butcher (Nov 15, 2019)

I would not use vinegar or acetic acid, yes they may dissolve lead easily, so what, you can nail a picture on the wall real fast with a large sledgehammer with a healthy swing of the tool. if I posted all of the reasons why I personally would not try and dissolve lead as a soluble acetate I would fill a book.

I can understand your confusion, with the terminology and the term solder.
Brazing and soldering are two different things the processes are different so are the solders or brazing alloys used are different, many of the terms are used interchangeably.

soft solder or soldering is done at fairly low heat, hard soldering or brazing is done at a much higher heat (getting copper piping cherry red hot...), welding is done at an even higher heat where we melt the metals together into an alloy of a welded bead...

Brazing, 
silver solder can be an alloy of 5-95% silver with an alloy of copper, zinc, nickel, manganese, cadmium, tin, silicon, phosphorous. sulfur,... Termed silver solder or brazing solder, this alloy melts at a very high temperature. and is used in brazing not used in soldering (these terms are also used loosely and often times interchangeably in the field of work).
In high silver alloys of the brazing silver HCl would not work well as the silver will form a passivated silver chloride crust, (although alternately would be useful to use to dissolve copper pipe and leave the silver brazing)...

Soldering,
silver solder here is normally alloyed with lead or tin and other lower melting metals to make a low melting alloy like a lead-bismuth tin...

I can also understand you thinking that you were correct in some of the points of the debate of using caustic versus HCl, not knowing this difference between soft and hard silver solders...

It is only until we can admit when we are wrong that we can learn to be right. nothing wrong with being wrong, we are all sometimes, it is when our pride gets involved that it makes us wrong, and blocks us from overcoming our ignorances.


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## Bertho (Nov 15, 2019)

butcher wrote: » 14 Nov 2019, 23:18
Many times a choice would depend on conditions...
Have you tried putting the salts back into solution with HCl? Most of the metals that were soluble before should redissolve.
I boiled is twice in HCl and got rid of some stuff. 
After looking at your solubility info, I have been boiling it in water several times and it is slowly improving.
Bertho
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g_axelsson wrote: » 15 Nov 2019, 04:16

If you have something that is hard to dissolve then the solution might be to dissolve the gold and filter / decant off the gold chloride solution.

A trick Harold often advocated is to incinerate the material before dissolving the gold. It made it a lot faster to filter afterwards.

You might lose some gold, but at some point you have to decide how much time and money are you going to spend to get that last part of gold.

It is an interesting challenge and definitely not worth it financially but I like to learn.
Bertho


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## Williamjf77 (Nov 15, 2019)

I can say for myself when it comes to Internet forums and text only conversations I try to never judge an attitude or anything from a couple posts. A lot of text can come off as condescending or ignorant or cocky when in fact if it was said face to face it wouldn’t sound like that especially when dealing with international forums.

On the subject of the thread, it turns out my cpus in hcl actually was done the first night, the chips that still had pins on them were being held on by some other mechanical way and they easily came off with a little agitation.


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## butcher (Nov 15, 2019)

That is a big problem we cannot see each other it makes communication very difficult and can result in a lot of problems, the written word alone can easily be misunderstood, we also cannot see what the other is doing or has done, so we also have those obstacles to overcome, so we start of blind, and deaf (we can not hear a voice or tone of speech), now if we also have to get past the misspelling misuse of terms, language barriers.,,

It is hard enough to communicate with all of our senses and not end up in some kind of problem in understanding each other...

It is a wonder we can get anything done together.
edited --death with deaf
:lol:


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## Jmk88 (Nov 16, 2019)

Thank you all.

I will keep you posted of my process.

I am always happy to skype etc. Even if it’s at a late UK time! 

Kindest Regards


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