# Hydrochloric acid boil question



## Dougplogan (Dec 25, 2021)

I've been collecting gold foils from AP solution. I've just been using a coffee filter to retrieve foils then rinsed well with distilled water. After the filter dries out I stuff it down in a mason jar. Foils come from many different kinds of escrap. My question is when I go to boil in hydrochloric acid to further clean them will all these coffee filters break up and desolve? Should I add a few drops of sulphuric acid mid boil? Also originally I'd planned on using a beaker or mason jar for this. Just putting sand in a hot plate and sitting the jar on top. Ive not really gotten to this point yet so not sure if a stainless steel pot can be used if the nonstick coating effects things.


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## FrugalRefiner (Dec 25, 2021)

I wouldn't recommend mason jars for dissolving gold. A beaker would be better.

A sand bath spreads heat, but you still need a secondary containment vessel in case your beaker breaks.

I don't understand the comment about stainless steel with a non-stick coating. HCl will attack stainless.

Dave


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## Dougplogan (Dec 25, 2021)

FrugalRefiner said:


> I wouldn't recommend mason jars for dissolving gold. A beaker would be better.
> 
> A sand bath spreads heat, but you still need a secondary containment vessel in case your beaker breaks.
> 
> ...


I was wondering about stainless. I only mentioned it because in reading other posts I've come across pictures people have added were they were using metal pot doing a hydrochloric boil. It had pictures of foils before during and after. And the during was a metal pot. I do have beakers but the mason jars seem like they'd be less likely to break during heating. I've only processed once with ar. I learned then why the beaker is needed. When gold precipitated it stuck to the sides all around the jar.


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## Yggdrasil (Dec 25, 2021)

Hydrochloric acid will most likely dissolve your Stainless.
Nitric will not.
Generally speaking.
There are special classes of stainless, but 304 316 which is what you will find in ordinary stores will dissolve in HCl.


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## Dougplogan (Dec 25, 2021)

Yggdrasil said:


> Hydrochloric acid will most likely dissolve your Stainless.
> Nitric will not.
> Generally speaking.
> There are special classes of stainless, but 304 316 which is what you will find in ordinary stores will dissolve in HCl.


If I can find the post again I'll share it here to show what I was asking. I guess if I'm going to go buy something I was hoping to get to use it for multiple things. My thoughts were a metal pan I would be able to use for inceneration purposes as well. Out of curiosity the white ceramic baking dishes every one uses what are they called again. I'm guessing the glass baking dishes aren't ideal.


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## Dougplogan (Dec 25, 2021)

The filters I have are full of gold foils and a blackish powder. They don't seem very clean that's why I was thinking a hydrochloric acid boil. Plus it's several filters from different stuff. One is phron old cell phone boards with gold plating. That one has lots of green flakes from the boards breaking up. Is adding a few ml of sulfuric acid while doing the boil a good idea to help clean stuff up? One thing I am sure of is that I have avoided tin. Everything is processed in HCl before ap solution till all evidence of soldering is gone.


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## cejohnsonsr1 (Dec 25, 2021)

The issue with Mason jars is the relatively rapid change in temperature from hot to not hot. They’ll break. Good quality beakers are designed specifically to not break under these circumstances. Don’t use any kind of metal container for these processes. Steel is at the very top of the list of the series of reactivity. Anything you dissolve in it will cement out upon it. Stick with the high quality beakers mentioned previously. If you’re certain that all other metals have been removed, you have options as to how you dissolve the gold. AR, using small, incremental doses of Nitric, on heat, will dissolve the filter papers. Any trash or solids get filtered out after all the gold is dissolved. This will produce the least amount of waste, but requires the most care and vigilance while processing and is a bit more expensive. You can also dissolve with AP or AB but it takes a lot longer and generates considerably more waste and it won’t dissolve the filter papers, so you have to be very thorough when rinsing, which generates even more waste. No matter which method you choose to dissolve, filtering the pregnant solution and precipitation will all work the same way. Good luck with it and Merry Christmas!


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## butcher (Dec 25, 2021)

A pyro ceramic dish can be used for heating or as a catch basin with or without your sand bath.


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## Dougplogan (Dec 25, 2021)

cejohnsonsr1 said:


> The issue with Mason jars is the relatively rapid change in temperature from hot to not hot. They’ll break. Good quality beakers are designed specifically to not break under these circumstances. Don’t use any kind of metal container for these processes. Steel is at the very top of the list of the series of reactivity. Anything you dissolve in it will cement out upon it. Stick with the high quality beakers mentioned previously. If you’re certain that all other metals have been removed, you have options as to how you dissolve the gold. AR, using small, incremental doses of Nitric, on heat, will dissolve the filter papers. Any trash or solids get filtered out after all the gold is dissolved. This will produce the least amount of waste, but requires the most care and vigilance while processing and is a bit more expensive. You can also dissolve with AP or AB but it takes a lot longer and generates considerably more waste and it won’t dissolve the filter papers, so you have to be very thorough when rinsing, which generates even more waste. No matter which method you choose to dissolve, filtering the pregnant solution and precipitation will all work the same way. Good luck with it and Merry Christmas!


I've been using AP. Though I guess it was only AP the first time. Now I just mix some old AP with HCl and let it sit for a while. It worked faster when it was warmer outside but no real hurry I suppose. Thanks for the heads up on the mason jar. I'd have learned that one the hard way for sure. What I have now Is a dry mason jar full of coffee filters full of gold foils. All the foils came from AP solutions. I don't want to add them to ar just yet. Plus that many coffee filters I'd prefer to keep out of the refining process when time comes. Will they be digested if I do an HCl boil. I know I need to anyways to insure the foils are clean. I do have a small amount of sulfuric acid. I just read conflicting information on adding it to hcl


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## FrugalRefiner (Dec 25, 2021)

See What will hold up? Pyroceram.

Dave


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## Yggdrasil (Dec 25, 2021)

Dougplogan said:


> I've been using AP. Though I guess it was only AP the first time. Now I just mix some old AP with HCl and let it sit for a while. It worked faster when it was warmer outside but no real hurry I suppose. Thanks for the heads up on the mason jar. I'd have learned that one the hard way for sure. What I have now Is a dry mason jar full of coffee filters full of gold foils. All the foils came from AP solutions. I don't want to add them to ar just yet. Plus that many coffee filters I'd prefer to keep out of the refining process when time comes. Will they be digested if I do an HCl boil. I know I need to anyways to insure the foils are clean. I do have a small amount of sulfuric acid. I just read conflicting information on adding it to hcl


 Adding sulfuric will give you a big mess.
Use AR, it will dissolve the filters when hot.
Or any other method to dissolve the gold, but this involves many thorough washes and as a result more waste.


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## BLACKESTFOOT (Dec 25, 2021)

The glass catch dish is called
Corningware.


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## snail (Dec 26, 2021)

Key to identifying pyroceram from more modern substitutes is the part number.
The part number on pyroceram begins with a P prefix.


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## Dougplogan (Dec 26, 2021)

Yggdrasil said:


> Adding sulfuric will give you a big mess.
> Use AR, it will dissolve the filters when hot.
> Or any other method to dissolve the gold, but this involves many thorough washes and as a result more waste.


So basically it would be better idea to go to ar then wash at this point? I think I get adding sulfuric to a hydrochloric boil is a bad idea. At that point I'd have a problem filtering from there. The foils for the most part are fairly clean in the coffee filters except for ones that came from gold plated cell phone boards. And those just have green circuit board flakes were the boards started flaking.


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## Yggdrasil (Dec 26, 2021)

The filters can go to AR after you have made sure the copper chloride is dissolved.
No point in letting easy dissolved thrash follow your gold.


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## VK3NHL (Dec 26, 2021)

butcher said:


> A pyro ceramic dish can be used for heating or as a catch basin with or without your sand bath.


AND is an absolute must!
Common name ‘Corning Ware’


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## Dougplogan (Dec 26, 2021)

Yggdrasil said:


> The filters can go to AR after you have made sure the copper chloride is dissolved.
> No point in letting easy dissolved thrash follow your gold.


Even if it's 20 or more coffee filters. As far as gold content I'd be surprised if it's 5 grams. That many filters will still desolve in such a small amount of acid? I suppose I could burn off the filters. It maybe the easiest way to get everything down to smaller size


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## Yggdrasil (Dec 26, 2021)

Gold like carbon and vice versa.
In that case you should make sure it is completely incinerated.
No black specks left.


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## Dougplogan (Dec 26, 2021)

Yggdrasil said:


> Gold like carbon and vice versa.
> In that case you should make sure it is completely incinerated.
> No black specks left.


I'd be incenerating then washing with hydrochloric


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## Yggdrasil (Dec 26, 2021)

What will you accomplish by that?
The only problem by incinerated filters is that the ash may be hard to filter.
Dissolving copper chloride and tin is best done before incineration, in my mind at least.


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## Dougplogan (Dec 26, 2021)

Yggdrasil said:


> What will you accomplish by that?
> The only problem by incinerated filters is that the ash may be hard to filter.
> Dissolving copper chloride and tin is best done before incineration, in my mind at least.


I'm fairly sure tin is gone. Everything is left to sit in HCl for about 24 hours then is processed in AP. Then it's poured through a coffee filter to catch gold foils. That's all that's done so far. Some of the stuff is fairly clean but other stuff has black powder or green prices of circuit board pieces that broke off to fine to pick out. Either way I'm 100% certain the stuff needs to be cleaned up a little more before going to ar. It's all e waist stuff. It's not all clean finger foils.


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## cejohnsonsr1 (Dec 26, 2021)

Dougplogan said:


> I've been using AP. Though I guess it was only AP the first time. Now I just mix some old AP with HCl and let it sit for a while. It worked faster when it was warmer outside but no real hurry I suppose. Thanks for the heads up on the mason jar. I'd have learned that one the hard way for sure. What I have now Is a dry mason jar full of coffee filters full of gold foils. All the foils came from AP solutions. I don't want to add them to ar just yet. Plus that many coffee filters I'd prefer to keep out of the refining process when time comes. Will they be digested if I do an HCl boil. I know I need to anyways to insure the foils are clean. I do have a small amount of sulfuric acid. I just read conflicting information on adding it to hcl


If you can scrape the filters down to just one or two you’ll be better off. If you can at least trim away the excess filter paper that would help a lot too. AR will digest quite a bit of paper, but no sense making have to work any harder than necessary. Remember that the key is to add the Nitric slowly and in small doses using just enough to do the job. Then you won’t have to worry about denoxing. As to the sulfuric acid, you can add a few drops to precipitate any led that might have followed the gold to this point. If there is any led, it will be removed along with any other trash and solids when you filter the solution.


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## Yggdrasil (Dec 26, 2021)

Dougplogan said:


> I'm fairly sure tin is gone. Everything is left to sit in HCl for about 24 hours then is processed in AP. Then it's poured through a coffee filter to catch gold foils. That's all that's done so far. Some of the stuff is fairly clean but other stuff has black powder or green prices of circuit board pieces that broke off to fine to pick out. Either way I'm 100% certain the stuff needs to be cleaned up a little more before going to ar. It's all e waist stuff. It's not all clean finger foils.


When it is done in AP.
A quick HCl wash may take what is left, but it creates a lot more waste.
So as long it is what is left in the filters I'd just start a hot HCl and add a little Nitric and start stirring.
As the filters with content dissolve one may add more nitric as needed.
In the end you will have it all dissolved.
It need to be hot, but not boiling and stirred well.
After that filter the solution that now might be green if there was copper left. The filter well and wash through filter. The filter go in the used filter box.
Then precipitate by favourite method.
After stannous test of course.
Stannous after precipitation should be clear, but still put spent solution in stock pot.


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## Geo (Dec 28, 2021)

I started with used coffee pots from the thrift store. Used glassware should be used with a non-reactive catch pan. I have had coffee pots break for no apparent reason. I have also had some that still survive today although I never use them any more. Corningware, Vision ware (amber or cranberry) which is also made by corning ware make great catch pan. I have abused mine in ways that would make a grandmother cry with grief. Like dropping a pyroceram dish that is glowing red hot into water, not recommended but it survived and didn't even crack.








CorningWare - Wikipedia







en.wikipedia.org


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## kurtak (Dec 28, 2021)

Geo said:


> , Vision ware (amber or cranberry) which is also made by corning ware make great catch pan.



Thats what I use - anytime I see it in a thrift store I buy it just for my refining 

Kurt


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## Dougplogan (Dec 28, 2021)

kurtak said:


> Thats what I use - anytime I see it in a thrift store I buy it just for my refining
> 
> Kurt


I found some pyroceram on eBay. 13 bucks for two square dishes shipped


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## FrugalRefiner (Dec 28, 2021)

I find mine at yard sales / garage sales. I usually pay about a dollar or two per piece.

Dave


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