What exactly can I put in a stock pot?

Can pretty much any solution go into the stockpot? I'm trying to find more information and I'm really not very good at finding this information out please help me out.

There is no reason to put useless 'crap' into the stock-pot. My stock pot generally just gets solutions that have 'touched' gold, so after I drop my gold from AR by SMB, after the gold settles, I pour it off, evaporate it down, then throw it in the stock pot. Same would go for any recovered silver chloride.

I generally don't put HCl that I use to clean off solder into the stock pot, because that is basically Stannous Chloride (Even though there may be some silver in there). Depending on your setup, there may be some use in throwing any old AP solution in the stock pot, since it could hold gold if you went a bit heavy on the Peroxide.

My view is that the stock pot is basically where I cement out (using copper) any tiny quantity of values that I miss in my processes.

Thank you very much. I went ahead and put in used AR, and AP, along with a touch of hydrochloric acid. Added some gold bars, you know the bars that are basically gold plated pins. And of course some copper!

I find that no single stock pot is absolute.
They will all contain a broad spectrum of metals and compounds.
But it helps if you do your best to keep some things as separate as possible so the concentrations give you a head start in separation.
I use copper in all my primary waste stock pot's. first(Waste Pot 1) Au and P.G.M collector pot, if you have a large lab I suppose you might want to separate these as well but I am only a baby. Then I have my silver stock pot(W.P.2.) to which I put all my chlorides and silver wash water , I actually use it as a second settling tank for clear liquor form W.P.1. as well just in case any value has snook by. W.P.3 . is for Ammonia wash, only 5L but it gives you a day or two to deal with it.
They all except the ammonia feed into a secondary waste tank seeded with Iron scrap before going to P.H. augmentation and final liquid disposal .

You can generally put whatever in a stock pot. Ours usually have traces to grams/liter of 30-40 different transition metals with 20-100 ppm PGMs.

Generally though, you don't want free nitric acid!

Lou

justinhcase said:

I find that no single stock pot is absolute.
They will all contain a broad spectrum of metals and compounds.
But it helps if you do your best to keep some things as separate as possible so the concentrations give you a head start in separation.
I use copper in all my primary waste stock pot's. first(Waste Pot 1) Au and P.G.M collector pot, if you have a large lab I suppose you might want to separate these as well but I am only a baby. Then I have my silver stock pot(W.P.2.) to which I put all my chlorides and silver wash water , I actually use it as a second settling tank for clear liquor form W.P.1. as well just in case any value has snook by. W.P.3 . is for Ammonia wash, only 5L but it gives you a day or two to deal with it.
They all except the ammonia feed into a secondary waste tank seeded with Iron scrap before going to P.H. augmentation and final liquid disposal .

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justinhcase - When you do the pH augmentation on your final waste tank, do you use a pH meter or observe the color of the solution ? what chemical do you prefer for the pH increase ?

Lou said:

Generally though, you don't want free nitric acid!

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I would LOVE free nitric acid. :lol:

"justinhcase - When you do the pH augmentation on your final waste tank, do you use a pH meter or observe the color of the solution ? what chemical do you prefer for the pH increase ?[/quote]"
The PH meters do not seem to survive long in the refining shed so I use universal PH indicator paper.
It is 20p a role and it never runs out as long as you keep it in a sealed jar.
and sodium hydroxide is the cheapest and most available and soluble alkali to me.

justinhcase said:

"justinhcase - When you do the pH augmentation on your final waste tank, do you use a pH meter or observe the color of the solution ? what chemical do you prefer for the pH increase ?"
The PH meters do not seem to survive long in the refining shed so I use universal PH indicator paper.
It is 20p a role and it never runs out as long as you keep it in a sealed jar.
and sodium hydroxide is the cheapest and most available and soluble alkali to me.

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Thanks for taking the time to answer! Appreciate it! One last question, can you tell me what pH you aim for ? I think the tutorial says to aim for 2.5, but I'm not sure what the reason is for that, I assume Iron-hydroxide is not very soluble at that pH ? THANKS!

kernels said:

justinhcase said:

"justinhcase - When you do the pH augmentation on your final waste tank, do you use a pH meter or observe the color of the solution ? what chemical do you prefer for the pH increase ?"
The PH meters do not seem to survive long in the refining shed so I use universal PH indicator paper.
It is 20p a role and it never runs out as long as you keep it in a sealed jar.
and sodium hydroxide is the cheapest and most available and soluble alkali to me.

Click to expand...

Thanks for taking the time to answer! Appreciate it! One last question, can you tell me what pH you aim for ? I think the tutorial says to aim for 2.5, but I'm not sure what the reason is for that, I assume Iron-hydroxide is not very soluble at that pH ? THANKS!

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After I have taped of the waste into a clean barrel.
I bring the PH up until I start to get to about 11,most times that is enough to drop out the metal ions. some time's I have had to go up to 12 or 13 going by observation.
The important step is to draw off the liquid from the solid residue then bring it back down to between 8 and 6 9Ideal world it would be 7ph)before discharge . I use a cheep Sulphuric based drain cleaner for this instead of my Acid supply.
I have run this passed my friend who designs treatment plants and he says there system is built to handle effluent far more polluted than the end liquor and I worry to much. But I feel it is better to avoid any problems and even on a model scale system like mine it is an important part of understanding how an efficient system should work.

Fantastic ! Thank you for replying. I have my batch of waste to process soon and this information is gold.

Hi
After dropping gold from aqua regia solution with smb, we filter solution to separate gold powders. We also test the solution with stannous chloride and the test is negative for gold and pgms

Do you transfer this solution to copper stock pot? Or iron stock pot?

Thanks

If there is potential for other PGM's? If so, Yes. I keep my AP and AR solutions in one container, and solutions from my nitric digestions in another.

Thanks
When we filter it with filter paper and when stannous chloride is negative so there is no any potential of any PM's

Do you keep filtrate this AR solution with negative ST test for all PM'S in stock pot too?
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All of silver chlorides in stock pot will reduce to silver metal by copper. Right?

I do because I go after the copper next, so I will save any solution of AP or AR with high copper content. Iron will reduce the copper out which I often reuse in other processes especially to mix with other lower content gold covered copper items such as some pins. Saving the negative tested solutions can keep you from doing many small batch clean ups and can be broken down into a single phase or step. With that said, I sometimes work left over AR in small batch's when I have free time, just to save a little space, especially if the copper content as well as PGM's test negative. I try to never let my stock pot reach 5 gallons, for me, it is just to much trouble at that point to get caught up with. I will have a third pot that contains any dropped PGM's and gold from my stock pot that I save for future processing. Since they have things such as palladium and even some platinum, I most likely will have that processed later, hopefully much later when I have a fairly large amount of concentrated materials.

There are many different situations that can arise and need to be taken into account to determine what is the best situation for each individual. The material your working with, the method your using, time constraints can even help determine what is best for your situation.

As for copper reducing the silver chloride, I am not sure what you mean. From AR, most of my silver chloride comes out when I filter my AR. Silver don't normally play much of a part in my AR based stock pot, or at least hasn't in the past. The way I process most things that has a fair bit of silver is through nitric, which takes up the silver and helps eliminate it from my AR pot as it ends up in my nitric based stock pot at that time. Otherwise I remove it in my filtration of the AR.

saadat68 said:

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All of silver chlorides in stock pot will reduce to silver metal by copper. Right?

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In a word. No. Copper does not reduce Silver Chloride to metallic silver. You're confusing this with Silver Nitrate.

Well, it doesn't do it in a practical fashion.

Let's put it that way.

anachronism said:

saadat68 said:

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All of silver chlorides in stock pot will reduce to silver metal by copper. Right?

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In a word. No. Copper does not reduce Silver Chloride to metallic silver. You're confusing this with Silver Nitrate.

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No I didn't confused. My thought was maybe copper in excess acid in stock pot reduces silver chloride to silver like iron in dilute sulfuric or zinc in hcl

I just wanted to know what happen for silver chlorides in stock pot but it doesn't matter because even they reduce to silver metal, they convert to chloride again by excess hcl, aqut regia and etc

Thanks all

saadat68 said:

No I didn't confused. My thought was maybe copper in excess acid in stock pot reduces silver chloride to silver like iron in dilute sulfuric or zinc in hcl

Thanks all

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I'm probably being silly here however I don't see what you mean by this. On the one hand you're referring to Silver Chloride becoming metallic Silver, and on the other you're referring to Iron dissolving in Sulphuric Acid and Zinc dissolving in HCl - what's the connection?

Unless I am missing something these are completely different scenarios and types of reaction.

There is no any connection
My thought was wrong. It was just a supposition and also it is wrong
My supposition:
Iron reduce silver chloride in dilute sulfuric acid
Zinc reduce silver chloride
Aluminum reduce silver chloride
So my question was does copper reduce silver chloride in acidic solution?