SIMPLE CHEAP STOCKPOT COPPER

[Deceitful_Frank]

Good morning Fam,

I am fairly new to precious meal refining and have accumulated 2-3 litres for my stockpot. Several Gold precipitations using SMB plus decanting and pouring off over the Gold and washing with HCl. I have saved all these waste solutions. NOTHING silver related in here!

My question is to get your thoughts on throwing in old UK bronze pennies which are freely available here and very cheap. They are 97% Cu, 2.5% Zn and 0.5% Sn. As a new refiner I want to keep everything simple and cheap on this small scale for now. I could do what Sreetips does and source copper tube flat bar cable etc but would these coins be ok? Any issues with a small amount of zinc or tin if all I am really interested in right now is the last bit of Gold?

Thanks and regards, Frank

 

[nickvc]

Very bad idea the last thing you want to deal with is tin,just scavenge old copper pipe and open and flatten and put that in your stock pot.
If you do not understand what I’m saying about tin just search posts regarding tin in gold solutions...

 

[Deceitful_Frank]

Thankyou! yes I now remember someone saying something about Tin. Even 0.5% Tin probably isn't worth the risk.

 

[Stowmaster]

I used a copper radiator for silver precipitation, and was very surprised that almost 4% of impurities were found in silver during XRF, 1% of them zirconium. Therefore, I would not use unknown items. For copper, I would take an electrical wire, or 5 cents of American coins, if 25% nickel is not a hindrance.

 

[Deceitful_Frank]

I am guessing that reviving an old dead thread is atleast forgivable if its your own...

So clearly we don't want contamination of tin with our Gold but how about using this 97% Cu 2.5% Zn 0.5% Sn alloy for cementing Silver out of solution? I can get this for literally a THIRD of the price pure Copper will cost me. I know I could scavenge Copper from here and there but to be honest I have better things to do than ask around search and pester.

I plan to do a small test soon and dissolve 25g Silver in nitric acid for this purpose. Once I reclaim the copper from solution with angle iron I know it'll precipitate out with some tin but that doesn't bother me. Hell I'll just cast myself more bronze.

If anyone can point out something I am missing here and save me wasting this Silver and time that'd be great?

Thanks guys!

 

[Geo]

Same problem, different reason. Tin metal dissolved in nitric acid creates metastannic acid (hydrated tin oxide). It is a white fluffy powder that clogs filters and can create a colloid out of your gold during the refine. With cemented silver, there's no good way to separate the cemented silver from the metastannic acid.

 

[kurtak]

AS Geo pointed out - if you use a copper alloy that has tin in it to cement silver - the tin is going to end up in your silver cement (as metastannic tin) NOT in the copper when you cement the copper (nitrate) with iron

If you are going to use copper to cement silver --- use PURE copper - other wise you are just asking for problems (contamination) in your silver cement

Kurt

 

[Deceitful_Frank]

Thanks again guys much appreciated. I'm sure metastannic acid in ones cement silver isn't a complete lost cause but I'm a great believer in not making things difficult for myself! Perhaps I'll do a saved search on eBay keep an eye out for cheap copper as it occasionally comes up.

Plus if I am cementing the copper with iron I could reuse assuming i can find a cheap easy way to melt and recast it in quantity...

Regards.

 

[nickvc]

For your copper you can use old copper pipe opened up and if you can find copper scrap melt into thin bars and use them, even visit a scrap yard and buy some buzz bars or copper sheet, as you are not looking for huge volumes I’m sure they will help just take some cash 8)

 

[kurtak]

I'm sure metastannic acid in ones cement silver isn't a complete lost cause but I'm a great believer in not making things difficult for myself!

I am "sure" that metastannic acid in you silver cement will be nothing less then a real pain in the butt to get rid of once there :!:

You are FAR better served using PURE copper to cement your silver then using ANY kind of copper ALLOY which is more likely then not to cause problems down the line (of refining)

The whole point of cementing silver with copper is to eliminate contamination of the silver (other then a "small" amount of copper - soooo - why would you want to use an alloy that has the "potential" of contaminating the silver with "other metals" :?:

Kurt

 

[kurtak]

AND - for what it is worth - tin is considered a refiners "nightmare"

It's bad enough when tin is involved in what you are trying to refine

introducing it "as part" of your refining process is just flat out foolish :!: :shock:

using a copper alloy that has even a VERY SMALL amount of tin in it is the same thing as "introducing the tin into you refining process" :shock: :!:

NOT a good thing :!: :!: :!:

Kurt

 

[Deceitful_Frank]

Last week I was charged with the task of clearing out a garage at work and stumbled across a quantity of old copper pipe. I have cut off the old fittings and used tin snips to open the copper out flat but there appears to be a layer of pale green powder coating much of it.

I am thinking this is a mixture of copper oxide hydroxide and carbonate?

For the purpose of cementing silver to melt into shot for my cell, need I really worry about scrubbing all of this off? Perhaps there is a chemical soak that could help?

Thanks again guys and regards to you all!

 

[nickvc]

You want clean copper if possible to keep the cemented metals clean, if I remember correctly then you can use dilute sulphuric acid to clean the verdigris off .

 

[cosmetal]

Penny Brite Copper Cleaner https://contenti.com/penny-brite-copper-cleaner

This is a great non-toxic cleaner. I use it on any copper that I enamel.

James