Can I use large chemical drums for dissolving?

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One more thing I would like to ask --- why are you wanting to refine your sterling ?

I ask because unless you have a market already established wherein you can sell your refined silver for a premium above spot you are likely not going to make any more money by refining it as opposed to selling the sterling directly to a refinery

In other words - most refineries are going to pay you the same price (for the silver in your sterling) as they will pay you for your refined silver

Example; - the refinery I send my silver to - they pay me 93% of spot as long as I send them a minimum of 500 ozt silver whether it is 999 (plus) or sterling

to clarify - with the sterling - to get the 93% spot price - the sterling has to have (minimum) 500 ozt silver in it - so I have to send them (about) 550 ozt of sterling in order to have 500 ozt actual silver

On the other hand - if I refine it to 999 (plus) I still only get 93% spot as long as it's the (minimum) 500 ozt of silver

So - for the most part I simply send my sterling directly to the refinery

Most of the silver I actually refined was lower grade silver such as contact points (due to cadmium which some refineries deduct for) silver solder/braze, low grade foreign coins, silver sulfide recovered from picture fixer solutions, or silver recovered from doing gold filled, etc.

Also - I did have a few buyers that would buy my refined silver for a premium above spot but those markets (buyers) were limited in buying (a few kilos) at a time so it was worth having some refined silver on hand for when they wanted to buy

other then that most of my sterling I sold directly to the refinery as I got paid the same (on the silver) whether it was sterling or 999 plus refined

Kurt
 
304 stainless drum wielded to a 3/8 304 stainless plate sitting on a all stainless cooker.
Total cost... Just North of $1,000.
 

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One more thing I would like to ask --- why are you wanting to refine your sterling ?

I ask because unless you have a market already established wherein you can sell your refined silver for a premium above spot you are likely not going to make any more money by refining it as opposed to selling the sterling directly to a refinery

In other words - most refineries are going to pay you the same price (for the silver in your sterling) as they will pay you for your refined silver

Example; - the refinery I send my silver to - they pay me 93% of spot as long as I send them a minimum of 500 ozt silver whether it is 999 (plus) or sterling

to clarify - with the sterling - to get the 93% spot price - the sterling has to have (minimum) 500 ozt silver in it - so I have to send them (about) 550 ozt of sterling in order to have 500 ozt actual silver

On the other hand - if I refine it to 999 (plus) I still only get 93% spot as long as it's the (minimum) 500 ozt of silver

So - for the most part I simply send my sterling directly to the refinery

Most of the silver I actually refined was lower grade silver such as contact points (due to cadmium which some refineries deduct for) silver solder/braze, low grade foreign coins, silver sulfide recovered from picture fixer solutions, or silver recovered from doing gold filled, etc.

Also - I did have a few buyers that would buy my refined silver for a premium above spot but those markets (buyers) were limited in buying (a few kilos) at a time so it was worth having some refined silver on hand for when they wanted to buy

other then that most of my sterling I sold directly to the refinery as I got paid the same (on the silver) whether it was sterling or 999 plus refined

Kurt
I buy as an investment mostly so for me I am the end buyer. I would rather have bars than piles of scrap. But if I can get scrap far cheaper it makes sense. I might pour some 1 oz rounds and try to sell them just for some cash flow but mostly I just want to have bars instead of scrap and I would save a lot of money doing it myself vs selling to a refiner and then buying bars at a premium.
 
I buy as an investment mostly so for me I am the end buyer. I would rather have bars than piles of scrap. But if I can get scrap far cheaper it makes sense. I might pour some 1 oz rounds and try to sell them just for some cash flow but mostly I just want to have bars instead of scrap and I would save a lot of money doing it myself vs selling to a refiner and then buying bars at a premium.

I don't want to tell you what to do - but - if all you are doing is "stacking" your silver there is a better route to go (IMO)

Instead of buying LOTS of nitric - setting up to dissolve "large" batches of sterling - then cementing the silver back out of the silver nitrate - then pouring shot or bars to run in a silver cell - then having to deal with all the chemical waste you will have to deal with in that process --- & other things you will need to invest in to set up for this kind of full on refining (like a real lab with fume hood, chem storage, fume scrubber, furnace for melting your end product, etc. etc. etc.)

Keep it simple - get a propane furnace that will hold a number 4 crucible (not one of those "cheap" electric furnaces) along with a 1 kilo cast iron mold - melt your sterling & pour kilo bars - get some number stamps & stamp them with 925

Kilo bars "stack" very nice & take up MUCH less room then a bunch of sterling scrap (like flatware, trays, bowls, trophies, etc.)

Then - if - you want to refine "some" of that sterling to make "some" 999 plus silver for making 1 ozt rounds/bars you can run those kilo bars in a silver cell to get your 999 plus silver --- if all you are really wanting to do is "some" small batch 999 (plus) for "some" rounds/bars

This set up - on a small(er) scale will take MUCH less investment MUCH less chems & create MUCH less chem waste (the chem waste being the elephant in the room)

Your kilo bars of sterling aren't going to go anywhere - until you want them to - whether that be send them into a refiner - or refine them your self

At least that is how I do it - all my sterling is poured to kilo bars - IF (the BIG IF) I decide to ship to the refinery the kilo bars are already poured & take up much less room (box) for shipping - or - if one of my clients that pays a bit more then spot for 999 (plus) calls for some 999 (plus) I fire up my cell & run the sterling kilo bars as anodes in the cell

You can turn out 9999 silver in the cell as long as you understand when/how to control the copper corruption of the electrolyte when running the cell --- part of the learning curve

For what it is worth

Kurt
 
I don't want to tell you what to do - but - if all you are doing is "stacking" your silver there is a better route to go (IMO)

Instead of buying LOTS of nitric - setting up to dissolve "large" batches of sterling - then cementing the silver back out of the silver nitrate - then pouring shot or bars to run in a silver cell - then having to deal with all the chemical waste you will have to deal with in that process --- & other things you will need to invest in to set up for this kind of full on refining (like a real lab with fume hood, chem storage, fume scrubber, furnace for melting your end product, etc. etc. etc.)

Keep it simple - get a propane furnace that will hold a number 4 crucible (not one of those "cheap" electric furnaces) along with a 1 kilo cast iron mold - melt your sterling & pour kilo bars - get some number stamps & stamp them with 925

Kilo bars "stack" very nice & take up MUCH less room then a bunch of sterling scrap (like flatware, trays, bowls, trophies, etc.)

Then - if - you want to refine "some" of that sterling to make "some" 999 plus silver for making 1 ozt rounds/bars you can run those kilo bars in a silver cell to get your 999 plus silver --- if all you are really wanting to do is "some" small batch 999 (plus) for "some" rounds/bars

This set up - on a small(er) scale will take MUCH less investment MUCH less chems & create MUCH less chem waste (the chem waste being the elephant in the room)

Your kilo bars of sterling aren't going to go anywhere - until you want them to - whether that be send them into a refiner - or refine them your self

At least that is how I do it - all my sterling is poured to kilo bars - IF (the BIG IF) I decide to ship to the refinery the kilo bars are already poured & take up much less room (box) for shipping - or - if one of my clients that pays a bit more then spot for 999 (plus) calls for some 999 (plus) I fire up my cell & run the sterling kilo bars as anodes in the cell

You can turn out 9999 silver in the cell as long as you understand when/how to control the copper corruption of the electrolyte when running the cell --- part of the learning curve

For what it is worth

Kurt
Thanks Kurt definitely great advice! I have heard mixed opinions on using silver cell for 925 but it does seem practical and probably a lot cheaper. Ill have to research it more. I do like the idea of melting 925 into shot or bars and just storing that for now.
 
Thanks Kurt definitely great advice! I have heard mixed opinions on using silver cell for 925 but it does seem practical and probably a lot cheaper. Ill have to research it more. I do like the idea of melting 925 into shot or bars and just storing that for now.
Some people refine with two silver cells in series. They pour the shot/anode bars from sterling, run them first time through the "dirty" cell to obtain crude "99+" silver, leaving all base metal junk in the first pot. You must deal with the accumulating copper anyway, but to obtain 99% silver from sterling, you can go quite high with copper content in the cell :) Then this refined silver undergo second "pure" cell rafination to 999+ purity, not compromising the "pure" electrolyte with tons of copper :)
It is good to make calculation about how expensive the nitric dissolution pathway is vs. how effectively you can do scheme mentioned above - double silver cell. Labor vs. cost.
To me, double cell method is much cleaner, no clouds of NO2 are produced. Aside of making AgNO3 electrolyte for the first run.
 
Some people refine with two silver cells in series. They pour the shot/anode bars from sterling, run them first time through the "dirty" cell to obtain crude "99+" silver, leaving all base metal junk in the first pot. You must deal with the accumulating copper anyway, but to obtain 99% silver from sterling, you can go quite high with copper content in the cell :) Then this refined silver undergo second "pure" cell rafination to 999+ purity, not compromising the "pure" electrolyte with tons of copper :)
It is good to make calculation about how expensive the nitric dissolution pathway is vs. how effectively you can do scheme mentioned above - double silver cell. Labor vs. cost.
To me, double cell method is much cleaner, no clouds of NO2 are produced. Aside of making AgNO3 electrolyte for the first run.

You can also "extend" you run time before copper starts co-depositing by increasing the silver concentration of the electrolyte you start with as the copper does not start co-depositing until silver ions are reduced & replaced by copper ions --- so if you start with a higher silver concentration you can run the cell longer before you upset the balance between silver ions & copper ions in the electrolyte causing the copper to co-deposit

OR - when you figure the copper ions are close to corrupting the electrolyte to the point of co-depositing you can siphon off half your corrupted electrolyte & replace it with fresh electrolyte

Ether &/or both of those things will extend you run time before concern for copper co-depositing --- again - there is a learning curve

As the saying goes - there is more then one way to skin a cat --- running a "break down" cell & then running a second purification cell is one of those ways

Kurt
 
The only way to beat a silver cell for doing sterling is to do formate reduction. In a large scale, I think you underestimate the difficulty of filtration of your silver cement.

Cheapest entry into a good barrel to dissolve silver is a keg. Cut the top off it. You can get them on facebook marketplace as they are directed at the home brew crowd.

I've used quite a few different stainless pots for silver. I am running 100% for destroying them...but alas, that is life. I had a really nice pasta cooker that I loved. It held up great til the handle broke off, then it went downhill fast.

The fumes will be a lot easier to handle on a silver cell than they will straight dissolution as well.
 
The only way to beat a silver cell for doing sterling is to do formate reduction. In a large scale, I think you underestimate the difficulty of filtration of your silver cement.

Cheapest entry into a good barrel to dissolve silver is a keg. Cut the top off it. You can get them on facebook marketplace as they are directed at the home brew crowd.

I've used quite a few different stainless pots for silver. I am running 100% for destroying them...but alas, that is life. I had a really nice pasta cooker that I loved. It held up great til the handle broke off, then it went downhill fast.

The fumes will be a lot easier to handle on a silver cell than they will straight dissolution as well.
What do you mean the difficulty of filtration of the cement?
 
The only way to beat a silver cell for doing sterling is to do formate reduction. In a large scale, I think you underestimate the difficulty of filtration of your silver cement.

Cheapest entry into a good barrel to dissolve silver is a keg. Cut the top off it. You can get them on facebook marketplace as they are directed at the home brew crowd.

I've used quite a few different stainless pots for silver. I am running 100% for destroying them...but alas, that is life. I had a really nice pasta cooker that I loved. It held up great til the handle broke off, then it went downhill fast.

The fumes will be a lot easier to handle on a silver cell than they will straight dissolution as well.
Formate reduction sounds interesting more research to do lol
 
What do you mean the difficulty of filtration of the cement?
Have you ever seen 1,000 oz of silver cement? Dissolving the silver is the easy part, and frankly, in terms of infrastructure, the cheap part.

Go price a 24" buchner funnel.

I've got 4 different 25 cm funnels and and assortment of receiving flasks and pumps....

1,000 oz silver you should eb able to get 95% accountability easily, and pay $1 an oz to get a minted product back to you. At current silver prices, that's $2400. I have four 25 cm buchners, the vacuum flasks, dissolution containers, etc etc. Well over $2400 and I am not able to do 1,000 oz lots nearly competitevly. Sometimes it's best to just pay up.
 
Have you ever seen 1,000 oz of silver cement? Dissolving the silver is the easy part, and frankly, in terms of infrastructure, the cheap part.
AMEN! The dissolving is the easy part. Filtering and drying is a pain in the ....
I have a stainless restaurant griddle like the waffle house uses. About 3 ft X 6 ft. I can throw 100 lbs of powder on it and stir it around like hash browns with a large stainless sheet rock knife. I can dry about 100 lbs in 30 minutes.
 
AMEN! The dissolving is the easy part. Filtering and drying is a pain in the ....
I have a stainless restaurant griddle like the waffle house uses. About 3 ft X 6 ft. I can throw 100 lbs of powder on it and stir it around like hash browns with a large stainless sheet rock knife. I can dry about 100 lbs in 30 minutes.
Does it really even have to be dry wouldn’t the 2000F dry it up pretty quick?
 
Any water left in the powder will need to evaporate before it can start melting. As water evaporates it robs the furnace of heat to convert that water to vapor. You will either expend energy in the drying phase or in the furnace phase. Either which way there is no free lunch. It's more about time and efficency. On a small scale that might not matter, but as you scale up it comes into play. A lot of my clients like it returned in powder form. In order to do proper weighing and fee calculations i have to have it dry.
 
Any water left in the powder will need to evaporate before it can start melting. As water evaporates it robs the furnace of heat to convert that water to vapor. You will either expend energy in the drying phase or in the furnace phase. Either which way there is no free lunch. It's more about time and efficency. On a small scale that might not matter, but as you scale up it comes into play. A lot of my clients like it returned in powder form. In order to do proper weighing and fee calculations i have to have it dry.
Ah I hear ya. That definitely makes sense for sending back powder. I guess I probably wouldn’t care much planning to use free waste oil so burning off the water probably won’t matter much. Maybe let the powder bake in the 100 degree sun for a few days before.
 
snowman & silver 1 - you guys are awesome - thanks for contributing to this thread

As the saying goes - there is more then one way to skin a cat --- skinning cats different ways is part of the love of refining (IMO)

For what it's worth --- I would say about half the silver I processed I got from magnetic disconnects

I got the disconnects by the pickup truck load from a couple scrap yards I delt with

Some of those disconnects had points in them that had 1 ozt silver per contact point/pad - so 12 ozt silver per disconnect - & when you have a pickup load of them it's a PAY DAY

Anyway - just wanted to say you guys are awesome & are part of what makes this forum worth being a member of

Kurt
 
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