Refining silver, cementing vs salt/lye sugar?

[Hartbar]

Good day, just finishing about 20oz silver refine.
After numerous times doing the salt/ lye method, I tried the cementation process.
Source material was sterling silver, not sure on yield or purity yet with cement method but seems like a lot of rinsing, distilled water use and waste water solutions.
I thought the cement method reduced the above?
Copper seems to be my issue.
After about 25 / 30 rinses with hot distilled water, occasionally adding few drops of HCL to water, I’m still testing and seeing copper in waste water, even though water looks clear and good PH.
I’m thinking maybe when you cement, you add about 6oz off copper back into solution on top off the 2oz originally in the sterling? It’s one rinsing process, but about 5 to 6 hours.
With the salt method, it’s a short rinse removing the 2oz of copper from original 20oz of sterling, the another after lye and sugar.
Honestly for me between the two methods, it’s a toss up.
Curious on any opinions.

 

[Yggdrasil]

Good day, just finishing about 20oz silver refine.
After numerous times doing the salt/ lye method, I tried the cementation process.
Source material was sterling silver, not sure on yield or purity yet with cement method but seems like a lot of rinsing, distilled water use and waste water solutions.
I thought the cement method reduced the above?
Copper seems to be my issue.
After about 25 / 30 rinses with hot distilled water, occasionally adding few drops of HCL to water, I’m still testing and seeing copper in waste water, even though water looks clear and good PH.
I’m thinking maybe when you cement, you add about 6oz off copper back into solution on top off the 2oz originally in the sterling? It’s one rinsing process, but about 5 to 6 hours.
With the salt method, it’s a short rinse removing the 2oz of copper from original 20oz of sterling, the another after lye and sugar.
Honestly for me between the two methods, it’s a toss up.
Curious on any opinions.

The Sulfuric Iron method needs less rinsing if I'm not mistaken.

 

[Hartbar]

The Sulfuric Iron method needs less rinsing if I'm not mistaken.

I’m not familiar with that, I’ll take look, thank you.

 

[nickvc]

If you are aiming to fully refine the silver via a cell then the small amount of copper solution left is of little consequence , a good rinse is all that’s needed as the cell will remove any remaining contaminants.

 

[Martijn]

I’m not familiar with that, I’ll take look, thank you.

They all need thorough rinsing.
And cementing can be done in different ways influencing the outcome.
Use clean thick copper bar and submerge completely. Don't leave any copper sticking out.
Then take out the copper when the cement darkens. Cement the last bit separate. This will keep comtamination with copper to a minimum.

With the iron sulfuric method you can have rust forming while rinsing, i add a drop of H2SO4 to the first rinses to avoid rust or iron hydtoxide stains in the beaker.

With the lye and sugar method you need to wash the chloride until no salts are present. This last one uses the most water imo.

 

[GuyGuyGuythe1st]

Sorry I am late to the party!

If I can give you any pointers.

I use a pancake griddle to heat my solutions/solids. Using a home depot 5 gallon bucket lid with a hole I cut out on the top of the lid. I was able to fixture an electric drill to the top. I bought 100% plastic paint mixers on amazon or eBay. Works great for string corrosive solutions. Set it right on top of my glass beakers. Plug it in, 2 or 3 rinses (1 to 2 gallons). Its usually pretty clear water. Also you can pH test the water to show if its acidic.

With heat and aggressive stirring it will wash the chloride better with less waste water. Also with the same griddle I usually have another beaker just boiling to reduce the waste water anyways. So when I treat it, its more concentrated solutions, less liquids to deal with. I have even forgot for days at a time that the griddle was on and it just crystalizes that copper. You just have to rehydrate it a little.

Works way better than hand stirring or multiple washings. You could also do it with a magnetic stir bar. Just make sure its strong enough to move all the solids. The finer the chloride salt, the more it tends to clump up and hold the copper solution in it. That's why you need aggressive agitation

^This is possible why all my glassware always has stains!