Electrochemistry SILVER REFINING CELL

[goldmet]

This silver refining cell is constructed of PVC. It has a very comfortable way to recover the silver crystals.

 

[goldmet]

This silver refining cell is constructed of PVC. It has a very comfortable way to recover the silver crystals.

This is the shot silver

 

[goldmet]

This silver refining cell is constructed of PVC. It has a very comfortable way to recover the silver crystals.

This is the shot silver

Any doubt answer with great pleasure.

 

[Lou]

Very nice post.


How do you remove the silver from the bottom of the cell?

 

[goldsilverpro]

Very nice post.


How do you remove the silver from the bottom of the cell?

That was the first thing I saw also. How do you remove the crystal?

 

[Lou]

We had two that were the same looking and it all went to the bottom. Had to drain the whole thing.

 

[4metals]

Italimpianti has a similar cell although from the side view it looks like a square tank. It too has a steep sloping bottom except the bottom flattens out and is about 8" wide so a stainless steel scoop on a pole is used daily to lift out the crystal. Just open the front hinged door and use the scoop seen to the left to empty the crystal that has slid down the slope and collected at the bottom.



From this picture you can see where the sloped bottom ends and the flat section is for scraping.



These units are self scraping so they only need to be attended once in 24 hours and can run over a weekend if you have a full charge of anodes installed. The unit posted by the OP can easily made to be self scraping as well.

 

[zachy]

What should be the voltage and amperage, and especially the anodic bags, that do not let go to the cathode, the contamination, what should be the initial composition of the electrolyte? how many grams per liter should the silver electrolyte have, and how much copper should be used to change it?

 

[4metals]

A silver cell runs well with a concentration of 50 to 60 grams per liter. Titration using the Volhard method makes this easy to control.

The voltage is usually between 3 and 4 volts

The amperage is usually 25 to 50 amps per square foot

The anode bags are 9 ounce polypropylene. I have had good luck fabricating a PVC pipe hanging basket and using anode bags custom made to fit tight so the bags don't touch the anodes and the slimes routinely fall to the bottom. The basket and bag are mounted so the anodes can be hung on an anode bar for easy positioning and removal. The anodes can be easily lifted from the basket anode bag and cleaned and while they are out, the slimes that have fallen to the bottom can be vacuumed up and the solution filtered and returned to the cell. Eventually the anode bags get too clogged and are incinerated and melted to recover the trapped values. Don't let the slimes build up too deep in the anode bag, routinely clean the anodes and the bags.

And when the copper approaches 50 grams per liter it is time to consider changing out the solution

 

[FrugalRefiner]

And when the copper approaches 50 grams per liter it is time to consider changing out the solution

Do you have a simple test for that similar to the Volhard for silver?

Dave

 

[Lino1406]

Simple test for copper: take a sample, add ammoniak, watch level of blue

 

[FrugalRefiner]

But how do you quantify?

Dave

 

[Lino1406]

Produce a series of known concentrations, e.g. 10, 25, 50, 75...with liquid from initial cell.
Use same amount of ammoniak for each. Etc.

 

[FrugalRefiner]

Thanks Lino. I already do a similar thing. I created some 100g./liter copper nitrate, then did successive dilutions, saving small samples along the way. I have some small sample vials with the varying concentrations and I compare them to the electrolyte in the cell. Other contaminants can affect the color, but since I process primarily sterling, copper predominates. It's close enough to let me know when the copper is getting high.

Dave

 

[4metals]

Ideally an AA would come in handy, but short 1 AA try this;

View attachment Copper analysis in silver cell.docx

 

[FrugalRefiner]

Outstanding! Thank you very much!

Dave

 

[zachy]

What is the value of the PH of the cell? and the bathroom must have agitation, I read yes, with pump and air.
Apparently nobody knows about the subject ....

 

[vjodhani]

This silver refining cell is constructed of PVC. It has a very comfortable way to recover the silver crystals.

In the first picture why are your pouring molten metal into water via crucible?
What are you trying to make with it? Is it beads?

 

[Shark]

Some use the poured shot in their cell instead of poured bars or sheets. Many feel these shot are quicker to process.