Grey not shiny silver from silver cell

[bes8718]

I have a muslin cloth as the anode filter

Graphite cathode 2" x 0.8"

About 80gl electrolyte previously used for about 300g of 98-99% pure silver

Tried the cell at 2.5v, 1.8v, 3.5v and the Amps were about, 0.33, 0.21, 0.58.

 

[bes8718]

That previous run with the electrolyte produced about 200g of nice shiny crystals and 100g of grey not shiny crystals

 

[bes8718]

This is the current silver after about 4 hours

 

[bes8718]

The previous run with the 200g of shiny and 100g grey crystals. And all the grey crystals formed from the bottom up and were very fragile

 

[anachronism]

Just out of interest have you tried a Stainless Steel basin as the Cathode?

 

[BGDOCK]

The grey kinda looks like copper was starting to deposit on the crystals how much silver was dissolved in 1L?

 

[FrugalRefiner]

Just one more thought... The electrolyte may become depleted at the bottom since there's no circulation. That could lead to slower/smaller crystal growth at the bottom, which could appear grey, much like gold dropped from dilute/dirty solutions becomes darker than the nice light brown color from concentrated/clean solutions. Just a thought.

Dave

 

[bes8718]

The grey kinda looks like copper was starting to deposit on the crystals how much silver was dissolved in 1L?

Roughly 80g. Do you reckon it could be a problem with the electrolyte?

 

[bes8718]

Just one more thought... The electrolyte may become depleted at the bottom since there's no circulation. That could lead to slower/smaller crystal growth at the bottom, which could appear grey, much like gold dropped from dilute/dirty solutions becomes darker than the nice light brown color from concentrated/clean solutions. Just a thought.

Dave

Interesting, how would I fix that if it's the case?

 

[bes8718]

Just out of interest have you tried a Stainless Steel basin as the Cathode?

I've not. I did this one because it seemed simpler

 

[BGDOCK]

Add more silver next time , 125g -150 g of silver per liter is a good starting pt.

 

[bes8718]

Add more silver next time , 125g -150 g of silver per liter is a good starting pt.

Alright will do thanks for the advice. But why does the concentration affect it?

 

[Yggdrasil]

Alright will do thanks for the advice. But why does the concentration affect it?

The concentration affects the conductivity.
The higher the concentration the higher the conductivity, which means you need lower Voltage to push the ions through the solution.
This in turn reduces the "force"/speed the ions travel with and it can build heavier crystals.
If you do not have circulation the electrolyte becomes depleted in the area around the Cathode, which creates a region with low concentration.
To counter this, it is wise to a have something to create circulation. Pump, stirrer or what ever.
The stainless steel bowl are simpler than your setup, since the bowl itself is the Cathode, no need for a dedicated cathode.
It is not ideal but quite good.

 

[bes8718]

The concentration affects the conductivity.
The higher the concentration the higher the conductivity, which means you need lower Voltage to push the ions through the solution.
This in turn reduces the "force"/speed the ions travel with and it can build heavier crystals.
If you do not have circulation the electrolyte becomes depleted in the area around the Cathode, which creates a region with low concentration.
To counter this, it is wise to a have something to create circulation. Pump, stirrer or what ever.
The stainless steel bowl are simpler than your setup, since the bowl itself is the Cathode, no need for a dedicated cathode.
It is not ideal but quite good.

I see, thank you very much for the detailed response it's very helpful. I'll look into getting a bowl now

 

[Yggdrasil]

I see, thank you very much for the detailed response it's very helpful. I'll look into getting a bowl now

How much Silver are you processing?

 

[bes8718]

How much Silver are you processing?

About 260g just now

 

[Yggdrasil]

About 260g just now

Look at the numbers, there will be 150g in one liter of electrolyte.
Not much left for the anode then.