Electrolyte for silver cell questions

[Cmarett]

Hello everyone, I am about to put my first silver cell into operation and have a few questions on the electrolyte. I have searched for these answers, but the information I find is either very conflicting with other information I find, or very scientific speak and hard to understand and follow. Hoping the group can help. Thanks in advance.

Question #1 / How do I know the amount of impure silver that I can run through a cell before the nitrate solution is used up or becomes too contaminated with copper?

Question #1.5 / How do I know at what point the cell has become too contaminated, and the nitrate solution needs to be changed?

Question#2 / Assuming my silver nitrate solution is 90% pure and 10% impure, What should I be using as a ratio on this silver nitrate solution per liter of distilled water?

Again, thanks in advance for any help.

 

[command2001]

Hello everyone, I am about to put my first silver cell into operation and have a few questions on the electrolyte. I have searched for these answers, but the information I find is either very conflicting with other information I find, or very scientific speak and hard to understand and follow. Hoping the group can help. Thanks in advance.

Question #1 / How do I know the amount of impure silver that I can run through a cell before the nitrate solution is used up or becomes too contaminated with copper?

Question #1.5 / How do I know at what point the cell has become too contaminated, and the nitrate solution needs to be changed?

Question#2 / Assuming my silver nitrate solution is 90% pure and 10% impure, What should I be using as a ratio on this silver nitrate solution per liter of distilled water?

Again, thanks in advance for any help.

No answers???? I could use the information myself.

 

[4metals]

I am used to Silver cells on a much larger scale than your setup. Larger cells use a daily titration to determine the concentration of Silver in solution and add nitric acid accordingly. Obviously, small cells are not going to be routinely titrated so some accommodations need to be made.

I can write a spreadsheet to help you to get started but there will have to be some guesstimations to determine how much Silver is in solution. The problem is sterling Silver is 7.5% copper and copper takes 3.4 times more nitric to dissolve. So as your anodes dissolve, the nitric available to continue to dissolve new silver at the anode diminishes. This causes your silver nitrate concentration to drop.

To start out, what is the volume of your cell? And how much refined Silver can you remove daily? (or every couple of days). From these numbers we can work backwards to figure how much nitric you need to add to make up for the excess consumption by the copper in the alloy.

As far as how much copper can build up in the solution, classic cell chemistry allows the operating Silver content, which you want to maintain at 60 grams. per liter defines how much copper can be in solution before the copper starts to cross over and contaminate your refined Silver. By tracking your anode consumption, you can determine the copper in solution based on the amount of anode dissolved.

As I said, I have never operated a small silver cell so the controls I suggest may not be do-able for you. So if some other members whose expertise is in small cells chime in, maybe we can come up with some documented guidelines for future use by everyone.

 

[nickvc]

When I ran my cell I made up the electrolyte using cement silver so it was contaminated with a little copper and I added nitric based on the color of the electrolyte as it ran , my feed stock was sterling much gold plated so I was after the slimes but it produced around 100 + kilos of fine silver and the slimes were worth chasing.

 

[4metals]

This is a spreadsheet used for the smallest cell I ever worked with. It is a cell which produces 3000 ounces of Silver per week (7 days) of continuous operation. I realize your small will not be titrated so we have to come up with a work around. I have entered the volume of the cell based on what I think your volume will be.

 

[FrugalRefiner]

I use sterling to make up my electrolyte. Some copper is desirable in the electrolyte.

I made a series of copper nitrate solution samples from 10 grams per liter to 50 grams per liter. When the color of the electrolyte matched the color of the 40 grams per liter sample, I treated the electrolyte to remove some copper.

Dave