Electrochemistry Desired AG concentration in silver cell?

[mikeinkaty]

I'm making a spread sheet showing drop in AG concentration as a cell is used. What, in gms/cc, is the desired range? I know most people recommend 150gm/L to start with but what is the minimum concentration after which the cell should not be used. I think this may depend on other factors such as current used and quality of Ag being processed. I'm assuming .990 silver that was dropped with copper.

Edit - I found it. Gsp had posted it as 3-4oz/gal or 22 - 30 gms / liter.

I'm also going to chart a curve of the increase in copper concentration just for grins. But, shouldn't the Ag be shot before the Cu concentration gets to great?

Then of course, what are the options when the Ag concentration gets to low? Drop what Ag is left and make a new batch, or, replenish the AgNo3?

Mike

 

[goldsilverpro]

I'm making a spread sheet showing drop in AG concentration as a cell is used. What, in gms/cc, is the desired range? I know most people recommend 150gm/L to start with but what is the minimum concentration after which the cell should not be used. I think this may depend on other factors such as current used and quality of Ag being processed. I'm assuming .990 silver that was dropped with copper.

I'm also going to chart a curve of the increase in copper concentration just for grins. But, shouldn't the Ag be shot before the Cu concentration gets to great?

Then of course, what are the options when the Ag concentration gets to low? Drop what Ag is left and make a new batch, or, replenish the AgNo3?

Mike

To me, for most things, spreadsheets are 100%, without a doubt, totally worthless and misleading. They make assumptions that are not always true. I hate them. They tend to promote refining as a cut and dried thing, which is totally false. They don't take into consideration that things NEVER work out perfectly. Like plating, refining is a matter of of knowing all the options, going with the best bet, and then making adjustments to make things work. Refining always involves troubleshooting, since nothing ever works out as perfectly planned. I think that spreadsheets are very detrimental to the learning of how to refine. They promise things to newbies that rarely come true. They give false hopes. Spreadsheets promote definites, but there are no definites in this business. If you are too inept to figure out the numbers on your own, you will never be successful in this business.

Just my opinion.

 

[mikeinkaty]

I'm making a spread sheet showing drop in AG concentration as a cell is used. What, in gms/cc, is the desired range? I know most people recommend 150gm/L to start with but what is the minimum concentration after which the cell should not be used. I think this may depend on other factors such as current used and quality of Ag being processed. I'm assuming .990 silver that was dropped with copper.

I'm also going to chart a curve of the increase in copper concentration just for grins. But, shouldn't the Ag be shot before the Cu concentration gets to great?

Then of course, what are the options when the Ag concentration gets to low? Drop what Ag is left and make a new batch, or, replenish the AgNo3?

Mike

To me, for most things, spreadsheets are 100%, without a doubt, totally worthless and misleading. They make assumptions that are not always true. I hate them. They tend to promote refining as a cut and dried thing, which is totally false. They don't take into consideration that things NEVER work out perfectly. Like plating, refining is a matter of of knowing all the options, going with the best bet, and then making adjustments to make things work. Refining always involves troubleshooting, since nothing ever works out as perfectly planned. I think that spreadsheets are very detrimental to the learning of how to refine. They promise things to newbies that rarely come true. They give false hopes. Spreadsheets promote definites, but there are no definites in this business. If you are too inept to figure out the numbers on your own, you will never be successful in this business.

Just my opinion.

We're all entitled to our opinions......

 

[Lou]

Yes, everyone has opinions and mine is very different from GSP. I agree 100% that a spreadsheet isn't worth much if you don't know the fundamentals and can't react in a dynamic fashion to changing conditions. 99% of a good refiner's job is getting the material pared down into a form that is like everything else they run or fits in the standard pipe line. This is why people doing karat gold are a dime a dozen and people doing more complex extractions (reclamation/concentration then refining) are less numerous and often much bigger operations. It's important to identify the unit operations required for a given type of material--many feedstocks share common steps. The real devil is in the details of getting the material to fit where it can process with everything else.

I actually am very much a numbers guy and like spreadsheets for the organizational and computational advantages they offer. I use them for keeping up every batch for the silver cells, for hydrolysis reactors, silver assays, for digestions, for heats, pre/post weights, month-to-month expenses (fixed and for determining net variable margin) and much more.

Each electrolytic cell has its own sheet in Excel that is written conditionally with IF THEN to highlight when electrolyte needs maintained to encourage maintenance at appropriate intervals. It gives the cell production, current density, concentrations and projects output as the anodes are rotated in/out. Each reactor has its own as well, which tells me how much of whose stuff of what assay is in a given process and generates an expected lead time. These cross-reference with and link to the environmental spreadsheet so that I can keep a mass balance of what chemicals have been used for environmental quality compliance. It helps me identify which process uses the most expensive chemicals or generates the most fume to be scrubbed. These are the processes we try and work on improving or else eliminate altogether.

Of course, any spreadsheet is only as good as its worst mistyped number or wrong formula or process difficulty. Trust but verify. There is no substitute for knowing when something has gone wrong. Spreadsheets can be very useful for pinning down problems but they need to be backed by practice. They can be written on theory and edited on reality.

 

[goldsilverpro]

Mike,

Sorry. I spent most of the day yesterday sitting in a hospital. I was exhausted and in a lousy mood last night and I took it out on you. I apologize.

As Lou said, for production control in a refinery, spreadsheets are great. Those are not the type of spreadsheets I was talking about. A very simple example of the type I don't like would be one that gives the dollar value of karat gold. The variables would be the karat, the weight, and the spot price. Most of these I've seen assume that the karat stamped on the jewelry is the actual karat. Most of us know this is rarely true. A novice using this spreadsheet would over evaluate their material. In other words, it would give them false hopes. Another example would be the inquartation and nitric/water spreadsheet you made when you first came on the forum. I worked with you on the perfection of it but, if I remember right, we never came up with something entirely suitable for the nitric usage. There were just too many unseen variables that weren't on the spreadsheet: nitric strength, open, closed, or partially closed reaction vessel, temperature, etc. If a newbie used it, things probably wouldn't work out. Those online calculators often have the same problems. I hate them as well.

To me, being able to do the math yourself is a big part of being a successful refiner and there is no substitute for it. From day one, I have tried to teach the math involved and am always pleasantly surprised when I see how many people have become adept in it. Being able to do the math yourself shows understanding and maturity. Using a spreadsheet is sort of a "one pill" approach for the newbie but that rarely works as predicted. Spreadsheets and online calculators teach nothing. They're too cut-and-dried and, as many of us know, nothing is cut-and-dried when it comes to refining.

 

[mikeinkaty]

Gsp -

I hope whoever was in the hospital is doing well now.

I think I explained pretty well in that other spreadsheed that the calculated amount shown would be the upper limit, without reflux, and that the person should start with half that amount and work up to what ever it takes. 1.22 was the factor I used.

BTW - My 62% technical grade nitric must be stronger or reflux is doing one heck of a job. It's behaving almost like 70%. I ask the lady at the plant what the strength was and she said, "at least 62%, or more. I don't know for sure."!

Mike