Siver cell leftover electrolyte

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Gwar

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I restarted my silver cell and ran about 10ozt of shot through the basket, I am going to have a few jars of electrolyte after I shut it down, is it possible to recover any Ag from the liquid that may have not been processed? What would be the best method to cement it out if possible and do I have to add anything or perform a special procedure to do so ?
 

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Gwar

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I have a few more ozt to run through, the electrolyte is a few weeks old, I did have a jar with un-contaminated solution that I used to replenish the stock, the crystals are dense and thick but not a lot of growth, my setting are 1.10v, 3.5amp, 4.0watts, the biggest area of success is the middle bottom of the cell..
 

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kurtak

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, I am going to have a few jars of electrolyte after I shut it down,
First - I have not really been following your process &/or what you have been posting - however I see that orvi & AMS-pro have been helping you so you are getting VERY good advice

However - looking at the picture of your electrolyte (recovered after running your cell) in this post I am seeing "a bit" of a problem (though not a big problem)

Why is the electrolyte so cloudy ? --- it should not be cloudy like that - it "appears" that somewhere in your process a very small amount chloride is getting into your silver nitrate creating a very small amount of silver chloride

As I say - it's not a big problem - but it should not be happening at all so we need to figure out when &/or this is happening

So - at what point in your process are you seeing this "cloudy" appear in your other wise "clear" silver nitrate

Kurt
 

Gwar

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Hello kurtak, thanks for the response, in regard to the cloudy appearance in the electrolyte, the attached picture of the jar was taken when I had to stop the cell and travel for a week, I suctioned off all of the liquid into the jar for future use, usually the electrolyte is clear with a visual rippling inside as it cools, after a few conversations with AmsPro and orvi, I started to use smaller amounts of HNO3 and if it seemed the nitric wasn't all used I added more Ag until a small amount of the bar was left over, however, I am still confused as to the amount of distilled water to add after the process. I will explain my last try, I started with


Pure Silver oztPure Silver GramsNHO3 ml NeededDistilled Water ml
385.0585.0585.05
1.546.65100100
131.1100100
131.150100
131.100
I then added 300ml of distilled water and let cool. I have read that many set up cells by the litre, and that would be fine by me if I did the proper math, I ran out of the shot that I had made from a batch of coins yesterday and based on the advise of FrugalRefiner I used a method by 4metals to extract the remaining Ag from the electrolyte, I was surprised at the amount of cemented mixture that I recovered and was quite frankly confused as to why there is so much (attached photo), I did harvest approx 12ozt of crystals, I have been reading as many threads as I can pertaining to Ag and the procedures used and heed the recommendations by more seasoned members in order to have a better understanding of where I am going wrong and how to address it in future situations, again, many thanks for taking the time to add to the thread, Mike
 

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4metals

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What is the total volume of your silver cell? From that we can determine how much metal to digest to create a new solution and how much Distilled Water to add to dilute to make an operating solution.
 

orvi

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OMG, FrugalRefiner, that works wonders !!
Stirring of the liquid, in means of aerating or magnetic stirrer, or drill-stirr bit is necessary for achieving quick and complete precipitation. It also hepls to remove the precipitated metal from the surface of copper quickly, helping to form cleaner precipitate with less passivation CuO drop-off (if the redox potential is high = strong AgNO3 solution). I experienced darker precipitates of silver (obviously contamined with Cu+Cu2O+CuO) when the precipitating metal cannot easily fall off the copper surface - I used twisted copper wire. Some precipitate get stuck in between the turns of the coiled wire and when carefully peeled off, dark deposit was found underneath.

With proper stirring of precipitate, and thus whole volume of liquid, it is easy to achieve full precipitation (negative NaCl test) in matter of one hour and even less.
 

Gwar

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Hello 4metals, The best answer I can offer is that it varies, I have two cell configurations, one is a 64oz jar using a graphite cathode and Ag as a anode, the other is a SS bowl using the Ag cathode, the SS is roughly 7" in diameter and 5" deep, or perhaps I misunderstand the question..
 

Gwar

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I also must admit, I have never been a slow-moving individual, I rush everything I do, I think I need to SLOW down and observe, operate and complete one step at a time, in the correct order and precise.
 

orvi

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I also must admit, I have never been a slow-moving individual, I rush everything I do, I think I need to SLOW down and observe, operate and complete one step at a time, in the correct order and precise.
I have similar problem myself, but I learned how to "manage myself" over the years to the acceptable level of "rush" :D

Sometimes slight discrepancies that happen in the course of refining push you to the deeper understanding of the subject. I do not mean making some dumb mistakes, but some conceptionally OK things, which happen to proceed bit funky or not as planned. You just need to be dilligent, moderate your "rush" a bit and always want the answer "why ?".

As an example, blackening of the Ag precipitate when cementing on copper. I also didn´t known what is going on. Firstly, I just thought that it is just more finely divided silver, but when the powder fell from the copper surface, I clearly saw blackish colour on the surface. I put the copper out, washed it with water, and wiped the surface with bit of paper towel to obtain that mysterious black powder.
Putting the towel into HCl revealed extremely faint green i doubt my eye only see it because i expect it :D but one pour of ammonia into the test sample developed nice blue colour = black stuff contained copper.

So then I learn that stronger Ag solution can passivate copper and thus contamine the Ag cement.

Similarly, cloudy solution of electrolyte is clearly a sign of something which shouldn´t happen. Then comes the hard part - finding what is going on and how to prevent it. From my experience, cloudiness could arise when pH of solution is too high. If this isn´t the case, there is probably some impurity in the solution. Or just anode mud leaking from the basket :)

Learning comes in so many different ways, you just cannot consider all at any moment. But you can focus, study, self-test the hypothesis, and this will help you to tune up your procedures and raise the quality of your refined products :) and it also apply to anything in the life, not just refining.
 

4metals

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Stirring of the liquid, in means of aerating or magnetic stirrer, or drill-stirr bit is necessary for achieving quick and complete precipitation. It also hepls to remove the precipitated metal from the surface of copper quickly, helping to form cleaner precipitate with less passivation CuO drop-off (if the redox potential is high = strong AgNO3 solution). I experienced darker precipitates of silver (obviously contamined with Cu+Cu2O+CuO) when the precipitating metal cannot easily fall off the copper surface - I used twisted copper wire. Some precipitate get stuck in between the turns of the coiled wire and when carefully peeled off, dark deposit was found underneath.
I always preferred air agitation through a plastic pipe containing the copper. The air dislodges a lot of the Silver and helps keep the Copper clean and exposed for more Silver to drop. Lots of guys use copper pipe which works fine but it can be difficult to clean the copper from the pipe ID. Flattening the copper pipe helps but nothing is as effective as a Copper slab with good circulation past the slab. Generally pieces of the copper used for cementing break off when it gets thin and this results in a lower assay of the Silver cement. Never an issue if you are just collecting Silver from old electrolyte to make new anodes.
 

4metals

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The best answer I can offer is that it varies, I have two cell configurations, one is a 64oz jar using a graphite cathode and Ag as a anode, the other is a SS bowl using the Ag cathode, the SS is roughly 7" in diameter and 5" deep, or perhaps I misunderstand the question..
I like to operate a cell at 60 grams of Silver per liter. To make up your 64 ounce cell assume 64oz x 28 ml/oz = 1792 ml. Let's call it 1.75 liters. 1.75 x 60 = 105 grams of Silver needed in the cell. weigh out the Silver keeping in mind sterling is 7.5% Copper so you will need more sterling to get the Silver content to 60g/l. Add a mix of nitric and distilled water slowly to digest all of the metal but do not add any excess. Then dilute this concentrate with distilled water to 1.75 liters and you will have a good working electrolyte to start with.

If you were running higher purity Silver the cell would run great with no additional nitric additions as the solution will deposit one silver atom at the cathode and dissolve one at the anode and stay in equilibrium. Unfortunately the copper content of sterling consumes that nitric as the copper requires more nitric to dissolve than silver so the copper levels in solution climb and the silver levels drop. In larger production cells this is overcome by nitric acid additions based on daily titrations to determine the quantity of nitric needed to keep up the Silver concentration as the Copper levels climb.

To avoid titrations on a simple small cell you can calculate the Copper that dissolves in the cell and add 4.15ml of 70% Nitric Acid to make up for the nitric that was consumed to dissolve every gram of copper.

The copper can build up to levels equal to the Silver concentration if you keep the acid balanced by constant slow additions and don't exceed 600A/m2 current density without copper contamination of the cathode.
 

Gwar

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Sounds like a plan, I have the materials to complete this and will start right away in the a.m., many thanks for the detailed instructions, I will make a record of all my movements and share soon, again, Many Thanks !! Mike
 
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