Silver and copper cell?

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

autumnwillow

Well-known member
Joined
Apr 1, 2010
Messages
450
Silver cell:
I only need about 100g of silver in a week.
I plan to use a 500ml beaker with SS304 cathode.
The anode bag will be from a grocery bag.
The silver will be in shots (copper cemented silver from inquartation wastes).
If I use 90g/L as the electrolyte with 50% distilled water and 50% nitric, wouldn't the anode shots be dissolved immediately because 1.22ml of nitric acid consumes 1g of silver and also generate fumes?
Does the cell have to be in a hood?
Rectifier capacity is 10amps, I only plan to use 3v.

Copper cell:
I can't seem to find any articles regarding copper cells, specifically copper nitrate solutions from cemented silver wastes.
Most of the cells I see are sulfuric acid based.
Is it as simple as running a SS316 cathode and anode?
 
If I use 90g/L as the electrolyte with 50% distilled water and 50% nitric, wouldn't the anode shots be dissolved immediately because 1.22ml of nitric acid consumes 1g of silver and also generate fumes?
The electrolyte is basically a silver nitrate (in your case above 90 grams fine silver per liter (1000ml of solution) the excess nitric assure some excess acid).

Does the cell have to be in a hood?
Yes, if done indoors, although the cell should not gas excessively, as long as voltage and current are not run too high, some gas evolution is still possible, acid fumes can destroy most any metal in the work area.
Rectifier capacity is 10amps, I only plan to use 3v.

Copper cell:
I can't seem to find any articles regarding copper cells, specifically copper nitrate solutions from cemented silver wastes.
If your wanting to recover copper try using an inert anode like carbon graphite, this will help to remove the majority of the copper metal from the copper nitrate giving you a dirty nitric that can be reused in some processes.

A copper nitrate solution can be changed to a copper sulfate solution, by adding sulfuric acid and evaporating, or better yet distilling off the gases bubling the NOx into water with a little hydrogen peroxide to make nitric acid (which can be a cleaner acid for reuse although dilute can be concentrated if needed), if distilling off the nitric I would add more copper metal to the distilling flask to assist in driving off NOx gases...

copper nitrate will work in a cell, but copper sulfate make a better electrolyte for copper.


Most of the cells I see are sulfuric acid based.
Is it as simple as running a SS316 cathode and anode?
Nope.
depending on what your goal is, stainless steel for an anode would be a bad choice in any case in my opinion, the anode dissolves into solution Unless inert, stainless steel would put chromium into solution as well as iron, if your goal is to displace the copper from solution using a pure soft iron would be better, this can be done easily without electrolisis....
Stainless steel for the cathode would work ok as long as the cathode was removed when power was removed from the cell.
 
I have already tried to drop copper by raising the pH to 2.5 and throwing in a bunch of iron scrap, though I am not sure what kind of iron I have dropped in the solution, I only see very small amounts of copper like crystals, and most are black crystals. The reaction is also very slow (weeks) before the crystals showed up. I will try to take about 500ml solution out and add nitric acid to it because I've read somewhere that in order for the electrolysis to work the pH should be 1.7 - 2.0.

I will save the liquid and buy a distillation apparatus to make nitric acid, it'll be costly but I'll do it for you since you have been helping me! Haha

So the whole recycling process from inquartation wastes would be:
1) Cement silver with copper
2) Recover copper by electrolysis
3) Drop iron with magnesium hydroxide.
4) Distill liquid in water with hydrogen peroxide to recover nitric.

Thank you butcher for your time. I appreciate it.
 
I will save the liquid and buy a distillation apparatus to make nitric acid, it'll be costly but I'll do it for you since you have been helping me! Haha

Distilling rigs are not that expensive, and can be very useful, you can buy distilling lab glass , or you can do like I do, and buy a nice lab glass distilling rig, and keep it in a box unused, (saving the pretty lab glass) and build yourself a home made distilling rig from materials you can get at most any second hand store, with some Teflon sheet material and chemical resistant hose from the hardware store, you wil need to understand the capabilitys of the materials used and gain a good understanding of safety when using distilling rigs, note with heat they can be under pressure, and also create a vacuum when cooled, which if not properly used can suck back a cold liquid into a boiling glass container of hot acid (which can become dangerous if not used properly) like many things we do study and understanding the safety of what you use or do is the most important part of any process we use....

So the whole recycling process from inquartation wastes would be:
I would not call this an inquartation method.

Like I said before what process you use really depend on what your trying to accomplish, and what your goals are, knowing how reactions work and what happens can let you do things differently depending on your goals, say my goal is to do a recovery process and make a usable byproduct, or recover an usable acid from that byproduct, instead of a waste product I may do things one way, if the goal is just a recovery process with no plan of reuse of a byproduct I may do it using another method...

1) Cement silver with copper
2) Recover copper by electrolysis
3) Drop iron with magnesium hydroxide.
4) Distill liquid in water with hydrogen peroxide to recover nitric.

From the above statement I do not see you having much of an understanding of the different processes or and understanding of the byproducts, and how they would react chemically Keep studying, before trying anything...



Just some options after cementing the silver with copper (leaving you with a copper nitrate solution).

Treat the solution for waste (see dealing with waste in the safety section).

Reuse the copper nitrate to recover gold from other materials, in a metal displacement reaction, Study the reactivity series of metals...

Use the copper nitrate to make nitric acid, to give you an idea of one way, see my posts on a process I use which is called killing two birds with one stone, there I explain one type of homemade distilling rig I use (I have made several different ones using different materials).

The copper nitrate solution can be saved, and can be used as a source of nitrates in many different
types of recovery processes.

Copper nitrate can be made into copper sulfate to use in other processes like a copper cell, (or to recover silver from silver plated copper recovering metal copper in the process), or as a sewer line root killer.
(While converting copper nitrate solution into copper sulfate solution, you can make nitric acid from the reaction ( NOx gases of this reaction), through a distilling process during the conversion by collecting the gasses of the reaction, and bubbling them into water to make nitric acid as a byproduct.

You can remove most of the copper from the copper nitrate solution using electrolysis and an inert anode like graphite, and reuse the nitrate solution in a cell to dissolve more silver (or copper...) in a recovery process, Laser Steve explains one way he did this with a silver cell for sterling silver to recover the silver, reusing the electrolyte by removing a good portion of the copper. look for his sterling silver cell...

There are many different ways we can use byproducts of reactions, that we may normally think of as waste, understanding the reactions and the byproducts and how we can possibly use them can give us several different options, to get use out of we may normally have to pay to treat and pay to dispose of as waste...
How you do a process or what process you use can be decided on many different factors, like what is the best process, is this a recovery or refining process, which will be the best method? do I have other options? costs? will I add contaminates with one process verses another, can I benefit from the byproduct of the reaction and reuse it in another process, can I convert the waste product into a useful reagent, for other processes I use?
The list goes on and on, understanding of the different processes, and the reasons we use them, how to use them, understanding the chemical reactions, and how to convert one reagent into another reagent chemically can be very useful in deciding what you plan will be in the lab, as chemist on a low budget you can come up with many options of reusing waste products.

Industrially this is where many of the chemical reagents come from, they can be waste byproducts of other processes. the company's did not want to pay for waste disposal of, or from gases of a reaction they needed to scrub to keep in compliance with environmental laws, like the sulfuric acid you buy it is most likely a waste product from another process, they decided to market as 98% sulfuric acid (drain cleaner), finding a use for their waste.

Study, and educating yourself is the real way to gold in what we do, too many people focus on a little glittering metal focusing their mind on getting some glitter, and bypass what will give them the most in what we do, education is the real gold, and the best way to get that gold.
 
This is my first silver cell.

It was running at 3v on a 10amp power supply. 73g/600ml saturation. SS304 bowl, grocery bag anode basket, PET bottle for the anode container. The problem here is the crystal growth is very slow, 24 hours and probably just around 15-20 grams produced.

I increased the voltage to 4.8v and the crystal grew tall, probably about 5mm in just 8 hours.
I diluted the solution by adding 350ml distilled water and moved the voltage up to 3.6 volts. Not sure of what the effect is yet.

The anode to cathode distance is only about 1.5 inches, I have read in the forums that it has to be at least 4.0 inches, but why?
This is just a trial silver cell so I can study the variables needed to grow fast, pure, large and dense crystals.

I'll try to run this one at least 48 hours to see how the crystals would grow. I think I am just being not patient enough.
 

Attachments

  • 20151030_231448.jpg
    20151030_231448.jpg
    3.3 MB
In the picture I see the solution looks green, this confuses me.

I would expect to see some blue from a little copper in solution (making copper nitrate in the electrolyte with the clear silver nitrate solution).

Is the electrolyte color actually green?
Is there other metals in the electrolyte solution?
Or is there a lot of copper involved in the anode, and an excess of nitric in solution?
 
It was green when I dissolved my melted silver cemented shots. Dark green to be exact. It started to turn to this light green color when I diluted it. I am not sure why, but maybe because the cemented silver was not really washed well? I was expecting it to be a little bit blue but it turned out to be green.

I used the same cemented silver copper shots for the anode. For the past three days of the electrolyte running there has been no color changes, still this light green color.

I don't think there was excess nitric as there were some undissolved black powder in the solution when I was dissolving silver. I only used 90ml of nitric, 100ml of distilled water for a 74.0 gram silver shots. I poured the 100ml water in the beaker then I added 40ml of nitric at first, waited for the reaction to finish, added another 40ml, waited, then finally another 10ml. Filtered, then diluted with water.
 
With a green electrolyte I would suspect palladium.

Read this http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=18929
and this http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=19004

Göran
 
According to those threads Pd will not contaminate the silver crystals as long as the voltage is low. I will test with DMG after I have finished this batch.
DMG and water in microwave? Not DMG, NaOH and water?
 
I dissolved DMG in a small 40ml beaker by putting 2.1gms of it, adding water to about 45ml, then slowly adding caustic flakes to the solution while stirring until all of the DMG dissolved.

When I poured the DMG in the used green electrolyte, I had a fluffy black precipitate. It's not the yellow one. What is it?

When it settled down, it looks greyish with some yellowish stuff at the bottom. I think its silver? Why did it precipitate? :roll:
 

Attachments

  • 20151116_223541.jpg
    20151116_223541.jpg
    2.4 MB
  • 20151116_223628.jpg
    20151116_223628.jpg
    3.8 MB
  • 20151116_183118.jpg
    20151116_183118.jpg
    2.9 MB
How do I reverse this?
Which part of my dissolving DMG method was wrong?
I don't think that redissolving this in nitric acid is the solution as for what I know powder materials have a very large surface area. Correct me if I am wrong but I think that if I re-dissolve this in nitric it would just overflow or create a very exothermic reaction.
 

Attachments

  • 20151117_110921.jpg
    20151117_110921.jpg
    1.8 MB
What pH does the solution have?

Regarding the exotherm reaction you mention, it is a question of masses versus time. A dropwise addition by a burette or something similar while letting run an electric stirrer will not create an overflow. Nevertheless it it wise always to have 4/5 free space in the vessel.

Use small ammounts of solution at any time you try something for first time.
 
pH is 4.9

I will try to add small amounts of spent silver nitrate to see what happens. I will use a test tube this time.
 
As green as that solution is, I would question the silver that you used, what all metals are involved? was it silver? Or was there other base metals you dissolved that were just silver colored and you thought it was all silver?
 
butcher said:
As green as that solution is, I would question the silver that you used, what all metals are involved? was it silver? Or was there other base metals you dissolved that were just silver colored and you thought it was all silver?

The silver used was from inquarted wastes cemented with copper. So everything below the copper series that dissolves in nitric acid should be present.

Was my way of dissolving DMG wrong?
Sodium hydroxide (caustic) does precipitate silver oxide but I've read in these forums on how to dissolve DMG. I followed the steps but I got to this mess.
 
Read hook,
make DMG without Naoh boil 100ml distal h2o with one gram DMg this is used to test Pd, the Naoh with DMG is used to precipitate pd usually, surely DMG wont dissolve fully so boil for five minutes and filter.
take 5 drops of solution add two to three drops of water and pour two drops of DMG test it should give you fluffy orange or yellow precipitates.
 
I was able to successfully re-dissolve the silver oxide and the yellow salt in a spent nitric acid(used from inquartation). I was slowly adding the acid at first, reactions were minimal and didn't seem exothermic. As soon as I was able to fill almost the top of the beaker it still didn't dissolve fully. So I just decided to put the entire beaker in the plastic gallon with spent nitric acid and fished out the clean beaker afterwards. :lol:

I re-read hoke's book and dissolved 2g of DMG in 200ml of boiling water in a 250ml erlenmeyer flask, it took almost an hour to do it and I was adding small amounts of distilled water to keep the level at 200ml. After it has fully dissolved, I let the erlenmeyer flask cool in a bucket of water and got a white precipitate. I tried to redissolve this white crystals by heating but the beaker itself was jumping away from the heat source so i stopped it.

What could have I done wrong? The cooling part? Or is this normal? Do I just filter out the white crystals? Or is there something wrong with my DMG powder?
 

Attachments

  • 20151231_182752.jpg
    20151231_182752.jpg
    4.7 MB

Latest posts

Back
Top