Electrochemistry sodium thiosulfate vs. Sodium Chloride.

[Refine2017]

In an electrolytic process what is the difference between sodium thiosulfate vs sodium chloride. Will one corrode electrodes faster, slower? When using silver electrodes what will become of the anode mud/slime. I ended up with silver sulfide. Just how toxic is the sodium thiosulfate method. My entire lab smelled like sulfur and was wondering if this is a bad idea? Any advice?

 

[Lino1406]

Thiosulphate ion forms sulfur in acidic environment

 

[rickbb]

Sodium thiosulfate is photographic fixer used to remove un-exposed silver from photographic films and papers.

Sodium chloride is salt, you put it on your food to flavor it.

If you use sodium thiosulfate as an electrolyte and run too much current, (for the amount of silver in solution), through it you will "burn", (for lack of a better word), the silver and cause that sulfur smell as well as converting your silver into black silver sulfate sludge. (Instead of plating it out as shiny metallic silver, if that is what you were doing.)

My guess is you used too much current/volts in whatever process you were doing.

 

[goldsilverpro]

What are you trying to accomplish? Provide detail, please. You won't get a reasonable answer until you do. You waited 3 weeks before you got your first response and your not providing information is the reason why.

Did you pick those chemicals because that's what you happened to have laying around or is there a method to your madness.

 

[joseph1990]

yes it will corrode the silver electrode. Once you get the thiosulfate leached into silver, just take the solution and boil it until all liquids are evaporated. You can start a fire on your stovetop in the garage if it sits too long in crystal form making a sizzling noise. You should now have a crystal form of silver sulfide/oxide and thiosulfate. Then you scrape out the stuff and either you can go straight into refining it or throw it in a BBQ pit and let it anneal so that the silver particles are stable. That last part works wonders by the way. Now you need a coffee/spice grinder. Once you grind all of your stuff you throw in 7 grams of NAOH IN 120ML water for every 10 grams of the powder and continuous stir with heat after 30 minutes of stirring. Now this will help in getting rid of extra sulfur in the future, then after an hour add 40 ml of hydrochloric acid. Now you have silver chloride and your life becomes much better later trust me!
Another method which I initially used was adding 100ml of 69.5% nitric acid with 20grams of the powder outside, then after 10 minutes of the nitric dioxide fumes gone come back in and stuff the thing in the microwave for about 45 seconds and voila you have silver sulfate in the solution, dilute then displace with copper. Nitric acid is too expensive so I used the original method. Any other method will create sulfur problems in the future.

 

[goldsilverpro]

yes it will corrode the silver electrode. Once you get the thiosulfate leached into silver, just take the solution and boil it until all liquids are evaporated. You can start a fire on your stovetop in the garage if it sits too long in crystal form making a sizzling noise. You should now have a crystal form of silver sulfide/oxide and thiosulfate. Then you scrape out the stuff and either you can go straight into refining it or throw it in a BBQ pit and let it anneal so that the silver particles are stable. That last part works wonders by the way. Now you need a coffee/spice grinder. Once you grind all of your stuff you throw in 7 grams of NAOH IN 120ML water for every 10 grams of the powder and continuous stir with heat after 30 minutes of stirring. Now this will help in getting rid of extra sulfur in the future, then after an hour add 40 ml of hydrochloric acid. Now you have silver chloride and your life becomes much better later trust me!
Another method which I initially used was adding 100ml of 69.5% nitric acid with 20grams of the powder outside, then after 10 minutes of the nitric dioxide fumes gone come back in and stuff the thing in the microwave for about 45 seconds and voila you have silver sulfate in the solution, dilute then displace with copper. Nitric acid is too expensive so I used the original method. Any other method will create sulfur problems in the future.

This convoluted, many step, unprofitable method that Joseph proposes is only more proof to me that, if you want to refine silver, get some nitric. Nitric is only $4 or $5 per gallon in bulk.

 

[joseph1990]

yes it will corrode the silver electrode. Once you get the thiosulfate leached into silver, just take the solution and boil it until all liquids are evaporated. You can start a fire on your stovetop in the garage if it sits too long in crystal form making a sizzling noise. You should now have a crystal form of silver sulfide/oxide and thiosulfate. Then you scrape out the stuff and either you can go straight into refining it or throw it in a BBQ pit and let it anneal so that the silver particles are stable. That last part works wonders by the way. Now you need a coffee/spice grinder. Once you grind all of your stuff you throw in 7 grams of NAOH IN 120ML water for every 10 grams of the powder and continuous stir with heat after 30 minutes of stirring. Now this will help in getting rid of extra sulfur in the future, then after an hour add 40 ml of hydrochloric acid. Now you have silver chloride and your life becomes much better later trust me!
Another method which I initially used was adding 100ml of 69.5% nitric acid with 20grams of the powder outside, then after 10 minutes of the nitric dioxide fumes gone come back in and stuff the thing in the microwave for about 45 seconds and voila you have silver sulfate in the solution, dilute then displace with copper. Nitric acid is too expensive so I used the original method. Any other method will create sulfur problems in the future.

This convoluted, many step, unprofitable method that Joseph proposes is only more proof to me that, if you want to refine silver, get some nitric. Nitric is only $4 or $5 per gallon in bulk.

I'm sorry, you mean $40-$50 bucks right? Please tell me the place because I would definitely appreciate this.

 

[goldsilverpro]

I mean $4 to $5 per gallon for about 67%, technical grade nitric acid - perfect for the refiner's needs. However, the rub is that price is for a 55 gallon drum. The very heavy-duty drum is made from 304 stainless and there is about a $900 deposit on the drum. You get 100% of the deposit back when you return the drum. Also, you will need to be a business to buy from these large chemical companies, like Univar or Brenntag, who have warehouses in most cities.

There are smaller companies, here and there, that repackage technical grade chemicals into smaller quantities. For nitric, that is usually in 5 gal or 13 to 15 gallon SS carboys that also require a lesser deposit - sometimes they have nitric in 1 gallon jugs. The prices are somewhere between the 55 gal drum price and the ridiculous prices you are paying. The bigger the container, the cheaper the nitric.

Many of these repackagers are known by members of the forum. Let us know where you are located and someone will likely help you out.

 

[Palladium]

Current price off the dock in B'ham, Al


Quote .40/# + $400.00 deposit each drum for 600# drums of nitric acid 67%.

In commercial quantities you don't buy it by the gallon, you buy it base on weight. A certain amount of a chemical dissolved in water at a certain percentage weighs a certain weight. Were it 33.5% then the price per lb would be .20 cents per lb. From above a 55 gallon or 600 lb drum cost .40 X 600 lbs = $240 / 55 gallons = $4.36 gallon with a $400 deposit (refundable).

 

[Palladium]

From this we can figure it takes 1.45 ml to dissolve one gram of sterling silver.
55 Gallons = 208198 ml.
208198 divided by 1.45 ml = 143584 grams dissolved.
143584 divided by 453.5 ( gram per lb) = 316.5 lbs of sterling.
$240 divided by 316.5 lbs = 75.8 cents per lb.

Now out of lb sterling you will get 453 grams X 92.5% = 417.22 grams of .999 silver.
417.22 divided by 31.1 grams Troy oz) = 13.4 oz.

75.8 cents per lb divided by 13.4 oz = about 5.7 cents an oz in chemical cost for this step!

 

[Palladium]

15 gallon carboy = $200 deposit at about $100 or $6.67 gallon.

 

[Palladium]

Current copper cost (spot) $ 2.85 lb
$2.85 lb divided by 453 grams per lb = .63 cents a gram.
1 gram of copper will precipitate 3.4 grams of silver.
31.1 grams in a oz divided by 3.4 grams = 9.15 grams of copper needed per oz.
9.15 grams of copper X .63 cents per gram = 5.76 cents per oz processing cost.

So far it cost 5.76 cents + 5.7 cents in nitric = 11.46 cents .

so 11.4 cents divided by spot $16.82 = .68 %
Then comes the added cost of ...........
Ever wonder why silver payout is a lot lower compared to gold oz for oz? :mrgreen:

 

[Palladium]

Lets go a different route.

Silver chloride.
One lb of salt will precipitate about 27 oz of silver or 454 grams of salt = 840 grams of silver = .54 grams of salt per gram of silver. 31.1 grams to a oz divided by .54 grams salt = 16.8 grams of salt per oz.

Salt price lets say for the little guy $1 a box to do 27 oz = 3.7 cents an oz in salt cost.

Now we have 5.7 cents in nitric + 3.7 cents in salt = 9.4 cents for this step or .56% ( about one half of a percent compared to .68 percent for the other route ).

Plus no problems because of excess nitric use!

Then comes the added cost of ...........

 

[joseph1990]

thanks for the info palladium, holy 5hit!
I kind of have to agree with goldsilverpro, I'm realizing that refining silver is a total waste of time compared to refining gold. Less chemicals, less hassle and most of all much greater profit margins. Problem is that start up capital in purchasing the gold is heftier.

How do you guys deal with filtering? I need something that can handle 3 gallons. I can't imagine using these small filters, it's literally taking me about 5 hours to do one batch. Going back and forth waiting for the darn thing to go through. I'm guessing larger surface size would equate to faster filtering times, someone needs to invent a flat rectangular filter, gravity should take care of the rest.

 

[Topher_osAUrus]

t..., someone needs to invent a flat rectangular filter, gravity should take care of the rest.

That Palladium....
He's some sort of mind reader :shock:
http://youtu.be/PXZQrpMM9XE

 

[goldsilverpro]

I fixed your link, Topher. I just removed the {youtube} things.

I've always made more money with silver than with gold. In general, there's lots more of it out there, fewer people are interested in it, it's more straightforward to process, and there are fewer refiners doing it. The main disadvantages are that it takes more equipment and space.

For filtering silver solutions, I prefer a 5 gallon bucket with a piece of plywood with a hole cut in it for the funnel, sitting on top. At times, I have had as many as 10 or 12 of these going at the same time.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=251&p=1892&hilit=bucket+plywood+hole+funnel#p1892

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=25162&p=266591&hilit=bucket+plywood+hole+funnel#p266591

You can use large plastic funnels along with the large coffee filter papers available from restaurant suppliers - some are about 24" in diameter. Although coffee filter papers aren't as good as lab papers, they will work. Big lab papers can cost $1, or more, each.

 

[rickbb]

To speed up filtering I made a vacuum system out of plastic 5 gal bucket with lid and small shop vac. Use a large plastic colander and the large coffee filters. Works well but looks cobbled together.

 

[goldsilverpro]

Although I always had several different sizes of vac filters, usually from 3" to 18" or, I still used gravity filtering about 90% of the time. I mainly used vac for filtering pure gold. After all the rinses, I dried the gold with a light bulb about 8", or so, above the funnel and sucked the hot air through the gold. The gold powder gets so hot you can't touch it. If the bulb is too close, it will burn or char the paper and then you have to start over. About the only thing I used the big vac for was certain sludges. For many things, the vac filter was a pain. For some things, like old AgCl, it can pack tight and give a drip every minute or so.

Usually much easier to set up a few gravity filters. Before filtering, I put the solution in a bucket, let it settle and then siphon it. I first filter the siphoned, fairly clear solution and when that has all run through the paper, I filter the settled solids in the same paper. Doing all that, it goes pretty fast and siphoning is the most labor intensive part of the operation.

 

[Topher_osAUrus]

I fixed your link, Topher. I just removed the {youtube} things.

Thank you,I forgot the native youtube embedding was not working properly
.