Question About Dropping My Silver From Solution With Table Salt

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scrapparts

Well-known member
Joined
Jun 23, 2016
Messages
142
Hello members,

I have some silver solution that is Nitric Acid and water. The source material is .999 silver rounds.

I have dropped my silver before with the copper and it works fine, with the exception of having to treat the powder with HCL to get rid of the copper. Nevertheless, I don't have any problems doing that way. The issue I have is that I have approximately 2 gal jugs with my solution in it and I don't have much copper to drop all my silver in minutes, vs days.

My point is that I want to drop all of my silver immediately instead of having to wait days, or add large copper bars to make it all drop faster... So, I'm thinking about all the ways I know the silver can be dropped out of solution, but I have only tried the copper.

Which would be faster....

1. Add large amounts of copper.
2. Add lye and corn syrup
3. Add table salt.
4. HCL (I only have Muriatic Acid)

I was reading and learning about no#'s 2 and 3, but I still get kinda confused as to if you can use table salt to drop the silver from solution, why aren't people doing that way as a standard way, eliminating the cost for the copper for the cost of some table salt?

If the table salt would work, that would seem like it would be the fastest way to drop the silver. Just my opinion.

I've seen the videos and watched extensively on many methods to drop silver out of solution, but most of the videos I've seen, the solution was either greenish or blueish green to blue and the silver was dropped using method no# 2.

I recently saw a video where HCL was poured into the beaker with the silver nitrate in it and instantly the solution turned milk white and formed a foam-like sponge in a matter of seconds, and all the silver was dropped out of solution. The problem with that one for me is that I don't have any HCL. I could do a 5ml or so test to see if it would work or not.

Although I never performed any of the methods mentioned above except no#1, I am confident in doing any one of them without having to figure out the next steps.

But my biggest question is.... Can I use table salt, or even sea salt and drop my silver from solution in one day, ready to melt?

I only wish I had more copper, and more vessels to put my silver in, then I could see me getting all my silver dropped in one day, but right now with what I have, it'll be days before all my silver can be dropped out of solution.... plus I am going to need more copper to do it that way too.

Thanks

scrapparts
 
scrapparts said:
My point is that I want to drop all of my silver immediately instead of having to wait days, or add large copper bars to make it all drop faster... So, I'm thinking about all the ways I know the silver can be dropped out of solution, but I have only tried the copper.

Which would be faster....

1. Add large amounts of copper.
2. Add lye and corn syrup
3. Add table salt.
4. HCL (I only have Muriatic Acid)

I was reading and learning about no#'s 2 and 3, but I still get kinda confused as to if you can use table salt to drop the silver from solution, why aren't people doing that way as a standard way, eliminating the cost for the copper for the cost of some table salt?
I think you are confused, you don't "drop silver" with alternative 2-4.

1. Gives you back metallic silver directly.
2. Is used to convert silver chloride to silver
3 and 4. Any chloride solution (HCl, NaCl, CuCl2...) will drop silver chloride, not metallic silver.

You should at least try a small test sample and add chloride to a silver nitrate solution just to get acquainted to the reaction. You could save the silver chloride and try to convert it back into silver metal with lye + sugar or iron + sulfuric acid.
There are a lot of methods to convert silver chloride back into silver metal.

Some people prefer going via silver chloride to silver while other prefer cementing on copper.

If you add hydrochloric acid to a silver nitrate solution then it will convert it into silver chloride and nitric acid. Copper nitrate and most other contaminants will not be affected by it.
This could be a great trick if you pay a lot for nitric acid. Removing silver from silver nitrate with HCl would convert the silver nitrate to nitric acid again, but if you add too much HCl then it would create a problem the next time you want to dissolve silver. This method is best used for fine silver or silver on stainless steel where the contaminants don't build up so fast.
GSP have a great post about using this method to remove silver from stainless steel bearings.

Göran
 
Thanks for the information Goran.

I got confused with some of my terminology and that is another thing I need to understand so I can explain myself better. Below are terms used here on this forum but isn't in the "Glossary of Terms" at http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=23400, and those terms are..

silver chloride
silver nitrate


So, when I dissolved my silver in Nitric/water I made silver nitrate? Also, when I use copper to drop silver out of solution, the dropped silver is cemented silver and not silver chloride?

How do I get my solution from silver nitrate to silver chloride?

Thanks again for the explanation so I can keep on reading and understanding all of the terms of whatever I do when I'm refining.

scrapparts
 
Correct

The silver, being dissolved in nitric acid is then a nitrate metal salt. Silver nitrate. Silver nitrate has a great affinity for chlorides, so adding a chloride solution (brine, HCl, even a ton of chlorinated tap water [bad example, dont do it])
It will convert it from silver nitrate, to silver chloride, which is an insoluble salt.

It will then need converted to silver metal before melting. I prefer sulfuric and iron. But, to each their own.

Silver metal has a very rich chemistry, and is a thing of beauty. Without it, we would have never had photography or a myriad of other things.
 
Topher_osAUrus said:
Correct

The silver, being dissolved in nitric acid is then a nitrate metal salt. Silver nitrate. Silver nitrate has a great affinity for chlorides, so adding a chloride solution (brine, HCl, even a ton of chlorinated tap water [bad example, dont do it])
It will convert it from silver nitrate, to silver chloride, which is an insoluble salt.

It will then need converted to silver metal before melting. I prefer sulfuric and iron. But, to each their own.

Silver metal has a very rich chemistry, and is a thing of beauty. Without it, we would have never had photography or a myriad of other things.
Thanks Topher_osAUrus.

That makes more sense to me, I guess it's also the way you explained it. The more I learn a term, and then know how and when it's used, it already helped me understand the way I need to proceed.

Ok... Now that I do have silver nitrate, I can add table salt to it and then it will be converted into silver chloride? And from that point, I would then add lye and kayro to convert the silver chloride to elemental silver?

This is so interesting even more because I'm learning what the silver terms mean, which means I'm understanding it more when I read it. I am so glad I asked this. I looked around but I couldn't find what I was thinking I should have known on the forum.

Side Note.... will someone tell the mods to add the terms ...
silver nitrate
silver chloride

to the Glossary? If I searched for it, it's very possible that someone else has searched there too and didn't find the meaning. If you know a term that's not listed in the Glossary, let the admin know so they can add them.

Thanks again for the information because I have a better grasp of these terms, especially when I'm reading about them. Hopefully I can help someone else that may come up against this issue later on.

scrapparts
 
Correct. Well, in the "gist of it" way anyways.
Adding table salt will precipitate the silver as it's chloride salt, but, it's better to have the salt in aqueous solution before adding it. That way it doesn't end up causing any issues. (minor ones like clumping, and excess salt) Just add the brine to the nitrate solution and you will see the silver precipitate out immediately.

Wash it very well before going to the conversion stage.

Sometimes it seems like it takes silver chloride forever and a day to settle out. Add a little acid to the wash water, Loewen suggests this in his books, and it does help.

After washing most the color out of the chloride, do a couple hot water washes to remove any lead chloride contamination. Bring it up to near boiling temp, and hold it there. Give it a good stir, then let it settle, then decant or siphon the hot water off. If there was lead, it will be in that hot water wash and you will see it drop out of the solution when it cools down. You can use the same water over again after cooling and decanting from the lead chloride crystals that have formed. This will help on waste volume.

After it's washed completely clear, move on to the conversion process of your choice.

Silver has a lot of waste associated with it, so it's good to find little ways to keep it down. A big one is, only cover the powder with a little excess, don't fill it up to the brim of the bucket or anything, as it really doesn't help the situation. Just creates more waste.

If you want to learn more about silver, try to find Silver by butts and coxe, and silver metallurgy by h.f. Collins. Both great books, there are 2 more silver metallurgy books I have, but haven't read through all of them yet, so I cannot lend an opinion on them at this moment.
 
Topher_osAUrus said:
Correct. Well, in the "gist of it" way anyways.
Adding table salt will precipitate the silver as it's chloride salt, but, it's better to have the salt in aqueous solution before adding it. That way it doesn't end up causing any issues. (minor ones like clumping, and excess salt) Just add the brine to the nitrate solution and you will see the silver precipitate out immediately.
The way you explained this is just the way I needed it. It's so simple, yet I was confused about creating a nitrate and then "converting/conversion" it to chloride. I can truly say that I understand it now and I have made my notes.


Topher_osAUrus said:
Sometimes it seems like it takes silver chloride forever and a day to settle out. Add a little acid to the wash water, Loewen suggests this in his books, and it does help.
Sorry, but I don't understand that part. Are you saying that after I add the salt to the solution and the conversion is completed (or should be), let it settle out, then add nitric acid to the wash water or HCL? Am I being fair by assuming everything should settle in a matter of minutes?

Topher_osAUrus said:
After washing most the color out of the chloride, do a couple hot water washes to remove any lead chloride contamination. Bring it up to near boiling temp, and hold it there. Give it a good stir, then let it settle, then decant or siphon the hot water off. If there was lead, it will be in that hot water wash and you will see it drop out of the solution when it cools down. You can use the same water over again after cooling and decanting from the lead chloride crystals that have formed. This will help on waste volume.
Fully understood.

Topher_osAUrus said:
After it's washed completely clear, move on to the conversion process of your choice.
I fully understand. This will be the fun part, yet very exciting to experience something I never done before (converting silver nitrate to silver chloride AND to elemental silver).

Topher_osAUrus said:
Silver has a lot of waste associated with it, so it's good to find little ways to keep it down. A big one is, only cover the powder with a little excess, don't fill it up to the brim of the bucket or anything, as it really doesn't help the situation. Just creates more waste.
I fully understand this.

Topher_osAUrus said:
If you want to learn more about silver, try to find Silver by butts and coxe, and silver metallurgy by h.f. Collins. Both great books, there are 2 more silver metallurgy books I have, but haven't read through all of them yet, so I cannot lend an opinion on them at this moment.
I will look for them and add them to my library.

I'm so happy right now because I learned something that I was unsure of and now I have a better understanding, all because I wasn't afraid to ask. Although my questions weren't unique concerning the silver conversion, I just couldn't seem to find my answer(s) in any one-place online to put it in simple form (refining isn't simple either).

I have learned so much from you today Topher_osAUrus, along with Goran.... and many many other members here on this wonderful forum.

FrugalRefiner said:
You just did, and I just did.
I want to thank you too Dave. You're all such a helpmate here on this forum.

"Refiners helping one another" is what I see going on here.

Thanks for all the responses to this thread. Hopefully someone can benefit from this thread, because I know I did. It feels great to know you learned something that you didn't know before and can retain/remember it too.

Thank you Gold Refining Forum!!!

scrapparts
 
Loewen's book "small scale refining of jewelry wastes" is another good one, couple small errors, but overall pretty solid.
-anyways,

In it he suggests adding a wee bit of nitric to your wash water if the AgCl seems to be taking awhile to settle (which it can, and will sometimes. There are actually a couple different "types" of silver chloride ..fluffy, curdy -mentioned in Collins' book-...not sure if it has to do with the way the crystal structure nucleates or if its more dependant upon saturation of silver ions when converted to chlorides or... ...I'm going off tangent here, sorry)

Back to it
Silver chloride when precipitated out of nitrate solution, for me, has had a tendency to settle fairly quick, though ten minutes is probably rushing it. But, that will be up to your discretion. Use your best judgement. If its taking a day for a couple hundred grams to settle. Make the next wash water around 10% nitric solution, and it will settle faster. A little heat helps a lot too.

This reminds me of how hoke mentioned wetting filter paper with a little acid will help capture fine particulates. Im sure there is a perfectly logical explanation as to why these phenomena happen, but to me its just magical (for now... Until Göran ruins the magic for me again :D )

Questions are how we learn, each of us adsorbs knowledge differently, so long as it shows you have done some of the leg work (and you have), never be afraid to ask a question here. We are all learning, even the gods among us, like our moderators, still must surely be learning even though they have mastered this art.
 
What I don't understand is why take triple nine silver rounds and dissolve them and then try to drop the silver back out? Did you need 2 gallons of silver nitrate for some reason and now no longer do?
 
rickbb said:
What I don't understand is why take triple nine silver rounds and dissolve them and then try to drop the silver back out?
Experimental reasons. Nothing lost, just learning from using pure silver rounds. Doing it this way I was able to 1) verify that the silver was indeed pure and not fake and 2) get the knowledge to know that when I do dissolve silver I can tell if it's pure or not by looking at the solution after everything is dissolved, looking at the solution after it has been filtered and looking at the filter itself.

This was a great experiment for me and nothing was lost in the process, and I learned something new too.

rickbb said:
Did you need 2 gallons of silver nitrate for some reason and now no longer do?
I already have about 2 gallons of silver nitrate accumulated from dissolving pure silver rounds and some hand poured bars I bought. I dropped a few hundred grams of silver using copper, but the problem is that unless I have large amounts of thick flat copper bars, the cementing takes days to finish.

Yesterday I went to working with the solution and I poured table salt in the nitrate solution and the silver formed into more like pellets instead of curds. It was flawless and it took less than a minute to get all the silver to bead up. after I stopped stirring, I added some more salt to see if any more silver was in solution and there was no more. After that, the silver settled to the bottom of the plastic bucket within seconds and the top part of the solution is clear.

I do have to admit this though, while watching videos of how this is done it looks exciting, but it doesn't compare to actually doing it yourself and getting the same exact results as seen from the videos.

I didn't get to use the lye and kayro syrup yet. I will do that today.

Questions I have.

1. Do I need to pour off the excess solution or do I slowly pour/stir in the lye as it is? I have a lot of excess solution.

I have pictures that I will post today sometime that I took yesterday.

2. Is there any Nitric acid still in the excess solution?

3. After the lye has finished reacting, how long could the silver sit before you have to add the kayro syrup?

Thanks again for all the replies and support you all have provided me with. This is what makes learning fun and exciting.

scrapparts
 
scrapparts said:
Experimental reasons. Nothing lost, just learning from using pure silver rounds.
That is a great reason. Wish more people would do it.

scrapparts said:
2. Is there any Nitric acid still in the excess solution?
Just check the pH. You know you have nitrates in solution so if it is acidic then you also have nitric acid. With the excess chloride you added it would make it a weak aqua regia solution.

Göran
 
g_axelsson said:
scrapparts said:
Experimental reasons. Nothing lost, just learning from using pure silver rounds.
That is a great reason. Wish more people would do it.

scrapparts said:
2. Is there any Nitric acid still in the excess solution?
Just check the pH. You know you have nitrates in solution so if it is acidic then you also have nitric acid. With the excess chloride you added it would make it a weak aqua regia solution.

Göran
Thanks for the reply.

Either way, do I need to pour off some of the excess solution?

Silly me, :oops: , I do have pH test strips, yet I forgot to test the solution. I will do that today and keep my strips where I can see them this time.

I guess I should have asked "Can I still use the excess solution for other experiments or just add it to my stockpot?"

Question no# 1. Still unsure.

Question no# 2 is understood. I should have thought of that one too.

The reason for question no# 3 is to know if I added the lye, could I wait hours, days or even weeks to add the kayro and still have no problems?

I know some of my questions may not be common (maybe so), but I am experimenting with silver in a way that I never had before. I already know I'm not losing anything (as long as I don't dispose anything) it just prepares me for something not really intending to do or happen.

scrapparts
 
I think GSP or LazerSteve made some comments in a recent thread on how long it might take or how to see if the conversion is complete.

I have collected some references for silver chloride on http://goldrefiningwiki.com/mediawiki/index.php/Silver_chloride
Check the links on that page, there is a whole lot of information in the threads referenced.

To your questions, if you have some nitric acid left in solution it is probably quite weak. If you add more chloride than is absorbed in the silver chloride then you can't use the extra acid for dissolving silver, the chloride will passivate the surface with a coating of silver chloride.

If you started with pure silver then adding the clear liquid to your stock pot isn't saving anything. The silver is already out and what you have left is a slightly acidic sodium nitrate and sodium chloride solution. Maybe use it for neutralizing caustic waste if you have that.

And in refining, it is always a good thing to pour off excess solution if there are no values in it. In this case you should wash the silver chloride to get rid of contaminants. In this case there are not that much to start with but imagine that you started with sterling silver. The more copper you can wash away the less contaminants in the end and a cleaner final product.

Göran
 
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