Silver trouble

[Xydoman]

Hello everyone. So I'm having trouble with my first batch of silver. I've dissolved about a pound and a half of silver contacts from various sources, circuit breakers, motor starters, relays etc. They're pretty clean for the most part, but still contain some bits of copper and brass from the brackets.

They were dissolved in nitric acid. I then took the solution and filtered it to get the remaining chunks of whatever wouldn't disolve. Wasn't much but enough that I felt it should be removed. I then squirted a tiny bit of hcl in the jar and the AgCl was formed. Here's where it starts getting wonky.. I think. I filtered the AgCl to remove it from the solution and put it in a container to dry. It was lost on me at that point that I needed to wash it, so it wasn't washed. I left it over night, and the next day I noticed that there was a brilliant white precipitate in the "waste solution" that was about to be discarded. So I decanted what I could, which left a little bit of the solution still presant, and added the filtered AgCl to the container. When I shot a little bit of hcl into the discarded solution, it became really milky colored, and it was obvious that there was still a ton of AgCl in it, so I literally just poured it all back in with the rest of it, essentially rendering a lot of the preceeding steps absolutely pointless. I DO realize this now, and I'll do well to take a bit more time and do a bit more research with the next batch.

Anyhow, so at this point I had a solution that was a beautiful turquoise color and very thick and milky. I stirred, added lye, waited.. Observed dark gray chunks hitting the side of the jar, then repeated, till the whole solution was gray. Then I realize that I had no sugar... DOH!!
My house rarely runs out of sugar, but here I am, sugarless. And further hindered again by lack of info, not realizing I needed the sugar immediately, I put the solution aside and planned a grocery shopping trip. Fast forward about 3 hours later, I return home with the sugar. I started stirring it in. I'm afraid I've added too much, or did something else wrong, but I'm hoping I can still save it. What I have now is a really thick dark solution.. I can't really even explain the color, except for maybe a mix of turquoise and dark gray.

So if I could get someone to walk me through saving my batch I'd greatly appreciate it. Ive already figured out a couple of things I did wrong, and I've decided that from now on, I'm not wasting any more time or material on a batch of anything, without thorough research and a good grasp of every step in said process, AND ensuring that everything I need is available the moment I need it. Thanks you guys.

 

[FrugalRefiner]

Your first mistake was dissolving a pound and a half of contacts for your first batch. Always start a new process with a small test batch.

You dissolved a pound and a half of contacts, but only squirted a tiny bit of HCl into the solution.

You put the AgCl in a container to dry. Never dry your AgCl.

You dumped everything back together.

You started your lye / sugar process without having everything you needed.

Those are just some of the big mistakes. Set everything aside safely and study the processes more. It's going to take multiple steps to recover. You undoubtedly have unconverted AgCl because you let it dry. You probably have unconverted silver oxide. You may have some metallic silver. No single process is going to make it all better.

Dave

 

[Xydoman]

That's exactly the type of advice I come here for, and exactly the advice tgat I WILL follow. I do appreciate if. So where would you suggest beginning? It's Ben nothing but YouTube so far for silver. J had similar issues with learning about gold recovery, and with helpful advice here on thus forum, u dix exactly what you recommend here, snd now I've got it down good enough to be productive with a few of the more simpler processes. So it looks like I'll have the same road to traverse with this part of it as well. I'll put the jar aside for now, and the heap of scrap will go to my dad's so as not to tempt me lol.

 

[galenrog]

First bit of advice is to ignore YouTube unless the video is recommended by a longtime member here. YouTube can kill.

Since I have never made similar mistakes, I will leave suggestions on how to recover to better refiners than I.

Time for more coffee.

 

[Xydoman]

Understood. Would you have a 2nd bit?

 

[Elemental]

Disclaimer: This is a thought from another metal refining beginner, so please do heed the advice of the more senior/professionals on this forum.

For the future, I would like to recommend a simpler solution for you, let's avoid silver chloride all together. Next time, after creating a Silver Nitrate Solution, I would recommend that you procure some simple copper grounding wire, make a coil out of it and suspend it in your solution(agitate the copper to have the silver drop off the wire). This will drop the silver that is in solution out as "silver cement" and leave you with a copper nitrate solution (with a mix of other metals that have a higher reactivity than copper).

You'll want to make sure you add some DISTILLED WATER to this before you begin crystalizing the silver out of solution. If you use tap-water or any other source of chlorinated water, you will generate additional silver chloride, which we are going to try to avoid. If your solution is too concentrated, the silver will grow on the copper wire and not fall off, stalling the reaction as no more silver nitrate solution can reach the copper wire.

Allow the reaction to run for a day or two and test using a clean/shiny piece of copper wire. If you can put it in the solution for 4-5 minutes and it remains shiny, you've dropped all of your silver.

After that, stir and rinse the silver cement with plenty of hot DISTILLED WATER. Once you have rinsed the silver cement, allow it to dry. I use an heated ceramic dish for this. Then you can then melt the dried silver cement and should have approx. 99% pure silver (ideally).

Take your copper nitrate solution, you should have a gallon or two of it by now after dilution of that much silver and put it in a bucket with a lid and toss the remains of the copper coil in the bottom. This is your silver "stock pot". As you process more silver, you'll want to put your copper nitrate solution in here to react with any remaining silver. You can filter this solution later to recover any silver that got past your initial reaction.

After I have my 99% poured as a bar, I run in through a electrolytic silver cell to completely purify it and remove other precious metals, but that is an entirely different conversation.

I hope this helps a bit. Also a final piece of advice, as a former chemist, if you are just mixing chemicals without a plan, you're risking time, money, and safety. Please have a plan prior to any wet-chemistry (lab-work). You should know going into your lab how much of each chemical you need, the reaction process you are running, what your limiting reagent is for each reaction step, and that all your safety systems are in place.

Below is a cut-sheet of my instructions for processing silver, my apologies but the reactions and math in another attached document:

Steps for Refining Silver
1. Melt sterling silver and slowly pour into water basin to make silver corn-flakes.
2. Measure out 110 grams of silver corn-flakes and place in a clean 500mL beaker.
3. Add 150mL of distilled water to beaker.
4. Heat the beaker on a hot-plate to 80 degrees Celsius
5. Add 50mL of 70% concentrated nitric acid
6. Cover with a watch glass allow reaction to proceed until no more brown fumes are generated.
7. Add 50mL of 70% concentrated nitric acid
8. Cover with a watch glass allow reaction to proceed until no more brown fumes are generated.
9. Add 50mL of 70% concentrated nitric acid
10. Cover with a watch glass allow reaction to proceed until no more brown fumes are generated or all the silver is consumed.
11. If all the silver has been consumed, add more silver in 5-gram increments until no more fumes are generated and there is silver in the bottom of the beaker.
12. Decant solution into a clean 1,000 mL beaker.
13. Add 150mL of distilled water to beaker.
14. Add copper coil to beaker
15. Add 5 drops of nitric acid to the beaker
16. Allow reaction to proceed until no more silver cements out of solution on a clean piece of copper wire.
17. Decant copper nitrate solution into a silver stock pot.
18. Wash silver cement multiple times until solution is clear.
19. Dry silver cement in crock pot
20. Transfer silver dust to a melting crucible and melt at 2,000 degrees Fahrenheit
21. Melt purified silver and slowly pour into water basin to make silver corn-flakes.
22. Setup a silver cell and generate purified silver crystal. Need to mix electrolyte while crystals form.
23. 150 grams per liter of silver for electrolytic solution
24. Run Cell
25. Collect an purity silver crystal, melt into 100g ingot.


FINAL NOTE: Copper Nitrate is a nasty chemical. Do NOT pour it down the drain. Either take it to your local hazmat for disposal or properly learn how to treat it to safely dispose of it. Here is a link to a Material Data Safety Sheet for pure copper nitrate: https://beta-static.fishersci.com/content/dam/fishersci/en_US/documents/programs/education/regulatory-documents/sds/chemicals/chemicals-c/S25282.pdf

Edited: Upon re-reading your initial post, it was realized that your entire batch was used in your initial reaction of trying to make Silver Chloride. This post will not help you to recover from that mistake, but may be of use in future refining.

 

[Xydoman]

I really appreciate it. This WILL help in the future. As fir this bucket of... Whatever it is, I'm going to save it till u kniw more aboug the process and am able to predict certain things as I can now with my gold recovery. It's a hobby, do tgd loss isn't detrimental or anything, and thanks for the advice about the wet lab work. I didn't completely consider the planning aspect. And you're absolutely right. From now on no more guessing, no more haphazardly throwing this solution into this one to condence things.. Yeah, this silver endeavor has me making irrational moves, and I'll heed your advice.

 

[Elemental]

I am glad you found the information useful. As for your initial foray, just learn from it. The silver is still there, in your bucket. If you stick with this and as you learn more, you'll figure out how to extract it. Think of it like cooking, you don't just go out and make a beef wellington without a recipe. I mean, you can but I think you already know how that ends up. Learn and write your own recipe (instruction) cards. As you learn things, modify them. You'll be pouring silver in no-time.

Much like yourself, this is a hobby. All scrap silver purchased is at a known loss as I don't sell my pure silver ingots. They just get tossed in a small chest in hopes of selling them when my daughter is older. It's fun, and let's me practice my wet-chemistry skills from college.

 

[FrugalRefiner]

a beef wellington

Mmmmm... I haven't made a welly in years, though they were venison. Wonder if I've still got a nice cut in the freezer for one.

I stack my silver for my kids and grandkids. I hope I'll never have to sell, but it's there just in case.

Dave

 

[Xydoman]

Hmm. Cooking.. I follow you. I love cooking.. Wasn't always the greatest. Screwed up quite a fee meals to get to where I am now. I will throw down the fancy stuff even if it's just me eating alone sometimes lol. Thanks again.