Can someone please explain in detail, exactly how to wash silver chloride to get it ready for the next step?

Xydoman

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Please help.. I've got some real basic procedures of gold recovery and refining down pretty good now, to the point where I'm actually producing gold. So I have no idea how I got it in my head that learning how to produce silver was going to be a cinch.. Cuz it's not lol.

I HAVE had success producing a couple of ounces of silver from circuit breakers and relay contacts using aqua regia. It's kind of hard to go wrong there. But I have failed repeatedly at turning AgCl into elemental silver. It's been disaster after disaster, and I've traced it down to the washing of the AgCl. Everywhere I look, the instructions simply tell me to wash it... OK.. I've tried washing it using my own methods based on my own mental projections, but I've obviously been doing it all wrong. I've got buckets and buckets of attempts gone a wry.

So now, I've gotten as far as I always get before things go south, and I've stopped to consult the forum. I don't know why I didn't just ask in the first place rather than pour through a vast sea of videos and text, none of which has done me any good. So a teacher will be needed to move me through this hurdle. And I thank the kind soul in advance for being just that for me, whoever it may be.

The current solution is made up of probably 500 g of silver plated sscrap, mainly the plated bits out of breakers and contractors. Right now, I have a gallon pickle jar, about 35% full of AgCl, with about 4 cm of Distilled water on top. The AgCl isn't white though. It's kind of a turquoise or a teal.. Hell, might even call it baby blue. I can't just call it blue, or just green, because it's neither. But the consistency is about what u think it should be, kinda like cottage cheese. Although, I DID wash it a few times with water, by filling the jar, giving it a swirl, letting it settle, then decanting. I've done that 3 or 4 times, and the color hasn't changed a bit, and now, it's lost the cottage cheese consistency and has taken on a thick slushy appearance . So can someone please walk me through the process to wash this.. Or if the color is my problem, how do I get it to be white. The procedure I've been using has came straight out of this forum, although the exact posts escape me for the moment. I just know I'm doing something wrong in this washing step tho. I really appreciate the wisdom that yall impart on me. Because of yall, I'm producing gold, so I know yall can set me straight here. Thanks.
 

Martijn

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Add hot tapwater, stir, let settle, decant, repeat. Test a small bit of wash water with Ammonia or NaOH for copper traces.
Keep Ammonia out of your normal waste stream (as I've been told once)
Lots of small washes are better then a few big ones. You're basically diluting the water and decanting the contamination from the silver chloride. Washing with hot water has an added advantage of dissolving any lead chloride present. Most salts are more soluble in hot solutions than cold ones. So any slightly soluble contaminants will be absorbed faster by the hot water, resulting in a cleaner AgCl.

Have you considered cementing your silver nitrate directly on copper in stead of converting to AgCl? And then run it through a silver cell?
Many have achieved three nines fine or better with the chlorine-sugar-lye method, but the steps need to be followed and (imo) you will have more waste water to deal with. It's a personal preference I guess. I go for cementing and have a bottle of occasional AgCl that formed from tests or mistakes. Which I'm saving for testing and demonstration purposes.
 

Xydoman

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Thank you so much. This is exactly what I needed. And yes, I've actually found a couple of ways to get my silver, while avoiding AgCl altogether. Much easier. All this waste will likely take me quite a while to deal with. I'll likely be quite capable once I'm done with it lol. Then I'll never wsnt to touch it again. Lol. But thank you a million times For the instructions. I wonder why they're so hard to come across.

BTW.. I've recently started using copper instead of smb to precipitate gold out of solution. My yield seems to have gone way up. Can u poi t me to sone good info on using copper to get to my silver as well?
 

Martijn

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A good way to reduce your waste solutions beside not overshooting your acids is evaporation. If you have a lot to process.
After getting out all you can in the stockpot and the iron pot.
Some waste solutions can be reused. Like AP.
If you have a place in the sun (where no kids or pets can get to and neighbours are not bothered by smelly waste) you can evaporate a lot off.

Your cemented precious metals will be contaminated with bits of copper when you cement on copper. Have you tried Harold's washing procedure to get shiny gold?

https://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=325

When cementing silver (or gold) on copper it's important to submerge the copper beneath the surface to avoid copper oxide forming at the surface. Use a thick fishing wire and replace it when it shows signs of wear.

The solution should not be to concentrated to avoid a hard coating of silver on the copper, stopping the process. It should form 'beards' of silver hanging from the copper. If you tap the beaker the silver should fall off.
The last bit that cements out is less pure.
Running a simple silver cell with that silver poured into shot will get nearly pure silver.

Good luck.

Martijn.
 

Topher_osAUrus

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Xydoman said:
I HAVE had success producing a couple of ounces of silver from circuit breakers and relay contacts using aqua regia. It's kind of hard to go wrong there.

Either I'm missing something, or there's a bit of a mixup here.

If not, and you are using AR to dissolve silver, you will be missing a lot of values that hide under the outer crust (layer) of AgCl.

Nitric + di h2o = good for dissolving silver, and getting it all dissolved.
 

Xydoman

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The method I'm referring to, is as follows.. Altho I am a noob and font fully understand too much of any of this yet.. As a consequence, I've learned some tough lessons that have taught me well, to ONLY perform processes that I can get good, thorough instructions for, and understand them well before I embark on the project, NEVER deviating. Ive managed not to hurt myself thankfully, but have wasted tons of material that I now have sitting in so many dang buckets, waiting for a day when I'm knowledgeable enough to do something with them.. Although I'm afraid that knowledge will have to consist of how to dispose of it rather than process is, as I dont think I have enough youth left in me to learn what to do with it all. If only I'd have found this forum FIRST.. ugh.. Anyways.. Here's the AR process I've been using.

Whip up some AR and cover about 30 - 50 grand of silver contacts.. As I understand it, the hcl prevents the hno3 from attacking the silver, as the rest of the base metals are consumed by it. Then wash the resulting lumpy powder and dry, then melt. Altho, I've hit 2 batches in a row that were damn near impossible to melt with my map gas torch. The first 4 batches went very smooth. 4 real nice buttons, altho I couldn't testify to purity, but pure enough to keep me occupied.
 

Martijn

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The HCL in AR converts dissolved silver into silver chloride and that covers the piece you are trying to dissolve. The (base) metals underneath are not consumed, because of the AgCl layer covering the metal piece.
So knocking it off every now and then will help.
Drying your AgCl powder has been discussed and is advised against, I believe.

But why use AR when nitric alone will do the job just fine? You only need AR for precious metals like gold and platinum.
No HCL or chlorine in the mix > No AgCl is formed, and you can cement silver nitrate out on copper, rinse and melt.
If you really want to have Silver Chloride, you can filter the AgNO3 and convert it all with HCL or table salt.

What are those buckets containing? Only solutions or also half digested metals? More Silver digestions with AR? rinse waters? Experiments gone bad?
Have you kept track of what went in? We can help you process and dispose of that waste safely and retrieve some values from it.
It will also help you learn to understand all this better.
We all have made mistakes, but learning from them is important for you and other members.
Those buckets will fail at some point, contaminating your soil. Best to treat them ASAP.

Martijn.
 

Palladium

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Those silver contacts should be just about pure silver and tungsten. Not sure what kind you are doing. Forget the ar route completely. Somebody has lead you wrong or you are misunderstanding if that's what you are doing. I don't feel like doing a lot of typing so here is a post by Chris to explain it.

Close approximations:
- 7 pounds of silver per gallon of 70% nitric
- 100 tr.oz. per gallon
- 26.4 tr.oz per liter
- 822 grams per liter
- 1 gram per 1.22 ml

For your 110 grams of silver, therefore, it will take about 134 ml of 70% nitric.

For several reasons, these figures never come out to be 100% exact - due to reaction temperature, amount of dilution, actual strength of the concentrated nitric, etc. However, for planning purposes, they are very close. They assume that the dissolving vessel is open and not sealed in any way. They also assume that the 70% nitric has been diluted 50/50 (to 41%) with distilled water when dissolving the silver. When using this 50/50 solution, the volumes above, of course, are doubled. They also assume that the silver is pure to start with.

If the silver contains copper, such as in sterling or coin silver, the approximations will be slightly different, since:
- one gallon of 70% nitric will only dissolve about 2 pounds of copper
- about 4.3 ml of 70% nitric will dissolve 1 gram of copper

For 1 gram of Sterling silver - 92.5/7.5, Ag/Cu:
(1.22 x .925) + (4.3 x .075) = about 1.45 ml of 70% nitric or 2.9 ml of 50/50 nitric

For 1 gram of Coin silver - 90/10, Ag/Cu:
(1.22 x .90) + (4.3 x .10) = about 1.53 ml of 70% nitric or 3.06 ml of 50/50 nitric

Note: The amount of nitric needed to dissolve copper (1 gallon/2 pounds) also can be used as an approximation for some other base metals, such as nickel, zinc, or copper alloys, such as brass. This same figure, 1 gallon/2 pounds, can be approximated when dissolving some base metals, such as copper or iron, in 4 to 1 aqua regia.

Here again, except under very stringent controls, there can be no exact figures given for the amount of acid needed. For planning purposes, however, the above amounts have been proven in practice to be very good approximations. You can use these figures as a starting point and then make adjustments, one way or another, if needed. This is not rocket science.
 

kurtak

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Xydoman said:
I HAVE had success producing a couple of ounces of silver from circuit breakers and relay contacts using aqua regia.

As Martijn pointed out - you DO NOT dissolve silver with AR (aqua regia) - you use nitric to dissolve silver

Whip up some AR and cover about 30 - 50 grand of silver contacts.. As I understand it, the hcl prevents the hno3 from attacking the silver, as the rest of the base metals are consumed by it. Then wash the resulting lumpy powder and dry, then melt. Altho, I've hit 2 batches in a row that were damn near impossible to melt with my map gas torch

the reason you are having trouble melting is because of the silver chloride crust formed on the surface of the silver by putting the points in AR first - which is why Martijn said to use nitric not AR - &/or - they are the tungsten/silver type - MAPP gas does not get even close to hot enough to melt tungsten

Palladium posted

Those silver contacts should be just about pure silver and tungsten.

to clarify --- the contacts from circuit breakers are made of tungsten & silver - they run around 30 - 40 % silver & around 60 - 70 % tungsten - they are NOT an alloy - rather - the silver is tied up in a sintered matrix of tungsten - tungsten does not dissolve in nitric - therefore - to recover the silver from the tungsten matrix you have to "leach" the silver out of the tungsten matrix

to do that you have to literally boil the contacts in the nitric acid - for about 8 -10 hours to get the silver out of them --- therefore - (due to evaporation) you need to dilute the nitric more then 50 % (about 40/60 acid/distilled water --- DO NOT USE TAP WATER) & then add some D-water from time to time during the leaching process to make up for evaporation

therefore you want to process this type of points on there own & separate from other types of contact points

contact points from relays &/or magnetic disconnects will normally run around 98 % silver to "near" pure

however - keep in mind that that they make hundred of types of points alloyed with different other metals including but not limited PGMs

Kurt
 

Palladium

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If you use ar you will wind up with tungsten oxide (Yellow powder) mixed in with silver chloride and then you have a real mess to separate.I learned that from processing ceramic processors.
 

Xydoman

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Ahh, I see. I do have a bucket full of the yellow stuff. As for the rest of the waste, I was talking to a friend of mine who us also into the recovery, who is actually In school AND enrolled in a chemistry class.. And he was interested in my waste buckets. He fully disclosed his intentions, admitting that there were definitely quite a bit of values in them, based on the amount of material I've burned thru learning this tough lesson, and his aim is to fix my mess and recover the metals, while taking the giant burden off of me who has no way to deal with it.. My words lol. Anyways, we struck a deal.. He gets the waste, and I get to help him process, allowing me to effectively learn important aspects of this hobby. He's on me pretty hard about taking safety very seriously. I'm lucky to be acquainted with one like this.

As for the AR deal up top, you guys are so right. It turns out that my problem with processing AgCl, which led me down the erroneous AR path, was the very thing my buddy insists that I learn before I continue any further... Do not assume I know anything lol. Basically, I was cutting a corner here and there.. Smh.. I honestly don't know wtf I was even thinking seriously. If I'm following a procedure, follow it TO THE T!! He's out if he catches me guessing or cutting corners again. He says he won't b around when my inattention to each detail inadvertently gets me sick or worse. Thus being drilled in, I have ran 2 successful batches of contacts dissolving in hno3 and refining with lye and sugar. There's nothing to it as long as I stay the course... Exactly as it's been laid out. My yield is, up, and it's extremely satisfying watching these reactions happen at my hand. So thanks for everything guys.
 

Topher_osAUrus

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Why make silver chloride at all?

Just cement the silver onto copper.

If you have all your solutions and materials you previously processed, the values are all still there. You just need to familiarize yourself with the testing of solutions for contained values.
That will make it easy to discern if you need to recover values from one of your buckets, or move it on to waste treatment.
 

Martijn

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Xydoman said:
and his aim is to fix my mess and recover the metals, while taking the giant burden off of me who has no way to deal with it.. My words lol.
You really need to be able to clean up your own mess.

Study and discuss 'Dealing with waste' with your friend:
Some aspects and practical things of this science are not taught in chemistry.

https://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300https://goldrefiningforum.com/phpBB3/viewtopic.php?f=47&t=1300

It will give you a better understanding of recovery of pm's. How to separate them from base metals.
Like cementing silver on copper e.g.

Martijn.
 
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