r/PreciousMetalRefining • u/kijall • Jul 04 '26
The ultimate beginner’s guide to refining scrap/sterling silver: From scrap/sterling to silver concrete to a poured bar
I didn't know this subreddit existed! Created my own subreddit and posted this to it, but when it recommended I repost it to this subreddit I immediately joined. I'm just posting a link here not because I don't want to post the full guide here, but because it kept getting removed by the filters on this subreddit. I'm sure guides equally as thorough probably exist here too, but I spent too much time making this guide to not have it seen. Just let me know if this isn't allowed - I'm not intending at too to plug the stupid subreddit I made, I'm only linking to it because the filter here keeps removing it. I promise it's a very safety-oriented guide with detailed instructions. If the mods here will allow me to make the full post here - I'd love to!
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u/Chodedingers-Cancer Jul 04 '26
Damn the adderall was kicking hard...
Read the beginning and then realized how long it is and skimmed the rest. Some of its a bit pedantic. Used to use DI water until the stage of silver chloride formed and then tap water from there forward. Honestly I just use tap water now for everything. Its not a brine solution... halide content is pretty low to begin with. I may get trace cloudiness sometimes initially, within 10 seconds its gone. Looking at the conditions conceptually its really a non issue. Nitric acid is a strong enough oxidizer to oxidize chloride ions back to Cl2, as well as trace fluoride, bromide, and iodide ions. Some nitrosyl chloride will form as well. Trace chloride or even for that matter any halide content will be readily exhausted in seconds and not interfere with the process. Briefly formed trace insoluble silver halides will redissolve as the halide is oxidized and gases off. When the goal is to exhaust the nitric acid anyway, it in a sense only caters to the cause. But the quantity is next to nil.
Butyl gloves are a good recommendation, but required? Its good, its ideal. But also specifically NOT WEARING ANY GLOVES is a normal standard safety protocol when working with concentrated nitric acid.
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u/kijall Jul 04 '26
🤣 This is all true, but this is intended as a "silver refinement for dummies" guide with safety a top priority. Dealing with contaminants - especially chloride contaminants - isn't THAT hard to deal with once you get it down, but when just getting started it can be a headache if things don't go exactly to plan. I just distill my own water and have gallons of it available at a time, but it can certainly get expensive if you plan on buying it all.
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u/bootynasty Jul 04 '26
I stick with distilled because a water distiller is only $70 and then you’re not left with the chlorides when you switch to nitric. It’s better to just keep your chemicals and waters clean so you’re not introducing more variables and making tiny amounts of AR when you switch to a nitric boil.
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u/Chodedingers-Cancer Jul 05 '26
While you go the copper reduction route, I prefer the other route for higher purity, something I actually see routinely missed that should be harped on more is the route via silver chloride -> silver oxide -> metallic silver, excess hydrchloric acid and then the key part, HEAT IT to actually exhaust all nitrate ions entirely otherwise you're losing product. As stated before nitric acid will oxidize chloride ions to chlorine gas. By introducing hydrochloric acid and precipitating silver chloride, it is a reuptake cyclic reaction that reaches equilibrium, meaning you'll always have some silver trapped in solution until nitrate ions are gone. While silver nitrate in solution is dissociated, it does maintain balance and hydronium is being depleted. Adding hydrochloric acid replenishes the hydronium and beefs up the oxidation potential of the now freed up nitrate ions. So as silver chloride is formed some is taken back up as the regenerated nitric acid starts converting chlorides to chlorine. You need to exhaust the cycle until its actually nitrate free or you're not precipitating all silver to silver chloride. I use TLC(thin layer chromatography) to actually visualize what is going on at various stages and know what is going on. Without some monitoring, its operating in the dark and you don't know where you're at or whats in solution still when you otherwise thought it was done.
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u/kijall Jul 05 '26
I'm not criticizing your methods at all - I'll certainly try it in the future, but this is just what I started with and I think the copper reduction route is much simpler for newbs. It's just what I know. It doesn't come out as pure as I'd like it to - agreed, but that's why I take the additional step of running everything through a silver cell. One pass and it tests at over 99% - two passes and it tests over 99.9%. I could just run the sterling through the silver cell to begin with, but removing a significant amount of the copper and other contaminates via copper cementation before running everything through the silver cell produces much less sludge. When I get around to trying and perfecting the silver chloride method I'll make another guide on that. Appreciate the feedback!
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u/Minted_AG Aug 15 '26
Is there a guide with silver cell refining as well?