Refining silver from smithing

A. Hi Celena. You might try Facebook for private contact.
Sorry, but this is a public forum since 1989, and we do not facilitate private hookups for a bunch of reasons: they dis-serve the advertisers who make the forum possible; they cut the other posters off from any answers and resolutions offered in private; it makes for boring reading when postings end with "contact me for further info at ..."; it encourages spam and we already suffer about a thousand spams every day.

Hopefully our readers will try to help you publicly, and hopefully you'll find the private contacts you wish on Facebook or elsewhere. Apologies.
Luck & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. I used to dissolve out my silver scraps in Nitric acid (at around 30% strength) This gave me a solution of Silver Nitrate (which is poison and will also burn or mark you or your sink or clothes - it will also burn out a wart or corn with several applications! It can also be used to purify water (but I do not know what is a safe way to do this.) I assumed that any lead or copper or zinc did not react with nitric and just fell to the bottom as "dirt". I poured this solution into a fresh glass (leaving the "dirt" behind. Then I mixed in a hot fairly strong salt solution and the silver nitrate precipitated out a white substance which you could filter off with a paper towel in a funnel. This white precipitate can be heated with your torch in a crucible and I got what I believed to be pure silver. I used to use it for casting as I suspected it was not as pure as I would have wished. I gave the remaining liquid a second dose of hot saline in case it still contained any silver. My father in law, a chemist (in Aruba!) gave me this procedure.

A. Not to mess with expensive nitric acid from the pharmacy I found the cheaper way to refine silver. I put 50 gram of Sodium Nitrate from a garden supply shop, (is a common fertilizer) in half liter sulfuric acid from a car supply shop (is common lead battery acid [affil links]) and in it unclean silver, in as small parts as possible, milled flat and cut, and/or filings, in a glass coffee pot that can take a gas flame and boil it for one or two hours, (no need for a lid as the water in the weak acid evaporates and makes it stronger) or until all is dissolved, pour the liquid through a common coffee filter. What undissolved metal stays in the filter goes in the next batch. Then I add very fine common kitchen salt, dissolved in a little hot water or just like that; dry. The white yoghurt like substance (precipitate) comes down in the liquid, until more salt does stay salt. Then pour the liquid through a new coffee filter and rinse with water until clean, to check add a little ammonia [on eBay or Amazon]c (Janitor strength from the hardware store). If the rinse water turns blue, rinse more. Good to rinse last with distilled water (which I catch from my air conditioner). Put the filter with the white stuff in a crucible in a burnout oven if you have, heat to 800 °C, then remove from oven and put the torch, (Propane Oxygen will do) to get 100% pure silver. If you have no oven, let the filter dry , dip in alcohol and heat with torch. Same result. The same procedure for low karat gold, what stays in the filter after 2 hours cooking put in muriatic acid [affil links] with Sodium Nitrate, the gold will dissolve in room temperature, slowly, over night. Filter the liquid, what stays in the filter, rinse well and pour off what is light, any bits and pieces are good for a next time.

Dissolve some Urea ( also from the garden supply shop) in hot water and pour it slowly in the acid. It will foam and get hot, put your container in a big glass bowl in case it runs over. After the urea solution has gone in sprinkle Metabisulfite (is a salt butchers use to keep meat from turning brown, also used in wine making, water purifying, a common house hold item in a pharmacy) and see it foam and smell it stink, do work upwind. When brown-red particles go down, that is the pure gold.
Instead of Metabisulfite you can use common copper, old water tube or electric wire. As long as the copper dissolves the gold is pushed out of the acid. When the copper does not turn black any more the gold is out of the acid. To test for gold in the acid, make test water. That is pure tin, (lead free water tube solder from the plumber department hardware store) dissolved in a little muriatic acid. Put a drop on a paper towel, then add a drop of the liquid to test for gold. If it gets black gold is in, if it does not turn black all the gold is precipitated.
Good luck and have baking soda [on eBay or Amazon] at hand to neutralise any acid spill. Put a bowl with baking soda in water to dip hands and rinse acid tools.
Filter, wash and rinse like the white stuff, the pure gold does not turn black after cooling in air.

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Ed. note: Thank you, Alexander. But readers, please remember that the internet is a giant one-room schoolhouse and that some of the instructions you "overhear" on the internet may be totally inappropriate for a home environment or for application except by trained professionals.

A. Just a warning, anyone who is using these methods: dissolving the silver in nitric acid works well, be sure not to breath in the toxic fumes. Also, the white powder formed after adding salt to the silver solution is silver chloride. Heating this powder with a torch will give you pure silver, but it also produces pure chlorine gas, so be very careful if you are using this procedure. A safer way to recover the silver is to mix the silver chloride with sodium carbonate / washing soda [affil links] (can be bought at pool supply stores), heat to around 1200 degrees C, then pour out the mixture. Products are table salt and pure silver, which will separate in liquid phase due to extreme density differences. If you know anything about chemistry, you can work out the reactions and mass ratios. Cheers, happy refining.

A. Assuming your scrap is either .925 or sterling there isn't much need to really refine it and it's impossible to refine to purity without a electrolysis. The purity of anything marked 925 or Sterling is already 92.5% pure silver. One method of reducing some of the impurities would be to dissolve the silver in a 30-35% nitric acid solution. This solution will give off poisonous and acrid fumes so use a hood, vent or do this outdoors. for an ounce of silver scrap (again assuming it's .925) you might want to use about 1.5 oz of diluted nitric. when no more silver is present, filter the solution and then you can recover the silver by adding muriatic (HCl) or regular non iodized table salt. Both will precipitate the silver as silver chloride which will have to be reduced to metallic silver by either a calcining process or reducing with zinc. An easier method of recovering silver from silver nitrate is to simply add a piece of clean copper. This will cement your silver as cement silver which will run about 94% pure. Again, to refine the silver to 999 purity, it will require electrolysis

A. The simplest way to extract gold from mixed ore after powdered to over 100 microns?
right on the mining site, with less complicated resources possible, fast easy and efficient, please any one know how?
thank you
I always pray for the peace of Jerusalem so you may prosper (that is what the Bible states) I follow!

A. An easy (all disclaimers included) way to separate fine gold from jewelry is an old method called "Parting"

I put this site up a few years ago. Some of it is incorrect, like the names of things. But parting is an old method and it works.

I wouldn't recommend it to the casual putterer, but if you're not scared of dying, it's fun!

custommadesilver.com/Tutorials/Refine.htm

A. When firing, add your material to your crucible and cover completely with a cap of soda ash. And don't be conservative about it. Place a bowl cap/cover on the crucible and fire it until all the soda ash is molten. Then remove the bowl cap/cover and let it fire for an additional five minutes. This should solve your problem of metal contamination. If I'm not mistaken the soda ash will allow the other contaminants to burn out, NOT the silver.
I just did it. I have spent the last two days mining.
Today was test firing. Hoorah!! .97 troy oz.!
Blood red on the tester!

A. Dear sir,
Main thing: if your material is a metallic or in powder or ore form; and how much quantity of Silver in percent (test in lab) is important for refining process.