# Refining karat gold



## buddyboy (Jun 23, 2008)

Hi Guys, I'm in need of some help. I would like to refine some 10k scrap I have to somewhere near 22k to pure. I don't think I need pure as I want to melt it & mix it with 14k to achieve 18k. I've had some experience in casting silver jewelery & would like to try gold. A whole new ballgame I'm finding out!!! The more I read the more intrigued I've become. I haven't found much on karat gold, mostly computer parts, but with the amount of knowledge out there I know you guys can help me. Now the reason for not purifing completly is to my way of thinking, maybe I don't need as strong of chemicals & that the over all process would be simpler. Correct me if I'm wrong. I think I need to (shot) the gold?? Pour from a high place?? How high, 8', 10'?? Mix it with silver, 3 parts silver & 1 part 10k?? Soak in nitric acid? Will 32% work?? I think that's what I can get at the chemical store. Am I on track so far. How do I retrieve the gold from this operation?


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## Lou (Jun 23, 2008)

I doubt they have a chemical store in California, at least one where they sell nitric acid! Normally they want to protect you even from your toilet paper in your state.

First off, you don't refine gold to 22K. You refine it to 24K and alloy down. It's pretty much all or nothing. My suggestion to you is read more. It sounds like you have the basics down.


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## buddyboy (Jun 23, 2008)

Wouldn't I be alloying it down by adding 14k back to it? I tried to answer your response Lou, & possibly sent it direct to you. I didn't see it posted. I have a heck of a time with computers & here I am trying to refine gold. Any way I think you are right on the nitric ban in Calif. I think I called them about higher strength muratic acid. I am some what close to Nev. & contractors who need the good chemicals to treat wood for termites and other stuff that works just have to bite the bullet &go over & get what they need. Anyway I only have a few ozs. of 10k & maybe should just have it done by a refiner. I've heard a few horror stories about being ripped off & such. I took enough to a gold buyer thinking I could trade for a 1oz. bar but it was about a 270.00 penalty. Anyway I thought I would use less chemicals by not going for pure gold & simplify the process somewhat.


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## Lou (Jun 23, 2008)

I got your message and sent you back the recommendation that you go to Aragold. They will refine the metal for 2%. In fact, so reliable and trustworthy have they been to me, I sell my gold to them exclusively. At a 98% buying price or a 2% fee for refining even low grade material, I can't compete--all of my karat material that is Pt and Pd free goes to them and I let them do the refining. Saves me time and money. As far as I know, they are the best people to sell gold to for the quantities and qualities we, as ''amateurs'' deal in on a regular basis.

Regarding the PGMs...that's another story, there are no really good buyers unless you have a lot of it and the money to spend on an assay. I myself buy Pt, Pd, Rh, Ir, Os, and Ru and am competitive in my fees with smaller refineries. So if anyone has some PGMs they'd like to sell, feel free to talk to me!


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## P_CARROLL (Jun 24, 2008)

I can vouch for ARA gold. Every transaction Ive had with them has benn above board.


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## buddyboy (Jun 24, 2008)

Hey Guys, Thanks for the info on the refiner. I certainly couldn't beat that price & don't have to search for supplies or endanger myself working with chemicals. Take care, Bud


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## docone31 (Jul 7, 2008)

buddyboy,
If all you are going to do, is cast some gold, you do not want to refine it.
I am going through the same thing. I cast gold.
With your scrap, in your melt, use NewCast. This will make the gold look like new when cast.
In the reheating of karat gold, you can get away with it once, then it turns orange. It will polish up yellow, but will quickly turn back to orange.
I have a mess of scrap from my bench. I also want to get good casting grain. I have tossed around the concept of refineing, but I will limit it to the buttons I made that had gold filled accidently mixed into them. I will cast with NewCast when I make my other castings.
In inquarting, melt the silver and gold together, then take the crucible and hold it up over the water. Keeping the heat on the melt, slowly drip into the bucket. This makes small shot, kinda spread out. The chemicals can attack the shot from all directions as they have smaller surface area.
I also have a batch of gold filled, from my wire wrapping. I plan on dissolving the base metals with HCL, then doing the HCL/Clorox refineing.
If just casting, melt the batch with NewCast, and add grain to pick up the karat. Works real well.


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## buddyboy (Jul 7, 2008)

Thanks for the response. I guess what I wanted to do was make my own casting grains & add them to 14k to enrich the mixture to 18k. This was a wild idea as I have a fair amount of 10 & 14 scrap & thought I could beat the refiner by refining the 10 & adding back pure to my 14. I have been advised of a refiner that only charges 2% & I don't think I could even chase around & locate chemicals for that price. Thanks , Bud


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## docone31 (Jul 7, 2008)

I got into all this for the same reasons.
My solution, was to use the scrap gold from the customer. That way, karat was not an issue. Their gold, their casting. With a once melt, the casting is not compromised.
My refineing needs are for the nuggets of gold filled/karat. I have a few. I also have gobs of gold filled, and gold by the inch.
When I bump karat, I get the appropriate casting grain to do it.
I am tossing around how to put 30ft chain into a cell. I think, I am going to go the AP route, with my gold filled also.
I have several rolling mills, so I plan on flattening the small buttons I made of the mix.
Why did I make the mix?
I used to melt the weeks keepings into a nugget. Every once in a while, some gold filled was on my soldering station. Whoopsie. I can always tell from the yellow deposit from the melt.


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## buddyboy (Jul 7, 2008)

I,m trying to make some free form jewelry. I've melted 10, 14 & 18 & dropped it into muratic acid over small quartz pebbles. It comes out beautiful. Especially the 18k. If you get lucky it grabs on the quartz & makes a really nice piece. This is what drove me to where I'm at. I appreciate this forum as there is a lot of Knowledge out there & most are willing to share with a stumble bum like myself & they help to keep you from hurting yourself. I have melted some of these items over & over & have not had anything discolor yet. I eventually want to sell some of this stuff & don't want any unhappy buyers so maybe I should have someone test wear some to make sure of this. If they turn orange I would'nt be happy.


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## docone31 (Jul 7, 2008)

I am not certain, freeforming and wearing as a pendant will do the same thing as wearing as a ring.
When I first started out as a jeweler, I melted gold and rolled it out to make sizing stock. That is where the issues came into play. Wearing dripped gold would not have the same wear factors.
Hey, if you want to do some great free form pendants, try dropping melted wax into water.
Take the wax and sprue and burn out same as silver. Cast the gold into those shapes!
I make those, and set diamonds, emeralds, etc... 
people love them.


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## buddyboy (Jul 7, 2008)

When I was making silver jewelry I was in a class & had the use of their equipment. Now all I have is a torch & am working pretty low budget. So if I can sell some of this stuff I will upgrade & get an oven & centrifuge. Pretty much just a hobby. When you "inquart" will HCL/CLOROX remove unwanted metals from karat gold?


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## docone31 (Jul 7, 2008)

I do not know about the acid stuff yet. There are others who will.
In regards to limits with equipment.
Hockey puck!!!!
My last ex-wife, I came home from the shop and all the tools, money, gold, stones, equipment, furniture, curtains were gone. All I had was the days take and some costume jewelery.
Steam casting.
All it takes is a large flower pot, a Coleman stove for camping, a torch set up for about 14$ some investment, yes you do need that, some aluminum foil, a can of tuna a wood dowel, and ambition. Oh yeah, I forgot to mention silver, or gold. Oops, forgot to mention the soup can!
That was my first steam casting rig, and it made me enough to get a place to live, make some jewelery, get a shop, get fully equipped again, replenish my gold, stones, and silver.
I wrote a small tutorial on this process in ring making, believe me, if I can do it, so can you.
I just finished sending this wife to school. She came out a master jeweler, and stone setter. She taught herself to knot pearls.
I am not putting you down with this post. I hope you know that. I felt overwhelmed once I had to start from the bottom, again. Kinda like leaving school with all the tools and someone you can ask what ifs to, and facing the variabilities of jewelery.
Believe me, casting is simpler than people make it out to be.
It is the artist that makes the casting.


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## buddyboy (Jul 8, 2008)

Hey I like that idea! I seen something on steam casting once. Don't remember if it was on this site or not. I'll do a little research on it. Thanks for the memory jog.


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## docone31 (Jul 8, 2008)

Look under Potato casting.
I used to do that also. Just cut a potato in half and jam it onto the melt. Makes steam.
It can be done, you can do it.


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## Harold_V (Jul 9, 2008)

buddyboy said:


> When you "inquart" will HCL/CLOROX remove unwanted metals from karat gold?


Depends on what you use for inquartation. If you choose to use silver, which makes sense for those that have access to both silver and nitric acid, you won't have any issues with your metal not dissolving, and you need not fear dissolving any of the gold prematurely. 

Silver, in the presence of chlorine, won't dissolve, but will form, instead, a hard coating of silver chloride, preventing any further dissolution of the base metals or the gold. It is, in effect, about the same thing as hard anodizing aluminum. 

Harold


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## buddyboy (Jul 10, 2008)

Thanks for the comeback on inquartation. I found on the web a method for purifying a small amount of karat gold. Melting the gold, adding some sodium nitrate, some broken glass?, 20 mule team borax, then break away glass after cooling & you'll have roughly 95 fine gold! Has anyone heard of this & will it work. This sounds simpler than inquartation & ideal for a small time hobbyist like myself.


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## docone31 (Jul 10, 2008)

Could you click the URL on here, I would love to read that.
I have wondered that many times if it is possible to at least flux some of the at least dirt out of karat gold.
I think acids are a way, and electric refining is definately a way. I am not sure about fire refineing.


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## buddyboy (Jul 10, 2008)

I read this article some time ago & wrote it down in a notebook. I'm computer illiterate & don't know how to copy some things. Anyway that was the gist of it & I think the article was written by a man from Austraila. I'm hoping for some feedback on this. Maybe I should post it under a different section. At the time I found it I couldn't locate sodium nitrate in Calif. But have since found it on ebay.


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## Harold_V (Jul 10, 2008)

When you melt gold that is alloyed, unless you oxidize the base metals, and use a flux that won't reduce the oxides, but absorbs them instead, there is little reason for you to expect the quality of the gold to be improved. In fact, quite the opposite tends to be the norm. Alloyed gold is degraded each time it is melted, and is one of the reasons that old gold needs to be reprocessed. Badly oxidized gold alloy is often the source of inclusions in jewelry castings. 

My personal opinion? 

I wouldn't spend any time even reading the article. It makes almost no sense. One does not refine gold by heating, unless the Miller chlorine process is used. 

Harold

edit: corrected spelling


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## goldsilverpro (Jul 10, 2008)

I agree with Harold. I suppose it is theoretically possible to remove that much copper with sodium nitrate, but you might destroy 100 crucibles doing it.

Some metals can be slagged out by piping oxygen into the melt, but copper isn't one of them. See Rose's, "Metallurgy of Gold."


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## buddyboy (Jul 10, 2008)

hi, I've been searching hard for the article but haven't found it yet. As I recall he also suggested using a charcoal briquet. It definetly was a poor boys method. He also had some humor in that he suggested using some of the wifes crystal as the broken glass.


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## docone31 (Jul 10, 2008)

Charcoal, in a large way would absorb O2. When I solder, or pour my melts, I pour through charcoal into the ingot mold.
It could be, that is the theory of cupelation. At the temperature of the melt, I doubt very much lead as an example would be liquid. The lead oxide would be absorbed by the charcoal, as well as other O2 components. Then boric acid will draw out the carbon particles.
I know, when I have melted gold filled into a nugget, there will be an oxide layer that rolls around on top of the melt. There is also a yellow deposit on the backside of the melt area. It turns white upon cooling.
When I make a quick button for rolling out, I take a 4 X 4 piece of lumber and put the scrap on the end. I then start melting. As it roils, the lumber makes charcoal. As the hole it makes gets larger. I use the end grain, as when I melt on top of a piece of wood, chunks get stuck on the melt when it cools. The end grain does this less so. It also acts as back flame when melting.
I never thought of burning into oxides the contaminants in some of my buttons. It makes sense though.


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## Harold_V (Jul 11, 2008)

Hoke talks of improving the quality of marginally pure gold by introducing potassium nitrate (please correct me if I have the reagent wrong---it's been a long time). 

I tried that in the process of trying to improve the quality of my gold when I first started refining. I consider the process a complete bust. 

If you want quality gold, eliminate as much of the base metal that is practical, then dissolve the remains and selectively precipitate the gold. Wash well, using a good washing procedure, then if you're intent is better than 3N5, a second refining of the resulting gold may be in order. You might also consider casting anodes and parting the once refined gold. 

Anything beyond that is a waste of time-----depending on your goal. 

Harold

edit: sigh! corrected spelling (both times). Will I ever learn?


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## buddyboy (Jul 11, 2008)

Harold, Would silver be preferred over copper for inquartation? I have a large amount of copper scrap & possibly wouldn't have to try to reclaim it as I would the silver. Also I have read alot about using nitric acid to dissolve the unwanted material but have never seen what strength it should be. I have a recipe from this forum to make some & if I read it correctly it will be 50%. Would that be suffient? Thanks for any help you can offer. Bud


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## Noxx (Jul 11, 2008)

Buddyboy, silver is preferred for inquartation since it takes less nitric acidto dissolve compared to copper. It also melts easier.

35% nitric acid is good for dissolutions.


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## Harold_V (Jul 12, 2008)

Yep---What Noxx said. You can then use the abundant copper you have to recover the silver. It's much easier to work with silver, with the only caveat being that you must use distilled or de-ionized water if you want to avoid creating silver chloride. I never let that be a problem when I was processing inquarted materials. What little that was formed using tap water was eventually reclaimed. 

Back to the silver chloride problem, whether you use copper or silver makes little difference. Any of the yellow gold alloys, including rose gold and green gold, will contain some silver. It's virtually impossible to process gold and not process silver. 

Harold


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## buddyboy (Jul 13, 2008)

OK. You gold gurus, How do you or can you soften a piece of 14k so I can do a little reshaping of it? Or does this come back to wax mold work & casting. Thanks


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## Irons (Jul 13, 2008)

buddyboy said:


> OK. You gold gurus, How do you or can you soften a piece of 14k so I can do a little reshaping of it? Or does this come back to wax mold work & casting. Thanks



To soften(anneal) gold alloys, they are heated to just below the melting point (alloy dependent) and allowed to cool slowly.

Here's a useful page on Gold alloy properties:

http://tinyurl.com/9xc9v


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## buddyboy (Jul 13, 2008)

To Irons, Thanks for that web site & the annealing info. Is that a picture of you or the real mcCoy? Gabby Hayes was my favorite cowboy when I was a child. I saved cereal box tops & sent off for his hat. Much to my sisters dismay. I even had his lingo down, & could bug 'em to no end. Thanks again, Bud


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## Irons (Jul 14, 2008)

buddyboy said:


> To Irons, Thanks for that web site & the annealing info. Is that a picture of you or the real mcCoy? Gabby Hayes was my favorite cowboy when I was a child. I saved cereal box tops & sent off for his hat. Much to my sisters dismay. I even had his lingo down, & could bug 'em to no end. Thanks again, Bud



That's gabby but all I need is the hat. lol

An interesting side note. Copper is the opposite. To soften it, you heat it and quench it rapidly. Brass is the same way. I always anneal rifle cartridge cases before reloading the first time by wrapping the case below the shoulder in a wet paper towel and then heating the neck to a dull red heat then plunging the case into cold water. one side effect is that some of the zinc in the brass alloy evaporates and the alloy in the annealed area is slightly reddish than the rest of the case. You will probably get the same phenomenon with Gold alloys that contain Zinc or as in Green Gold, Cadmium. Be careful when heating Green Gold alloys as Cadmium will evaporate like Zinc and is very toxic. I knew a guy who almost died from welding steel that was Cadmium plated. He was sick for a long time.


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## buddyboy (Jul 14, 2008)

I've experienced cracking in 14k if you try to move too much metal. So possibly it's the copper fighting the gold as both want different annealing. Thanks for the warning on green. I have none but I'm a flea market nut & never know what you'll find.


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