Melting Gold - blonde needs advise

Hello I'm wanting some time to melt some small pieces of gold I have accumulated into some form of nugget to wear... at the moment I have it
in panned form in small flakes from Idaho. I have my own kiln and can produce a reduction atmosphere if needed but just wanted to get some advise from a few folk so that I don't make a mess of it! Anyone fancy a chat about this sort of thing? regards Heather in England
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For jewlery we just melt it in a crucible using Oxy Propane or Oxy Acetlyene. No reducing atmosphere needed, then pickle the surface.

jk
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Heather, Get a piece of wood charcoal ( Compressed Bricquets are my last choice ) and drill or carve an indention deep enough to keep the small flakes from blowing about. Use an Oxygen + Natural Gas , Oxygen + Propane , or even an Oxygen + Acetylene torch adjusted to a nuteral flame . If you do not have a Oxy - Gas torch, take it to someone and let them heat it. Heat with a flame large enough to melt but not so agressive as to blow out the small flakes . When molten dump the gold into water . This should form a freeform nugget . Continue remelting untill you like the form of the nugget . Pickle it in any acid water pickle or alum water pickle ( 10 % solution ) Solder a 22 K or 24 K jump ring for a chain and wear with pride. Use a easy or medium 18 K or 22 K solder . This Nugget is still native gold unless you add or remove anything .If You intend to sell it, check with the UK hallmarking authorities first.
Check Rec.Crafts.Jewelry on the Google groups or contact me off group . I can send resources easier via email, than I can over this group. ROBB.
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ROBB wrote:

Never, use 22 karat or especially 24 karat for a jumpring. Both are much too soft, and will not last very ling. Use 18 karat.

Do not use easy or medium solder. Use hard solder.
Abrasha http://www.abrasha.com
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On 15 Dec 2003 12:50:57 -0800, snipped-for-privacy@earthlink.net (ROBB) wrote:

Imported Idaho gold isn't subject to UK hallmarking authority. Once in hand in-country past customs, it's metal to be used however you might care to.
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Seems like good info - but I have a question (open to anyone for an answer). I know gold is in different "qualities" i.e. 10K 14K 18K 24K, etc., and it's other metals introduced into the gold to change the "K" of the item, correct? Questions are: 1. When melted, do all the impurities (other metals) float to the top, sink, or what and how are they removed from the pure gold? 2. What is and how would you do "pickeling"? Thanks Ken.
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Ken, Sterling wrote:

no
no
they (usually copper, silver and other metlas like zinc, and/or nickel or palladium for "white gold" )form an alloy with the gold.
Definition of alloy: a mixture containing two or more metallic elements or metallic and nonmetallic elements usually fused together or dissolving into each other when molten; "brass is an alloy of zinc and copper", "steel is an alloy of iron and carbon"

This is done in a process called "refining". It is a fairly complicated and exhaustive process, as well as very poisonous, because of the different chemicals used. But in a nutshell this is what takes place:
DISSOLUTION: Acids react with gold, silver, copper and other alloy constituents to form gold chloride solution, silver chloride precipitate and copper nitrate solution.
FILTERATION: Silver chloride precipitate and insoluble matter is seperated from solution containing dissolved gold and copper.
REDUCTION: Gold reagent, added to solution, reduces gold chloride to pure gold oxide precipitate.
WASHING: Gold oxide is removed from the remaining solution containing dissolved copper, is chemically washed and dried. You can now melt the gold powder and re-use as required.

In the jewelry workshop, pickling is the process that removes oxides from the gold alloy after it has been heated with an open flame for annealing or soldering. Typically a 10% warm sulphurioc acid solution is used for it. Or a more friendly compound (like SPAREX), which can be bought in granular form and added to warm water. That is what I use for safety reasons, and because it doesn't eat holes in my clothes.
WARNING!
If you contemplate making a sulphuric acid pickling solution, remember this: AAA, ALWAYS ADD ACID!!! I cannot write this bold enough or add enough exclamation marks. Never add water to acid, you'll regret it. If you're lucky you'll only lose your eyes!
It's better and a lot safer to use a solution like Sparex, you don't have to worry about acid explosions.
In goldsmithing school in Germany we were taught a rhyme to remember this:
Erst das Wasser, dann die Sauere. Sonst passiert das Ungeheure
First water, then acid Otherwise the "tremendously terrible" will happen
Abrasha http://www.abrasha.com
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That mnemonic reminds me of a cautionary poem told by my science teacher when introducing us kids to sulfuric acid:
Poor little Billy isn't with us any more because what he thought was H-2-O was H-2-S-O-4
Abrasha wrote:

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You don't need any sayings or mnemonics for this.
The problem is simple, the dilution is exothermic. So you put the stuff with the largest thermal capacity there first, in the largest volume.
Thus any heat developed by the small droplets of acid as they enter the container of water is tempered by the large thermal mass of the water.
Doing it the other way causes local boiling and spattering. :(
Jim
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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jim rozen wrote:

This just proves that you DO need those sayings AND mnemonics, because your average goldsmith or person doesn't know about "exothermic" and/or "thermal capacity". They are not scientists or chemists.
The "people" that I was being trained with in goldsmithing school were high school aged teenagers.
Abrasha http://www.abrasha.com
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Well. Nobody here anyway. The trouble with all the cute-sy poems is sometimes they get twisted around and you do the wrong thing.
Jim
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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jim rozen wrote:

Nothing cutesy about it. It has saved lives! Abrasha http://www.abrasha.com
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I dunno.... I kinda like the AAA always add acid.... Simple to remember and pretty tough to screwup I mean it's not always add WATER because that'd be AAW, which is what you would be saying if you did it wrong. Ken.
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On Tue, 16 Dec 2003 23:08:02 GMT, Ken Sterling wrote:

Always add Aqua would screw you up pretty good.
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.... and just when I was doing *so* well, too...... :-) Ken.
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Lot more complicated than I would have thought..... I was thinking you would just melt an old ring or two in the ladle, the skim off the copper, zinc, etc., and then you would be left with pure gold to play with... Figures - nothing can be simple. Thanks for all the info - that was great. Ken.
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Hi Ken... I liked your little explanation here, and want to chat more with you in private if I may... write to me, snipped-for-privacy@dawnmist.demon.co.uk speak soon I hope Heather
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<Ken Sterling> wrote in message
snip---

Interestingly, very few metals will stratify when once alloyed. Silver will separate from iron, but not if gold is present. Gold and iron readily form an alloy, although it has poor qualities.
The precise method for separating gold from other elements is not difficult, but it does require the use of three acids, nitric, hydrochloric, and sulfuric. I'd willingly provide a very satisfactory chemical process to anyone so interested. I refined gold for over 20 years before selling my refining business when I retired back in '94. I was fortunate to have a loved hobby turn into a business, getting me off my machines after 26 marathon years of machining.
Harold
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I'd very much appreciate you posting for us the chemical process for removing gold from alloys.
Thank you for your time.
On Wed, 17 Dec 2003 02:06:07 -0800, "Harold & Susan Vordos"

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Hi Joe,
I'm not sure that posting this information would be the best way to go. The process is extensive if you desire enough information to actually do the refining, so the post would be a lot more like posting a book. There are a lot of steps along the way that should be described in order for the process to be successful. If, however, you are more curious about what is done, and not necessarily why, then I could probably cut it down to a couple of pages, maybe even less.
Because all the metals encountered in alloyed gold don't behave the same way, you have to jump through a few hoops to get to the gold. The main culprit in yellow gold, silver, makes the separation impossible if you do not follow the right procedure. Also, because the platinum group is often encountered when refining, the process is far more involved than may be apparent. Depending on the nature of the material being refined, there are various processes that, while they resemble one another, are different from one another. Processing filings from a jeweler's bench is different from processing old rings, for example. Different yet again for polishing wastes.
If you'll give me an idea what interests you, I would be willing to provide more information, but hesitate to spend days typing, only to find that you were more interested in a Reader's Digest version to satisfy curiosity. It would be likely that I would send the information directly to you instead of posting.
Harold
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