Use more Nitric to skip inquartation?
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Inquarting is to bring the Gold to 25% so the Nitric can access all the Silver.
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My apologies, I meant to say if the content is say;
Au 80%
Ag 17%
Other base metals 3%.
Would it be worth inquarting or would you just use nitric then AR?
Thanks mate! Already reading through Hokes book for the second time.
stella polaris
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You must inquart. Now the gold "protects" the silver and noting would happend. As Yggdrasil say, the gold must down to 25 % for the nitric to work.
Too much Gold to be able to reach other than the outer layers of Silver and base metals.
And too much Silver to be able to use AR, unless you make small shots and have proper mechanical stirring/grinding.
As a rotating reactor or a mechanical stirrer that are able to break the Silver Chloride layer of the metal.
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Say you had a mechanical set of rolls, which could squish the Au to a very thin layer. How thin would the say 90% Au, 10% Ag have to be rolled to, to achieve a 3-9's refine?
I have two further questions if you wouldn’t mind answering.
I’m going to go with the inquarting route.
In Hokes book she says to use silver to inquart instead of copper due to not being able to pull that copper back out of solution when finished.
Are there any other benefits to using silver>copper ?
I ask because I have a large amount of gold I’m wanting to refine (roughly 500g) and I feel like destroying 1.5kg of my silver bullion bars/coins would cost me more ( due to loss of premium/resale ) than it would just buying 1.5kg of copper and losing that.
My second question is in regard to furnaces. I’m leaning toward a propane furnace ( VEVOR VEVOR 12KG Propane Smelting Furnace Kit Melting Furnace Double Burners 2700℉ | VEVOR AU ) to melt the gold/copper alloy together.
Would there be any reason to go with an electric furnace ? They seem to be way more expensive with a smaller crucible size.
Many thanks!
I’m going to go with the inquarting route.
In Hokes book she says to use silver to inquart instead of copper due to not being able to pull that copper back out of solution when finished.
Are there any other benefits to using silver>copper ?
I ask because I have a large amount of gold I’m wanting to refine (roughly 500g) and I feel like destroying 1.5kg of my silver bullion bars/coins would cost me more ( due to loss of premium/resale ) than it would just buying 1.5kg of copper and losing that.
My second question is in regard to furnaces. I’m leaning toward a propane furnace ( VEVOR VEVOR 12KG Propane Smelting Furnace Kit Melting Furnace Double Burners 2700℉ | VEVOR AU ) to melt the gold/copper alloy together.
Would there be any reason to go with an electric furnace ? They seem to be way more expensive with a smaller crucible size.
Many thanks!
I have no recommendations regarding furnaces.
For Copper vs Silver, the inquarting material is not lost, but as you say destroying bullion/coins of know value will not be entirely economical.
But if you have plain bars no problem, the Silver is easily recovered.
Copper needs 4 times the amount of Nitric to dissolve and as such will cost more in chemicals and then there will be 4 times as much waste to process.
There are several reasons to use silver to inquart first silver will need less nitric and second any PGMs present will dissolve along with the silver , you do not need to use fine silver but you can use scrap sterling.
The thinness of the metal goes only to ability to dissolve, not to the fineness of the end product.
That is entirely dependable of your process after dissolving.
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Meant to add , after rolling to micron thin, then placing thin , rolled sheet in Nitric. What would be the required thickness of the rolled sheet of 90/10 alloy, to achieve 3-9's Gold, without in quarting?
I think you still need to refine it after, there will always be pockets and grains not accessible.
So dissolve in method of Choice and then precipitate with method of choice.
There may be some theoretical thickness that may give good results, like leaf Gold or such.
One of the most interesting things that makes this forum so educational, even to members with a lot of refining experience, is the fact that so many members have questions like “I have a machine that will allow me to pretreat by doing X”. Be that X atomizing, or rolling it thin in a rolling mill or any pretreatment our large number of readers can dream up.
Your particular situation, having silver bullion you paid a premium for, is not one faced in mainstream refining. But it has been said before that copper is a workable substitute to inquart but it has disadvantages as pointed out above. You could consider going to second hand shops or yard sales and acquiring scrap sterling silver to inquart with. Classic refining uses Silver to inquart. And classic refining is what most answers here will suggest. But everyones needs, and equipment, and skill levels vary which makes every unique question a learning opportunity for either the OP or our members.
As far as the question of gas or electric furnace, or induction melting I would advise for the home or small scale refiner to use gas. It has a larger melt capacity per dollar upfront cost. I refined with gas for years before induction furnaces were invented and never had issues. As far as small electric resistance heat melters I would stay away. Electric resistance is fine for assay furnaces but I’m not a big fan of the little hand pour easy melt electric furnaces. They just don’t hold up.
I have inquarted my gold with silver, melted, poured into shot, boiled in water/nitric (3:1) and filtered off the solution.
The nitric solution turn a lovely shade of green or blue ( you can see the shade in the filter paper ) which I then filtered and noticed these reflective crystals on the paper and in the solution. I chilled the solution and more crystals appeared.
Is this solid silver nitrate ?
The nitric solution turn a lovely shade of green or blue ( you can see the shade in the filter paper ) which I then filtered and noticed these reflective crystals on the paper and in the solution. I chilled the solution and more crystals appeared.
Is this solid silver nitrate ?
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It will depend on your Silver source first, then the alloy of the Au material. Silver nitrate is a liquid, so don't know if you mean some solids filtered out, or if the liquid component is 100% Ag nitrate.
Silver source was 9999 Perth mint coins. Au alloy was about 80% Au, rest of the alloy was Ag, Cu, Fe.
I did a boiling Hydrochloric bath on the Au alloy before inquartation.
My apologies, I meant to ask if that was Silver Chloride crystals that had precipitated in the Silver Nitrate ? I haven’t put in any other chemicals. All I can think of is that I didn’t wash the alloy properly after the initial HCL bath and it the HCL has precipitated silver chloride from the Silver Nitrate solution.
I didn’t think Silver chloride formed reflective crystals like the ones photographed though.
This is my first time refining, however so I could be totally wrong about that.
It is a solid but it is very soluble in water
Is there a way to test if it’s silver chloride or silver nitrate ?
I don’t currently have many serious acids available though, only HCL and Nitric. I can get some Sulphuric from site if required.
