99.5%? Is it possible?

[HAuCl4]

I bet he got robbed anyway. :lol:

 

[HAuCl4]

During my trip, and due to the introduction of "the atomizer", the obvious question kept popping in my head:

Can gold of sufficient purity be quickly produced using only "the atomizer" followed by some carefully designed fluxing and/or salt cementation method?.

Have you done any experiments in this direction 4metals, anyone?.

I think it could work well if there are no PGMs in the feed, maybe with more than 1 atomization in the sequence. No aqueous treatments has a nice appeal.

I wonder what Vanoccio Biringuccio could have achieved in terms of fineness, had he had access to an atomizer... :shock:

 

[4metals]

Interestingly enough, I am working with atomization on sterling silver for that same purpose. My logic is that by adequately fluxing the sterling and taking advantage of the huge surface area, and the ability of the fluxing materials to contact the majority of the material, the copper can be oxidized out of the alloy. I doubt you could ever get it all so that's why I never considered karat material.

Once the material melts most of the fluxing action is at the surface of the metal pool that is why the contact between the atomized metal and the flux is so important. If the metallic copper doesn't oxidize early on it may not go, so determining flux to atomized karat ratios are paramount to success. That is what I'm working on now.

With proper fluxing, enough copper can be removed to produce an alloy that has low enough copper to run in silver cells easily without the "copper buildup blues."

 

[HAuCl4]

Interestingly enough, I am working with atomization on sterling silver for that same purpose. My logic is that by adequately fluxing the sterling and taking advantage of the huge surface area, and the ability of the fluxing materials to contact the majority of the material, the copper can be oxidized out of the alloy. I doubt you could ever get it all so that's why I never considered karat material.

Once the material melts most of the fluxing action is at the surface of the metal pool that is why the contact between the atomized metal and the flux is so important. If the metallic copper doesn't oxidize early on it may not go, so determining flux to atomized karat ratios are paramount to success. That is what I'm working on now.

With proper fluxing, enough copper can be removed to produce an alloy that has low enough copper to run in silver cells easily without the "copper buildup blues."

Very nice. I think "the time spent at a high temperature but below melting point" is likely a very important parameter. As you say, as soon as the material melts, the flux action is greatly diminished and confined to the surface of the melt.

These middle age guys were bringing gold from 37% to 90%+ in one pass using table salt, urine, and crushed brick...and no atomizer...so I think the idea has some merit.

You, yourself have used scavenger fluxes on leached inquarts to bring 99% gold to 9995 with great success, so there is only that band from 90% to 99% to bridge the gap.

In my head it is possible. Just need to do the experiments...sometime.

 

[4metals]

I wonder what Vanoccio Biringuccio could have achieved in terms of fineness, had he had access to an atomizer..

I actually have his book, The Pirotechnia of Vannoccio Biringuccio It is amazing the things you can get from old books.

http://books.google.com/books?id=ru...ei=ypspScTbE4yYyATt_7y2Bw#v=onepage&q&f=false

 

[HAuCl4]

It must be an amazing book. I've only read a few paragraphs that were available free online.

 

[jimdoc]

You should be able to find the reprint of the book 4metals mentioned on Ebay.I think I paid about $10 for mine.

Here is another oldie on pdf;
http://www.archive.org/details/deremetallica00agri

Jim

 

[HAuCl4]

Thanks for the book jimdoc. I'm pretty sure I'll get the other book in .pdf for free as well from someone, sometime. 8)

 

[jimdoc]

I have to check my old hard drives,I may have it on pdf also.
It is hard to keep track of all the downloads I have,I will have to
organize them all someday.

Jim

 

[HAuCl4]

Interestingly enough, I am working with atomization on sterling silver for that same purpose. My logic is that by adequately fluxing the sterling and taking advantage of the huge surface area, and the ability of the fluxing materials to contact the majority of the material, the copper can be oxidized out of the alloy. I doubt you could ever get it all so that's why I never considered karat material.

Once the material melts most of the fluxing action is at the surface of the metal pool that is why the contact between the atomized metal and the flux is so important. If the metallic copper doesn't oxidize early on it may not go, so determining flux to atomized karat ratios are paramount to success. That is what I'm working on now.

With proper fluxing, enough copper can be removed to produce an alloy that has low enough copper to run in silver cells easily without the "copper buildup blues."

For the sterling cleanup, have you already considered bubbling dry air through the melt in a clay crucible with a bone-ash/borax plug on top, and a crucible cover to keep the splashing down?. Akin to Miller but with air instead of Cl2. It would likely save on the fluxing later.

 

[4metals]

I have done that, and it does work, but it is by no means quick. I've even tried to boost the speed by adding supplemental O2 with the air. Still it takes hours and determining when your reaction is complete, ie. all the copper (or most of it) is out is not a quick spot check.

By working out the flux to atomized sterling ratios I hope to produce a consistent result so anode sized melts (250 to 500 oz) can be done and poured directly into anodes for the cell.

 

[HAuCl4]

I see. It makes sense. Definitely hard to beat the atomizer for exposed surface area and speed of reaction.

Have you timed the time for a leach of an atomized gold-silver inquart in hot nitric?. It must be almost explosive-fast. It is probably very fast too with sulfuric acid. Different application. Sorry to digress.

 

[4metals]

Atomized inquart would be too violent and too fast in Nitric. When I do inquarting I use a scrubber designed to regenerate nitric in an O2 rich atmosphere, since retention time is critical in the design of a scrubber the reaction rate has to be considered. The inquarted silver is usually digested in coarsely grained shot for that reason.

I'm afraid atomized inquarted alloy would break some glass!

 

[HAuCl4]

Atomized inquarted alloy digested in sulfuric acid in a heated cast iron kettle sounds like a very expedite, simple and economical solution for material without PGMs. Only issue is that the price of silver is not what it used to be, and large lots need much metal, larger furnaces, etc.

Your HCL-Clorate process with atomizer is very hard to beat for an all-in-one economical and fast solution. Maybe only if the fluxing experiments work out and only if no PGMs.

I'd say that the atomizer is the biggest innovation in a very long time.

 

[ck]

deleted

 

[4metals]

There are 2 different atomizer types, wet and dry. The wet is what is used for refining as the material is going to be used in an aqueous chemistry anyway. The PDF posted by CK is a dry atomizer, the dry atomized powder is collected dry in a chamber and it is a huge advantage when making solvent or oil based pastes for brazing or other powdered metallurgical applications.

The dry atomizers are much more complicated, and about 3 times the price.

 

[MargueriteMingorance]

There are 2 different atomizer types, wet and dry. The wet is what is used for refining as the material is going to be used in an aqueous chemistry anyway. The PDF posted by CK is a dry atomizer, the dry atomized powder is collected dry in a chamber and it is a huge advantage when making solvent or oil based pastes for brazing or other powdered metallurgical applications.

The dry atomizers are much more complicated, and about 3 times the price.

Actually, the pdf says the atomized spray is quenched in water. It does look complicated, though.

 

[4metals]

Water atomizing is surprisingly uncomplicated.

 

[qst42know]

Several methods are described in this book with many diagrams and charts.


http://books.google.com/books?id=6aP3te2hGuQC&pg=PA102&lpg=PA102&dq=atomizing+precious&source=bl&ots=wO2MEMO__b&sig=XZC7n4C50XGAtf3H5f-1b70FN9o&hl=en&ei=LqexTIUXi_6cB-j5oJsG&sa=X&oi=book_result&ct=result&resnum=1&sqi=2&ved=0CBIQ6AEwAA#v=onepage&q=atomizing%20precious&f=false

 

[4metals]

Excellent book, and worth the $280 price tag if you are considering building your own atomizer. It took a month for my copy to arrive, I doubt it's because everyones reading it, more like they had to dust it off to find it.