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Surface grids on melted gold


GeoJack

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using any flux?

I would guess it's oxides of elements other than gold , such as copper silver tin manganese iron and a smattering of rare earths.

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just surface crystallzation.......maybe to cold of a mold. were you just trying to melt or smelt it? A good smelt should have gotten rid of the iron......

Edited by El Dorado
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just surface crystallzation.......maybe to cold of a mold. were you just trying to melt or smelt it? A good smelt should have gotten rid of the iron......

That's what I'm thinking. Pore Temp may have been low.

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Just melting, no smelting. Smelting is adding material right? Mixed flux with gold, waiting until the gold disappeared and the glob was red hot. Cooled and busted away the flux to obtain button. Remelted dore until molten, cooled.

Every time the same.

Edited by GeoJack
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smelting is using certain flux mixes. Generally flux ingredients will oxidize out base metals and they will get locked up in the flux. What are you using as a flux and what kind of torch?

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Your gold could be high in other metals,lead,copper,zinc,silver,PGM's and sulfides.(complex) just add a small pinch (5%)of powdered pool chlorine to the flux and melt it again. should clean it right up. we had a bunch of gold that did this to us and this solved the problem. use a borax/silica/salt flux. the metal that goes into the flux is recoverble but requires a whole new process to recover and unless you have a lot of it (old flux) not worth the trouble. AzNuggetBob

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Used Hank Chapman's Flux mix, Borax, Soda Ash, Silica & Manganese.

MAP Pro torch and propane torch in this set up. http://files1.kyozou.com/Picture.aspx?width=210&height=210&id=17511432

I'll remelt as there are some spots with some material still in it on the gold. Will add the chlorine salt. Ratio?

Bob, what is the process for recovery of the small balls of gold in the flux? X-ray tested at 92% AU, 6% AG prior to melt.

Edited by GeoJack
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your problem is most likley that you are using a torch, you should be smelting with a very hot fire.

heres a recipe buy some flux for bullion, use a crucible, and a furnace propane, elec, we just use a mesquite wood fire.

you have to remeber smelting is so we can get the purest product to market, one needs to heat for at least 30 minute + 15 just to be sure you are getting things hot enough to remove the crap, having a good store bought flux is best also.

heres a pic of a bead ( left in the crucible till cool, and some nuggs we made from pouring hot into water, that pattern on the surface is normal and we use to indicate purety of our product if it is pure it will draw in at the center of the button and will often show crystalization, if you get this your product is very sellable.

notice a little glass left on the nuggs but they look good hope this helps.

GT........

post-27224-0-00825400-1406905037_thumb.j

Edited by Gold tramp
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Gold Tramp,

Using store bought flux and crucible in kiln, two torches heating the crucible, Melt Your Own Gold is the supplier as mentioned above. Most melt times are at least 45 min. to 1 hour before I extract from crucible. They state 5 - 10 minutes. Let cool and bust off flux.

I've gotten the button before without the black coating and it looks like yours with the crystalline pattern on the surface.

I'll melt both again today as I have more to add to the mix and will see what comes out. Didn't get the hot tub crystals, HD only had big containers for pools.

I am getting the dimple in the middle when cooled. From my X-ray of 92% AU and 6% AG prior to smelting, there shouldn't be that much iron to remove right?

We'll see in a bit.

Thanks again all.post-25522-0-74493500-1406916776_thumb.j

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How much you want for that button El D?

It's already turned into jewelry...... I have posted this before... its another button from a smelt. They can be quit beautiful

http://www.nuggetshooter.ipbhost.com/index.php?app=gallery&image=225

Edited by El Dorado
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GeoJack

You can Google this to get more info. its called the F.B. Miller process. and was also used by the Rand refining co. S.Africa. for refining gold and gold containing by-products. they produce bullion for the Sydney mint.
They use chlorine gas but you can also use a small amount of powdered chlorine.for your metal Id say no more than 5% powdered chlorine by volume.equal parts borax/silica/salt flux. I normally use a graphite crucibles with this process.
make sure you have plenty of flux as too much chlorine is hard on clay crucibles.
I use this process if suspect Im dealing with complex ore with a lot of base metals,pyrites, sulfides thats causing crystallization.
As always use it in a well ventilated area only. I dont like using to much bone ash for this as it tends to make the flux too thick and hard for any Metallic droplets to settle to the bottom of the crucible.JMO
This process will get your gold to 996-997 fineness.


Here is a few shots of some bars I was pouring a few years ago.sorry about the photos as they are photo's of photo's. I use a different flux for these.

these bars ran 60/40 gold-silver and weigh approx.10 oz.s each,
and as you can see after the black flux is knocked off they are brite and clean, no porosity or crystallization. the gold is from a small semi trailer mounted cyanide leach pilot plant we set up on some old tailing piles.
I poured at least one bar every other day as we rotated (load/strip)the carbon columns.
AzNuggetBob

http://s245.photobucket.com/user/aznuggetbob/media/5d79b29a-b54f-4c36-b572-50e2bfab8b0d.jpg.html

http://s245.photobucket.com/user/aznuggetbob/media/cc5ef38c-6bba-4bb9-ac57-eae24094d2f5.jpg.html

Edited by AzNuggetBob
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You can use this process without any problems. I recomend when pouring dont scrape off the flux, we didnt.
just let it cool to the point it becomes solid and dump it out of the mold. DO NOT quench. this tempers and possibly crystallises the bar depending on temps.
after it cools just pound the hardened flux off with a hammer. the refiner will thank you.
Trust me on that one. good luck Jack.
AzNuggetBob

Edited by AzNuggetBob
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  • 2 weeks later...

I use two Mapp gas torches on my set-up.....melts in no time at all.

Now that is a nice looking button

Edited by El Dorado
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That was my first bet. I did the same thing with some silver and it came out like that. Deferent Pattern but Crystals the same. Next pore was hotter and all came out good and shiny. Borax and Sand helps keep the Heat.

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