Smelting cons

[IDAu]

The whole assay ton sample thing is cool, but I quickly realized without an analytical balance it’s nearly useless to me.

Does this sound like a good way to approach something I can pull data from?

If my math is correct, 1/2 OPT should come out as 1g per 141 pounds.

So if I pull a 70 pound sample, run it, and smelt the cons, I should get a roughly 0.5g button if it’s 1/2OPT. It gets me something I can actually weigh, and don’t have to miserably try to separate tiny varying mesh gold to weigh, losing some along the way.


If that’s a good approach, is this a decent flux recipe for sulfides? I don’t know the exact composition of my cons. I see a tiny bit of copper, possibly some Pb or Hg, and lots of iron.

For every 30g of cons-
40g litharge
28g sodium carbonate
30g borax
3g silica
A few iron nails

Thanks

 

[goldshark]

Without knowing what your cons consist of, your recipe will probably work to a degree. The only problem with crushing and grinding, then panning, is that it is not nearly as accurate as a good fire assay. You will lose Gold either to floating away, or still locked in the middling.Since I can't afford a scale down to .0001 gram, or better, I have adopted a ten assay ton method. This is accurate for a .1 Toz/ton assay using an $80.00 .001 gram accuracy scale. Another technique is to use a caliper to measure the diameter of the prill. This works best on Au that has been in quarted, Ag removed, then heated to melt temperature. This will produce a nearly perfect sphere of Au. Another thread discusses the diameter verses weight conversion. I gave a link to the table, but it has been a while, so I don't know the name of the thread, or where it may be found.

 

[IDAu]

Without knowing what your cons consist of, your recipe will probably work to a degree. The only problem with crushing and grinding, then panning, is that it is not nearly as accurate as a good fire assay. You will lose Gold either to floating away, or still locked in the middling.Since I can't afford a scale down to .0001 gram, or better, I have adopted a ten assay ton method. This is accurate for a .1 Toz/ton assay using an $80.00 .001 gram accuracy scale. Another technique is to use a caliper to measure the diameter of the prill. This works best on Au that has been in quarted, Ag removed, then heated to melt temperature. This will produce a nearly perfect sphere of Au. Another thread discusses the diameter verses weight conversion. I gave a link to the table, but it has been a while, so I don't know the name of the thread, or where it may be found.

Yeah, that’s what I’m worried about. I was crushing and panning and not finding much gold. But as soon as I got my shaker table set up and ran my sample through that, I found a lot more colors.

I figure if I take the cons from a 70 pound sample I will at least get something weighable. Or I won’t… and I’ll know to move on.

Where do you get a 0.001 scale for only $80?

 

[goldshark]

I got mine at the Tucson Gem and Mineral show last year. Google .001 gram accuracy scale on eBay. They list there for $24- 25. 00.

 

[SRM]

Amazon has several. I bought a smart weigh from them (50g - .001, $35) that calibrates well and has been trouble free. Lots quicker than using my old USGS surplus sartorius analytical balance

 

[IDAu]

Wow. I don’t know how I missed the small 0.001g scales that cheap, thanks!

 

[IDAu]

Amazon has several. I bought a smart weigh from them (50g - .001, $35) that calibrates well and has been trouble free. Lots quicker than using my old USGS surplus sartorius analytical balance

Definitely an upgrade, but I am worried about the precision.

The first few times weighing the standards it was +/-0.003. The next few times it was +/-0.013 and wouldn't return to zero.

Is that about normal for these cheaper ones, or should I return it and try again?

 

[goldshark]

It usually comes with a leveling bubble. That needs to be flat and level for accurate weighing. Also any slight breeze will affect the performance. If all that is done accordingly, then return it if it still isn't working. At that accuracy, even a slight wave of the hand will weigh the air pressure wave.

 

[goldshark]

Forceps are necessary for handling the prill. Finger oil will be weighed as well.

 

[IDAu]

It usually comes with a leveling bubble. That needs to be flat and level for accurate weighing. Also any slight breeze will affect the performance. If all that is done accordingly, then return it if it still isn't working. At that accuracy, even a slight wave of the hand will weigh the air pressure wave.

Thanks. Didn't think about oils! But I did make sure the draft cover was shut.