# erased



## patnor1011 (Jan 15, 2018)

If there are a high percentage of precious metals and a good amount of material there will be no shortage of buyers. 
Where did he get his assay and what does it say?
Is there a chance to upload it? Quite a few members do have experience with mining and ores but they need to know what is in there and in what quantities


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## nickvc (Jan 15, 2018)

Whatever he said it sounds like it could be bull looking at the xrf reading, where did he come up with these figures? 
At that sort of concentration of metals it would look metallic not like sand.


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## patnor1011 (Jan 15, 2018)

What he needs is proper fire assay by a certified lab. Nobody will buy sand based on XRF readings. XRF only measure surface and is not a great choice in this case.


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## nickvc (Jan 15, 2018)

I’m still calling bull, if that had that much precious metals as your friend claimed it certainly wouldn’t look like beach sand or perhaps it’s you posting looking for a bite, if anyone had a deposit that rich he wouldn’t need our help the big refiners would be climbing all over him with offers !


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## jimdoc (Jan 15, 2018)

engelman said:


> Thank you again but I just agreed with an Australian Refinery to take the sample.




Awesome, let us know how that works out.


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## snoman701 (Jan 15, 2018)

engelman said:


> He say that the number are 14% gold, 23% Rhodium, 10% Palladium, 5% platinum etc.. from each MT of sand. I know those numbers sound ridiculous but he say he invite who want to see and make tests and to send samples.



You can't just shoot sand with an XRF and expect the result to be at all representative of what is in there.

The XRF is programmed in precious metals mode, which won't even recognize elements that aren't commonly associated with precious metals, such as pretty much all of those that would be found in the sand portion (alumina, silica, magnesia, etc). I'm not entirely sure how accurate my statement about what specific elements are recognized, but I know there are elements that are omitted.


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## g_axelsson (Jan 15, 2018)

I agree with the people saying the results are unrealistic. Iridium at close to 50%... never in a natural source in bulk material.

Your friend is chasing a dream, not reality. It will be a harsh wake-up when the reply from the Australian refiner arrives. Either he accept that he doesn't have anything at all, or (more likely) he will accuse the refinery to steal his gold.

This is a situation when I would not even accept a free sample to refine. I would only be accused of foul play.

Göran


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## snoman701 (Jan 15, 2018)

Well...the iridium could actually be more gold, or platinum, or osmium. 

But the xrf results are completely unreliable either way. With sand like particles you'd first have to reduce to a powder, and at that point you might as well just finish the fire assay to get good numbers. The fire assay leaves less to the analyst. 


Sent from my iPhone using Tapatalk


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## Reno Chris (Jan 15, 2018)

XRF guns can be operated improperly. Proper operation of these devices are key to getting reliable and realistic results. They must be calibrated correctly or they will give meaningless results. I am guessing your friend is not operating the device correctly.


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## UncleBenBen (Jan 15, 2018)

I'll try a sample. I'll need a kilo of his concentrate shipped to the US, postage paid, to calculate a good representation of the product. If I find even half the Au percentage claimed then good days are ahead for us all.

If interested, send me a PM for the PO box number.


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## nickvc (Jan 16, 2018)

Just to give some perspective about gold mining the big mining companies are usually working in ounces, if that, per ton and your friend is claiming 4500 ozs per ton of material and that’s just gold not to mention the other precious metals, please warn him he is almost certainly going to be very disappointed by any results he receives from anyone.


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## sohwohn (Jan 17, 2018)

I've worked a lot with a table XRF machine and I'm telling you a handheld one is even more unreliable.

Even with my table XRF, I sometimes get false readings due to interference. For example, with presence of high amounts of Zn and W, it is impossible to determine whether there're Au or not. Especially raw ore usually contains like super little amount of PMs, 1% Au is like getting 1kg from 1ton. The so called high-grade Au ores we are dealing with in China are like 0.001% Au. So your ore grade is either making you millionaire or it's a false call. Your XRF result is showing at least 79.23% metal so it's (as mentioned above by others) almost metallic pieces. Smelt it and it will form alloy. However, according to the pictures, I think this is less like true.

My advice is to calibrate your XRF device first. To calibrate it, you need standards. To simplify, it's that you need to teach your device 'how does 99% Au look like' and 'how does 1% Au look like'. Then you make a super simple curve or linear coefficient. Then your device can estimate from 1% to 99% that how a 50% Au would show. Doing such calibration would give you semi-quantitative result. I expect Au grades usually lower than 0.05% and most likely lower than 0.005%. If it's such case, even 1% and 99% standards won't be very helpful. Because Au doesn't come alone in raw ores, it comes with other base metals. 1% Zn and 1% W can completely 'cover' 0.1% Au and you won't see anything to indicate Au from the spectrum.

The more standard way to use XRF device is to determine a sample's main contents. Like, when you find Sb, it's most likely with Au. When you find As, it's most likely with Au. Also, you get to know what to remove, so that to 'concentrate' the PMs. Or, you can use ICP, etch what you want and read the solution.

I feel like I'm leaving the subject. Anyway, for what you have there, it's impossible to do a proper and reliable assay. You better send it to qualified lab or get some other things to tune your XRF device.


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## sohwohn (Jan 17, 2018)

sohwohn said:


> I've worked a lot with a table XRF machine and I'm telling you a handheld one is even more unreliable.
> 
> Even with my table XRF, I sometimes get false readings due to interference. For example, with presence of high amounts of Zn and W, it is impossible to determine whether there're Au or not. Especially raw ore usually contains like super little amount of PMs, 1% Au is like getting 1kg from 1ton. The so called high-grade Au ores we are dealing with in China are like 0.001% Au. So your ore grade is either making you millionaire or it's a false call. Your XRF result is showing at least 79.23% metal so it's (as mentioned above by others) almost metallic pieces. Smelt it and it will form alloy. However, according to the pictures, I think this is less like true.
> 
> ...


In addition, XRF PM assaying can also be done by fire-assay. Smelt the sample and separate PMs from other base metals which have different lower melting and boiling points. This whole XRF + fire-assay thing is not simple and most likely cannot be done without experience. You need standards, you need to know Chemistry well to know what to put into the furnace. For example, my lab is using 20g Cu plates to determine PM values. We used real PM 99% powders to make our standards and we use these standards to compare spectrums of Cu plates smelted with samples. What I'm telling you is what happens in some labs and it absolutely can be easily done without facilities and experience.


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## g_axelsson (Jan 17, 2018)

sohwohn said:


> Especially raw ore usually contains like super little amount of PMs, 1% Au is like getting 1kg from 1ton. The so called high-grade Au ores we are dealing with in China are like 0.001% Au.


Slight mistake there... 1% is 10 kg/ton.
0.001% = 10g/ton, quite a good ore.

Thanks for the description of how to use an XRF.

Göran


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## sohwohn (Jan 20, 2018)

g_axelsson said:


> sohwohn said:
> 
> 
> > Especially raw ore usually contains like super little amount of PMs, 1% Au is like getting 1kg from 1ton. The so called high-grade Au ores we are dealing with in China are like 0.001% Au.
> ...


Yes, you're correct. 1% is 10kg/ton. Thanks for clarifying.


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