# silver from sands



## Mark Dando (Jun 24, 2013)

How do i recover silver from black sand concentrate ?? I have had the concentrate tested and it contains 3500 grams of silver per ton of sand which would be the best and safest way to recover the silver ?/


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## mda20 (Jun 25, 2013)

Welcome Mark Dando

I hope this link will help you.
http://gpex.ca/smf/index.php?topic=3686.0;wap2

Good Luck.


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## galenrog (Jun 26, 2013)

How was it tested?? XRF does not count.


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## Mark Dando (Jun 30, 2013)

please explain why xrf does not count if it has been done over numerous samples and the results have been analyzed through computer programme designed to cleanup results


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## Platdigger (Jun 30, 2013)

For it to be true, these sands must be right down stream of a very large silver deposit.
And then, I would be looking for that.


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## g_axelsson (Jun 30, 2013)

XRF tests the surface of objects. Was the samples milled and homogenized before XRF?
Any mineral grains in sand is either enriched on the surface or depleted by geochemical processes (weathering).

In this case a fire assay would tell you much more about what's inside the sand.

In any case, 3.5% is close to nothing for an XRF and could easily be showing this error depending on how it was calibrated and mistakes by the operator.

Do a test, create a sample with a kg of barren black sand and add 35g of silver powder, mix well and test it with the XRF. A standard and test solution is always good to have. Don't tell the operator which sample is the control.

Good luck!

Göran

(edit : math error, fixed a decimal problem)


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## galenrog (Jun 30, 2013)

g_axelsson just gave the short answer. Longer, more technical answers to why XRF is not the preferred way to determine quantative analysis of sands can be found using the search function on this forum. I prefer to have ores and mineral sands fire assayed for the values I expect to find.

I have had one of the local scrap yards use XRF on some slag from a small smelt a few years ago. The results were over 3% gold and 8% silver. This practical test showed me that XRF machines should be used only for what they were designed to do, testing solid homogenous masses, not slag or sands.

I would ask what a proper fire assay analysis shows.


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