Math Help

[alloy2]

Below is the precipitate from one pound of ore, the weight of the metals in the filter is .3 gr. what is the correct mathematical formula to figure out how many grams per long ton of ore.

I multiplied .3 by 2200 ending up with a incredulous amount of material which can not be right.

Thanks

 

[Smack]

Metric ton is 2204.6 lbs.

 

[alloy2]

Metric ton is 2204.6 lbs.

Thanks Smack, In the world of scrap the metric ton is rounded off to 2200 lbs, the rounding of numbers in the scientific world is unacceptable.

I still would like to have my numbers confirmed, if one pound of ore contains .3 grams of precious metals how many total grams of precious metals would there be in a metric ton.

 

[nickvc]

It may be the photo but the material doesn't look that clean, the amount you recovered needs very very accurate weighing and very clean and pure values to obtain a clear idea of the total amount when you are multiplying by 2200 even a small variance makes a big difference.
My advice is to carefully dissolve your powder, precipitate it again and dry it in situ in a beaker after very good washes, transfer the fully dried powder to a very accurate scale and weigh again.
To be honest if your figures are only 50%'of the original posted you have found a very good ore 8)

 

[alloy2]

It may be the photo but the material doesn't look that clean, the amount you recovered needs very very accurate weighing and very clean and pure values to obtain a clear idea of the total amount when you are multiplying by 2200 even a small variance makes a big difference.
My advice is to carefully dissolve your powder, precipitate it again and dry it in situ in a beaker after very good washes, transfer the fully dried powder to a very accurate scale and weigh again.
To be honest if your figures are only 50%'of the original posted you have found a very good ore 8)

Thank you nickvc, yes I realise this was a crude process but is one I use to prove values before spending money on an assay which could be barren of values.

This sample came from an ancient river bottom, the values are locked up in sandstone, the leach I used was cold unheated still some values in the black sand that did not dissolve. Without a proper assay I'm only guessing and like most prospectors I usually get it wrong.

I'm going to send a sample in for an assay and will post the results here once I have the report back from the laboratory.

 

[Harold_V]

I'm not troubled by the potential yield (21 oz/ton), but I am troubled by what I see. The material in the filter may or may not be gold--it certainly can be oxides of iron.
Armed with that idea, did you give the material a wash in hot HCl? If not, that's precisely what I'd do before jumping to any conclusions about yield, or even the presence of gold, unless you have obvious evidence that it exists (visible flakes or better).

Harold

 

[alloy2]

I'm not troubled by the potential yield (21 oz/ton), but I am troubled by what I see. The material in the filter may or may not be gold--it certainly can be oxides of iron.
Armed with that idea, did you give the material a wash in hot HCl? If not, that's precisely what I'd do before jumping to any conclusions about yield, or even the presence of gold, unless you have obvious evidence that it exists (visible flakes or better).

Harold

Thank you Harold, I used cold HCL and let it sit for about a week, as per your advice will run another sample.

 

[nickvc]

I'm not troubled by the potential yield (21 oz/ton), but I am troubled by what I see. The material in the filter may or may not be gold--it certainly can be oxides of iron.
Armed with that idea, did you give the material a wash in hot HCl? If not, that's precisely what I'd do before jumping to any conclusions about yield, or even the presence of gold, unless you have obvious evidence that it exists (visible flakes or better).

Harold

Thank you Harold, I used cold HCL and let it sit for about a week, as per your advice will run another sample.

Keep this sample in your beaker until clean and dry and then weigh on accurate scales, let's hope you have found a good source.

 

[4metals]

Another thing to consider is moisture, the paper was dried but it can pick up moisture cooling off in air if it is humid. In a lab, you would first weigh the paper before using it. Then use the filter paper, dry the paper, cool it in a dessicator, weigh it, and dry it again and cool it in the dessicator again. If it does not lose any weight after the second drying you can assume the paper is dry. This is called drying to constant weight and it is pretty much a standard protocol for weighing anything on filter paper.

It does not take much water to make up the 0.3 grams you measured so make sure you're not weighing water.

I do not know how much of a lab you have access to but you could also ash the paper and do a fusion and a cupellation. Then the weight of the bead can be assumed to be precious.

 

[Lou]

At the least use ashless papers and ignite until constant mass.

At that point a balance precise to a mg is required

 

[g_axelsson]

The obvious question is... did you test with stannous to make sure it was gold in your solution in the first place.

Then as people have pointed out, weighing something in a filter is tricky at least, and since your scale only gave one decimal the true value is probably within +/- 0.05g both at dry weight and with precipitate. It means that the result can be off +/- 0.1g at the worst even if there is no moisture absorbed. In other words, the result is within 0.2-0.4g.

Göran

 

[upcyclist]

Then as people have pointed out, weighing something in a filter is tricky at least, and since your scale only gave one decimal the true value is probably within +/- 0.05g both at dry weight and with precipitate. It means that the result can be off +/- 0.1g at the worst even if there is no moisture absorbed. In other words, the result is within 0.2-0.4g.

Good point. Since any digital scale rounds unseen digits to get that last digit, the final digit in any readout is on shaky ground. This is true even for more precise scales, because it doesn't take much of an air current to push the weighing plate down with enough force to change the readout by several milligrams. This is why precision scales use an enclosure around the weighed object.

When I'm cutting sparkly rocks, and my scale gives me hundredths of a carat, I advertise it rounded to the tenths. Of course my scale is not "Legal For Trade", either, so I use other workarounds. I don't say "This 4.12ct rock sells for $100/ct", I say "This rock is priced at $410 and weighs 4.1ct".

 

[alloy2]

After reading all the great advice given had decided to let an accredited laboratory do an assay, dropped the sample off this afternoon told the results should be ready in a week or so.

Good or bad I will post the results here.

 

[nickvc]

I have my fingers crossed for you.
It's always good to hear of others doing well 8)

 

[alloy2]

The deep purple crystals showed up after pulverising some of the larger fractions. My first thoughts were that these were garnet, your thoughts welcome.

Without the aid of the camera flash those pieces in daylight appear black.

 

[upcyclist]

Even if they are garnet, they're mostly only good for emery paper. It is a clue to keep your eye out for nice crystals while you're out there, though.

Unfortunately, gold ore processing (crush it all) and gemstone mining don't get along so well, so unless it's gem-quality corundum or something like that, you're better off smashing it