# Processed some fingers but low yield, is this normal?



## archeonist (Aug 17, 2012)

Hi guys, last week I processed some fingers using Lazersteve's method with AP. It was a small batch, only 70 grams of close cut fingers, just to see if I understand the process. Everything went well, the fingers came off and when I collected them it looked very promesing. Dissolved the foils in AR, this went well too. Finally precipitated using SMB, went also very well. After one day I collected the powder and after drying I got no more gold than only 0,17 grams. Is this a normal yield?


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## NobleMetalWorks (Aug 17, 2012)

archeonist said:



> Hi guys, last week I processed some fingers using Lazersteve's method with AP. It was a small batch, only 70 grams of close cut fingers, just to see if I understand the process. Everything went well, the fingers came off and when I collected them it looked very promesing. Dissolved the foils in AR, this went well too. Finally precipitated using SMB, went also very well. After one day I collected the powder and after drying I got no more gold than only 0,17 grams. Is this a normal yield?



Depending on the fingers, the thickness of the Au, how much of the surface area is actually covered in Au, etc.

If we can accept the following figures

about 2 grams of Au per lb of close cut fingers

about 453.5 grams in a lb

Then we can divide the average 2 grams of Au per lb but the number of grams in a lb to get a figure of about how much Au there is per gram

2/453.5 = 0.0044101433296582

Now we can take this number and multiply it by the grams you processed

0.0044101433296582 x 70 = .0.308710033076075 or for argument sake, you should have around .3 grams for your effort.

That's a little more than what you extracted, so, for argument sake again, we figure your fingers at 1 gram per lb, you would yield .15+

So to answer your question, you are within the lower ranger of yield, not the lowest. If I had to guess I would say your finger boards are from between 2000 and 2006. Where your fingerboards newer, shiny, on green board?

Scott


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## archeonist (Aug 17, 2012)

Hi Scott, that is a very quick reaction on my post, thanks! You very well answerd my question and I'm learning again. The majority of the fingers are from the 21st century so your guess is absolutely correct. I know I had a little loss during the process but I now know that a little loss is a big loss when yields are small. By the way this batch was a mixture of RAM an PCI fingers, some were shiny and some were not.

Thanks again!

Erwin


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## NobleMetalWorks (Aug 17, 2012)

My friends and family are always amazed at my salt water tanks because they are so huge, and they have so much going on in them, specially people who have tried small salt tanks.

The problem with a small salt water tank, is that when something goes wrong it happens super fast, and fish die quickly because you don't have the volume of water to act as a buffer.

Whenever you do small quantities, it makes things more difficult I think, from my own experience.

Don't feel bad about your yield though, it's better to do a small amount, realize you can improve, and when you are better do a larger amount. I'm sure your yield is actually better than a lot of people who do it for the first time.

People also seem to see a lot more gold in things than there really is. Here is some information that might put things into perspective for anyone else reading this post.



> Gold is so soft and malleable that an ounce of it could be stretched into a wire 50 miles in length, or be flattened into a sheet 100 square feet in area.



Scott


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## Geo (Aug 17, 2012)

archeonist, i didnt see you mention testing with stannous chloride. are you sure you precipitated all the gold that was in solution.if you didnt test, theres no way you can be sure.trying to refine without testing is like a doctor trying to operate in the dark. it doesnt work out well for the patient just like it wont work out well for your outcome.


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## archeonist (Aug 19, 2012)

@Scott, thanks for your positive input, it helps me staying motivated to test some more batches!

@Geo, you're absolutely right about the stannous, I didn't test the solution after SMB. The solution was almost clear so I presumed that there was hardly any gold left in solution. Next time I use stannous.

Another thing that is important is to wet the filter before you bring your gold solution in. Otherwise the solution will be drawn into the filter and has to be washed out with a lot of water. I didn't do that so there I lost some gold too.

Thanks for your replies guys! 8)


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## NobleMetalWorks (Aug 19, 2012)

archeonist said:


> Another thing that is important is to wet the filter before you bring your gold solution in. Otherwise the solution will be drawn into the filter and has to be washed out with a lot of water. I didn't do that so there I lost some gold too.
> 
> Thanks for your replies guys! 8)



You're right about wetting the filter prior to filtering. As you get better with your process, you will find your yields will increase. Also, you might want to consider processing your filters for values also. I retain and process all my filters as if they contain values. I have had a few pleasant surprises doing so.

You also might want to pick up a copy of the Laboratory Companion by Gary S. Coyne. There is a lot of really good information and reference material in the book on materials, equipment and TECHNIQUE. I purchased a fairly new one from Good Will, but I know there are ways and places you can download the electronic version as well if money is an issue.

Scott


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## Tzoax (Feb 13, 2018)

I asked myself many times the same thing - why is my yield results of processing fingers too "low" (based on average reported yields). And after many tests by changing little details each time processing, i found it - in my case it was because i was using filter papers. No matter what type of filter paper i used my results was in range 1.65-1.88g of gold per kilogram of close cut fingers. No matter what filter paper i used - a small gold particles went through filter paper. I will never again use filter papers for filtering AP (fingers, pins, gold traces on PCBs etc).

Instead i am using *charmin plug with regular wet towels*. First i wash wet towel very well in a stream of water, then i insert one wet towel into the funnel tube (very tight)... 

Filtering is a little bit slower...but my yields drastically goes up - with processing fingers and pins with AP.
It was one of the best thing i learned so far that made my yield results go up.
Alex


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