Gold Fingers

[arisas]

Ok so i weight my gold fingers and they are 200.2 grams after adding HNO3 with H2O 1 to 1 part i filter them and i got about 2 grams so i would say from 100 grams of Gold Fingers there is 1 gram of gold foils now my question is after the refining processes how many grams i would have...?

 

[jason_recliner]

You would find some others' results with the keyword "yield". At the end of the day it only matters what YOU get.
You're looking for a definitive percentage of gold in your foils by mass, but it will depend on the starting material and how aggressively you etched them.

Also you have likely dissolved and re-cemented some gold by using 1:1 HCl:H2O2, which is way too much peroxide. That could increase the gold percentage by mass in your collected foils, but only if it includes all the dirty looking powder. Otherwise it would reduce it. {edit:} Either way, it's not the best plan. Read some more about the copper (ii) chloride / Acid peroxide / "AP" process and you will learn why only a splash or two of peroxide is really required.

 

[g_axelsson]

Jason, he used nitric acid diluted with water, not HCl and peroxide. So there shouldn't be any dissolved gold.

To weigh foils is hard. It can contain a lot of water and other crap even if they appear dry and clean. So it's almost impossible to say how much you would have after refining.

How well you managed to clean the foils will be apparent on the color of the AR.

Last time I had some gold foils from nitric treatment I washed it lightly then added HCl to dissolve the gold. It actually dissolved all the foils without me adding any more nitric, the amount still sticking to the wet foils was enough.

Göran

 

[jason_recliner]

Jason, he used nitric acid diluted with water, not HCl and peroxide. So there shouldn't be any dissolved gold.

I totally misread it. Shame on me.

 

[MarcoP]

Göran, did you used straight nitric?

Marco

 

[g_axelsson]

Göran, did you used straight nitric?

Marco

Yes, it was a small experiment in a test tube and I used the resulting gold chloride for my standard gold solution so there were not a lot of foils. Not saying it would work in a large batch but shows the truth behind always incinerate when switching acid unless you want to dissolve gold.

Göran

 

[butcher]

Even if there is not any nitric acid left on the foils, there could be nitrate salts left on the gold foils, like copper nitrate, then when you add acid HCl some of the hydrogen from the acid can act to convert the copper nitrate salt into a little bit of nitric acid mixed with the HCl, basically making a type of poormans aqua regia, which can put some of the gold into solution.

Incineration the high temperature can decompose the salts of metal and acids, driving off the acid portion of the salt as gases, in this case the nitrate salt of the copper nitrate on the gold foils will decompose to NOx gases, mostly consisting of NO and NO2 gases, basically converting the copper nitrate to a copper oxide (which when the HCl acid is added will not dissolve any gold, but the HCl can easily dissolve the copper oxide).

 

[Anonymous]

To be fair, if you are going to further recover gold from the foils using AR I would question the need to add an incineration step into the process. A couple of good washes in distilled water usually does the trick perfectly well.

 

[arisas]

Jason, he used nitric acid diluted with water, not HCl and peroxide. So there shouldn't be any dissolved gold.

I totally misread it. Shame on me.

Its okey its my fault i should have put some pictures with the reaction of the diluted Nitric Acid

 

[arisas]

Well i have a little pill box that i save all the foils i recover from CPU's, pins and stuff and i just started on a big scale a few days ago until then i was just testing ...but now i'm searching for the best next step to take i don't want to lose any gold by making mistake

 

[gold4mike]

My long term average after roughly 100 pounds of edge fingers is 2.2 grams of gold per pound of fingers. I cut them close using a sheet metal shear and don't have much unplated fiberglass in the feed material.

 

[silversaddle1]

My long term average after roughly 100 pounds of edge fingers is 2.2 grams of gold per pound of fingers. I cut them close using a sheet metal shear and don't have much unplated fiberglass in the feed material.

And people seem to pay $100.00 a pound for them on ebay. Crazy ain't it?

 

[Anonymous]

Yep absolutely crazy isn't it silver?

I agree with Mike. Approx 4.5g per Kg as a long term average.

I've had some at over 10g per Kg before but those were special 8) 8)

 

[arisas]

Yep absolutely crazy isn't it silver?

I agree with Mike. Approx 4.5g per Kg as a long term average.

I've had some at over 10g per Kg before but those were special 8) 8)

tomorrow I'm starting the next batch after the reaction i will measure again and post more test results

 

[gold4mike]

I didn't find time to process all my fingers this summer and have 20 lots of one pound each up on eBay right now for $89.00 per pound. I've sold 6 so far and several people have asked me to reduce the price since they're listed for more than their estimate of the gold content.

I have "stuck to my guns" so far since there is no reason to sell them for less if I don't have to. I assume people are buying them on speculation that gold will go up soon. I fully believe it will, but need to free up some cash for Christmas or I wouldn't part with them.