# BDG - Separatory funnel and left overs???



## Paige (Jul 18, 2007)

Having put my AR & BDG into a separatory funnel, I shook it for 5 minutes and let it sit.

The bottom part which is supposed to be clear, still is as dark as unprocessed AR.

I am using a 500ml sep. funnel.

I have kept the "stuff" on the bottom, to out through again and again. I keep getting light yellow fluid on the top to later drop with oxalic acid but my AR doesn't seem to be dropping all of its gold.

I have not thrown anything away. Could it be that my AR was so rich with gold that it just is going to take many passes with BDG to get it all out?

I have a 1L sep. funnel on the way to speed things up.

NOTE: BDG will dissolve some plastics!!. It comes in metal can.

Paige


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## Noxx (Jul 18, 2007)

Hello Paige, don't worry, I'm here to help you 
Ok, how much gold did you have in solution and how much BDG did you use ?

Understand that your AR will clear if there is *only* pure gold dissolved in it. The BDG takes only gold chloride and leave all others in the AR. That's why your Aqua Regia is still colored. 

Give more than one shake to your mix of AR and BDG. I did 5 shakes of 5 minutes each to get all the gold. You don't want to leave some in AR right ?  But just test your Aqua Regia with Stannous Chloride to see if there is still gold in it. If not, go to the precipitation of your gold.

BDG will also melt styrofoam (sp?).

I hope it helps... If you have more questions, just ask !


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## Paige (Jul 18, 2007)

Thank you for helping me, Noxx.

This gold in my AR has been thru three passes, with in between cleanings of water, HCL, Sulph. acid, ammonia, ammonium chloride, sodium chlorate, (to get rid of any PMG's). My AR is a rich golden color, but with each pass with DBG, it doesn't seem to be picking up much of the AR. The AR remaining at the bottom of the sep funnel is still dark golden yellow, and as I run it through, the DGM only seems to be picking up very little of my AR-Gold chloride. I used a minimum of Nitric so I didn't have much to cook off. DID NOT USE urea. It's like the AR has a mind of its own and doesn't want to give up any gold chloride!

I did shake it for several minutes. And let it sit for over an hour.

I have tried using 250ml of DMG w/ 250 ml AR. 250 ml DMG w/ 200 ml AR.

H E L P ! ! ! 

Paige


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## lazersteve (Jul 18, 2007)

Paige,

Your problem could be related to the acid molarity in your AR. The patent for BDG use states the HCl concentration of the pregnant solution should be between 0.5N and 1.75N, that is 0.5 mole HCl per liter to 1.75 moles HCl per liter. Diluting your AR could be one solution to your trouble.

Another possible solution is that your BDG may be saturated with gold. According to the same patent BDG will hold approximately 10 grams of gold per 200 mL. Following the patent guidelines of a 50/50 ratio of AR to BDG in the funnel you have 200mL diluted AR to 200 mL BDG in a 500 mL funnel. The good news is that you can reuse the BDG after you drop the gold from it using aqueous oxalic acid. 

As Noxx stated you need to really shake the funnel vigourously to get the BDG in contact with the AR solution. Don't drain off the stripped AR lower layer until the top layer has settled out clear. The patent recommends a 10,000 RPM centrifuge to speed the separation. Put all your lower layers in a separate vessel and test for gold after the first pass of BDG. The patent recommends 2 extraction passes and 3-5 diulute HCl rinses of the BDG afterwards.

I hope this helps you solve your problem.

Steve


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## Paige (Jul 18, 2007)

Lazersteve & Noxx,

Many thanks to both of you for helping me. I think I will try dilution with distilled water & increase my shake time.

Paige


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