# BDG and golden refuse in seperatory funnel



## Paige (Jul 19, 2007)

I ran another batch of my AR and the BDG is clear and there is a golden colored liquid at the bottom. I think that I know why, now. Andthis might be helpful to others.

If you leave nitric in the light it turns from clear to a dark golden color. Sunlight will darken Nitric is minutes.

I believe that I have all of the gold out of solution and the remander in the bottom of the separatory funnel is barren solution. As I continued running this through over and over, I got all of the gold out, hence my BDG is clear. The color of the good stuff on top had been geting lighter and lighter.

Will test AR solution with stannous chloride tomorrow to confirm that it is all gone.

Does this sound right?

Paige


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## lazersteve (Jul 19, 2007)

Paige,

If the BDG layer (upper) is clear you have most likely successfully removed all of the gold. Always perform the stannous chloride test to be sure. 

Steve


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## Paige (Jul 19, 2007)

Lazersteve.

It was the color of the lower part which was throwing me.

Paige


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## lazersteve (Jul 19, 2007)

The gold will into the upper layer, don't worry about the color of the lower layer. The lower layer contains all the other metals, leftover acids, and trash. NOTE: PGM's could still be in your lower layer.

Steve


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## NobleMetalsRecovery (Jul 22, 2007)

BuDG is intended for recovery of gold from HCL solutions, NOT nitric or AR solutions. If you're working with AR, the nitric should be removed by boiling it down 2 or 3 times. I think I've seen that you do that already. Urea may not be an acceptable method becuase it may contaminate the BuDG.


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## Paige (Jul 22, 2007)

Thanks Steve and Lazersteve.

I boil my AR to get rid of nitric. Afraid I might be boiling off some gold????

I just boil in a large beaker.

Should I be using one of those flat bottom glassware things that narrows at the top and condensing my evaporate to save any gold going up in the boiling process?

Or just don't boil too rapidly?

As Harold_V has taught, I always check my solution by hanging a bracelet chain in the solution to make sure there is no more reaction.

Paige


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## goldsilverpro (Jul 22, 2007)

Can someone tell me the advantages of using BDG? Why not just directly drop the gold out of the acid solution. Why go through this totally extra BDG step? If you say, the gold is purer, I would question this. All my life, I have gotten pure, salable gold without going through this completely extraneous BDG step.

If you do use BDG with real aqua regia, why not control the nitric usage so that there is no extra present after the dissolving is complete? This way, maybe the boil down step wouldn't be needed.

Personally, I would avoid any method that would force me the boil the solution down.


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## NobleMetalsRecovery (Jul 22, 2007)

Forgive me for answering this in an academic fashion since my hands on experience with BuDg is very little. I have used BuDG to collect AU values and then PP (precipitated) the AU only a few times.

The following is theory:

If you're dropping gold from a HCL solution then there's no need to boil it. My interest in BuDG is it's ability to pull gold out of a big mess (unfiltered debris), and then purify it and drop it clean, all in one operation. 

Let's say you have a mess that's a pain to filter. You could add BuDG, shake it up real well and then remove the BuDG. The BuDG will now contain the Au and some base metals. You can scrub the BuDG with a 10% solution of HCL. The HCL will pick up the base metals. Now separate the BuDG from the HCL. Now once you PP the AU it will be around three 9's fine.


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## aflacglobal (Jul 22, 2007)

I like that avatar chris. Now if i can just get mine back. lol


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## NobleMetalsRecovery (Jul 22, 2007)

Laser Steve and Paige,

I see you talking about upper layer and lower layer. The upper layer will USUALLY be the BuDG, but it doesn't have to be.

I've loaded the BuDG with so much gold that I once had 3 layers. A BuDG (heavily gold ladden) layer on the bottom, the acid layer in the middle, and another layer of BuDG on top with very little gold. I remixed it and then it formed only two layers, the BuDG was now all on the bottom, and the HCL on the top.


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## Harold_V (Jul 23, 2007)

Paige said:


> I boil my AR to get rid of nitric. Afraid I might be boiling off some gold????



If you are actually boiling, I'm afraid you are, indeed, losing gold. 

The story is long, and hardly worth repeating, but the short version is that prior to my first fume hood, I ran from a bench in my garage, directly under a window in which I'd placed an exhaust fan. My travel trailer was parked a couple feet beyond the window, in direct line with the fan. (What the hell was I thinking?)

I was evaporating a solution one day and noticed that it was going a little too fast. A few days later, a large area, fan shaped, was covered in light purple dots. I had to rub the siding with compound to remove the stains. 

When evaporating, keep watch on the cloud that leaves the dish. If it contains the slightest hint of color, you're losing gold. Insure that the temperature is always below the boiling point. Even when you add a button of gold to consume free nitric, if the button is actively dissolving, keep a watch glass over the beaker. You'll notice that gold chloride forms on the watch glass and drips back into the beaker. Once the action is subtle, you can remove the watch glass and begin the evaporation process, eliminating the final traces of nitric. 



> I just boil in a large beaker.



That should be adequate, especially if you add a button to help consume the free nitric. An evaporating dish is better if you rely on evaporation alone---it presents a larger surface area, therefore expels heat at a greater rate, and evaporates quicker.



> Should I be using one of those flat bottom glassware things that narrows at the top and condensing my evaporate to save any gold going up in the boiling process?



An Erlenmeyer flask? 

I don't see the need for one of those in any of the refining operations unless you're using one with a spigot and a Buchner funnel for vacuum filtration. Erlenmeyer flasks defeat the purpose you're trying to achieve. 



> Or just don't boil too rapidly?



Exactly!



> As Harold_V has taught, I always check my solution by hanging a bracelet chain in the solution to make sure there is no more reaction.



I suggest you move to a piece (button) of pure gold. A chain, yellow gold, is capable of forming enough silver chloride on the surface to present a false indicator to you. It might show no action when there was still considerable nitric present, but isolated from the chain by the chloride film that forms. 

My procedure was to use a button of relatively pure gold, gold that needed to be re-refined, anyway. I weighed it before adding it to the solution I intended to evaporate, then weighed it afterwards, so I knew how much gold I had added to the process. That was important for me because I ran my customer's gold on an individual batch basis, and had to know what belonged to me. 

Harold


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## Paige (Jul 23, 2007)

I will follow your advice, Harold_V.

Thank you.

Paige


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## Paige (Jul 23, 2007)

I think that I will get one of those 5 gram bars of 9999 gold off of eBay (at rip of prices), punch a hole in it and hang it in my AuCl3/AR by plastic thread to see if I have any nitric left.

I have learned that when I first began purifying, I used WAAAAAAAAY too much acid. Now, I use small amounts and try to have undissolved gold left at the bottom and filter it out for another batch.

Paige


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## goldsilverpro (Jul 23, 2007)

Noble Metals, have you thought of a reason, in academic fashion, why there would be 3 layers? Doesn't make much sense to me.


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## Noxx (Jul 23, 2007)

?
Habitually BuDG is floating on water... not at the bottom.
Since every acid we use is heavier than water, I don't see how it could be the lower layer :?:


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## aflacglobal (Jul 23, 2007)

Difference between specific gravity and relative density


Relative density is a dimensionless ratio of the densities of two materials. The term specific gravity is similar, except that the reference material is water. Relative density can help quantify the buoyancy between two materials

Specific gravity is a special case of relative density. While specific gravity has a reference density of water, relative density can have any reference density that is used. It is best to specify the reference material when using relative density.

Which states "the relative density of the object with respect to the reference material".

While relative density will not change as long as consistent units are maintained, the relative density is relative to its reference. The relative density of an object relative to mercury, is different than the relative density with respect to water (specific gravity).

Taking the relative density with respect to alcohol, water has a specific gravity of 1.2, and the iron has a specific gravity of 10.

Taking the relative density relative to water, the numbers would be .78, 1, and 7.9. 
With respect to iron, the numbers are .1, .12, and 1. These are all correct relative densities, however it is with different reference points.

:?:


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## steveonmars (Sep 24, 2008)

What is BuDG?

Steve


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## lazersteve (Sep 24, 2008)

Steve,

It's butyl diglyme; aka: BDG, DBC, dibutyl carbitol etc

Steve


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## NobleMetalsRecovery (Sep 24, 2008)

Normally you have 2 layers. HCL on the bottom, BDG on top. If you load the BDG with enough gold, it will sink. Now you have BDG on the bottom, and HCL on top. Now if you add some fresh BDG, it will float on top of the HCL. So you now have 3 layers. BDG on top, no gold in it, HCL in the middle, and BDG on the bottom, lots of gold in it.


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## Noxx (Sep 25, 2008)

Haha I didn't know that. The patent states that the gold concentration in DBC should be adjusted to 50g/L. It does not sink at that concentration.


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## Lou (Sep 25, 2008)

Just curious Noxx, what is your procedure for using BDG?


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## Noxx (Sep 25, 2008)

What do you mean by what is my procedure ? Do you want me to describe the whole process ?

I don't mind doing it, it would just be long.


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## goldsilverpro (Sep 25, 2008)

It would be great, Noxx, if you can find the time.


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## NobleMetalsRecovery (Sep 25, 2008)

The whole procedure is available on the Website of the manufacturer. If you want, I will locate it.


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## Lou (Sep 25, 2008)

That would be nice as well, but I am very interested in what Noxx is doing.


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## goldsilverpro (Sep 25, 2008)

Me, too.


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## Noxx (Sep 25, 2008)

Oh well, then give me some time and I will...


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## Irons (Oct 3, 2008)

goldsilverpro said:


> Noble Metals, have you thought of a reason, in academic fashion, why there would be 3 layers? Doesn't make much sense to me.



The specific gravity of the BDG increases as it takes up Gold to the point where an inversion takes place and the loaded BDG sinks to the bottom. If you don't stir the BDG, the solvent in contact with the leach will load up and droplets will begin to sink through the leach and collect on the bottom.
You have to be careful not to agitate it too much or an emulsion will form and both Gold and BDG will remain in the leach. I found that bubbling air from the bottom provides sufficient agitation.

The technical literature from the manufacturers covers this.


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## Platdigger (Oct 3, 2008)

Irons!

good to see you posting again man
Randy


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## Irons (Oct 3, 2008)

Platdigger said:


> Irons!
> 
> good to see you posting again man
> Randy



Still not feeling up to snuff. I'm getting there.

Relative density is probably a better descriptor now that I think about it.

You can also recirculate BDG into the bottom of the leach and the droplets will pick up Gold as they rise to the top. This is the same concept as a counter-current, continuous flow system where the leach enters the top of a column and flows downward and the BDG is recirculated from the bottom and rises to the top where it is extracted.

Working with solvent extraction is as much of an art as a science.


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## Noxx (Oct 3, 2008)

Phase inversion happens when you load BDG with gold in a concentration higher than 120g/L



> Working with solvent extraction is as much of an art as a science.



Chemistry is a sort of an art...


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## Lou (Oct 3, 2008)

As for it being an art, damn right it is Irons! And this is just for gold--there are other SX systems... Let me tell you that an emulsion is a royal pain to deal with unless you have a lot of time, or a lot of ammonium chloride/sulfate to salt it out with; as far as I'm concerned, liquid-to-liquid is the way to go.


Let me know if/when you want to do that drum deal.


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## NobleMetalsRecovery (Oct 4, 2008)

Solvent Extraction using Ferro Chemical Butyl Diglyme

Ferro’s BUTYL DIGLYME is very selective in removing gold from various anode slimes using highly effective solvent extraction techniques. The discussion below is a very brief summary of the gold extraction process using Ferro BUTYL DIGLYME. For a complete brochure, please contact Ferro Customer Service at (800) 321-9942

NOTE:If you contact them they can email you a brochure with complete instructions.


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## Irons (Oct 4, 2008)

Noxx said:


> Phase inversion happens when you load BDG with gold in a concentration higher than 120g/L
> 
> 
> 
> ...



It's like the difference between an artist and a painter.

Anybody can buy paint.


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