Just Finished my FIRST ever GOLD BAR 1.025 Troy Ounce

[Harold_V]

I would recommend you do any further secondary (re-refining) refining without melting, and especially without inquartation. Traces of silver that may have been included in the first refining will be removed in the second refining, but, most importantly, the barren solution after precipitation will be a good indicator to you of what is being removed in the second refining. By inquarting, you continue to include one of the things you hope to eliminate---traces of silver. I understand your need to experiment---my comments are meant for the future, whereby you already understand the mechanics of inquartation.

Drag down is generally the problem with contaminants, assuming you have used a selective precipitant. By the time you have dissolved the once precipitated gold, the traces of contaminants that were present are well diluted by the volume of solution, so secondary drag down is vastly reduced. You can expect good quality, even when the first refining is questionable. That, of course, assumes you use a good washing procedure. How one washes recovered gold is just as important as are the other processes.

I took note of your comments about using a watch glass. Make that a habit, as when you are dissolving, the vigorous vapors that emanate from the solution carry values with them----including silver from the silver nitrate solution. Keeping your vessels capped with a watch glass minimizes potential losses, plus it makes for much easier heating.

Well done! I see an absence of the bronze color of the original ingot.

Harold

 

[HAuCl4]

I had to put my shades on to look at the bar!. Congrats!. 8)

 

[HAuCl4]

By inquarting, you continue to include one of the things you hope to eliminate---traces of silver. I understand your need to experiment---my comments are meant for the future, whereby you already understand the mechanics of inquartation.

One of those analytical chemistry types told me years ago, that if I really wanted to make really pure gold, the first thing I should do was to inquart and nitric part twice but with pure nickel, before doing any processing with AR dissolution. I thought he was nuts, and I knew better. It only made some sense recently, but I have never done it. His reasoning was that he wanted an easily removable contaminant as the main contaminant, and not lead, copper, silver, or PGMs. This was long before solvent extraction was more widely known.

What do you guys think?. :?:

 

[kadriver]

Using nickle to inquart - does it alloy with the gold easily?

does nickle dissolve in nitric acid as easily as silver does?

Can the nickle be recovered as easily as the silver is for reuse?

Is pure nickle easily obtainable?

Sorry, all I have is more questions - but now I am curious.

This sounds like an interesting new experiment.

Thanks - kadriver

 

[HAuCl4]

I suggest you pass on this for now. If only because nickel has a relatively high melting point. Let's wait for the other guys to comment, since this is not standard procedure anywhere, and nickel is relatively expensive.

 

[kadriver]

Good suggetion - Thanks

 

[Oz]

Nickel is also far more toxic as a salt or in solution than silver is.

 

[Harold_V]

In a nut shell, I think it's total BS. What possible reason could one have to employ nickel? It's expensive, melts at a high temperature, and creates unnecessary work. Sounds a lot like adding a hand full of dirt to the laundry to insure clean clothes.

It makes no sense re-introducing ANY contaminant, regardless of the ease in which it can be removed, if your objective is pure gold. The second dissolution leaves no reason for inquartation----no reason at all. If you feel the nitric digest serves a purpose, once precipitated gold can be heated (in a casserole) to insure there are no chlorides present, then the gold washed in dilute nitric prior to dissolution the second time. After all, that's the objective----not inquarting--which does nothing more than reverse the first precipitation.

Even if the gold to be processed has come from an exceedingly dirty solution, nothing more is added by this method. The resulting solution would, likewise, now contain but a trace of the original contamination, so drag-down would be but a miniscule portion of the original, evident by the color of the barren solution.

Harold

 

[HAuCl4]

Harold:

This is my reasoning and how it makes some sense in my head (not an explanation given by the chemist). It may be all wrong but here it is:

Let's say for the sake of argument that one starts with 1 Kg of 997 gold obtained by silver inquarting and parting with nitric. That's 997 grams Au and 3 grams of X (Ag mostly, with Cu, Pb, Pd, others, etc).

Now one adds 3,000 grams of 999.9 Ni, melts and alloys well (I agree a pain because Nickel has a high melting point, but let's continue).

We have an alloy of 4,000 grams, with 997 grams Au, 2999.7 grams of Ni, 0.3 grams of Y (the Nickel contaminants, whatever they are) and 3 grams of X. The non-gold portion of the alloy is 3003 grams of mainly Nickel, let's call this SHT (insert joke here :lol: ).(2999.7 Ni + 0.3 Y + 3 X).

After parting in nitric again (assuming we get to the 997 level exactly again) we are left with 997 grams of gold and 3 grams of SHT, where SHT is made of 99.89% Ni+ 0.1% X + 0.01% Y. So we can see that the silver, lead, copper, etc contamination has been made in the order of 0.33 grams on average, and the Nickel is now the main contaminant. So if we dissolved this in AR now, we would have very little silver chloride, lead compounds, copper, pgms, etc.

Now if we do the process of alloying again, the contaminants would be very low order traces, and we would basically have 997 grams of gold alloyed with 3 grams of the pure Nickel that we are using.

This new alloy of gold and nickel (after parting in nitric again) would be much easier to use to produce UHP gold, because all the "tough" and persistent contaminants have been diluted, and only Nickel is relevant.

One single dissolution in AR at this point (With UHP chemicals, UHP water, clean vessels, etc), and a DBC extraction/ precipitation and we would be looking at a really pure piece of metal at a reasonable cost.

I guess this is all academic discussion, because there is no urgent need to produce gold beyond 9999 purity.

I welcome all reasoned criticisms to the above "argument/procedure", and its holes which may be plenty. 8)

 

[goldsilverpro]

It's a waste of time discussing it, in my opinion. Totally impractical, for reasons that Harold already mentioned (and I can think of others).

 

[rockpicker1]

This is not the first, but it came from 3 lbs. of head ore.

 

[rockpicker1]

These two came from 16 lbs. of head ore.

 

[bhartley]

I don't have any experience melting gold, but from what I know about melting other metals, it looks like your gold is solidifying as soon as it contacts the mold. I think you'd get a prettier ingot if the gold had a chance to properly fill the mold before solidifying.

Just to satisfy my own curiosity:
How much are you heating the gold after it melts?
How hot do you preheat the mold?
Do you use a ductile cast iron mold or a graphite one?

 

[golddie]

I think Harold said he never used urea in refining and in the forum I am coming across many post that say they are using this thing.
From what I see it kills the free nitric so that there is less in the air.
I would like to know how much of urea is used in proportion to the quantity of the solution
Thanks

 

[goldenchild]

I think Harold said he never used urea in refining and in the forum I am coming across many post that say they are using this thing.
From what I see it kills the free nitric so that there is less in the air.
I would like to know how much of urea is used in proportion to the quantity of the solution
Thanks

It's personal preference if you want to use urea or not. It's nice if you want to get to dropping the gold quickly without having to denox. Put a few pellets in and stir completly dissolving the pellets. Continue adding until there is no more reaction (fizzing). If your'e good at managing how much oxidizer you put in with your HCL you won't need it though.

 

[Barren Realms 007]

I think Harold said he never used urea in refining and in the forum I am coming across many post that say they are using this thing.
From what I see it kills the free nitric so that there is less in the air.
I would like to know how much of urea is used in proportion to the quantity of the solution
Thanks

It's personal preference if you want to use urea or not. It's nice if you want to get to dropping the gold quickly without having to denox. Put a few pellets in and stir completly dissolving the pellets. Continue adding until there is no more reaction (fizzing). If your'e good at managing how much oxidizer you put in with your HCL you won't need it though.

Just because it stops fizzing dosen't mean you have gotten all of the nitric out. Especialy if you deal in large volumes of solution.

 

[goldenchild]

Just because it stops fizzing dosen't mean you have gotten all of the nitric out.

Ok. Not out but neutralized.

 

[Barren Realms 007]

Just because it stops fizzing dosen't mean you have gotten all of the nitric out.

Ok. Not out but neutralized.

Even then not totaly neutralized at times. I have 100 gals of solution that I am pumping around to day to see what has settled after it was processed and still showed positive for PM's and I have been cementing the solution with copper. And another 80 gals to filter out today to drop the PM's that I ran on heat to get the nitric out.

It just takes patience to accomplish this at times.

 

[goldenchild]

Even then not totaly neutralized at times. I have 100 gals of solution that I am pumping around to day to see what has settled after it was processed and still showed positive for PM's and I have been cementing the solution with copper. And another 80 gals to filter out today to drop the PM's that I ran on heat to get the nitric out.

It just takes patience to accomplish this at times.

Yes. Patience is the key with all our processes. When you are cementing out the PM's, effectively you are also denoxing. I hope you recover a brick Barren 8)

 

[Barren Realms 007]

Even then not totaly neutralized at times. I have 100 gals of solution that I am pumping around to day to see what has settled after it was processed and still showed positive for PM's and I have been cementing the solution with copper. And another 80 gals to filter out today to drop the PM's that I ran on heat to get the nitric out.

It just takes patience to accomplish this at times.

Yes. Patience is the key with all our processes. When you are cementing out the PM's, effectively you are also denoxing. I hope you recover a brick Barren 8)

Me too, I will still need to reprocess it once recovered.