Turn 999 gold to 9999 gold

[Martijn]

electrolizing is better. but i think it is no need to increase the impurity, the price is little difference, if do further refining, it cost too high and may lost the recovery.

your post makes no sense. what do you mean?

 

[anachronism]

your post makes no sense. what do you mean?

I don't think it's any more than a language thing Martijn. Especially tough when both you and Xing are conversing in English which is not your primary tongue.

 

[Yggdrasil]

I don't think it's any more than a language thing Martijn. Especially tough when both you and Xing are conversing in English which is not your primary tongue.

I agree, he still has made some strange suggestions that are hard to decode in other threads.
So it may not be only a language/translation issue.

 

[Xing]

your post makes no sense. what do you mean?

oh, sorry, a little mistakes. I mean that it's no need to improve the purity from 999 to 9999.

if you want to increase the purity, the electrolysis is a better method, but it cost a long time and need high cost. like you need prepare the electrolyte, anode plate and so on.

 

[Xing]

I agree, he still has made some strange suggestions that are hard to decode in other threads.
So it may not be only a language/translation issue.

thanks for your suggestions, my mother language is not English, i try my best to practice. here is good place i could find some professional words and methods.

 

[andu]

Electrolysis is too complicated option for one refine, you'd need about same amount of pure gold electrolite. As 4metals pointed out, dissolving the whole of it lowering temperature and dropping the silver as chloride then filtering seems best and simplest option.

 

[Argentum Auricle]

I found that you dont need electrolysis to attain .9999 purity gold. My last batch of refined gold (from clean karat scrap) tested at .9999 on a Metalytics PM tester, and I didnt electrolyze. Instead I refined in three phases, using three different chemical separation methods: inquartation/parting, aqua regia dissolution, and gas refining using HCl and Cl2 and SO2 gas only. In my opinion, it's not that hard to accomplish (at least at the scale I operate) if you take care, use pure chemicals and only DI or de-ionized H20 in all steps, and wash/rinse collected precipitates well. This is repeatable - everytime I refine, I produce .9999. Why stop at .999 fine when the cost is so low to get an additional 9? For me, its about the perfection though, and not the decreased cost effectiveness of gettng to .9999. FYI - I make all of my own reactants using cheaply acquired chemicals from local hardware stores. I make most of my chemicals for pennies on the dollar, compared to buying commercial/lab grade from chemical suppliers.

 

[giahylxag]

Update.
I got someone willingly trade my bars for a swiss bar.
This pleased my OCD mind

 

[4metals]

FYI - I make all of my own reactants using cheaply acquired chemicals from local hardware stores. I make most of my chemicals for pennies on the dollar, compared to buying commercial/lab grade from chemical suppliers.

This is an interesting statement. Perhaps a little more details would benefit some of our members.

 

[Argentum Auricle]

This is an interesting statement. Perhaps a little more details would benefit some of our members.

Absolutely.

For example: Right now, 500mL of 67% technical grade HNO3 costs about $50 USD (plus S&H) online.

However, I can go to Lowes (regional corporate hardware store) and purchase $20 worth of KNO3 and use about $0.50 worth of store-bought 93% H2SO4... using my simple $40 distillation setup, I can make about the same amount of HNO3, in whatever concentration I like - dilute, azeotropic, WFNA, RFNA... all for about $23/500mL (67%). This includes the cost of electricity to distill. Considering 500mL of HNO3 is usually $60 after S&H, it costs me ~$37 less to make it, rather than to buy it.

And before someone asks why i dont buy in bulk... I do this at home, as a hobby, in my spare time. I have nowhere to store cases of HNO3, HCl, H2SO4, KNO3... so on and so forth.

Not only do i enjoy the satisfaction of refining PMs to the utmost purity, I also get the same satisfaction from making my own, ultra-pure RFNA!

 

[Argentum Auricle]

This is an interesting statement. Perhaps a little more details would benefit some of our members.

Also, I'd like to point out that I purify all store-bought acids via distillation, as well. I can buy a gallon of 34% HCl (cement etcher), for $15. I can then distill that into lab grade for just the cost of the electricity.

I do this for H2SO4 and HCl... getting the sulfuric to ~98% in the process.

 

[Argentum Auricle]

This is an interesting statement. Perhaps a little more details would benefit some of our members.

I should probably also mention something about dry reactants... I'll buy these at hardware stores too and purify via re-crystallization methods. I've found that even though many products state they contain 100% of something, doesn't always mean they are free of contaminants. For instance Spectracide Stump Remover says 100% KNO3, but it most definitely is not. There are contaminants (stabilizers maybe?) that interfere with reactions leading to weird side-products. I purify to .9999+ via re-crystallization (usually twice), then it can be used confidently for reactions and making HNO3. I do this for nitrates, sulphamic, SMB... etcetera.

 

[4metals]

Thank you for that description. And just as a point of reference, what quantity of fine gold is in your typical refine?

 

[Argentum Auricle]

Thank you for that description. And just as a point of reference, what quantity of fine gold is in your typical refine?

About an ounce at a time for gold. About a kilo at a time for silver. Pd & Pt is whatever comes from my waste recycling operation... maybe a half gram of each per year.

 

[Argentum Auricle]

Thank you for that description. And just as a point of reference, what quantity of fine gold is in your typical refine?

In all of 2023, I only refined maybe 4 ozt of fine gold; 2 kilos of fine silver, and a half gram of Pd from waste.

 

[Golddigger76]

I should probably also mention something about dry reactants... I'll buy these at hardware stores too and purify via re-crystallization methods. I've found that even though many products state they contain 100% of something, doesn't always mean they are free of contaminants. For instance Spectracide Stump Remover says 100% KNO3, but it most definitely is not. There are contaminants (stabilizers maybe?) that interfere with reactions leading to weird side-products. I purify to .9999+ via re-crystallization (usually twice), then it can be used confidently for reactions and making HNO3. I do this for nitrates, sulphamic, SMB... etcetera.

The spectracide stump remover is certainly not pure potassium nitrate, if you make a fully saturated solution with it there's a very clingy white substance that is easily removed with filtering.
If I am refining gold plated boards I will remove the solder with hydrochloric acid, pour it off and rinse them once the solder is gone, then I will cover the boards with hydrochloric acid I cut the boards into pieces that will fit into a 2000 ml beaker, I will pour a little bit of the saturated potassium nitrate in with the boards and hydrochloric acid and then put it on heat for a half hour, then let it sit for a few days.
This will strip the gold off the boards and even the hard to get plating that is inside of the holes for the components to be soldered into.
Most of the boards that I refine are 1970's and 1980's testing or communications equipment with very thick plating which is why I doi it this way.
When I used to use AP on this type of boards the plating is so thick that the gold in the holes for the component wires took a lot of work to get the gold out of them, literally had to either spray them out with a strong stream from a squirt bottle or use a piece of wire to push them out, they are like little gold spools.
This is a form of poor man's aqua regia and I will use this solution on several beaker loads of the cut up boards and add more potassium nitrate as needed when it slows down dissolving the gold, when I say add more I mean a little bit as in 5ml of the saturated Kno3
If you add to much your going to be using a lot of sulfamic acid to denox it, on the last batch of boards I put it on heat again and do my best to use up all of the nitrate, if it takes a day or two on the last boards I don't mind because I don't want to add any more potassium nitrate at this point unless completely necessary.
This will give you a dirty solution so you need to keep your nitrate level up so the gold doesn't try to cement out before your done but the gold precipitates very good with copperas, and then refined at least once more but most the time twice more since it is a dirty solution and the chances of dragging down base metals is possible, that is why I use copperas and not smb on the first refine, on the 2nd refining I will use smb, and third refining copperas.

 

[4metals]

Also, I'd like to point out that I purify all store-bought acids via distillation, as well. I can buy a gallon of 34% HCl (cement etcher), for $15. I can then distill that into lab grade for just the cost of the electricity.

I can appreciate the effort for making your own nitric acid because of the expense in lower quantities that hobbyists use.

The benefit for Hydrochloric Acid escapes me because the amount of gaseous losses getting down to azeotrope concentration, unless of course you are trapping those gasses in a gas washing bottle. Plus, any impurities in the liquid are concentrated in the azeotrope strength acid, which is roughly half the volume of the 34% you can purchase.

I should probably also mention something about dry reactants... I'll buy these at hardware stores too and purify via re-crystallization methods. I've found that even though many products state they contain 100% of something, doesn't always mean they are free of contaminants. For instance Spectracide Stump Remover says 100% KNO3, but it most definitely is not. There are contaminants (stabilizers maybe?) that interfere with reactions leading to weird side-products. I purify to .9999+ via re-crystallization (usually twice), then it can be used confidently for reactions and making HNO3. I do this for nitrates, sulphamic, SMB... etcetera.

As far as crystallization goes the, purity is only improved if you know beforehand what the impurities in the original product are. Otherwise you can easily bring down impurities with the recrystallization of the original salts.

This being said, the chemistry of it all is fun. Can you post a photo of your distillation apparatus?

 

[Argentum Auricle]

I can appreciate the effort for making your own nitric acid because of the expense in lower quantities that hobbyists use.

The benefit for Hydrochloric Acid escapes me because the amount of gaseous losses getting down to azeotrope concentration, unless of course you are trapping those gasses in a gas washing bottle. Plus, any impurities in the liquid are concentrated in the azeotrope strength acid, which is roughly half the volume of the 34% you can purchase.


As far as crystallization goes the, purity is only improved if you know beforehand what the impurities in the original product are. Otherwise you can easily bring down impurities with the recrystallization of the original salts.

This being said, the chemistry of it all is fun. Can you post a photo of your distillation apparatus?

You are correct that there are gaseous loses when distilling HCl, but is is still necessary. The HCl I buy is almost always contaminated. The last gallon bottle was so contaminated with iron it was a vibrant yellow color. This was unsuitable for my lab, so I distilled out all the impurities. They dont follow the distillate, as they aren't usually volatile. All impurities are left in the boiling flask, and the pure (less concentrated) acid is in the collection flask. I usually end up with something like 26% HCl after distillation... but this is lab grade (according to my own analysis) and still cheaper than buying from suppliers.

You are correct in that i have to have a vapor trap (NaOH) when distilling HCl. Otherwise, it is no good for me or the environment.

 

[Argentum Auricle]

I can appreciate the effort for making your own nitric acid because of the expense in lower quantities that hobbyists use.

The benefit for Hydrochloric Acid escapes me because the amount of gaseous losses getting down to azeotrope concentration, unless of course you are trapping those gasses in a gas washing bottle. Plus, any impurities in the liquid are concentrated in the azeotrope strength acid, which is roughly half the volume of the 34% you can purchase.


As far as crystallization goes the, purity is only improved if you know beforehand what the impurities in the original product are. Otherwise you can easily bring down impurities with the recrystallization of the original salts.

This being said, the chemistry of it all is fun. Can you post a photo of your distillation apparatus?

As far as purifying my dry chemicals, It seems to me that many times, the suspected contaminants are insoluble - easily filtered out after the solute is dissolved. Then recrystallizing the salt after filtered. I am always concerned there are other salts contaminating my materials, which is why analysis is often part of my process. Via analyses, I am able to confirm the purity of my products, within 95% confidence.

 

[Argentum Auricle]

As far as purifying my dry chemicals, It seems to me that many times, the suspected contaminants are insoluble - easily filtered out after the solute is dissolved. Then recrystallizing the salt after filtered. I am always concerned there are other salts contaminating my materials, which is why analysis is often part of my process. Via analyses, I am able to confirm the purity of my products, within 95% confidence.

Admitedly, all of the steps I take are a big part of why it takes me 3 months to refine one ounce of gold!