separating gold "dust" from firing flux

[Harold_V]

But, the gold IS coming out pretty clean in the end. So, when it doesn't all melt into one button, it was because there was too much base metal in the mix?

Not necessarily. If the flux can absorb the majority of crud, the metal, regardless of degree of purity, often will come out bright and shiny. As long as you isolate it from oxygen, it has little reason to discolor.

My experience indicates that flux is usually too viscous, which discourages gravity from helping form a uniform button. Just adding fluorspar to the heat will often be more than enough to allow the beads to agglomerate, as will the addition of soda ash. Soda ash, like fluorspar, is rather aggressive and dissolves your dish in the process, so use it sparingly. It's an excellent way to clean a dirty dish, by the way. Get the dish red hot, then introduce soda ash. As it melts, the dark residual flux will start to dissolve, leaving behind droplets of metal, and a clean dish. When you've added enough soda ash to clean the dish, add some borax, then pour the entire heat off into a cone mold.

Remember that you get metal back. Don't toss old melting dishes, which always contain values, even though you can't see them.

(about a rosebud)
I have one, but have not tried using it on the gold.

I used mine with natural gas----not acetylene. You have to be careful that you have a functional flame before introducing it to the dish. If it pops, you can blow the contents away. It doesn't take very long to get used to the proper setting. I melted lots up to 10 troy ounces that way----rarely used my melting furnace when inquarting. Too slow and cumbersome when I could get the material inquarted and poured into shot in less time than it took to fire the furnace.

Harold

 

[Harold_V]

Where do I buy it ?

If all else fails, masonry supply stores usually have it in 100# bags. Ask for silica sand.

Harold

 

[Harold_V]

The precious metals dealer contacted me with the results of a fire assay and stated the gold in the rods was greater than 99% pure. The color in the photo is not the way they looked in real life, they are actually very yellow. The photo makes them appear reddish.

I should have considered that possibility, Steve, and I apologize if I said anything to disturb you. It was not meant that way. To be very honest, it was the color that triggered my comments. Pure gold comes out yellow, and requires no cleaning of any kind to brighten it. If pickling brightens gold, it's because oxides are being removed from the surface. That's a sure sign of contamination.

I'm only doing this for fun as a hobby. The main reason I recover gold is so that I'll have a retirement fund when I'm ready to quit working.

I, too, started out with that idea in mind. It was illegal to refine when I got started, but the law was changed shortly thereafter. Several people got a laugh when I told them what I was doing----but you might imagine who got the last laugh. I retired when I was 54. Refining made it possible.

I've read about assayers using conical molds with gold using lead or litharge as the flux in the same fashion described by Harold.

They work so well that I made a pattern and had a larger version cast in ductile iron. I also had an even larger one cast from a borrowed cone mold, this one about 12" in diameter. It's the only way to separate values from flux effectively.

On the subject of Aqua Regia, I started out using it and really don't want anything to do with all the hazards. The chemicals and methods I use now can be handled safely indoors and produce results that please me. Harold you are right, I may end up coming around full circle and start using AR as a final purification step to attain the fully refined gold you speak of.

Thanks for all the good advice,

Steve

Indications are you've come up with a system that is rather impressive, and yields gold of acceptable quality. You may not have need as long as you're selling to a refiner. A bench man might not enjoy gold that has traces of the wrong material involved. Lead, for example. It's death on the ductile qualities of gold. To insure that I didn't dispense gold of questionable quality, it was always double refined. I always exceeded the industry standard of 9995. In order to make the second refining worthwhile, I'd hold first run gold until I had a large quantity, then refine it in several 75 ounce lots all at one time. That was a good amount to precipitate in a 4,000 ml cylinder, assuming I started out with the vessel filled with ice.

Harold

 

[shadybear]

So what are the specs and info on this secret acid-peroxide method?

 

[Noxx]

I will tell you in few days when I will find how lol.

 

[lazersteve]

Hey Guys,

Follow the chart below to see the proper chemical formulas and ratios.

Remember this material is copyrighted ( not by me ).

I've done some work using these formulas and they are definitely accurate. I have more specific information for those who are interested in the 'SUPER SECRET' Chlorine Water Method!!!

Pay close attention to the Dissolution Rate Column, it shows that the peroxide method is nearly triple the effieciency of the Cyanide ( eeek!! ) Method, while the Chlorine Water method is a full 45 times faster than peroxide, of course the "Buzz Saw" of gold is good old Royal Water aka. AR (Aqua Regia)!

Enjoy,

Steve

 

[Noxx]

Steve ! I want to know the SUPER SECRET of chlorine water ! Please.
Thanks a lot.

 

[lazersteve]

This post has slowly drifted off the original topic. I'll start a new one under the Refining/ Recovery Techniques.

Noxx,
Here's a sample of what you can do to a 486 cpu using Acid Peroxide:

Steve

 

[Noxx]

Lol so crazy. I love it.
We'll talk in your other post, thanks.

 

[PRECIOUS METALS]

lazer steve hold the secret ,ok what would it take to get step by step instructions ,lets trade secrets

 

[TXWolfie]

It's a method I developed myself to get past the hazards of AR while still getting maximum yields with mimimal effort. I worked up the ratios by trial and error. After working out the details, I fine tuned the process buy researching college web sites. I've put together a pdf file of etchants from several of these sites. Email me and I'll send it to you. The acid is standard muratic acid (HCL) and the peroxide is just the household variety (3%).

Steve just out of curiosity does the percentage of peroxide matter. I have seen products with percentages up to 40% instead of the store 3% type

 

[Geo]

It's a method I developed myself to get past the hazards of AR while still getting maximum yields with mimimal effort. I worked up the ratios by trial and error. After working out the details, I fine tuned the process buy researching college web sites. I've put together a pdf file of etchants from several of these sites. Email me and I'll send it to you. The acid is standard muratic acid (HCL) and the peroxide is just the household variety (3%).

Steve just out of curiosity does the percentage of peroxide matter. I have seen products with percentages up to 40% instead of the store 3% type

sorry, im not steve , but i can answer that one. 3% is just fine for the purpose of acid/peroxide. the only difference of adding more O2 than 3% is more of your gold will go into solution before the reaction starts. remember the objective is to separate the gold from base metal instead of dissolving gold during this process.. the addition of peroxide to the solution is to jump start the creation of copper chloride. hcl acid alone will not dissolve copper and etching will only occur in the presence of copper chloride. ok, as i understand it hcl+H2O2 makes copper produce copper oxide and hcl will convert copper oxide into copper chloride which in turn will dissolve copper in the presence of oxygen so unless you want to spend alot of time agitating the solution and adding H2O2 periodically, you will need to add an air supply.

 

[TXWolfie]

It's a method I developed myself to get past the hazards of AR while still getting maximum yields with mimimal effort. I worked up the ratios by trial and error. After working out the details, I fine tuned the process buy researching college web sites. I've put together a pdf file of etchants from several of these sites. Email me and I'll send it to you. The acid is standard muratic acid (HCL) and the peroxide is just the household variety (3%).

Steve just out of curiosity does the percentage of peroxide matter. I have seen products with percentages up to 40% instead of the store 3% type

sorry, im not steve , but i can answer that one. 3% is just fine for the purpose of acid/peroxide. the only difference of adding more O2 than 3% is more of your gold will go into solution before the reaction starts. remember the objective is to separate the gold from base metal instead of dissolving gold during this process.. the addition of peroxide to the solution is to jump start the creation of copper chloride. hcl acid alone will not dissolve copper and etching will only occur in the presence of copper chloride. ok, as i understand it hcl+H2O2 makes copper produce copper oxide and hcl will convert copper oxide into copper chloride which in turn will dissolve copper in the presence of oxygen so unless you want to spend alot of time agitating the solution and adding H2O2 periodically, you will need to add an air supply.

That answered my question, thank you Geo.

 

[asimbilly]

hi can any help me plz

 

[Geo]

hi can any help me plz

with what?

 

[Harold_V]

hi can any help me plz

A couple things you need to know if you hope to survive on this board.

Do NOT use text message lingo. I'll ban you in a heartbeat if you persist. When you post on this forum, speak in clear, concise English, to the best of your ability, so readers don't get the wrong message.

It is very important for you to learn the basics of refining before you can hope to benefit by asking questions. You can do that by downloading a copy of Hoke's book, and by reading the forum, so you become familiar with terminology that is used routinely in refining and the discussion of processes. If you receive advice on processing without that basic knowledge, that will lead to you asking more and more questions, and you won't be able to process what you have. There is no shortcut---you must apply yourself and learn the ways of refining. We help those who help themselves---and often chase off those who refuse.

Harold

 

[Dravin]

Where can I get Silicia ? And can I substitute Sodium Nitrate with Potassium Nitrate ? I have 25 lbs of kno3 lol. :lol:

hi Noxx, from my research it would work out just fine. Same ratio aplies to k as it does to na.