# inquartation question



## banjags (Jan 17, 2008)

I plan on starting to purchase karat jewellery to supplement my income from processing computer scrap. I understand that we must inquart (melt)the karat jewellery with silver so the gold content is less than 25% of weight. Then dissolve base metals in 50/50 dilute nitric acid. 

1st question - Is there an alternate to dilute nitric?
2nd question - Can hydrochloric and clorox be used instead of Aqua Regia.

What would be a good price point (% of spot)to purchase karat jewellery at and still turn a decent profit after cost of processing, assaying and so on. I would probably primarily be purchasing from pawn shops. 

On a totally different topic. For those of you that have built your own gas furnace. Do they got hot enought to melt gold? All the plans that I have seen are for aluminum. I have an Oxy-Acetylene torch to use for melting temporarily, but that is not what I want to always use to do my melting.


----------



## Irons (Jan 17, 2008)

make an electrolytic cell and plate the Silver out for reuse. Use the inquarted Gold as the Anode and put a Dacron bag around it to catch the Gold and PGMs. If you set your potential and current correctly, all you should plate out is Silver. If there's a little Copper, it won't hurt if all you are going to use it for is inquartation.


----------



## lazersteve (Jan 17, 2008)

banjags said:


> 1st question - Is there an alternate to dilute nitric?
> 2nd question - Can hydrochloric and clorox be used instead of Aqua Regia.



1) Hot sulfuric acid will work to in place of nitric.

2) Yes. The resulting gold honeycomb/powder will dissolve with HCl-Cl. Any solid pieces which remain will be difficult to dissolve.

Steve


----------



## Noxx (Jan 17, 2008)

Irons, what do you use as the electrolyte ? Ammonium Chloride ?


----------



## goldsilverpro (Jan 17, 2008)

Banjags. A standard natural gas and air furnace will go to about 2400 F, or so.

Until Irons mentioned it, I had never heard of or considered using a silver cell for dissolving silver inquarted karat gold scrap. Interesting. Great idea. I think it could easily be done, at least for yellow, green, and red alloys, which contain only gold, silver, copper, and a little zinc. White gold, with it's nickel or palladium, may cause a problem. 

After silver inquarting, on an average of 50% gold - ballpark numbers: Au = 25%, Cu = 20%, and Ag = 55%.

A silver cell contains AgNO3, Cu(NO3)2, and a little nitric acid. In operation, it dissolves the Ag and the Cu and other base metals. It plates out only silver (until the copper and other metals rise too high in the solution). The gold doesn't dissolve but is trapped in a cloth filter. According to Rose, the gold can be as high as 35% for the cell to work.


----------



## banjags (Jan 17, 2008)

Irons said:


> make an electrolytic cell and plate the Silver out for reuse. Use the inquarted Gold as the Anode and put a Dacron bag around it to catch the Gold and PGMs. If you set your potential and current correctly, all you should plate out is Silver. If there's a little Copper, it won't hurt if all you are going to use it for is inquartation.



Not entirely sure I understand... I though in order to process karat jewellry you had to add silver, not remove it? prior to Nitric bath.


----------



## Irons (Jan 17, 2008)

banjags said:


> Irons said:
> 
> 
> > make an electrolytic cell and plate the Silver out for reuse. Use the inquarted Gold as the Anode and put a Dacron bag around it to catch the Gold and PGMs. If you set your potential and current correctly, all you should plate out is Silver. If there's a little Copper, it won't hurt if all you are going to use it for is inquartation.
> ...



Right, you add Silver to get the Gold content around 25% and melt it into an anode then electoplate out the Silver and Copper which leaves the Gold and any PGMs trapped in the bag around the anode as a mud or Gold sponge. You then dissolve this mud in HCl/Cl and precipitate out the Gold.

You can then reuse the Silver you plated out for another inquartation.


----------



## banjags (Jan 17, 2008)

ahhh. I get it now. Are these electrolytic cell easy to build? Where could a person find a schematic. What chemicals are used in them?


----------



## Irons (Jan 17, 2008)

Noxx said:


> Irons, what do you use as the electrolyte ? Ammonium Chloride ?



The SHOR process uses Ammonium Chloride electrolyte, with a bit of peroxide and Gold Chloride as a catalyst.

There's more than one way to skin the skunk. Plating out Silver and Copper is pretty much a no-brainer, especially if you're not interested in the quality of the plate and just trying to recover the metal.
Wollaston demonstrated copper electrplating in 1801, before people really understood what electricity was.

Electrolysis is faster than just digesting it and you recover the Silver on the spot without having to precipitate it out later.


----------



## goldsilverpro (Jan 17, 2008)

Irons,

I don't think you recover the silver, "right on the spot", from the Shor process. It's in there as an ammoniacal complex.

What electrolyte did you have in mind?


----------



## Irons (Jan 17, 2008)

goldsilverpro said:


> Irons,
> 
> I don't think you recover the silver, "right on the spot", from the Shor process. It's in there as an ammoniacal complex.
> 
> What electrolyte did you have in mind?



You don't recover it on the spot from the SHOR process, but from the acid electrowinning cell.

We're trying to discuss two different process flows at the same time. If i'm confusing GSP the newbies must be apoplectic.


----------



## Irons (Jan 17, 2008)

Irons said:


> make an electrolytic cell and plate the Silver out for reuse. Use the inquarted Gold as the Anode and put a Dacron bag around it to catch the Gold and PGMs. If you set your potential and current correctly, all you should plate out is Silver. If there's a little Copper, it won't hurt if all you are going to use it for is inquartation.



This will make AFLAC feel better.

The Copper will plate out before the Silver. If you use a electrochemical potential of Hydrogen as 0.00 Volts, Copper is +0.336Volts and Silver is + 0.771 Volts.

I know Silver is the reccomended inquartation metal for Gold but the melting point of Copper is only 20 degrees Centegrade ove that of Gold. It would simplify things a bit from a plating standpoint and the small amount of Silver left in the bag would be finely divided and would dissolve quickly in dilute Nitric.

Since the point is to recover the Gold and any PGMs, it really doesn't matter if you plate out the Copper and Silver together if all it's going to be used for is inquartation.

The only real advantage to using Silver is the lower melting point and it only takes half the amount of electricity to plate Silver vs Copper. In a large scale operation, that would make a difference, but al the scale here, it's not such a big factor.


----------



## goldsilverpro (Jan 17, 2008)

I'm not confused. Having many 1000's of hours of production practice, in dealing with both Ag and Cu electrolytic systems, I feel the Ag system would be far better, for many technical and practical reasons.


----------



## Irons (Jan 17, 2008)

goldsilverpro said:


> I'm not confused. Having many 1000's of hours of production practice, in dealing with both Ag and Cu electrolytic systems, I feel the Ag system would be far better, for many technical and practical reasons.



I'm sure you're right. Even if a small amount of copper that was in the carat gold plates over with the Silver, it's no big deal. The whole point I was trying to make is that, by using a cell, the base metals get stripped out without much fuss. It saves on chemicals too, since the base metals don't have to be digested along with the Gold. Having a lot of base metals in the first digestion is a pain in the butt.


----------



## banjags (Jan 17, 2008)

does anyone know if there are instructions to build a cell on this site hidden somewhere. I could find anything. This sounds like it could help with the bottom line by cutting some costs. I found some on ebay... yikes. One was like a measuring cup or a bucket with a battery charger hooked up. Is this normal?


----------



## lazersteve (Jan 17, 2008)

Banjags,

Both Harold and GSP have posted a ton of excellent info on the subject here:

Silver Cell Thread

Steve


----------



## Irons (Jan 17, 2008)

http://www.freepatentsonline.com/4182671.html

Electrolytic silver and gold refining cell
Document Type and Number:
United States Patent 4182671 

an electrochemical parting cell

This is obviously not a new idea.


----------



## Harold_V (Jan 18, 2008)

Irons said:


> make an electrolytic cell and plate the Silver out for reuse. Use the inquarted Gold as the Anode and put a Dacron bag around it to catch the Gold and PGMs. If you set your potential and current correctly, all you should plate out is Silver. If there's a little Copper, it won't hurt if all you are going to use it for is inquartation.



Bad idea, in general. Electrolytic parting cells tend to be rather fussy on their feed. If the major metal being parted is compromised by other elements, they quickly build a heavy coating on the anode, resulting in diminished, and eventually, complete cessation of parting. I had trouble with my silver cell when parting anodes that were high in platinum group metals, having to resort to pulling the anodes and hand scraping them to expose new surface. The PGM's formed a hard skin instead of sloughing off. Continued operation of the cell just pulled the silver out of the electrolyte. It was a lesson learned the hard way. 

The other problem you encounter (with a silver cell) is if copper content exceeds desirable proportions, not only does copper co-deposit (no big deal for the intended purpose) but the cell starts growing what can best be described as moss, very fine stringers of silver that quickly short the cell. 

My first experience was with a copper cell, which failed miserably, for pretty much the same reasons. Could be that with some more research I could have overcome the problems, but it simply wasn't worth the effort. 

Not saying that electrolytic parting won't work, but acid parting is so much easier and faster that I abandoned any further attempts. 

Harold


----------



## banjags (Jan 18, 2008)

Steve - I have watched your cell contruction video. Easy enough!
Do they still make fishing weights from lead?
Will your cell setup work for karat gold? 
Do I use the same 2 chemicals?

I was reading a post about a divided cell using salt water. He never made any mention about inquarting the gold, and processed a 9 karat ring. Would that be a way around having to do the inquartation?
If I understood that post rigth inside the cup was a solution of hot water and salt (table salt?) and hydrogen peroxide. What was the solution in the big bowl? What else could a person use that is conductive as the little bowl?


----------



## lazersteve (Jan 18, 2008)

Banjags,

The cell shown on my site is not for karat gold.

The reason to use the glycerin is not fully known and the cell should work the same without it.

Scavenger was working on the salt cell and he used a crucible for the inner 'bowl'. I think the big bowl was just the salt solution without the peroxide.

Steve


----------



## banjags (Jan 19, 2008)

just a plain old ceramic crucible? is there anything else that could be used?

Is there an easy way to tell if fishing weights are lead so I can make my own cathode? or do you still sell all the stuff to make a cell?
Do you recall how much peroxide was used?
This would work much faster for de plating headers pins I assume?
What metals are unaffected in a cell like yours lazersteve. Is it just copper?


----------

