Is this the right track?

[goldsilverpro]

The reason being is that gold above 6K I believe tends to shield the reaction of the nitric on the base metals.

Actually, you can leach all the base metals from 10K using hot nitric. I most always ran 10K class rings that way. When they were finished, they were brown and completely held their shape. You could still read the writing on them. When you punched them with a stirring rod, they collapsed into a pile of gold powder.

 

[Barren Realms 007]

Thanks GSP,

Then the brown color that the ring has taken is on the right track. I put it in a new batch of Nitric this morning that I had finished last night. I don't have it in hot nitric just outside temp that shold reach about 95 deg today. There is a silver cloud coming off the ring today so I guess it is working on it to some degree. Should I put it in hot nitric to speed it up or just let it set?

 

[goldsilverpro]

I think you'll need to get it hot to completely penetrate the ring. I would use fairy strong nitric, maybe 60 - 70% by volume. I have never used homemade nitric on this. It may not work well. You can tell when it's finished by probing it with a glass rod. If is still feels solid, it is not finished. When it's finished, it will be mush.

If I had read the entire thread and found that you were using homemade nitric, I may not have made these suggestions. With homemade nitric, I would think that heat would be especially important.

 

[Barren Realms 007]

It has been having some sort of reaction, the nitric is milky looking in color this afternoon. I will see if I can get a picture of it up later tonight.

 

[nicknitro]

Barren Realms,

Another Side note. When you speak of AP not touching it, AP relies on a build-up of copper chloride to etch the gold off of what ever object you are refining. Certain factors in base metal effect that statement such as, does the object have any copper in it? At any rate Nitric and AP are two different animals used for specific functions in refining.

I would guess at best "your" homemade nitric like the kind I made before is likely less than 30%, so GSP aka Chris is very wise to advise heat. Just watch out for the fumes, they are very hazardous at best deadly at worst. I just figured an inquartation would help remedy this situation. If the rings weighed 2-3 grams, you could melt them with 4-5 grams of copper/silver then redissolve in standard nitric leaving the same brown powder. Then if silver was used cementing it back out with copper material. Still though heat would probably be advised so I guess I'm just adding a step. LOL

Homemade Nitric can be expensive, so I hope you have enough material to overcome the startup costs of the chemicals involved .
At any rate read up on the processes, it will help you out in the long run. GSP, Steve, Harold and others are your best friends in these situations.

Chris,

At what karat is inquartation recommended for refining karat jewelry 10K +, I thought I remembered Steve posting a topic about 6K which equals 25%. The 10K method produces a sponge of gold right? No? Is that why you say to break it up with stir rod?


Thanks all and Good Luck,
Nick

 

[goldsilverpro]

At what karat is inquartation recommended for refining karat jewelry 10K +, I thought I remembered Steve posting a topic about 6K which equals 25%. The 10K method produces a sponge of gold right? No? Is that why you say to break it up with stir rod?

I may have painted myself into a corner on this subject.

The 2 fire assay books I have both say to use a silver/gold ratio of between 2 to 1 (8K) and 3 to 1 (6K). They say that below 2 to 1, some silver will be retained with the gold. In fire assaying, this is very important since any silver retained would be reported as gold. In my case (plumb 10K is only a 1.7/1 ratio), it didn't make any difference.

When I ran karat gold, I rarely inquarted or, even, shotted. When I had a mixture of various karat jewelry, I first leached in hot strong nitric. I poured this off and then used hot aqua regia. The first nitric, in most every case, ate through all the 10K, leaving only brown powder. According to the assay books, I most likely had traces of silver left in the gold powder. I didn't care about this.

When I used aqua regia on what was left, usually a small percentage (probably a couple of percent) of the 14K, 18K, etc. was not totally dissolved because of a high silver content - it wasn't much unless there was green gold present. I accumulated this and, when I had a bunch of it, I inquarted it. Unlike Harold's situation, I didn't have to get 100% the first time. I might mention that most refiners use AR directly on the jewelry, without inquarting, although some may shot it first.

I recommend that you do not follow my procedure. I recommend that you inquart all karat gold to 6K, with silver, before processing. You then should have no problems and everything will come out automatically. A long time ago, I finally realized that for you guys, the inquartation method, as spelled out by Harold, is far better.

 

[Oz]

I recommend that you inquart all karat gold to 6K, with silver, before processing.

Unless I am missing something would not 8K be advisable giving 1/3rd gold and the balance predominantly copper and silver? 6K works fine of course but leaves you with a powder instead of sponge and it is a little easier to have process losses the finer the powder is.

With that thought in mind it is best to do all processes in the same beaker as has been recommended here before. Every transfer of material to a new container is an opportunity for loss. Given the small quantities many here process this becomes more important as to how great a percentage this loss is compared to total starting mass.

Laser Steve recommended something I have not heard for a while that is very good at scavenging losses. After removing PM powders from a beaker always wipe the beaker clean with coffee filter paper until you see no residue on a new piece of paper. It is not much, but just ask Harold how much of a savings plan used filters turned out to be for him.

 

[goldsilverpro]

Unless I am missing something would not 8K be advisable giving 1/3rd gold and the balance predominantly copper and silver? 6K works fine of course but leaves you with a powder instead of sponge and it is a little easier to have process losses the finer the powder is.

If you are inquarting, I would still recommend 3/1, Ag/Au or 6K. When fire assaying, the Ag and Au are combined in a cupel and they form a perfectly homogeneous alloy. When torch melting, this homogeneity is more difficult to achieve, especially for a novice. In a furnace, it's a little easier because you can stir it well before shotting.

If you're making 8K, the homogeneity must be nearly perfect in order to leach out all the silver. If not, you will have gold-rich areas that won't part. Also, these areas will not dissolve in aqua regia due to the high silver - been there, done that. If you reduce the gold to 6K, this will give you more lee-way in case the Au and Ag aren't blended perfectly.

 

[Harold_V]

I recommend that you inquart all karat gold to 6K, with silver, before processing.

Unless I am missing something would not 8K be advisable giving 1/3rd gold and the balance predominantly copper and silver?

No. It isn't better. If you alloy to greater than 30%, many of the problems of running without alteration are present, more or less defeating the purpose in inquartation. Understand, I'm not saying it doesn't work--it's just that you have the same problems, especially if you inquart with silver. Copper would be far different, because it dissolves in AR, unlike silver.

6K works fine of course but leaves you with a powder instead of sponge

Not true. If you inquart correctly, it does NOT turn to powder without help. It does that when you go below 25% gold, or if you stir. I had a strict policy about dissolving the base metals and silver after inquartation. NO STIRRING. It isn't necessary, not if you heat the solutions, and I did. Always. Follow the guidelines set forth by Hoke and you can't go wrong.

Harold

 

[Oz]

Some of the difference I may have encountered as to the sponge breaking apart may have been due to my calculations on how much silver to add was based on hallmarking. When in doubt I would think that too much added silver is better than too little. Using 1 beaker throughout the process and careful practice results in little loss even if your sponge breaks apart. It sure beats silver trapped in your sponge!

 

[Barren Realms 007]

Here are 3 pictures of the class ring last night.

View attachment 3

View attachment 2

View attachment 1

I put it on a hot plate this afternoon and am getting more action. The nitric has also started turning green.

 

[Barren Realms 007]

Here is an update on what is happening with the class ring. need some guidence on this please.

You can see the ring in the bottom of the jar. I had dropped in what was left of a couple of other pieces to go along with the ring. Apparently the copper has reacted with the Silver Nitrate and dropped the silver out of solution. There is no more reaction taking place. There is still part of the ring left.

View attachment 2

View attachment 1

In this pick the gold has settled to the bottom under the silver. What is my best recourse for this?
Do I remove the current Nitric and replace with new and redisolve the Silver?
Do I wash it melt it and redisolve in Nitric?

 

[Barren Realms 007]

This is a test message to see if I have the right settings for picture up load.

 

[goldsilverpro]

Barren Realms,

When I used nitric on class rings, it required a lot of heat - just below boiling. By the looks of the vessel you're using (a jar), you're not going to be able to apply that much heat without it breaking. Use a beaker or a Pyrex coffee pot and place it in a Corning Ware dish to heat, in case of breakage. You really have to drive the reaction with heat, even with 60 or 70% nitric. I didn't stir and often, after everything was leached from the gold, you could still read the writing on the now brown ring. When I mashed it with a glass stir rod, it crumbled.

I still don't know whether you're using home made nitric or the real stuff. If home made, you may be wasting your time.

 

[Barren Realms 007]

Thanks GSP. I was using home made nitric on the ring. I was able to get it to disolve after adding some heat to it. And yes those jars will crack! I have found if you raise the heat slowly they will work, althought it is a risky thing to do. I have had them crack but have not had them bust and loose my material. However I am not using them for use on the hot plate any more. I'm using glass coffee pots.

I do have a question for you tho. Will it mess up my solution if I use Sulfuric to drop any lead if I am using HCL/clorox? From what I am gathering it will not harm anything.

 

[goldsilverpro]

I do have a question for you tho. Will it mess up my solution if I use Sulfuric to drop any lead if I am using HCL/clorox? From what I am gathering it will not harm anything.

I don't think it will hurt but, since I have never used HCl/Cl, you'd better ask Steve.

 

[Barren Realms 007]

Ok thanks GSP. I have asked this question on about 3-4 threads but haven't gotten an answer yet.

 

[Oz]

Barren,

I use HCl/Cl2 regularly and add sulfuric to clean the solution of lead before precipitating my gold.

It should be noted that free chlorine will interfere with SMB precipitation. For this reason I always give my chloride solutions a boil to remove the free chlorine first. It is at this point I add sulfuric. I of course decant before moving on to gold precipitation.

I do not know what may result if you add sulfuric with free chlorine present.

 

[Barren Realms 007]

Thank you very much for that info Oz, that was what I was wanting to know. I was assuming this but didn't take into account the free chlorine.

 

[butcher]

I believe that a small amount,of H2SO4 sulfuric, would only mix with the chlorine, as free SO4 ions, and if the had lead ions to attach to, they would and precipitate them, not free anymore, too much sulfuric and it will start to displace the chlorine, pushing chlorine gas from your solution, especially if strong heat involved, or highly concentrated solutions, the other thing to think about is any precipitants would be suspect of sulfides, which may need roasted.

in evaporating a solution with sulfuric and hydrochloric, the chlorine not only has a lower boiling point, but also is less likely to keep hold of the positive ion of metal, so the chlorine will evaporate from the solution easily, sulfates will stick around even till dry. and even then you must get them up to over 600 degrees to drive them off from metal salts ,

I believe small amounts H2SO4 should be no problem and can be benificial when lead is concerned.