The Perfect Gold Refine from karat jewelry.

[SilverNitrate]

Here is my secret gold refining technique. I call it the PERFECT GOLD REFINE
Its really quite simple. First see my post here showing neutralizing of AR gold solution http://goldrefiningforum.com/phpBB3/viewtopic.php?t=2691
[img:700:525]http://www.gholar.com/tmp/gold-powder.jpg[/img]
This is for AR solutions containing approximately 50% Gold and 50% Copper. That is karat jewelry at a weight of at least 10 tr. oz
1) Dissolve the karat jewelry in AR
2) Filter away the silver chloride and other solids (get your hands on a glass frit filter)
3) Boil this filtered AR for 1-2 hrs
4) Filter this solution (removes more silver chloride)
5) Neutralize this solution with NaOH until before apparent color change.
6) Add in 2 tablespoons oxalic acid
7) Place this AR in a very large HDPE or LDPE plastic OR glass container
8) Pour in 50 ml of ethyl rubbing alcohol
9) Prepare a solution of sodium nitrite dissolved in water. About 2 lbs in 2 liters of water
10) Place this sodium nitrite in solution into a large drip funnel (separatory funnel)
11) Allow this to drip into the AR container at a rate of 2 drips per second
12) Let a period of 24 hours lapse
13) Decant off the top layer liquid and set aside
14) The gold should be rinsed off with water and ammonia in a vacuum filter funnel
15) Dry the gold and weigh. If the gold is less than whats estimated, you do have gold in the solution you sat aside. You can do the standard gold test also to make sure you don't have gold in your solution. If there is gold in the solution drip in more sodium nitrite solution and wait a day for the gold to separate. Oxalic acid forms copper oxalate which acts as a purposeful contaminate which allows the gold to fall out evenly. The ammonia rinse removes this copper oxalate. The ethyl alcohol acts as a de-foamer. Sodium nitrite's sodium attacks the chloride, and since gold chloride is the stronger acid and there is no gold nitrite, only the gold falls. When you refine gold this way you'll have some really great looking pure gold that is better than 999fine!

 

[Harold_V]

When you refine gold this way you'll have some really great looking pure gold that is better than 999fine!

Is that your opinion, or do you have assays to support your position? It makes little sense to me to use copper to precipitate gold, a subject that you and I have discussed previously. Copper is generally looked upon as a recovery process, not a refining process.

I am at a loss to understand why you'd pursue that avenue when you could use ferrous sulfate or sulfur dioxide and have the entire process completed in seconds instead of days, all without screwing around with alcohol and other reagents.

If I am missing something, please enlighten me. My opinion is there are many unnecessary steps that can easily be avoided, with equal or better results. I am particularly concerned for solutions that would contain the platinum group metals. Copper will precipitate them along with the gold. Not a good idea at all, it appears.

Harold

 

[Lou]

Some of the chemistry is there, but it is lacking in many other aspects.

You're mixing reducing agents (nitrite and oxalic), and using a pound per liter of NaNO2 is downright wasteful. Also, boiling any aqua regia solution in the presence of silver will cause the silver to complex and go into solution, thereby contaminating your gold. Your wash step might not be enough at the end.

Also, the NaOH precipitation...it's easy to mess that up if you do not know what you're doing, and it's only useful in very limited circumstances (but in that situation, it is a great tool!).

I'm not saying that you won't drop gold, but I will say that your gold will likely not have the quality that you advertise.

Bottom line, if you like processing gold this tedious, wasteful way, then by all means continue, but don't advocate a bad procedure here.

Good luck with it!


Still, why don't you use SMB then clean up with oxalic? Gold done that way can be 99,99 or better.

Lou

 

[SilverNitrate]

This process is for acquiring pure gold (24k) from 10k and 14k. So copper would be the main element one would want to have removed from gold. When all steps are done correctly there would be no contaminate with the gold powder. I prefer this method because the gold produced is a really dense powder, not a sponge or oxide or whatever. PGMs are either filtered out with the silver chloride or stays in the solution alone with the copper. When boiling the AR solution silver chloride actually concentrates more but when cooled to room temp it will drop as a solid. During the gold drop, silver chloride is not a contaminate because the small amount just as what ever copper oxalate will be removed in the final rinsing with water and ammonia water.
Its possible to drop gold as quickly as SMB, however inexperienced haste may lead to a significant foam over, the addition of alcohol reduces foam by 99%. Also NO2 gas is a concern as such the gold drop has to be done in a fume-hood.
As far as wasting NaNO2 I haven't analytically done the math as to what amount is sufficient. Because free acid amounts i.e. HCl will use the NaNO2 at the same time dropping gold. When the nitrite concentration is very high the copper forms ligands with the nitrite ions similar to the ammonium ion. So neutralizing the AR with NaOH is a good way. Another is to boil down the AR into a thick paste-like then add water, which is the best method, but the time and energy in boiling away over half a gallon of acid may deter.
When to do this... If you have a large amount of finished gold. If you expect to refine 5-10 ounces or more this is an excellent method. I never used this method for dropping from the process of a few pounds of fingers which only yield several grams of gold.

 

[Harold_V]

When all steps are done correctly there would be no contaminate with the gold powder.

That's simply not true. Any element that is extracted from a soup of various elements will be contaminated by traces of the other elements, if for no other reason, drag down. Drag down doesn't always rinse out, contrary to your claims----it is often trapped within the structure of the desired precipitant.

I have no doubt that you can achieve a respectable level of purity by your process, but I also have no doubt that I could equal it's quality by simply following the procedure proposed in Hoke's book----which is far less involved and cheaper to accomplish. Inventing a new mouse trap has little value when it offers no particular advantages.

Harold

 

[butcher]

very interesting project I'll bet you are learning alot. Who knows maybe you'll catch a bigger mouse , if not have fun, and learn somthing trying.

 

[SilverNitrate]

Hoke has touched on the subject of using nitrite, only saying it'll yield beautiful gold powder. The metabisulfite is more used because one would need twice as much nitrite. The uses are nearly the same as food preservatives. the nitrite is a -1 ion and SMB is a -2 so as it can drop twice the gold. However, I say the gold does rinse with ease and it looks much better.

 

[butcher]

I am used to removing the nitric from solution as NOx, here you are adding it, I have read of sodium nitrate for a precipitant but it confused me as to how it would work chemically. is the Ph the key? can you explain chemically how this works?
I really like ferrous sulfate.
and am working on building an SO2 generator (still haven't decided on desighn maybe someone here has built one and can give me suggestions), as think it would improve my refining.

 

[Harold_V]

Hoke has touched on the subject of using nitrite, only saying it'll yield beautiful gold powder. The metabisulfite is more used because one would need twice as much nitrite. The uses are nearly the same as food preservatives. the nitrite is a -1 ion and SMB is a -2 so as it can drop twice the gold. However, I say the gold does rinse with ease and it looks much better.

Yes, I've read your comments before, but you are avoiding the question.

Understand that I'm all for detailing methods that are helpful-----we learn by reading-----so any and all avenues should be explored, particularly when there are problems in being able to acquire reagents that are needed for processing.

I've made no secret of the fact that I am not a chemist-------so I am not in the position to analyze your method from the position of authority, but I'll ask once again. How is it you make the claim that your process will yield 4 nines or better? My question to you was simple to answer----either you have paid for an assay to verify that it does, or you haven't.

My experience with using copper to precipitate leaves a great deal to be desired, as does precipitation from solutions that are copper bearing. Gold recovered from such solutions was never free of copper, regardless of the degree of washing, and I knew how to wash gold powder successfully. I also had many instances of gold precipitating in a dense form, where it would settle instantly. A second refining, which was my routine, always disclosed the presence of copper (it was obvious by the color of the solution), albeit very little. Certainly enough to prevent 4 nines quality.

So then, I'm asking you once again-----have you had your resulting gold assayed, insuring that you are, indeed, achieving the 4 nines you speak of, or are you just spouting what you want to believe? Readers deserve the right to know the truth, perhaps saving themselves from pursuing a method that is not in their best interest. Right now, having read Lou's comments, I'm inclined to think that you are misleading readers. Lou, above all others, knows and understands the required methods for achieving exceptional quality, none of which rely on copper for precipitation.

I'd like to see a sample button of your gold, and I'd like to see the dish from which it came. It's easy enough to determine if you are achieving your claim by observing the end results. Will your end product stand the test of melting without a full flux cover? Does it remain bright and shiny? You seem to avoid ever showing these things.

Harold

 

[Anonymous]

Harold,
I think he said 999.

still seems too complicated for my country bumkin brain.

Jim

 

[Harold_V]

Harold, I think he said 999.

Yes, he said 999, and even greater------but that proves nothing. He's said several things, including running the resulting gold powder in a blender, but saying them doesn't make them the right thing to do, or true . Unless he can verify that he has had his gold assayed and the quality is there, his claim is valueless-----a figment of his imagination, or his expectations.

Having commented as I did, above, I wonder how large the blenders are that Johnson-Matthey uses?

I'm not keen on posts that suggest bazaar notions when there are processes that are easy and simple to follow and yield good results---that don't include adding to the mix the very thing you're trying to eliminate. A great deal of his process sends up red flags for me---red flags that demand attention.

If I can see evidence that his process works and yields the quality he claims, I have no problem with admitting I'm wrong---but I don't feel the least bit comfortable about having posts made that include grandiose claims that make no sense----and are allowed to stand without at least the smallest of challenges or questions. I expect that he should provide some evidence that his process performs as he suggests, or the process should be flagged with a caution note, one that states results can be achieved, but the quality may suffer. I don't doubt he enjoys success-----I do doubt he enjoys the success he claims.

Here's what troubles me the most. If you research the compounds of gold, you'll find that many are unstable---some so unstable that they instantly reduce to elemental gold when they are created. Said another way, they explode. This can be easily verified by a search of the Merck Index.

Considering compounds of precious metals can be explosive---- the idea of suggesting that readers combine reagents willy-nilly in an effort to do what can be done simply by other processes, all known to be perfectly safe, is troubling to me. Unless readers are well versed in chemistry, they should follow prescribed procedures and observe the safety precautions that accompany the processes. I don't think this forum should be used to propose anything that puts readers at risk, nor do I think it is wise to place Noxx in the position where he may have to defend against such actions.

Harold

edit: corrected spelling

 

[Noxx]

You are right.

 

[Anonymous]

I was just under the understanding that 999 is a lot easier to reach than
9999.

 

[SilverNitrate]

Ha, another poll option? This is another method with which I been trying since this year. I know for certain that there are no explosive compounds created especially when did as stated. I am not claiming four 9's simply because I haven't had the gold assayed at this point. But estimating from previous batches of different methods I have achieved 99.8%. The people I use their assay can only read to 9999 and not over. In the past I mentioned using a blender, ....that was when I stated that gold reduced from copper metal can be chopped in a blender along with nitric which would expose copper metal which tend to adhere to the gold sponge that forms. I never use the blender to chop gold from this nitrite gold drop... Here its not needed because the gold is very fine powder. When I have sample of this gold assayed I will post its result here. By the way Johnson Matthey owns Alfa Aesar a phamaceutical chemical manufacturer and surely they have some huge blenders.

 

[Lou]

I seem to recall that copper oxalate can be explosive given the right circumstances. Silver oxalate as well.

Moreover, if it's anything like iron oxalate, upon heating, it can form a pyrophoric powder.

Lou

 

[butcher]

nitric acid in blender with copper metal ? how far back do i stand? do i need safety glasses?
just joking but I wouldnt try that.

 

[Harold_V]

I was just under the understanding that 999 is a lot easier to reach than
9999.

That, of course, is true-----but the process in question has nothing to do with achieving greater purity. It's nothing more than a complex procedure that is unnecessary, and should not be being promoted, for it offers no advantages that you can't achieve by other means. In truth, it has no place on this forum. I see no reason to post processes that are to be construed as refining (instead of recovery) when they don't achieve at least the minimum acceptance level of gold, which is 9995. Certainly, higher is better.

I'm well known for having used only tap water for refining gold---as well as using tech grade reagents. However, I am not alluding to the idea that if you follow my advice, that you will achieve the ultimate in purity. You will produce gold of acceptable quality, however.

Producing exceptional quality is accomplished by eliminating any and all contaminants at every opportunity. Lou has discussed this issue at length, and is known for producing high purity metals. He doesn't achieve success by doing stupid things----he does so by following sound fundamental principles, which do not include the use of copper to precipitate values.

Harold

edit: changed one word, which was improper. No change in content otherwise.

 

[Harold_V]

nitric acid in blender with copper metal ? how far back do i stand? do i need safety glasses?
just joking but I wouldnt try that.

That comment should be proof positive that you are reading comments from a source that should be ignored. Clever ideas (I'm using that term broadly) that put others at risk are hardly my idea of anything that should be posted and promoted.

I wonder-----has this individual considered what effect the nitric has on the Oilite bearing in the blender? It's as if he has no concept of contamination from external source---------and------ from all indications, no concern for anyone's safety and well being.

Harold

 

[goldsilverpro]

On page 124 in Ammen's first edition, he gives a procedure for precipitating gold with sodium nitrite, although he doesn't say how much to use. He evaporates to eliminate the nitric, dilutes to 5% acid or less, and then adds the sodium nitrite, either dissolved or in solid form. If the gold doesn't drop, he dilutes further or adds a pinch of baking soda to reduce the acidity. If all is right, the gold should drop immediately. The amount of acid is critical. I see traces of all this in your procedure, although you've seemed to complicate things enormously.

What is your purpose of also adding oxalic acid?

A long time ago, I read that the addition of ethyl alcohol could be added to AR to eliminate the nitric. I tried it once and didn't like it, especially the horrible smell. I seem to remember that Lou mentioned some potential dangers (explosive?) in using the alcohol.

If you only use exactly enough nitric to dissolve the gold, and no more, evaporation or urea or alcohol are not needed. You just dissolve, dilute, settle, filter, and drop the gold with a sulfite. If a second AR is needed, it can be done very quickly. I have detailed how to do this many times on this forum.

I have read many times on the internet that sodium nitrite can be easily made by heating sodium nitrate, although no one gives an exact procedure.

 

[Lou]

Chris, you must've missed a recent post of mine (easily done). Oz, another member here, inquired about making nitrite and I answered him.

I've done this procedure:

Heat a nitrate with excess carbon and hold at a dull red heat. There will be gas evolution. The nitrate is reduced to nitrite. The resulting cake is broken up and powdered in a mortar and then taken up in hot water and filtered with cellite to remove the charcoal residual. This is filtered again through a finer filter paper to get a clear solution. This is then evaporated and crystallized in a shallow dish to yield relatively pure nitrite.

If extremely pure nitrite is needed, add the crude material to a solution of silver nitrate, chill and filter the solution, rinsing well with cold distilled water. The resulting silver nitrite is then reacted with pure sodium hydroxide in a stoichiometric quantity. Silver oxide precipitates and you're left with a very pure sodium nitrite solution. This is evaporated, crystallized over low heat, then put in a dessicator over a cup of conc. sulfuric acid.