inquarting with copper

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chrisjames

Active member
Joined
May 12, 2015
Messages
29
Hi guys,

I've asked a similar question in another forum but I have since refined the question in the hope of a definite answer.

I have various scraps of different karat gold, melted together would equate 18K. I live in the UK and am unable to get nitric acid.
I have a good grasp of many of the processes however am unsure if this will work and don't want a frozen reaction to then have to mess about with further steps.

My questions are as follows:

If I melt the gold together (to about 18k) can I then go straight to poor man's AR, to then dissolve and precipitate (I'm worried about possible silver content and therefore silver chloride build up)

Or

Melt the gold with copper to increase the percentage of other metals (Copper and gold over silver) and then poor man's AR to dissolve.

I assume that once the solids are dissolved I can neutralise any nitrate with urea and precipitate with SMB. Then go through the washes and another possible dissolve.

Again I am sorry if I am repeating myself however I am still not too sure what to do.
Thanks in advance,

Chris
 
First I'd forget about the Urea, it has no use in recovery/refining. From what I have read, you can use Sulfamic Acid to get rid of the excess nitric, or use the evaporation method. It's all on the forum. Again I have not done any recovery such as this, so I'm not 100% positive, but these are the routes I'd go.

Rusty
 
Thanks but the problem is that I don't have a licence, in the UK you need a licence to buy certain acids etc
 
Sulfamic acid will work to neutralize excess nitric. Careful when doing so though, the reaction can be vigorous. Sulfamic also has an added benifit... It makes sulfuric acid when it neutralizes the nitric which will help dissolve lead chloride and keep it out of your gold.

Sulfamic Acid is sold in granual form as tile grout cleaner.
 
Chris I have given you my best advice already, the silver content of nearly all 18 k alloys is very low so the silver shouldn't be a problem, try it and see if you find it won't dissolve simply remelt with added copper.
Like many pros I always dissolved my karated alloys directly in AR, the only problem was English 9k which has 12-15% Ag if it's Italian then no problem they used little to no silver to keep costs down, one caveat to that statement is if you have 9-14 k white which can be a silver based mix again only with reasonable quality goods.
 
Hi Nick,

Sorry I wasn't trying to go over your head and I had taken down what you said. I just wanted clarification as I have read other things that confused me slightly.

I mentioned before that I have different carats of gold. I actually have about a third 9k gold, some 14 and 18, lots of 22 and some 24k. That's why I'm so cautious about the silver content due to the 9k gold.

Thanks again,
Chris
 
chrisjames said:
Hi Nick,

I mentioned before that I have different carats of gold. I actually have about a third 9k gold, some 14 and 18, lots of 22 and some 24k. That's why I'm so cautious about the silver content due to the 9k gold.

Thanks again,
Chris
Click to expand...
If you have enough 22 and 24K to almost be the weight of the others, then you can simply melt it like it is and then use AR to dissolve it.

Or, just to test it out, take some of your 22 or 24K and melt it with some of the 9K and dissolve in AR. If it works out for that test, then try the rest. But, if you give an amount in weight of each of what you have, everyone else, including you will have a clearer idea of how you should proceed. By you saying that you have 22 and 24K make me think that you may not need to add anything to the metals to even break it down to 18K, if that's your goal.

Also, depending on your goal and the amount of each karat you have, you may find that there may be little to no silver at all in the batch you have.

Other than that, I say that you will need some Nitric acid and melt your items and pour into a bucket to make corn flakes and then proceed to the Nitric acid. Then, after you've exhausted all the nitric or adding more does no more reaction to the solution, then all you need to do is filter the solution, stick a piece of copper in it and if there is any silver in the solution, it'll drop out from the copper pipe. All of the solids from the solution batch should be just gold.

Remember, if you're really concerned about the silver, then you should get some nitric acid to separate it from the other metals. I'm sure there are members here on the forum that are somewhere near you that have some and can tell you where and how to get it.

Hope that helps!
 
My apologies, I've weighed the gold and here is what I have:

9k: 15g
14k: 13g
18k: 11g
22k: 18g
24k: 16g

The combined carat is approximately 18k
As I mentioned before I don't have a licence to purchase or aquire nitric acid as it is a controlled substance in the UK.

There is less 9k than I thought but I am still unsure if there is enough low carat to be a problem if I go straight to poor mans AR.

Regards,

Chris
 
Hi Chris

I asked in PM but you didn't get it apparently. Drop me a PM and let me know which part of the UK you're from mate.

Jon
 
From those figures, I would either one or the other....

1. Take an equal amount of each karat and melt them all together and then after melting do an acid test on it.

a) If it is higher than 18K, then I would take that piece and inquart that with a piece of copper and repeat the process and test with acid.
b) If it is lower than 18K, then I would add some higher karat gold to bring it up to 18K.

If you get the karat you want by doing that or something similar, then you should be able to determine what amount of each karat piece you need (maybe some copper too) to get to 18K.

The caveat to all of what I'm saying is that each piece is more than likely made from different sources and each source will most likely have a different metal than the other source. You would have to test it first.

But, for the sake of getting my whole batch to 18K, if it were me, I would simply melt 1-5g of each karat together and test it. The worst thing that could happen is that you'll have either less than 18K or more than 18K. Either way, it can be refined to 18K if needed.

If it's more than 18K, add some copper to it and remelt and test. If it's less than 18K, add a higher karat than what the test shows.
 
Adding copper would increase the amount of Nitric required over that of adding silver. I would suggest silver over copper any day.

My limited understanding of inquarting ( Harold is the best on here for that) suggests that you need the gold content to be at the highest 25% or under 25% overall. I could be completely wrong here of course because my small expertise is limited to IT escrap where inquarting has no place. Is 25% gold 18k?

I would look at the overall mix of the gold you have and work out what portions of it, melted together would give you the required percentages to inquart with no further additions of metal (If possible) and look at adding silver as opposed to copper.

I'm sure that an expert in this field would be able to define those numbers.

edit- copper for gold.
 
spaceships said:
Adding copper would increase the amount of Nitric required over that of adding silver. I would suggest silver over copper any day.

My limited understanding of inquarting ( Harold is the best on here for that) suggests that you need the gold content to be at the highest 25% or under 25% overall. I could be completely wrong here of course because my small expertise is limited to IT escrap where inquarting has no place. Is 25% gold 18k?

edit- copper for gold.
Click to expand...

Pure gold is 24k, when you inquart gold you are quartering the gold. So you would have 1/4 gold and 3/4 copper or silver...So 1/4 gold would be 6k roughly. I believe that's what harold had said.

Rusty
 
mls26cwru said:
Sulfamic acid will work to neutralize excess nitric. Careful when doing so though, the reaction can be vigorous. Sulfamic also has an added benifit... It makes sulfuric acid when it neutralizes the nitric which will help dissolve lead chloride and keep it out of your gold.
Click to expand...
Sulfuric acid doesn't dissolve lead chloride. It precipitates lead sulfate and therefore can be removed by filtration before the gold is precipitated.
 
goldsilverpro said:
mls26cwru said:
Sulfamic acid will work to neutralize excess nitric. Careful when doing so though, the reaction can be vigorous. Sulfamic also has an added benifit... It makes sulfuric acid when it neutralizes the nitric which will help dissolve lead chloride and keep it out of your gold.
Click to expand...
Sulfuric acid doesn't dissolve lead chloride. It precipitates lead sulfate so it can be removed by filtration before the gold is precipitated.
Click to expand...

Thank you for the correction GSP. I must have mixed up my reading somewhere :/
 
I'm not sure if it has been mentioned and I didn't see it but you do not need AR when inquarting. When you lower the karat of a gold alloy to 6K (you can digest 10K slowly) it enables the nitric acid to work around the gold and digest the base metal leaving a sponge like material of mostly pure gold. Since it takes much less nitric acid to digest a greater volume of silver as apposed to copper, silver is recommended for inquarting. Inquarting is considered a refining process and not a recovery process even though it can be used for the purpose.

The nitric acid should be diluted as much as 50% by distilled water when inquarting.
 
chrisjames said:
9k: 15g
14k: 13g
18k: 11g
22k: 18g
24k: 16g
Click to expand...
As a math problem, let's assume you do want to melt all these together and add enough Ag or Cu to inquart them (reduce the gold to 25%). I am assuming that you're unsure about the purity of the 24K. If you are positive it is 24K (999.5 Fine, or better), don't include it. When something is pure, don't mess with it.

(1) First, calculate the total amount of gold.
(15)(9/24) + (13)(14/24) + (11)(18/24) + (18)(22/24) + (16)(24/24) =
(5.625) + (7.583) + (8.25) + (16.5) + (16) = 53.958g

(2) Add up the object's weights:
15 + 13 + 11 + 18 + 16 = 73g

(3) Determine how much Ag or Cu to add. Multiply the total gold content times 4 and subtract the total weight of the objects:
Ag or Cu to add = (4)(53.958) - 73 = 142.8g

(4) Proof. Divide the Au weight by the total weight after inquartation.
Gold = (53.95)/(73 + 142.8g) = 53.95/215.80 = 0.25 = 25%

As an aside, the average gold % is 53.95/73 = .739, almost 18K.
 
To expand on my meaning, if you lower the karat to try and dissolve everything in AR, silver chloride will still make the job a big pain.
 
rewalston said:
First I'd forget about the Urea, it has no use in recovery/refining. From what I have read, you can use Sulfamic Acid to get rid of the excess nitric, or use the evaporation method. It's all on the forum. Again I have not done any recovery such as this, so I'm not 100% positive, but these are the routes I'd go.

Rusty
Click to expand...

No disrespect but how can you give advice about urea having no place in refining if you've never "done any recovery such as this". The best thing to do in order to not have excessive nitric in you final solution is to add nitric to your scrap incrementally allowing each addition to be exhausted. Unfortunately no matter how careful you are there is almost always unused nitric. If the amount left over is very small you've done well. Some people on this forum swear by the evaporation method and shun urea but in reality the evaporation method can be very slow and deceiving while urea is fast and predictable. Urea works just fine especially when dealing with small amounts of nitric. Urea absolutely does have a place in refining!
 

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