Quaternary alloys [coins]

[nimrood]

Hi!

I have a question regarding the recovery of silver from an Australian government-issued coin made from "q-metal." The Aus. government R&D'd this "qmetal" in the early 20th century and eventually minted a series of coins using this alloy. I have several of these coins and I am interested in recovering just the silver so it can be re-processed into custom-designed silver rounds with my family crest by a jeweler I've spoken with. The jeweler has agreed to make the coin but only when I can bring them them the "raw materials" to melt and fabricate. The jeweler is is willing to have the coins processed to recover the silver but forewarned me it would be in the $1200-$1500 USD range to process the coins.... much more expensive than the silver is even worth.

So, I decided and have collected some of the resources necessary to process these coins myself and extract the silver. The question is as follows: how do I process this particular "qmetal" with minimal loss of the silver? Yes, I know it seems a strange question but here is the coin composition:

10-11g total weight per coin
Qmetal alloy = 50% Ag / 40% Cu / 5% Ni / 5% Zn

That comes out to about 5g/Ag per coin. The Australian government was prudent to research this "qmetal" because it makes it difficult to simply melt the coins to recover the silver. I believe it also makes chemical recovery difficult as well. For example, from what I've read, if I try to dissolve these coins in HNO3 I think I'm going to get some interesting results.....the copper may cause some of the silver to dissolve and then immediately precipitate. The nickel may cause some of the copper to ppt out along with the silver... The zinc may cause some of the nickel to ppt out with the silver.... I'm just really not sure!!! I'm new to all this chemical processing of precious metals and I'd love some help regarding a procedure to get the silver out of these coins.

*UPDATE: Here is a link about these particular coins: http://www.cruzis-coins.com/florins/46.html

 

[etack]

sell the coins and by silver. Each coin only has about 5.50 USD worth of silver at 5g of silver each. It will not be clean silver and cost effective to recover then refine the silver.
or you can read the forum and try to make it work, and learn that for yourself.

Eric

 

[qst42know]

The only problem the "Q" alloy would cause is the base metals are big consumers of nitric acid. Your cost for technical grade nitric will determine if it's worth the trouble to refine.

Your coins may have a cash value near or above the silver value have you checked?

How many coins are you talking about that your jeweler was going to charge you this price as a refining fee?

$1200-$1500 USD range

 

[goldsilverpro]

Here are the numbers if everything is done perfectly. I'm not suggesting that the coins should be refined. I'm just saying that, if one wanted to refine them, these are the ball park numbers of what it would take.

All 4 of these metals will totally dissolve in nitric. One liter of 70% nitric, diluted with an equal amount of distilled water, will dissolve about 372 grams of these coins. Probably, some heat will be required at the end. This will produce about 186 g (5.98 tr oz) of silver in solution. It will require about 55 g of copper to cement this amount of silver out of solution, assuming that no excess nitric was used in the dissolving operation. The resulting silver, if collected and rinsed properly, will be about 99% pure, at best. To raise this purity, it will most likely require a melting furnace and the use of a silver cell.

Note: I edited this a bit. This is only a guide. These numbers are approximate and can vary in practice depending on such things as exact acid strength and the dissolving conditions. Also, to keep it simple, I assumed that it took the same amount of nitric to dissolve a gram of each of the 3 base metals. This is not exactly true but, in this case, it's quite close since I based the numbers on copper, which makes up 80% of the base metals.

 

[element47]

IMHO, you are starting with a very difficult feed material and will come to regret it, and by that I mean regret you ever started with that raw material. Should you succeed in refining this material to .999, it becomes a very soft and easily scratched metal; which is why US silver coinage (for example) was 90%, why sterling silver is .925, why Canadian silver coins are 80%. With the obvious exception of silver eagles and maple leafs, neither of which are meant to be circulated. Even if you truly desire .999 as the composition for your coins, I honestly cannot imagine why you would not simply buy generic silver rounds and have the coins made from them as your raw material.

 

[nickvc]

Well you've had GSP give you the costings to start the refining of your coins but in my opinion the advice to sell the coins as they are seems to be spot on especially if you can get close to the full silver value. Then simply buy silver in whatever form your jeweller needs.
The easiest way to create your coins is to have one cad cam designed and have them cast from your master, the cost I think would be around £200 for the master and then the casting charges and clean up costs, buying blanks and having a stamping tool made will be expensive and unless you have big volumes will be cost prohibitive.

 

[nimrood]

Well you've had GSP give you the costings to start the refining of your coins but in my opinion the advice to sell the coins as they are seems to be spot on especially if you can get close to the full silver value. Then simply buy silver in whatever form your jeweller needs.
The easiest way to create your coins is to have one cad cam designed and have them cast from your master, the cost I think would be around £200 for the master and then the casting charges and clean up costs, buying blanks and having a stamping tool made will be expensive and unless you have big volumes will be cost prohibitive.

Thanks all for this information... it has been very helpful!!!

Overall, I agree and had already concluded the best option is the sell the coins (since I got them dirt cheap) on eBay at spot + premium. Then, as was already suggested by some silver rounds and bring those to the jeweler. The jeweler will sell me the silver but at a higher price than I can get myself. The jeweler's quote for refining the coins is their cost for the refiner they use here in Atlanta ... it's expensive to refine small quantities. The jeweler uses a CAD system for casting custom orders. They will charge me about $175-$200/USD to create a custom round. They're one of the few jewelers in this area that do custom design work in their shop.

I have 40 coins (7.1 - 7.3 toz Ag) and I don't really care for them as much as I do my junk silver US coins. They're not in great condition so the numismatic value isn't really there. Full recovery of the silver should yield enough Ag to cast 7 1oz coins for distribution to my family. If you do the math my cost doubles if I have the jeweler send the silver out for refining.

Ultimately, I'm very intrigued by the idea of processing PM's from computer scrap. Particularly, the quantities of gold present in the old processors. I've been collecting the resources necessary for recovery & refinin. In fact started distilling another (modified) batch of lasersteve's nitric last night. I hope my mods have a higher yield than lasersteve's recipe... with his recipe I consistently get about 50ml vs. the claimed 160ml. Not quite sure what I'm doing wrong. Nevertheless, I can work with small batches.

Again, thanks for the input! I've found this forum to be a wealth of information over the past month as I've been reading, playing, testing, and experimenting in preparation for larger operations. I will continue to perfect my processes before I move on to more serious and larger tasks. I've learned a fair amount just by experimenting on these Q-metal coins.

 

[jimdoc]

Ultimately, I'm very intrigued by the idea of processing PM's from computer scrap. Particularly, the quantities of gold present in the old processors.

Just to let you know, it has been said that those numbers are not to be trusted in that list. You should do testing on your own to see what numbers you come up with, so you can trust them for decisions on values.

Jim

 

[nimrood]

Ultimately, I'm very intrigued by the idea of processing PM's from computer scrap. Particularly, the quantities of gold present in the old processors.

Just to let you know, it has been said that those numbers are not to be trusted in that list. You should do testing on your own to see what numbers you come up with, so you can trust them for decisions on values.

Jim

Indeed and point taken. With 15+ yrs experience in the InfoSec R&D space there is no better source of information than that which you gather yourself through diligent process, stats, and documentation. Verify, repeat, verify, and then get a peer review of your work.