Another Dental Gold Thread

[Lobby]

Refining dental gold is appealing to me, as it contains platinum group metals in addition to gold. Or said another way, selling dental gold to a refiner is distasteful to me, as I'm giving away PGM's. :mrgreen:

Yet the issue of amalgams containing mercury concern me. From Wiki "... consists of mercury (50%), silver (~22-32% ), tin (~14%), copper (~8%), and other trace metals."

Here's some dental I've got:

Neither of these, I assume, contain amalgam. Correct? By the way, should I incinerate to remove the white material?

I've purchased in the past dental which contains a hard, silvery metal in the inside. That's probably amalgam? The gold part is only the thin plate which is formed around the tooth, correct?

 

[Geo]

mercury is used in fillings and not the caps.

 

[Lobby]

Is it possible that I could receive a cap that had some of the amalgam in it?

 

[Geo]

it could be possible if the tooth was filled and then capped and the filling came out when the cap came off. you would be able to tell the difference between the two metals.

 

[fermi]

Where do you get these?

 

[Harold_V]

Harold

Neither of these, I assume, contain amalgam. Correct?

Correct.

By the way, should I incinerate to remove the white material?

Not necessary. If you feel you'd like to remove the white material, smack them with a hammer. In truth, it can be left in place, for when you inquart, it will be picked up by the flux in the dish.

I've purchased in the past dental which contains a hard, silvery metal in the inside. That's probably amalgam?

Correct again, and it's usually accompanied by the tooth. Again, hit it with a hammer. With a careful hammer blow, the amalgam can be easily separated from the tooth, or from the gold crown. Save the amalgam for the day when you have enough to warrant running a retort.

The gold part is only the thin plate which is formed around the tooth, correct?

Crowns are generally cast, not formed around the tooth. All depends on the method used, however. If you're not familiar with the casting process, it's the lost wax (investment) casting process that is used. It's very precise when applied correctly.

I processed a disproportionate amount of dental waste in my years. Great source of gold, with platinum and palladium as a bonus. If you use silver for inquartation, and cement properly, your silver will carry the platinum metals to the silver cell, where they will then be recovered from the slimes. That's a good way to deal with them, as they don't precipitate well from dilute solutions. They are concentrated by the silver cell.

Harold

 

[Lobby]

Thank you, Harold. You answered my questions so perfectly, even filling in the blanks with the questions you knew I had, but didn't pose.

 

[Lobby]

Where do you get these?

I have a scrap gold biz (graciesgold.com). Folks bring these to me as they become aware of the value of these.

 

[Lobby]

Here's some dental I got a while back.

Numbers 1, 3, 5, and 6 are typical dental gold. Number 4 contained no precious metals, although I didn't analyze it; it was very light. Number 2 was silver white; XRF showed 25% Pd and 75% Ag. (by the way, I don't have an XRF. Sigh.)

I still have number 2, in addition to the ones in the above pics.

A few more questions, if you don't mind:

- since I'm trying to recover PGM's, I suppose adding number 2 to the dental gold I wish to process is probably ok?

- should I worry about mercury amalgam when I process the ones with the teeth still attached?

- if so, how should I go about separating it?

 

[qst42know]

The amalgam if present will be a filling in the tooth the gold cap was glued to.

Hammer away.

 

[Harold_V]

since I'm trying to recover PGM's, I suppose adding number 2 to the dental gold I wish to process is probably ok?

Yes, after removing the tooth. Never melt anything with a tooth attached, for you never know when an amalgam filling is lurking beneath. I also recommend that you melt these things in the mouth of a fume hood, or with a fan at your side. Not behind you, where eddy currents can curl the smoke back in your face.

should I worry about mercury amalgam when I process the ones with the teeth still attached?

Always, as I stated, above. ( I have four gold crowns, all of which are over silver fillings.)

if so, how should I go about separating it?

We're back to your trusty old hammer. I used to have a short piece of chrome moly bar stock (4" diameter) on hand to use as an anvil. For me, that wasn't an issue, because I also operated a commercial machine shop. You may not have that option, but a short piece of railroad track, or any flat, heavy piece of steel will work perfectly well. Don't use cast iron--it chips.

Harold

 

[solar_plasma]

How many percent of the scrap price of pure gold would you guys bid on ebay for yellow alloys?

I ask, because after having read about hundreds of alloys, I understand that yellow alloys may contain from about 30-95% gold/platinum. My dentist even told me, there can also be yellow(!) non-precious alloys. My own pieces I saved are made of almost only gold with a density of about 18-19g/cm³. One yellow crown I bought on ebay has just a density of about 14,5g/cm³ and a white piece I got for testing, had only about 8,5g/cm³ and tested slightly positive (if I interpreted the slightly brown reaction right - not sure) for palladium.

 

[FrugalRefiner]

How many percent of the scrap price of pure gold would you guys bid on ebay for yellow alloys?

Nothing. Don't bid on that stuff at all. Stay away from it. OK, just kidding.

I have to admit, when I do place a bid on eBay, I'm always pretty sure I'm bidding against other forum members and I'm either running up the price on them or they're running up the price on me. :|

Maybe we should each choose a day when we bid and everyone else stays off. The next day, another member gets to bid, and so on until we get back to the first person. :twisted:

Dave

 

[solar_plasma]

I don't bid before the last seconds are ticking, I rather use the time researching and calculating yields and profiling the seller's history, consulting my pillow, then as far as I do not believe the seller bids by himself I place the maximum price for an estimated minimum yield. If I believe, he bids by himself, I just bid a little over the last price. That way I cover my costs even when I just refine half of a gram.On the other side do I watch 100 offers closely before I get one hit.

I always wonder why people start bidding earlier...even those who obviously are professional goldbuyers.

My problem in this case is, that I just can't find information about, what the average qualtity of yellow ebay dental gold is. Sellers could test their gold and only sell the "low grade".

 

[nickvc]

Solar there are way too many alloys for a general % of any values in dental scrap and in many cases it contains no values especially if it's white metal. If you google dental suppliers I'm sure you will find some charts that show the various alloys available but from memory most yellow gold items are around 12-16 karat but as I said with white metal it's a big gamble without actually testing each piece to see if they contain any values.

 

[solar_plasma]

Obviously there must be bigger players with very small margins and regular customers, who buy their gold at almost spot price, when they can pay over 22€/g yellow dental scrap. :roll: After my calculation they have to run 30g per hour to have a good income.