Gold

Those crucibles were used for assaying, and were discarded after one assay. They are also very fragile, almost always cracked in use, although they held together. They are a poor choice for use at the bench.

Harold

I know and understand that, but if you say ceramics and leave it as such, I think you'll find that enough people will not consider a clay dish as being satisfactory, when it is, and may even consider that Coors lab ware would be the best choice. If you've ever worked with any of that stuff, you know how it isn't fond of thermal shock, which is hard to avoid when working with molten metals.

Harold

Can't hurt to ask them. If I need something and am short of the minimum I usually pad the order out with snaptite findings and synthetic stones. They come in handy for the birthdays of the womenfolk. Karl

Yep, that would work fine, assuming it could be poured properly. A small trough might be carved in the charcoal to direct the gold alloy to the mold. I'd personally opt for the melting dish, to insure that it poured well, plus none of the gold got absorbed by flaws in the charcoal.

I always handled molten gold with a gloved hand. I dumped five troy ounces of molten pure on the floor once, when the holding tong allowed the melting dish to pivot, upending. I found that I could pour up to ten troy ounces with an asbestos glove, and do it reliably and comfortably. I also built an asbestos pan in which I did all my (torch) melting, aside from furnace melting in a crucible, when the volume was too great to melt in a dish.

Handling the melting dish or charcoal may be troublesome, depending on the approach. You have but a brief window of time to get the metal poured, particularly when such a small volume is concerned. Superheating it isn't a great idea because of the oxidizing of the base metal, which has an adverse affect on the alloy quality. Often manifests itself as porosity.

Harold

Those were used 100+ years ago, not today. Then they were probably state of the art. And forty miles from the middle of nowhere.

Steve

They still are state of the art. They are only intended to be used once.

Back in the gold scrapping flurry of the eighties, Helped a friend from Cripple Creek round up equipment for crushing those used bone ash cupels.

It turned out that after they pop off the button for the assay, there can still be a trace of gold on the cupel.

He crushed a bunch up and sent it off for assay. He had a better yield per ton then some hard rock mining operations.

Paul K. Dickman

When I was a kid, we used to go down to the Techatticup Mine in Nelson, Nevada. A huge operation, with cyanide vats, and the talings still there. In one area, there were countless broken crucibles. We looked and looked for whole ones, but never found one.

The mine was used in the Kurt Russell movie Road to Memphis, or something like that. After that, a guy bought it, found an entrance that was sealed, and opened it to find everything like the day they stopped mining, including matches for the candles. He cleaned it up, and now has tours.

They also cleaned up every scrap of every crucible there. I suspect that they did get some reasonable amount of gold out of there. Piles that were six feet thick were gone, and you could not find a piece of a crucible as big as your pinky fingernail.

Steve

White gold doesn't like graphite. The alloy in some attacks the graphite and alters the gold.

To my knowledge, they are still using them today. They are inexpensive, and as has already been stated, intended for one firing only. They are of poor, but adequate, quality for the intended purpose.

Harold