# recovering PMs from crucibles



## rick310 (Oct 9, 2013)

Hey guys i have a quick question, I did a quick search and i didnt find anything on how to recover Pms from crucibles. I have access to about a ton or more of crucibles that have gold and silver to it. anyone have a quick and easy method to recover the PMs. Not sure if i would have to grind them down first? any advise will be appricated or if you can send me a link


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## niteliteone (Oct 10, 2013)

You could try running them through a hammer mill and then panning out the PM's.


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## rick310 (Oct 10, 2013)

niteliteone said:


> You could try running them through a hammer mill and then panning out the PM's.


is there any more options?


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## Geo (Oct 10, 2013)

what was used as the flux? some flux can be broken down liberating the trapped prills. also, flux will hold a certain amount of PM's as a colloid.if the flux is shaded pink to purple could be and most likely is gold.


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## butcher (Oct 10, 2013)

I Have some Ideas I might try,

First I would probably see if at least some of the crucibles were in good shape,and could be reused, a collector metal like silver and some flux to collect values in a melt, then clean the crucibles per Harold's methods he has described for cleaning melting dishes.

If the crucible was not in too bad of shape, just using Harold's cleaning method may work just fine
cleaning the crucible for reuse.

Badly broken crucibles I would break with a hammer, crush to powder using mortar and pestle, screen, pan for beads of metal, and leach the ground material in acids to recover values.


My last choice would be a smelt with flux with a collector, this flux would be very hard on the crucible used and on furnace refractory, costly in fuel, so I would avoid this option, favoring those methods above.


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## rick310 (Oct 15, 2013)

Sorry guys I been busy but I'll post some pictures


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## rick310 (Oct 15, 2013)

not sure how to add a picture so added it as an attachment


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## rick310 (Oct 15, 2013)

heres an other one


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## solar_plasma (Oct 15, 2013)

Maybe you could gather a concentrate by using a power drill with a steel brush, catching any dust with fx. a vacuumcleaner, which should have a fine particulate air filter. The dust is toxical. Alternatively brush it wet.

edit: I would invent some wet steel brushing method. The dust is definately to avoid.

edit: or just polish them in a spinning barrel filled with sand, like a ball mill with sand instead or balls. You would end up with less material to process and many of the crucibles could be reused, I guess, when they are polished.

...just some cross-thinking, stupid teacher ideas


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## rick310 (Oct 15, 2013)

solar_plasma said:


> Maybe you could gather a concentrate by using a power drill with a steel brush, catching any dust with fx. a vacuumcleaner, which should have a fine particulate air filter. The dust is toxical. Alternatively brush it wet.
> 
> edit: I would invent some wet steel brushing method. The dust is definately to avoid.
> 
> ...


Not worried about saving the crucibles due to cross contamination


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## nickvc (Oct 15, 2013)

The only way I know of is to crush and mill the crucibles, pass the material through fine sieves to collect the larger pieces of values which can be refined and to take a good representative sample of the remaining material and have an assay done and then sell it on but only with an agreed assay,
Using chemicals to try and refine it is a no go as the material will absorb too much solution.
Another possibility is to use a collector metal such as copper and melt in all the pots to try and recover the values that way but it could be a long process.


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## Anonymous (Oct 15, 2013)

I think the first post from niteliteone was the right one.

The only alternative might be to run the resulting powder over a sluice too perhaps if you have the facility to do that? Would certainly be less back breaking than panning all that lot.


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## MysticColby (Oct 16, 2013)

is crushing even necessary?
any metal will be on the outside of the crucible, possibly inside flux. It has been my experience that borax that was melted will not readily dissolve in water, but it will dissolve in acid. At least for silver, I just submerge dirty crucibles in dilute nitric (like 10%) and put it on low heat for a couple hours. pour out the liquid (later add a piece of copper to cement the silver), rinse the crucible with water several times. let it dry for a week (probably excessive, but I'm in no rush), then slowly slowly heat it next time it's used. this removes silver and flux (sometimes the flux will drip down the side of the crucible, eventually glueing it to the furnace, which is not good)
I imagine similar could be done for gold?


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## johnny309 (Nov 8, 2013)

How about liquid lead?
It is nasty,but you can immerse in molten lead as a collector


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## Westerngs (Nov 8, 2013)

Are you in the US?

I would package everything in a gaylord box and send it to someone like Gannon & Scott, Mastermelt or Sabin Metals.

They will crush it, sample it and provide a sample to you. I would either rep the material myself or have someone like Inspectorate rep it for me.

If you can assay the material yourself, do so. If not, Ledoux, AH Knight or Inspectorate are good choices.


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