Bone Ash Binder for fireing DIY cupels

[bmgold2]

Since this thread came back up, I got my little cupel mold out and leached then dried some wood ashes. I mixed the wood ash 50/50 with Portland cement. I moistened it using the liquid mix from a previous post and quickly make up half a dozen tiny cupels.

They were supposed to be baked (microwaved) to dry them but I wanted to play with one NOW.

I used some ceramic wool to build a miniature furnace around the cupel and carefully dried it using a normal propane torch. Looking around, I found some lead pellets and cut a sliver off of one.

Melting that lead turned it into a tiny ball maybe 1/2 the diameter of a BB.

I switched to a MAPP gas torch running off a large propane tank and after what seemed a very long time, I got most of that lead soaked into the mini cupel. REMEMBER, these cupels are only 1/2" OD and about the same height. The Butler torch assay used very small amounts 1/20 (one twentieth) of a teaspoon of ore and getting a bead of gold of only 0.005 inches diameter in the end indicated 1.49 troy ounces per ton if only gold was present. Most beads would need parted.

Anyway, this makes me think that maybe this torch assay could be adapted to use a miniature propane fired furnace. Something like a soup can forge. Is this wishful thinking or could it actually work?

Personally, I gave up on the torch assaying. Not because it didn't work. I just think a chemical test would be easier for field testing to get simple YES/NO result. The torch assay would be useful for getting an idea of the amount of gold or other PM's in the good samples brought back to lab or yard. If it could work with a normal propane torch without added oxygen, then it might be possible to do the assays right at the site.

I have tried the tiny portable welding/brazing torches and they cost about a buck a minute to run just for the expensive oxygen so that isn't an option. A soup can furnace sounds like the perfect size for this miniature assay.

 

[ashir]

can not find bone ash in pakistan. may be avail but with diffrent names that no body knows is this bone ash!!!
a person told me that gelatin is bone ash.
another said dicalcium phosphate is bone ash. what i should buy to use as bone ash to make cupels??

 

[butcher]

Bone ash is made from burnt animal bones.
Portland cement or Magnesium cupels will also absorb PbO

 

[Owltech]

can not find bone ash in pakistan. may be avail but with diffrent names that no body knows is this bone ash!!!
a person told me that gelatin is bone ash.
another said dicalcium phosphate is bone ash. what i should buy to use as bone ash to make cupels??

use plain portland cement instead.

 

[ashir]

magnesium is too much expensive here. but plane portland cenent will work. if anybody know the other name of bone ash used in pakistan then must inform me. and here is no label of portland cement, its just written "cement", but i hope i can find some cement with labled as "portland cement"

 

[Owltech]

use just cement then. dry

 

[Yggdrasil]

Hi Ashir.
Boe ash from Wikipedia:
https://en.wikipedia.org/wiki/Bone_ash

But is as said, basically burnt bones ;-)

 

[gaurav_347]

magnesium is too much expensive here. but plane portland cenent will work. if anybody know the other name of bone ash used in pakistan then must inform me. and here is no label of portland cement, its just written "cement", but i hope i can find some cement with labled as "portland cement"

Search for 53 grade portland cement (Its white cement) . Take the regular cement and the white cement in 50/50 proportions . Screen this through a fine mesh so to avoid any lumps. Mix in some water but not too much and make your cupels. Once the cupel is made take a cloth piece drenched in water and smoothen out the surface of the cupel . let the cupel dry out for 24 hours and then proceed .

 

[gaurav_347]

This is fairly large size of the cupel used for large scale cupellation.

 

[ashir]

This is fairly large size of the cupel used for large scale cupellation.

nice to see ! but no one knows about plane portland cement. here i search in market today( as maximum markets are close on friday in pakistan) i ask them for white cement so i can find any marked label etc, but one give me wall putty, and some plaster of paris marked,packed, white powder! normal cement isavail easily here, but no one can say@ here it is plane portland cement"
may be i can find this from larger cities!

 

[ashir]

its too much confusing! ( same as bone ash)

here is this avail in karachi only. no grades mentioned , just 2 terms! normal cement, white cement!
even contacting with cement maker companies , no one can guide!!!!!

 

[gaurav_347]

you can even make it out of normal cement . White cement just gives it extra strength and gives it smootheining on the surface. You can use plaster. Try this brand as it is imported in INDIA .

https://www.indiamart.com/proddetail/opc-53-grade-pakistan-cement-d-g-khan-elephant-brand-13075159512.html

 

[Shark]

this might help....

https://en.wikipedia.org/wiki/Portland_cement

 

[ashir]

thanks gaurav and shark!!! got it and going to buy it. here is another request to gaurav'
must start a thread about coal and small tilting furnance, you show in a post named" smelting in india"

 

[Goldenfinger47]

I use sheetrock for dirty melts, to save melting dish's, but the dish's for higher grade material and bone ash for lead cupling.

Sheetrock as in the stuff tapers use?

 

[goldshark]

To get a good quality bone ash, you should boil all bones for at least an hour under a roiling (hard, intense) boil. You want to remove the gelatin. Then calcine the bones to a complete calcine ( 900 degrees C.), white hot for 1 hour, longer for larger bones. Crush to all minus 100 mesh.Mix with 10% cement, just enough water to get the material to bind, press to desired shape and size. Most mints required the cupel to dry dry for 2 years before use. Immediate use (within 2 weeks), is not recommended, due to shrinkage drying, cracking, and exploding possibilities. If it can be purchased any where, a manufacturer can usually do it for much less than you can make it.
Sheet rock, plaster of Paris, and calcium phosphate are pretty much the same thing. I have never used it for cupeling, so I don't know how well, or what effects it may have on a lead button.

 

[Ohio miner]

Those are quite big boxes. Nothing for someone who just need a few to try and learn the process.

They may be cheap to buy but shipping for a case is close to 500.00 that takes the cheap right out of it

 

[goldshark]

I just picked up a box of 100- 178 gram of lead absorption magnesite cupels. PM me, and I will sell you as many as you like, if you live in the US. Try to keep the amount under 10 , for best USPS shipping rate. I am in Az. for another 10 days, so don't have any in the car at the moment. They are very good, DFC . Think I paid around $4.00 each, will mark up $1.00 each + USPS shipping.

 

[Ohio miner]

I just picked up a box of 100- 178 gram of lead absorption magnesite cupels. PM me, and I will sell you as many as you like, if you live in the US. Try to keep the amount under 10 , for best USPS shipping rate. I am in Az. for another 10 days, so don't have any in the car at the moment. They are very good, DFC . Think I paid around $4.00 each, will mark up $1.00 each + USPS shipping.

Thank you for the offer I was looking for a large quantity as stated they are cheap at 187 for a case of 100. But they want 400.00 to ship them. I have already order 5 lbs of bone ash and have Portland on hand. I know they need to cure out. I have a shop oven I will put on 180 and let them stay in there for a week or so. If they do not work well I will get in touch with you. If I was out west I am sure shipping would not be so high. I do appreciate the offer. Maybe we will cross paths one day I just retired and purchased a claim in Montana. Good or bad I am also a member of GPAA. I am looking for a camper hope to spend my summer in Montana and maybe try to get to the south west in the fall. Heavy pans sir.

 

[goldshark]

If wanting to make your own bone ash, as I wanted to, just for the sake of doing it on your own, read a prior post I plagiarized. It is from a well respected assayer, with much knowledge. Once you do it, it will be faster the second time around. Should be a lot of material around from stock yards. Like anything, once you do it right, you are the master.