Smelting 41 kgs of mlccs followed by large scale cupellation

[Lou]

The manufacture of the cupels is to me the most fascinating part.

 

[gaurav_347]

The manufacture of the cupels is to me the most fascinating part.

it indeed is! These cupels are usually left to dry for roughly an hour before placing them under fire.

 

[Topher_osAUrus]

You know a lot about their processes... Are you sure you're not the cool guy with sunglasses? 8)

I don't mean to sound like a jerk. I have actually been watching all of the goldrecovery65 video's, and have a couple of questions for the poster. Such as, in one video, he takes ceramic cpus and uses HNO3, HF, and H2SO4 on them.

What benefit comes from the HF? Does he experience any dissolving of the gold prematurely from that method?(as I have read that any halogens in sulfuric can and will dissolve gold, especially at elevated temperatures) why not just go straight to AR?

Are his vessels titanium ones? Surely he is losing some values when decanting through that metal strainer, its mesh size looks pretty large for fine gold wires.

I do have more questions than that, but, wasn't sure if you wanted them in this thread, or if you would like to make a new one that encompasses all of your videos.

Either way, it's very interesting to see how people across the world are recovering gold. Thank you very much for sharing. 8)

 

[patnor1011]

Do not take everything he does. His work is what I would call sloppy. Like for example video where he processed sim cards. He had no clue about bonding wires in these, he went after plating only and when I pointed to him that he lost most of gold by not going after wires I guess he did not liked it and deleted my comment. I guess he only like those commentators from his side of world half of which are close to become his worshipers.

 

[4metals]

The process detailed here is essentially a fusion and fire assay on a large scale.

If I received the same material in for an assay, I would break them up and heat to a red heat to make them easier to crush. Then I would grind them in a mortar and pestle. He did the same with a melt furnace and a ball mill.

Then the powder would be mixed with lead (as litharge) and soda ash and borax and he chose to add a small quantity of oxidizer as niter. This entire mixture is placed in a furnace and when molten poured into a cone mold. The end result would be just as he achieved, the lead and all metals will melt and the slag will be taken off the top when solidified.

Then the lead alloy which is on the bottom of the cone mold is placed in a cupel and fired. The result is the same as his, a doré button containing all precious metals.

I would have used a cupel purchased for assay, or possibly if it were a pound sample (really unusual for it to be considered an assay) I would use one of Legend's 10" Mabor cupels. These big cupels will absorb an amazing 14 kilograms of lead. down side they cost $100 each. http://www.lmine.com/mabor-magnesi...abor-pc-cupel-production-size-10-p-4846.html

As Lou said, their making of a cupel in place is a really creative and effective (as I am sure it is much cheaper than a 10" Mabor) We can learn something from this.

They use old recycled lead from broken up cupels in the process. Cost saving for sure and it is the reason the skimming was required on the cupel while it was firing.

Without going back and reviewing his yields, from memory the silver was just under 15 ounces, Palladium just about 1.5 ounces and gold 10 grams. At current prices
Ag 15 oz @ $17.50 = $262.50
Pd 1.5 oz @ $750 = $1,125
Au 10grams/31.1 = .321 oz @ $1210 = $388

So 40 Kg of MLCC's was worth $1,775. Or $44 a kilogram Or $20 a pound. How do these numbers look to some of you who have processed these MLCC's.

With the exception of the waste from the chemicals used, (which I might add a lot of excess acid was used) the only waste is the lead volatilized in the process which on a large scale should be scrubbed, and the solids from spent cupels.

 

[4metals]

The cupels are made from a 50:50 mix of "Ash and Calcium Hydroxide" would that be bone ash?

 

[Lou]

Turns out there's tons of information to be had.

https://books.google.com/books?id=7TLnAAAAMAAJ&pg=PA649&lpg=PA649&dq=cupel+press+portland+cement&source=bl&ots=wJPMhlU3Dt&sig=wEmqWYkCRbSvl2_DLTLjzLP4QXo&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIGjAA#v=onepage&q=cupel%20press%20portland%20cement&f=false

https://books.google.com/books?id=i_JMAAAAMAAJ&pg=PA177&lpg=PA177&dq=cupel+press+portland+cement&source=bl&ots=fKwsd93pni&sig=xjTTAMrq8YYf8ulKEYJ_3dxOj2g&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIHDAB#v=onepage&q=cupel%20press%20portland%20cement&f=false

https://books.google.com/books?id=DGXwAAAAMAAJ&pg=RA1-PA33&lpg=RA1-PA33&dq=portland+cement+cupel&source=bl&ots=jDTD-JwKMX&sig=YmjvUHvr27tpUyctvE2Vktnp9pw&hl=en&sa=X&ved=0ahUKEwjfgNaT3-3RAhXCOiYKHbAYDlAQ6AEIMTAD#v=onepage&q=portland%20cement%20cupel&f=false

https://books.google.com/books?id=3WgtAQAAMAAJ&pg=PA264&lpg=PA264&dq=cupel+press+portland+cement&source=bl&ots=4brlVwXmQv&sig=rtsPhaPinJLFhW_rADP4aW6Q-4w&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIJTAD#v=onepage&q=cupel%20press%20portland%20cement&f=false

I know magnesia and calcia are the best to melt platinum in. Lime you can even press into blocks and melt very large quantities of platinum in with O2/H2, al la Deville, who melted several hundred kilograms.

https://books.google.com/books?id=xriMAgAAQBAJ&pg=PA286&lpg=PA286&dq=melting+platinum+lime+block+deville&source=bl&ots=FKCJzg8azS&sig=V3A1bacUi_QSenn29BAMiLjNWtY&hl=en&sa=X&ved=0ahUKEwj6s4-z3-3RAhVMQyYKHUvvCs8Q6AEITDAN#v=onepage&q=melting%20platinum%20lime%20block%20deville&f=false

I would like to make one such of those furnaces and do a couple kilograms (I don't even have a 100+ kg at a time to melt!)

 

[gaurav_347]

You know a lot about their processes... Are you sure you're not the cool guy with sunglasses? 8)

I don't mean to sound like a jerk. I have actually been watching all of the goldrecovery65 video's, and have a couple of questions for the poster. Such as, in one video, he takes ceramic cpus and uses HNO3, HF, and H2SO4 on them.

What benefit comes from the HF? Does he experience any dissolving of the gold prematurely from that method?(as I have read that any halogens in sulfuric can and will dissolve gold, especially at elevated temperatures) why not just go straight to AR?

Are his vessels titanium ones? Surely he is losing some values when decanting through that metal strainer, its mesh size looks pretty large for fine gold wires.

I do have more questions than that, but, wasn't sure if you wanted them in this thread, or if you would like to make a new one that encompasses all of your videos.

Either way, it's very interesting to see how people across the world are recovering gold. Thank you very much for sharing. 8)

Sir,
Unfortunately I am not the cool guy with the sunglasses. I know a lot about this processes as it's the way the informal E-waste recyclers recover precious metals.

In the video comments he usually answers all the questions. The reason he uses HF is to dissolve aluminum.

The vessel that he is using is made up of 304/316 stainless steel.

Regards,
Gaurav

 

[gaurav_347]

The cupels are made from a 50:50 mix of "Ash and Calcium Hydroxide" would that be bone ash?

Sir,

When he says ash it could be either burnt wood ash or burnt cow dung ash! They also add a little portland cement in this mixture. Some use only portland cement and wood ash 70:30 ratio to make their cupel.

Regards,
Gaurav

 

[g_axelsson]

Google books only shows small snippets of books to some regions of the world, for example I can only read five lines of text. I'm adding links to alternative sources so the rest of the world also could read it.

Turns out there's tons of information to be had.

https://books.google.com/books?id=7TLnAAAAMAAJ&pg=PA649&lpg=PA649&dq=cupel+press+portland+cement&source=bl&ots=wJPMhlU3Dt&sig=wEmqWYkCRbSvl2_DLTLjzLP4QXo&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIGjAA#v=onepage&q=cupel%20press%20portland%20cement&f=false
Alternative link https://archive.org/details/miningscien100unse

https://books.google.com/books?id=i_JMAAAAMAAJ&pg=PA177&lpg=PA177&dq=cupel+press+portland+cement&source=bl&ots=fKwsd93pni&sig=xjTTAMrq8YYf8ulKEYJ_3dxOj2g&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIHDAB#v=onepage&q=cupel%20press%20portland%20cement&f=false
Alternative link https://archive.org/details/samplingandassa00smitgoog

https://books.google.com/books?id=DGXwAAAAMAAJ&pg=RA1-PA33&lpg=RA1-PA33&dq=portland+cement+cupel&source=bl&ots=jDTD-JwKMX&sig=YmjvUHvr27tpUyctvE2Vktnp9pw&hl=en&sa=X&ved=0ahUKEwjfgNaT3-3RAhXCOiYKHbAYDlAQ6AEIMTAD#v=onepage&q=portland%20cement%20cupel&f=false
Alternative link https://babel.hathitrust.org/cgi/pt?id=pst.000007232183;view=1up;seq=161 Search for cupel to get the good parts

https://books.google.com/books?id=3WgtAQAAMAAJ&pg=PA264&lpg=PA264&dq=cupel+press+portland+cement&source=bl&ots=4brlVwXmQv&sig=rtsPhaPinJLFhW_rADP4aW6Q-4w&hl=en&sa=X&ved=0ahUKEwjT2dKn3u3RAhVD1CYKHTJGCTwQ6AEIJTAD#v=onepage&q=cupel%20press%20portland%20cement&f=false
Alternative link Not found yet

I know magnesia and calcia are the best to melt platinum in. Lime you can even press into blocks and melt very large quantities of platinum in with O2/H2, al la Deville, who melted several hundred kilograms.

https://books.google.com/books?id=xriMAgAAQBAJ&pg=PA286&lpg=PA286&dq=melting+platinum+lime+block+deville&source=bl&ots=FKCJzg8azS&sig=V3A1bacUi_QSenn29BAMiLjNWtY&hl=en&sa=X&ved=0ahUKEwj6s4-z3-3RAhVMQyYKHUvvCs8Q6AEITDAN#v=onepage&q=melting%20platinum%20lime%20block%20deville&f=false
Alternative link http://www.technology.matthey.com/wp-content/uploads/ as 27 separate pdf (00-...26-)
The lime block furnace is in chapter 15.

I would like to make one such of those furnaces and do a couple kilograms (I don't even have a 100+ kg at a time to melt!)

With my 12 grams of PGM:s I'm playing in another league.

Göran

 

[gaurav_347]

Has anybody been able to perform this on a smaller scale?

 

[4metals]

I was able to take 100 grams of powder ground and ball milled from this type material and using the identical flux ratio he used and end up after the fusion with a lead cone from a reasonably fluid flux, no noticeable beads were clinging to the crucible after the fusion. Which in an assay fusion are easy to see while the crucible is still red hot after the pour. I would expect a thinner flux from the addition of fluorspar which may increase the yield slightly because the flux did run thicker than I prefer but as I said I did not notice any bead left behind.

Cupellation in a standard 2" Mabor cupel yielded a 52 milligram doré bead.

I did not use lead recovered from previous fusions I just used granulated assay lead. The yield was as a doré bead which was white. It was in the range of result (actually a bit better than the video's yield) but I did not digest the bead and break it down into silver palladium and gold.

This proves the method is scalable.

 

[patnor1011]

Too bad that I cant locate any cupel sellers in EU. Shipping from USA is way too expensive. I would love to try some samples myself as I do have about 10 kilograms of good stuff so far and pile keeps growing. It would be nice to know what I do have there before I would have to send it somewhere to recover metals.

 

[4metals]

Pat,

Check into some of the resources listed in this thread for making your own cupels, I made a hearth for a cupellation furnace to absorb the lead and make doré bars and it was easy to replace the old base (cupel) and reline it for more material. If you notice they only heat from the top so a good burner focused from above and surrounded by refractory bricks should do the trick.

 

[gaurav_347]

I was able to take 100 grams of powder ground and ball milled from this type material and using the identical flux ratio he used and end up after the fusion with a lead cone from a reasonably fluid flux, no noticeable beads were clinging to the crucible after the fusion. Which in an assay fusion are easy to see while the crucible is still red hot after the pour. I would expect a thinner flux from the addition of fluorspar which may increase the yield slightly because the flux did run thicker than I prefer but as I said I did not notice any bead left behind.

Cupellation in a standard 2" Mabor cupel yielded a 52 milligram doré bead.

I did not use lead recovered from previous fusions I just used granulated assay lead. The yield was as a doré bead which was white. It was in the range of result (actually a bit better than the video's yield) but I did not digest the bead and break it down into silver palladium and gold.

This proves the method is scalable.

Sir,
Thank you for trying this method out and proving that this is scalable. In the video you can see their cupellation setup which is very ancient. Can the same be performed in a large muffle/cupellation furnace. I have a plan in place to make a muffle furnace with working area of 1 feet by 1 feet by 1 feet. I had discussed this previously also but i am just skeptical if the same process can be performed in a muffle type furnace. The main reason being opening the muffle door to remove the slags floating on the top due to recycling of old cupels. Will this cause issues to the process. I want to perform the same process but in an environmentally friendly way with all the scrubbers in place. The furnace will be induction based and the maximum temperature will go to 1200 degree celsius. Should the temperature be more than 1200 degree celsius to perform this process. I will be making my own cupels based on the ideas that you have provided. I just want to be absolutely sure before I invest in the equipments necessary to execute this process. Any help would be greatly appreciated.

Thanking you,
Gaurav

 

[gaurav_347]

Too bad that I cant locate any cupel sellers in EU. Shipping from USA is way too expensive. I would love to try some samples myself as I do have about 10 kilograms of good stuff so far and pile keeps growing. It would be nice to know what I do have there before I would have to send it somewhere to recover metals.

You can try this method out to make cupels . I am posting the links below. The youtuber is a member on this website. He goes by the name of Owltech. He has always been of great help.

Silver refining by cupellation
[youtube]http://www.youtube.com/watch?v=pqIMb-sDXuw[/youtube]

Making cupels
[youtube]http://www.youtube.com/watch?v=hyDlrVgJETw[/youtube]
Regards,
Gaurav

 

[4metals]

The cupellation I did was at 1000 degrees C and it worked fine so at 1200ºC you should do fine. Remember the alloy is heavily influenced by the melting point of lead which is quite low.

I have drawn a sketch from memory of the furnace I used in South America to cupel large lots of mining doré. This was a no frills system which effectively cupelled the material.

View attachment removable bed cupellation.pdf

The stack rose quite high as there was no bag house or scrubber to eliminate the lead fume. I remember asking how they deal with the lead and they responded "very high" ! So I got the hint.

The tray was a cast iron tray and the bone ash mixture was pressed into the tray and shaped so there was a depression large enough to hold all of the lead alloy. They had a lot of trays and when a used one came out it was emptied and the tray was refilled with the mixture and shaped to hold the pool of molten lead. They lay out in the sun to dry for a good week before use.

When the new tray was added, the roof slab was lifted off and the furnace was charged. The tray was about 18" wide (45 cm) and 36" long (90 cm). I think it would be desirable to add a hole in the center which could be covered with a brick to facilitate looking into the muffle chamber to check progress or add more material.

This could be easily made to whatever size you need based on the size of the tray you are using for the bone ash. The trays slide in from the side and are not dropped in from the top. A stack of refractory brick seals in the burn chamber after the tray is inside.

 

[patnor1011]

Thank you all, it seems like nice project for summer.

 

[Rougemillenial]

isn't this something I've seen Umar Iqbl do on Youtube. the guy is from Karachi, Pakistan and he has a channel known as gold recovery.

 

[gaurav_347]

The cupellation I did was at 1000 degrees C and it worked fine so at 1200ºC you should do fine. Remember the alloy is heavily influenced by the melting point of lead which is quite low.

I have drawn a sketch from memory of the furnace I used in South America to cupel large lots of mining doré. This was a no frills system which effectively cupelled the material.

removable bed cupellation.pdf

The stack rose quite high as there was no bag house or scrubber to eliminate the lead fume. I remember asking how they deal with the lead and they responded "very high" ! So I got the hint.

The tray was a cast iron tray and the bone ash mixture was pressed into the tray and shaped so there was a depression large enough to hold all of the lead alloy. They had a lot of trays and when a used one came out it was emptied and the tray was refilled with the mixture and shaped to hold the pool of molten lead. They lay out in the sun to dry for a good week before use.

When the new tray was added, the roof slab was lifted off and the furnace was charged. The tray was about 18" wide (45 cm) and 36" long (90 cm). I think it would be desirable to add a hole in the center which could be covered with a brick to facilitate looking into the muffle chamber to check progress or add more material.

This could be easily made to whatever size you need based on the size of the tray you are using for the bone ash. The trays slide in from the side and are not dropped in from the top. A stack of refractory brick seals in the burn chamber after the tray is inside.

Thank you Sir for the above details. I have finally given an order to procure a muffle furnace.