Wanting to sell my placered black sand

[goldshark]

Just a question. Assume we have barrels and barrels of black sands, classified, gold bearing... Could it be cyanide-leached ? Like regular ore processing, but with cons instead of milled ore. As I do not see any obvious problem with it, I do not tried it personally and you just cannot think about everything

Or better, some version of thiosulfate or thiourea leach... I am just curious, and I know that you have good knowledge about mining and stuff... Did you stumbled across something like this ?

I have no hands on experience leaching black sands with Cyanide. I have a copy of Zadra's original research papers, but haven't read them in 30 years. The one thing that I do remember, there is a high Cyanide consumption from the base metals. One of these days, I will try to re read his papers, at which time, I would feel more confident speaking about the process, and any possible skirts around the high FeO concentrations.
Our black sands are running 68% Fe. I have not tried a magnetic separation, but do know that a considerable amount of the residual Au is magnetic. I could run up a considerable lab bill for the hoped for recovery leach technique, for a 1000 tonnes of black sands, which only assay .4 Toz/tonne. My gut is still to find a 7 yard cement mixer, steel balls, caustic soda, and our favorite friend, Mercury. Run over a copper/mercury table (slowly), with a mercury trap, would be the most efficient method. I would think the recovery of the Au and Mercury, would be in the high 99.9% rate.
The huge losses of Mercury in the past, is due to the rampant addition in loose sluice boxes, attachments to Au in gravel, and flat out over feeding of sluice boxes.
A tight set up should not lose even a microgram of Mercury.

 

[Nountaineer]

I see this posting has nothing for a year.
Wondering if anyone has a good answer to process black sand quickly or fairly quick onsite.
I found a couple sort of beaches of black sand on sides of a river here in Idaho 10 or more years ago. I still visit this spot once in a while.
Panned several pan loads and there is much flour gold and lower you go you get larger pieces.
However I never figured out the proper process to use.
I had a dredge but black sand fills riffles too fast, improper tool for job.
Blue bowl will be too slow to acquire a reasonable amount.
I'm thinking manual manned bucket loads have to be proccessed.
Any ideas on a setup to process some minor tonnage sands/black sands manually?

I just started separating powdered platinum, palladium and gold with a simple but labor intensive method. I get the powdered metal suspended then pour it off into another bucket ending with a mud that I dry, screen and smelt .

 

[orvi]

I have no hands on experience leaching black sands with Cyanide. I have a copy of Zadra's original research papers, but haven't read them in 30 years. The one thing that I do remember, there is a high Cyanide consumption from the base metals. One of these days, I will try to re read his papers, at which time, I would feel more confident speaking about the process, and any possible skirts around the high FeO concentrations.
Our black sands are running 68% Fe. I have not tried a magnetic separation, but do know that a considerable amount of the residual Au is magnetic. I could run up a considerable lab bill for the hoped for recovery leach technique, for a 1000 tonnes of black sands, which only assay .4 Toz/tonne. My gut is still to find a 7 yard cement mixer, steel balls, caustic soda, and our favorite friend, Mercury. Run over a copper/mercury table (slowly), with a mercury trap, would be the most efficient method. I would think the recovery of the Au and Mercury, would be in the high 99.9% rate.
The huge losses of Mercury in the past, is due to the rampant addition in loose sluice boxes, attachments to Au in gravel, and flat out over feeding of sluice boxes.
A tight set up should not lose even a microgram of Mercury.

I am slightly interested in this possible process, as it would allow one to construct basic column-like leaching vessel with simple circulation peristaltic pump (resistant to chemicals, very cheap to get, easy to repair). Batch like system, easy to operate and monitor the conditions. Cyanide just came to my mind first. Maybe thiosulfate/thiourea leaches would perform better, I don´t know. Cyanide on larger scale is not that expensive, so maybe some more won´t hurt that much financially.

But I get your point, and I agree with you - mill and mercury would be easiest, with highest recovery. I just don´t like mercury Honestly - I like it a lot but I don´t like to use it due to obvious reasons.

 

[dialortz]

we are doing something like that too.

I just started separating powdered platinum, palladium and gold with a simple but labor intensive method. I get the powdered metal suspended then pour it off into another bucket ending with a mud that I dry, screen and smelt .

 

[dialortz]

we are doing something like that too.

meant to add...
specifically going for gold gravity separation, variation on flotation method, and of course, pgms should end up in the mud. smelting is not working well yet. working with modified wood stoves with air inlets...haven't even got enough gold yet to buy a crucible, let alone a real smelter. I'm hoping that last night and today might produce something saleable. it looks like we have 20 freaking lbs of material that after various separation methods over the past year should be only the heaviest of metals....
if this doesn't get something like gold by tomorrow I'm coming back with our whole story. watch out!

 

[dialortz]

bu

meant to add...
specifically going for gold gravity separation, variation on flotation method, and of course, pgms should end up in the mud. smelting is not working well yet. working with modified wood stoves with air inlets...haven't even got enough gold yet to buy a crucible, let alone a real smelter. I'm hoping that last night and today might produce something saleable. it looks like we have 20 freaking lbs of material that after various separation methods over the past year should be only the heaviest of metals....
if this doesn't get something like gold by tomorrow I'm coming back with our whole story. watch out!

must admit I've been to embarrassed to talk about it yet, be kind
. ok? thanks
dia
motherlode prospector

 

[Martijn]

Sharing and discussing your failures is proof of character imo.
Plus we can all learn from it.

 

[Nountaineer]

meant to add...
specifically going for gold gravity separation, variation on flotation method, and of course, pgms should end up in the mud. smelting is not working well yet. working with modified wood stoves with air inlets...haven't even got enough gold yet to buy a crucible, let alone a real smelter. I'm hoping that last night and today might produce something saleable. it looks like we have 20 freaking lbs of material that after various separation methods over the past year should be only the heaviest of metals....
if this doesn't get something like gold by tomorrow I'm coming back with our whole story. watch out!

I am yet to form a bead but have separated several grams of metal from the slag. Fired again today and will see if I have improved.

 

[Darkthirty]

meant to add...
specifically going for gold gravity separation, variation on flotation method, and of course, pgms should end up in the mud. smelting is not working well yet. working with modified wood stoves with air inlets...haven't even got enough gold yet to buy a crucible, let alone a real smelter. I'm hoping that last night and today might produce something saleable. it looks like we have 20 freaking lbs of material that after various separation methods over the past year should be only the heaviest of metals....
if this doesn't get something like gold by tomorrow I'm coming back with our whole story. watch out!

Rocket stove will get higher temps than a woodstove

 

[billgold]

Or you could find a utube video on making a melting/smelting furnace out of Kaowool.

Mt Baker Mining and Minerals (I think that is the name) often processes large lots of various ore, or other materials. I don't recall if he has ever processed a batch of black sand.

 

[Nountaineer]

I am yet to form a bead but have separated several grams of metal from the slag. Fired again today and will see if I have improved.

Another note for this , yesterday I formed fairly large chunks of metal at only 2300 degrees so 2800 as suggested previously is not necessary to process pgm ore. I added an additional tablespoon of borax just before firing.

 

[orvi]

Another note for this , yesterday I formed fairly large chunks of metal at only 2300 degrees so 2800 as suggested previously is not necessary to process pgm ore. I added an additional tablespoon of borax just before firing.

If it is sufficiently alloyed with other metals mp goes down. Or there aren´t any PGMs Simple as that. Most of the times, PGM concentration in various ores is miniscule compared to BM occurence such as Cu, Ni or Co/Fe. These, together with carbon form lower melting brittle alloys. Many times. It depends. PGMs pyrometallurgy and also hydrometallurgy is odd.

 

[Nountaineer]

All of my tests indicated high pgm. Gold at 9.37 consistently with the different grades. The platinum is multiplied as the grade improves and the gold remains consistent. I have found the middle grade to be 18.74 oz/ton and much more with the higher grades.

 

[dialortz]

18.74 oz a ton?!?. wow. That's pretty good!

 

[Nountaineer]

I have not tested the highest grades yet which are very impressive in appearance.