Gold/Silver Ore Buyers

solarsmith

Jr. Member
Mar 27, 2016
62
126
Denver
Primary Interest:
Prospecting
I am looking for any one or any mill that will buy head ore or concentrated ore. in amounts as small as 1 ton and grades as low as 1/2 oz per ton au for head ore and 5 oz per tonau for concentrates. There is no free milling gold in it and all gold is tied to pyrite. (sulfide). the new mill one mile from my mine is only doing sluicing at this time and can only recover free milling gold at this time. I will be happy to open this topic/thread to all mills and buyers of ore no matter how small or large there operation is. Bryan In Denver Colorado.:3barsgold:
 

SaltwaterServr

Sr. Member
Mar 20, 2015
471
642
Texas
Primary Interest:
Other
Google "processing sulfide ores" and you'll hit a few results for mills wanting your stuff.

How much are you looking at processing per batch because you might be able to do it yourself. Are you sure it is only pyrite and nothing else in there?

If you have the space, time, and not a lot to process you could go with biological processing of the sulfide and arsenic compounds. Takes about 3-4 days typically. Then to make sure, hit it with H2O2. Next step is chlorination, filtering, zinc precipitation, then smelt.
 

Tuberale

Gold Member
May 12, 2010
5,775
3,446
Portland, Oregon
Detector(s) used
White's Coinmaster Pro
I have a small 15-lb. chunk of au/ag/cu/other metals recovered from an early Spanish arrastra. Would be interested in any smelter willing to separate the metal(s) at a reasonable price. I recognize this is a small amount.
 

Mad Machinist

Silver Member
Aug 18, 2010
3,147
4,686
Southeast Arizona
Primary Interest:
Prospecting
Google "processing sulfide ores" and you'll hit a few results for mills wanting your stuff.

How much are you looking at processing per batch because you might be able to do it yourself. Are you sure it is only pyrite and nothing else in there?

If you have the space, time, and not a lot to process you could go with biological processing of the sulfide and arsenic compounds. Takes about 3-4 days typically. Then to make sure, hit it with H2O2. Next step is chlorination, filtering, zinc precipitation, then smelt.

This MIGHT be the Grail for arsenopyrite. It seems during the bioleaching process both ferric arsenate and ferric hydroxide are created. These two substances will react together starting rather quickly to form scorodite, which effectively locks up the arsenic rendering it stable. As time goes by more of the arsenic is locked up rendering it stable.

I need to do more research on exactly how this happens. I'll post up more as I find it.
 

SaltwaterServr

Sr. Member
Mar 20, 2015
471
642
Texas
Primary Interest:
Other
This MIGHT be the Grail for arsenopyrite. It seems during the bioleaching process both ferric arsenate and ferric hydroxide are created. These two substances will react together starting rather quickly to form scorodite, which effectively locks up the arsenic rendering it stable. As time goes by more of the arsenic is locked up rendering it stable.

I need to do more research on exactly how this happens. I'll post up more as I find it.

https://www.researchgate.net/public...ory_Mineral_Ores_for_Gold_Extraction_A_Review

I've been reading on it all day. It looks like our best bet for locking up the arsenic and avoiding having to deal with any sulfide gas products due to roasting.

Google this article: Gold recovery from a refractory pyrrhotite ore by biooxidation

From what I can tell, in the solid/liquid separation stage they dump lime into the bio-oxidized solution and it locks up the arsenic and turns the sulfur to gypsum.

From the one article, it looks like a residence time of 7 days was getting you almost 85% of the gold as long as you do a downstream cyanide leach process.

I wonder if chlorination and zinc digestion would work at the leaching and precipitation phases since I'm not keen on working with cyanide.
 

Last edited:
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OP
solarsmith

solarsmith

Jr. Member
Mar 27, 2016
62
126
Denver
Primary Interest:
Prospecting
for a small bit of sulfide ore a roast might be an idea to convert it to an oxide. and then a leach may work better. do the roast out side and down wind from every one . poison gasses will be created.
 

SaltwaterServr

Sr. Member
Mar 20, 2015
471
642
Texas
Primary Interest:
Other
for a small bit of sulfide ore a roast might be an idea to convert it to an oxide. and then a leach may work better. do the roast out side and down wind from every one . poison gasses will be created.

Do a roast or two in the open air and the EPA will come knocking on your door. They won't be selling girl scout cookies either.

All it would take is one upset neighbor and the EPA would be all over you like stink on a pig. I couldn't even imagine the fines for releasing hydrogen sulfide into the atmosphere. And if the newspapers or local news station gets notice of it on a slow news day?

No sir, I'd stay well away from roasting if at all possible. Even with the gas capture system Mad Machinist and I kicked around, it's still not the most attractive process.
 

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Mad Machinist

Silver Member
Aug 18, 2010
3,147
4,686
Southeast Arizona
Primary Interest:
Prospecting
for a small bit of sulfide ore a roast might be an idea to convert it to an oxide. and then a leach may work better. do the roast out side and down wind from every one . poison gasses will be created.

I spent some time talking to our environmental people today and the information I was given was eye opening to say the least.

The whole purpose of this is to find a better way to do this and paint us in an "environmentally friendly" light. And to shove all the eco lies straight up there arses sideways. And further research has shown me that the ferric arsenate/ferric (oxy)hydroxide method is the EXACT process that the EPA uses to remediate arsenic Superfund sites. Research has also shown me that this is one of the processes that is used to remove arsenic from municipal water supplies and the resultant product is then interned at the local landfill. As the ferric hydroxide crumbles down, it exposes fresh surfaces to react with the ferric arsenate thus further reducing the amount of available arsenic until it is all locked up. So the longer they are together, the less toxic the arsenic becomes.

I am starting to think that this could be used by us to "remediate" all the low grade arsenopyrite tailings out there, thus removing on more part of the "toxic legacy" of mining.

Don't let the eco freaks fool you. Take a look at the whole Lake Combi fiasco. They ARE NOT against mining when they are the ones who will benefit from it monetarily. They simply re-term the mining with words like remediation and clean up.
 

Mad Machinist

Silver Member
Aug 18, 2010
3,147
4,686
Southeast Arizona
Primary Interest:
Prospecting
https://www.researchgate.net/public...ory_Mineral_Ores_for_Gold_Extraction_A_Review

I've been reading on it all day. It looks like our best bet for locking up the arsenic and avoiding having to deal with any sulfide gas products due to roasting.

Google this article: Gold recovery from a refractory pyrrhotite ore by biooxidation

From what I can tell, in the solid/liquid separation stage they dump lime into the bio-oxidized solution and it locks up the arsenic and turns the sulfur to gypsum.

From the one article, it looks like a residence time of 7 days was getting you almost 85% of the gold as long as you do a downstream cyanide leach process.

I wonder if chlorination and zinc digestion would work at the leaching and precipitation phases since I'm not keen on working with cyanide.

Still have more reading to do to understand the process fully. I've been on Research Gate a lot along with JSTOR. I'm starting to think this may not be to bad to set up on a small batch type system using concentrated ore.
 

SaltwaterServr

Sr. Member
Mar 20, 2015
471
642
Texas
Primary Interest:
Other
Still have more reading to do to understand the process fully. I've been on Research Gate a lot along with JSTOR. I'm starting to think this may not be to bad to set up on a small batch type system using concentrated ore.

You have much experience with floatation for making cons?

It seems like the same basic process we use in marine biology to remove dissolve proteins from the water column. Bubble it up using a venturi water pump or assisted with an air pump and away it goes.

If we can do that, heck, I think we've got a dang good ecologically friendly-enough small batch system.
 

SaltwaterServr

Sr. Member
Mar 20, 2015
471
642
Texas
Primary Interest:
Other
I spent some time talking to our environmental people today and the information I was given was eye opening to say the least.

The whole purpose of this is to find a better way to do this and paint us in an "environmentally friendly" light. And to shove all the eco lies straight up there arses sideways. And further research has shown me that the ferric arsenate/ferric (oxy)hydroxide method is the EXACT process that the EPA uses to remediate arsenic Superfund sites. Research has also shown me that this is one of the processes that is used to remove arsenic from municipal water supplies and the resultant product is then interned at the local landfill. As the ferric hydroxide crumbles down, it exposes fresh surfaces to react with the ferric arsenate thus further reducing the amount of available arsenic until it is all locked up. So the longer they are together, the less toxic the arsenic becomes.

I am starting to think that this could be used by us to "remediate" all the low grade arsenopyrite tailings out there, thus removing on more part of the "toxic legacy" of mining.

Don't let the eco freaks fool you. Take a look at the whole Lake Combi fiasco. They ARE NOT against mining when they are the ones who will benefit from it monetarily. They simply re-term the mining with words like remediation and clean up.

You know, this sounds dumb, but look at politicians in general, but I wonder if we could get the EPA to pay us to "remediate" old tailings? Give us a grant, construction equipment, or start-up capital. Hell, there's guys on the Pacific coast that get paid to go fill up mine shafts to make them safe, we should be paid to save the Earf from Manbearpig.

Don't laugh, it's not the dumbest idea I've ever come up with.
 

jere64ca

Full Member
Jul 16, 2016
131
189
San Luis Obispo, CA.
Detector(s) used
GB Pro
Primary Interest:
All Treasure Hunting
You know, this sounds dumb, but look at politicians in general, but I wonder if we could get the EPA to pay us to "remediate" old tailings? Give us a grant, construction equipment, or start-up capital. Hell, there's guys on the Pacific coast that get paid to go fill up mine shafts to make them safe, we should be paid to save the Earf from Manbearpig.

Don't laugh, it's not the dumbest idea I've ever come up with.

I would sure like to see actual miners get some of the grant money, do ya think that miners could do a better job? The CA Waterboard struggles to give away millions of dollars in grant money every year to "watershed improvement" projects. Problem is you would have to form a 501c3 that in no way sounds like a mining company and keep your background secret or you will never have a chance of being awarded the grant. (you would have to have a damn good grant writer as well)
 

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