Roasting sulfides

[danec71]

What is the right temperature and for how long does it take to roast something like arsenopyrite to achieve the best results. I know the risks and safety.i want to do a test sample properly. I can already crush the quartz with this stuff in it and see gold. Want to know what could be inside.thanks

 

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[Professor of Engineering]

This may help?

Good Luck!

 

[tamrock]

That was rather interesting and somewhat entertaining to boot.

 

[Mad Machinist]

I don't recommend anyone playing around with arsenopyrite. If you have to ask how to deal with it, you shouldn't be playing with it.

Arsenic poisoning is a very slow and painful way to die. It takes a whole lot less arsenic than most people think to kill you.

If you inhale arsenic fumes, it goes straight to your bloodstream and the damage starts quickly and is pretty much irreversable.

 

[alaskaseeker]

Dangerous...

 

[DizzyDigger]

 

[danec71]

I appreciate the concern but I am well aware of the dangers. And I know better than to stand there and breathe these fumes. My question was only about the right temperature and for how long. I’ve heard different ideas and cannot google in a precise answer. The one I find most reasonable somebody told me was 900° for about an hour. I have sent the stuff in for an assay before a couple of times and that’s great to tell me what’s in there but I want to see some results. I have tried a couple different methods and was simpley looking for opinions on the subject. It’s fine if you really do have some concerns but don’t say it in a way that you’re assuming I’m an idiot . I would rather you ask me about my experience then assume that I’m in idiot. I wasn’t asking how to “deal” with it only Peoples opinions to achieve the best results through roasting

 

[tamrock]

I'm guessing know one here on this site really knows the answer to your question.

 

[gold tramp]

Question what are you tryin to achieve by roasting.
Are you leaching ?

Gt....

 

[rockbar]

Jason has a bunch of helpful videos. After watching this one, I gave roasting a try and was able to pan out about 25% more very fine gold from a sample of hardrock cons. The sample I roasted was only 2-3 tablespoons of heavy sulphides (probably just pyrite) for about 25 minutes over a propane stove turned up to high. I then dumped the roasted sulphides while hot in a pan of water to fracture them. I was surprised how much fine gold was released. This may not be practical on a larger scale, but it sure was a fun experiment. I'm not claiming any vast expertise in roasting, just sharing my results.

 

[danec71]

Thanks. This is the whole point. I have never heated them up and drop them into water to crack them to release gold. This is something I’ll try and these are the different techniques I was looking for it along with temperatures and time

 

[arizau]

Thanks. This is the whole point. I have never heated them up and drop them into water to crack them to release gold. This is something I’ll try and these are the different techniques I was looking for it along with temperatures and time

If you do that protect yourself from a possible steam explosion.

Good luck.

 

[Mad Machinist]

I appreciate the concern but I am well aware of the dangers. And I know better than to stand there and breathe these fumes. My question was only about the right temperature and for how long. I’ve heard different ideas and cannot google in a precise answer. The one I find most reasonable somebody told me was 900° for about an hour. I have sent the stuff in for an assay before a couple of times and that’s great to tell me what’s in there but I want to see some results. I have tried a couple different methods and was simpley looking for opinions on the subject. It’s fine if you really do have some concerns but don’t say it in a way that you’re assuming I’m an idiot . I would rather you ask me about my experience then assume that I’m in idiot. I wasn’t asking how to “deal” with it only Peoples opinions to achieve the best results through roasting

I'm not thinking your are "stupid" by any means. It's just that arsenopyrite is EXTREMELY dangerous if it is not dealt with properly. AMD to deal with it properly is not cheap. For the most part, when it comes to arsenopyrite, your better off not knowing what is in it. Most people when they find something good in arsenopyrite try to short cut the process to save some money and end up making a hell of a mess.

 

[Mad Machinist]

I'm guessing know one here on this site really knows the answer to your question.

Tamrock,

I know the answer. But it is by no means cheap or easy. Even setting up to roast samples is not cheap.

 

[tamrock]

Tamrock,

I know the answer. But it is by no means cheap or easy. Even setting up to roast samples is not cheap.

I was told it's a difficult process. I tried my way and I took one look at the cons under fire and held my breath. The slightest whiff of hot gas barely went in my nostrils and I tell ya that was something I'll never do again. Young and dumb I was. All that aside, danac71 was looking for a number and I've no clue. Is there a sweet spot temperature to roast pyrites?

 

[Mad Machinist]

I was told it's a difficult process. I tried my way and I took one look at the cons under fire and held my breath. The slightest whiff of hot gas barely went in my nostrils and I tell ya that was something I'll never do again. Young and dumb I was. All that aside, danac71 was looking for a number and I've no clue. Is there a sweet spot temperature to roast pyrites?

Tamrock,

You do know that Morenci is a test bed right? All the big names send us equipment amd claim we can't break it. We simply smile, chuckle a little bit and say challenge accepted.

https://www.metso.com/products/hpgr/

That one is ours. About the size of your average two story house. It was a gigantic pain in my arse for about 8 months. Nearly 3000 hours in it over 8 months. My wife framed our marriage license and hung it up on the wall so she still remembered she had a husband. Roller bearing g are so big they have to be laid flat or they will deform under their own weight.

But back to the arsenopyrite, aresinic trioxide is created and it is corrosive so stainless steel has to be used. Preferably 316. 316 gets hard to form and bend as it work hardens leading to cracks and to get a good weld on thinner metal you need to TIG weld it. It all adds up ready quickly.

A scrubber needs to built to process arseno properly and it does need to be build out of stainless including the water spray nozzles. Sulfur dioxide is also created in the roasting of arseno and once that is mixed with water sulfuric acid is created. See why stainless is needed?

 

[tamrock]

Tamrock,

You do know that Morenci is a test bed right? All the big names send us equipment amd claim we can't break it. We simply smile, chuckle a little bit and say challenge accepted.

https://www.metso.com/products/hpgr/

That one is ours. About the size of your average two story house. It was a gigantic pain in my arse for about 8 months. Nearly 3000 hours in it over 8 months. My wife framed our marriage license and hung it up on the wall so she still remembered she had a husband. Roller bearing g are so big they have to be laid flat or they will deform under their own weight.

But back to the arsenopyrite, aresinic trioxide is created and it is corrosive so stainless steel has to be used. Preferably 316. 316 gets hard to form and bend as it work hardens leading to cracks and to get a good weld on thinner metal you need to TIG weld it. It all adds up ready quickly.

A scrubber needs to built to process arseno properly and it does need to be build out of stainless including the water spray nozzles. Sulfur dioxide is also created in the roasting of arseno and once that is mixed with water sulfuric acid is created. See why stainless is needed?

I never delt with the open pits when I had AZ. Asarco Mission, Magma San Manuel and Humboldt were some of who I was calling on back then. Was an UG copper mine on Mount Lemon also that failed I can't remember the name of. Only Freeport I deal with to some extent is a contractor working at one of Freeport's Moly mines here in Colorado. I just ain't much of mill and process man. As for the correct temps I can only guess it varies depending on the complexity of the material you're dealing with. I know I didn't achieve what I was trying to do, but the source of it is something I've been aware of for a long time now.

 

[A11]

Sense know one here would really answer the question I'll do my best. In short there is no fixed temp. You will have to experiment with your ore. Diffrent elements in the ore will affect proper roast temp. Also there is dead, oxadizing, clorinating, and sweet roasts to do. All are diffrent and depends on the ore. I recommend looking into some of the older mining books that cover the process pretty well. For most part you will be looking at a range of 450F to 1000F all depending on your ore. Alot of times you will end up with a veriable roast were you start low for x amount of time then ramp up to another temp level. Recommend reading, trial and error, and send out samples for assay to determine proper temp and time for best recovery. Good luck.

 

[IMAUDIGGER]

My dad once knew a guy that recovered a sizable amount of gold through roasting ore.
I watched his clean up station and was amazed at the steady stream of gold dropping into the jar.
I remember at the time, he had $60K in ore sitting in front of his garage in 5 gallon buckets.

He operated for years - until he succumbed to some sort of poisoning related to his process.
His source of ore is still sitting up on a nearby hillside waiting for the next guy.