What's the best way to seperate Pyrite from gold?

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Smitty

Well-known member
Joined
Sep 24, 2007
Messages
158
Location
TEXAS
Hello wiser members.

My name is Andy. I came across this website thru Lazersteves grrreat website. I have a place I go to in the local area for panning and I get a lot of black sand and pyrite mixed in with gold. I'm looking for anyone with answers on how to dissolve the pyrite and leave the gold. The gold I'm getting is salt grain sized gold dust. Any answers would be great. :D
 
Easiest way, Mix the black sands with an equal amount of uniodized salt. Heat the mixture to scorching hot. Stir the mixture with a glass rod or piece of rebar. You canheat the mixture in a castiron pan if you want to. I'm talking about a red heat on a piece of iron. Dump the mixture in a bucket of ice water. (NOT THE PAN) From there, just pan out the gold or use whatever method you prefer.

The heat drives off the sulpher in the pyrites, and the thermal shock breaks the black sands, releasing more gold. The salt also acts to remove any organics that will discolor the gold.

Chuck
 
Nitric acid reacts with sulphides to give free Sulphur, The Nitrate salt of any base metals and free Gold.

In 1970, some friends sent me a wash tub full of pyrite from a Gold mine in Colorado that had been closed since the 19th. Century when the Federal Government closed the Gold mines to raise the price of Gold.

I called them up and asked them how much gold was in it. They didn't know.

I treated it with some dilute HNO3 and panned the sand and gravel that remained. There was about 2 ounces of nuggets and a quarter cup of fine Gold. That was some good ore.

They made over 7 Million the first year. That's 1970 dollars.

Don't use concentrated acid. It releases too many noxious fumes.

Don't do this indoors.
 
I'm gonna have to try both methods in the suggestions. Since I have both pyrite and black sand in my material. thnx people
 
OK here are some results from an AP solution bath. The solution immediateley started to fizzzzz showing that it was reacting to the Pyrite. It takes a lot of AP to dissolve a little amount of Pyrite. It started to turn a deep yellow to orange color. I actually had to pour it out when the fizzing decreased and pour some fresh AP into the material. The material I was working on was about half a tea spoon of pyrite / black sand mix. I also took a few grain sized pyrite to test the time it took to dissolve a 1mm piece of Pyrite in AP. After 2 hours in the solution it was still very much the same size it was when i left it.
 
Put it in a container with a loose fitting lit and put it out of the way somewhere outdoors. It may take a few weeks. Occasionally add some more peroxide to replenish the acid. Don't do this indoors. Arsenic poisoning is cumulative. If you can smell the Arsine, it's a lethal level. 0.5 PPM is lethal,140 PPM will kill you in seconds. It may take you a while to stop convulsing but you will be dead just the same.

Chemical reactions double in rate for every 10 Deg. Centigrade rise in temperature, so reactions will take longer as the weather cools.

That material has been sitting in the ground, unaffected for Millions, perhaps Billions of years, so don't expect instantaneous results. Some PGM Sulphides are even unaffected by AR.
Americans suffer from the Digital Camera effect. When Kodak first came out with the Brownie camera, people would take pictures, mail in the camera and two weeks later they were amazed to get their pictures. Now, with Digital Cameras, ten seconds is too long a wait.

Patience is a virtue in this business.
 
No offense but, the word "separate" must be the most misspelled word in the English language. At least half of the people on the net write, "seperate." It seems like I see it at least 10 times a day. A close second is "nickel." A lot of times, it is written, "nickle." I'm just as bad, or worse. If I didn't get that red dotted line underneath my misspelled words, my posts would be incomprehensible. Especially with the long words like "incomprehensible." I wish that dotted lines would appear when I use commas wrong. I never know exactly where to put them.
 
Since Pyrite is Iron, will not HCL or Muriatic put the iron into a solution making an iron chloride ?? leaving any gold out of the solution or will the gold follow suit and need be dropped out by another metal?

William
 
blueduck said:
Since Pyrite is Iron, will not HCL or Muriatic put the iron into a solution making an iron chloride ?? leaving any gold out of the solution or will the gold follow suit and need be dropped out by another metal?

William
Pyrite as found in placer concentrates is rarely Iron Sulphide alone. It could be a complex mixture of metallic sulphides including toxic elements such as Arsenic. In fact, unless you know differently, you should assume that Arsenic is one of the constituents as it is so common.

Pure Iron Sulphide dissolves quite readily in most acids, but unfortunately, you will find that many sulphides are very resistant to digestion.
 
I've been messing with dissolving pyrite and leaving gold for about 2 weeks now. It seems as if panning alone is going to be my prefered method right now. It takes a long time to dissolve the pyrite that was present and I was also concerned that I might have dissolved some gold into solution because the gold I as trying to seperate was very small. As soon as I put HCl into the material it did turn a dark yellow and that was before I added the Peroxide.
 
when panning fine Gold, screen your concentrates to a size close to the size of the Gold. You will lose less that way.
Be sure your pan and hands are free of oil otherwise it will work like flotation and carry the fines off.
I always pan fines at least 3 times to catch Gold that floated off before.

Fine Gold is a pain but that's all we have around here.
 
The best way to deal with Sulphide ore is to 1 move to another spot. Seriously though, the best and cheapest is to roast them. What you are trying to do is drive off the Sulpher (sulfides) Were talking a good long hot roast. It stinks. See 1.
 
Smitty,

Listen to Irons about arsenic poisoning. The initial poisoning is bad enough. Years later I had the lower half of my right ear surgically removed at the age of 42 because of basal cell skin cancer attributed to arsenic in my system. I was the youngest guy the V.A. had ever seen with this form of cancer at the time. My nose will be next. I have other tumors on my face and behind my right ear and shoulders etc. It's not fun being disfigured because of this stuff. Respect this material! Especially if you use a crusher or hammermill to pulverize this material making it easier to absorb it through your skin.

My exposure to arsenic was due to the negligence of the Penwalt Chemical Corp in Bryan, Texas on Finfeather Rd. The rather large sum of money I recieved in settlement is of course long gone but the cancer remains.

Sincerely,
Wayne
 
This is what I am doing now.

Dissolve the pyrite with HCl and heat. Decant the dark yellow solution, then put the fresh HCl and heat again. It is surely a long time.

I think, after this, I will put the remain solids into AR.
 
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