Is this your experience? 4 grams per ton with this material?
pyrite gold extraction
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solarsmith
Well-known member
my last assay of my concentrates which are 98% iron was 1.75 oz per ton AU. so its about 40 grams per ton. It takes about 4 to 6 hrs to make just 50 lbs of concentrate.
Gold in sulfides is usually treated by obtaining a concentrate and then oxidising that concentrate so that standard leach methods can be employed to recover the gold.
Depending on the type of sulfides, how these sulfides are located in the orebody and the gold grade of the actual sulfide fraction, the oxidising is usually done by either roasting the ore prior to cyanide leaching, bacterial attack on the sulfides or chemical processing under heat and pressure.
There are similar costs to treat sulfides as to treating barren country rock so in order to maximise treatment returns it is usual to firstly obtain a sulfide concentrate, usually by flotation.
The treatment methods are well known to those in the industry as are the costs and recoveries.
A lot of optimising work has been done by large companies so there are very few surprises in the oxidation steps.
Probably the least employed commercial method is alkaline attack on the concentrates, it is the cheapest and simplest of all the methods but takes the longest time to complete.
The gold grade of the sulfide concentrates can be up to several hundreds of grams per ton, it depends on the grade of the original orebody and the concentration factor from the upgrade.
Deano
Depending on the type of sulfides, how these sulfides are located in the orebody and the gold grade of the actual sulfide fraction, the oxidising is usually done by either roasting the ore prior to cyanide leaching, bacterial attack on the sulfides or chemical processing under heat and pressure.
There are similar costs to treat sulfides as to treating barren country rock so in order to maximise treatment returns it is usual to firstly obtain a sulfide concentrate, usually by flotation.
The treatment methods are well known to those in the industry as are the costs and recoveries.
A lot of optimising work has been done by large companies so there are very few surprises in the oxidation steps.
Probably the least employed commercial method is alkaline attack on the concentrates, it is the cheapest and simplest of all the methods but takes the longest time to complete.
The gold grade of the sulfide concentrates can be up to several hundreds of grams per ton, it depends on the grade of the original orebody and the concentration factor from the upgrade.
Deano
thank you for your advise and comments... they are much appreciated ... looking forward to hearing from others as well and will keep you informed of the results of a 1/2 kilo test after I properly document the results... with the Christmas season hear and a day Job it might take a bit
the second half of this process looks very similar to your process you show on YouTube ... its the first part that varies a quite a bit ... check back eventually I will post the results from my current test run
solarsmith
Well-known member
yes our concentration method is very unique. I have only heard of 2 other places on earth that it would work. remember gold is not magnetic but the iron it rides on is! give any one any ideas? hint I own hundreds of magnets. I will save that for another thread/video
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solarsmith
Well-known member
an exclent discription of what Im doing,
GoldReport
Member
This is quite an interesting thread. I would say finding gold in pyrite is certainly rare if it were just any old piece of pyrite. But since you say you got it in Colorado, your chances are higher. The concentration seems quite high, might have got lucky and are experiencing the nugget effect or you did indeed stumble upon quite a discovery. If it's possible I would want to continue testing pyrite that came from the same area.
The high concentration could also be explained by the fact that since you are buying just pyrite, not a chunk of rock with some pyrite speckled in, they've already concentrated it for you somewhat. Do you have any pics of the pyrite prior to crushing? It may be a mislabeled mineral that is actually a known gold bearing mineral and was just thrown in the pyrite bin at the gift shop.
The high concentration could also be explained by the fact that since you are buying just pyrite, not a chunk of rock with some pyrite speckled in, they've already concentrated it for you somewhat. Do you have any pics of the pyrite prior to crushing? It may be a mislabeled mineral that is actually a known gold bearing mineral and was just thrown in the pyrite bin at the gift shop.
I would like to also test pyrite from the Denver area... if someone is willing to send me some from around there documenting source would be advantageous... at this point I purchased some chunky pyrite from an on line seller who says it's from a gold mine in Peru... I have no way to verify that... I don't yet have a yield but it looks promising... always open for a location documented sample... weather from crush or chunky ... as of yet I have only run the large chunky stuff you would finf in a gift shop...
An excellent description of Deano's responses in general.
GoldReport
Member
As a separate question for you, let's say your potential ore (it's only ore if it's profitable right) is gold in disseminated sulfides. It looks like purple paint on the joints in the rock. Gravity separation still the way to go for initial sulfide concentration?
it would seem to me, gravity separation would work well for the visible gold and their connected sulfides however there are micro and sub micro sizes that are not captured these non visible sizes would probably escape in the waist pile... maybe someone with more experience can chime in ... but at least in my mind the only way to get that size is chemically? it would make an interesting experiment to compare known samples' both ways ... in other words equally divide a well mixed crushed sample and run one strictly chemically and one concentrated via gravity separation an check the yields...?
It is also a game of cost versus gain.
At which time does one stop throwing Dollars after Dimes?
It's certainly possible that if it's from a closed down mine where they're just breaking off samples and no longer assaying, that they got a bit of rich gold-bearing ore from a vein fragment. I've seen some rich sulfide ores at over 100g/ton.
BUT, the OP really needs to verify that what he's recovered IS ACTUALLY GOLD. Easiest thing is to melt it and see if it flattens easily with a hammer. If it does, and looks very 'golden', then it's probably high-percentage gold. If it flattens, but develops cracks, it could be a brass of some sort. If the button shatters, then it's a mix of unknown stuff and may have little or no gold.
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Every ore is different, in that The Au could be locked up in the sulfides, free milling, Tellurides, and any combo there in, as well as particle sizes. Courser Au, and some pyrites can be concentrated by gravity. However, the finest particles will many times float away. This is where chemical leach and floatation are a much better solution than gravity systems. There is no one size fits all milling/recovery system. Unless you fine grind, float recoverable particles, then leach the under flow off the float cells. As Yggy said, there is a trade off between recoverable economic quantities, then throwing dollars after nickels. This is where it pays to send to a good mining lab to determine what you have, and how you need to proceed in getting it. Jason from MBMM has some videos smelting ore, cons, and then the tails for recovery percentages. In the real world, an independent lab will umpire the results to determine if they are accurate.
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Picture won't expand, but I think the XRF says 96.4%
either way it is reasonable the original picture says 98.4 sorry for the typo... this site would not upload the Higher Definition picture
all the research that I can find (publicly available) discuss the Au bound as a sulfide (Gold sulfide (Au2S))
... what other bonds exist in the Pyrite ... I am acting on the premise that some free gold metal bonds to Iron (II) and yet some bonds to the sulfide as well with still some colloidal Gold settled out as free mill could this accounts for the differences in the crystal structure of the Pyrite? with FeS2 being Pyrite and CuFeS2 chalcopyrite or copper pyrite ... yet I find no real information on AuFeS2... The question being; in some Pyrite ore, is it reasonable to expect the Au to bind with Fe much like copper metal bonds as opposed to a sulfide bond?
... what other bonds exist in the Pyrite ... I am acting on the premise that some free gold metal bonds to Iron (II) and yet some bonds to the sulfide as well with still some colloidal Gold settled out as free mill could this accounts for the differences in the crystal structure of the Pyrite? with FeS2 being Pyrite and CuFeS2 chalcopyrite or copper pyrite ... yet I find no real information on AuFeS2... The question being; in some Pyrite ore, is it reasonable to expect the Au to bind with Fe much like copper metal bonds as opposed to a sulfide bond?
