magnetic black sands

[danec]

has anyone ever got any gold out of the magnetic portion of black sands.im not talking about the few pieces that might get picked up with them when you put a magnet over them to pick them.im talking about just the magnetics part.i dont want to waste time with that part of the sands if i dont have too.i dont think gold forms in magnatite anyways right.thanks.

 

[ejay111]

its there nano gold dust im a panner and used clr in glass jar with lid i let it sit for a week given eshake every 2 day you see it my problem is recoveing it safety any thoughts ?

 

[solarsmith]

I have seen a few articles describing gold in pyrite. 70% of the gold now being procesed is in a sufide form. gold pyrite is paramagnetic and will only respond to a very strong magnet. you can make gold pyrite magnetic by roasting it in open air to dull red heat. this changes it from a sulfide to a oxide and makes it magnetic. also it drives off the sulfer and arsinic creating a problem with fumes. ( an acid and a poison in one) I reacently found out all of the gold in my ore is in the pyrite a very small fraction of the total mass.( aprox 3%) the sulfer content of my ore is so low it is clasified as an oxide type. even so now knowing that all of the gold is in a sulfide form (pyuritic) that I am now preping my floatation gear for a sulfide type float.
pyrite loves to float in such a system. Once I get a good gold pyrite concentrate I will roast and then seperate the iron and gold with chems.
my progress has been slow due to a barn I am building for my gold mill equipment. All of my time is now being spent on construction of the barn.

Bryan in Denver Colorado 303 503 4799

 

[Traveller11]

Hello Bryan
I read in your post that you separate iron and gold with chemicals. I have placer material that is a good part magnetite and hematite. The gold ranges from ultrafine to micron sized free gold; almost impossible to separate by gravity methods.
I tried using the acid/clorox method on it, as taught by lazersteve. Although the solution, at first, turned a nice golden colour, it wasn't long before the iron kicked the gold out of solution and the colour changed to a canary yellow.
If you could share your process for removing iron, I would be most grateful.
Bob

 

[solarsmith]

I have not done that part yet. the ore I am working with starts out at 8 to 9% iron and I remove as much of the magnetic iron and magnatite as soon as it is milled with a magnetic sluce at the end of the ball mill. this catches about 2 or 3% of the iron (less to deal with latter) then I run it through the float cell will try to float only the pyruritic portion of the ore this is the trick to having somthing that is as high grade (oz per ton) as posible. if the grade is good I may be able to do a direct smelt (almost the same thing as an assay)
or I might just acid leach off the iron and other base eliments with a weak acid like citric and then direct smelt whats left. or even leach out all the metals and drop or plate out each elament one at a time. there is a lot of information on this forum on how to manipulate precious metals with common chems from local stores. before you start hitting ore with chems you will certainly want to concentrate it. Every thing I have read describes concentrates as 3x to 300x times the starting grade or head grade. If your starting with a head grade of 10 grams per ton and recover 90% at a 5x improvement factor you would be at 45 grams a ton. you could sell this to some mills/smelters if you had many tons of it. To try to wet chem recover this low of a grade yourself would be cost and time prohibitive. However I would not want do discorage any one from making the efort. The education you will get from your efforts will be priceless. There are lots of folks here that would love to help out. Some one with gold ore has hundreds of ways to process it . Factors that one might consider are , grade ,volume, penalty eliments, bonus eliments, location, permiting, cost of processing, cost of transporting, hazmat desposal, waste disposal, and many more.

thanks Bryan In denver

 

[Iron]

Hello Bryan
I read in your post that you separate iron and gold with chemicals. I have placer material that is a good part magnetite and hematite. The gold ranges from ultrafine to micron sized free gold; almost impossible to separate by gravity methods.
I tried using the acid/clorox method on it, as taught by lazersteve. Although the solution, at first, turned a nice golden colour, it wasn't long before the iron kicked the gold out of solution and the colour changed to a canary yellow.
If you could share your process for removing iron, I would be most grateful.
Bob

Hi,
I have managed to extract the gold out of black sand ( it was only 300gr black sand), I have get done assay result which it was shoving 251 Oz/ton. we developed the flux and Technic to do. Before you extract the gold the gold and PGM you need to liberate them from iron oxide , also with one similar technic you can produce dore bar then they are ready to refine by chemically or metallurgic . This is the key.
Good luck

 

[Hephaestus]

Wow! Isn't that a huge concentration? pretty impressive.

 

[Irons2]

I have seen Magnetite grains cracked open with tiny globules of Gold imbedded in them, also Sulfides partially digested, again, with tiny particles of Gold.
Every source is different and the Gold content may change in a distance of a few inches.

There is no one formula or process to extract Gold from Black Sands, if there is any Gold at all.

Usually, chemical digestion of Magnetite is very time consuming and creates a lot of waste that has to be disposed of properly.

If it was easy or economical, the Large mining companies would have done it long ago. I'm not trying to discourage people from trying. I have had some success recovering Gold from Magnetite, but it was from a source with known Gold and lots of it. One tiny bit of Gold here and there isn't going to pay.

Crush the Magnetite and inspect it under magnification to see if it contains any values, then take it from there, one step at a time.

 

[jeneje]

Just thinking here, the problem I see is getting the iron out. Would a cell like a silver cell with a lye solution work. I know you can use the lye to remove rust from old tools and such. Just a thought.
Ken

 

[butcher]

Cell idea, magnetite hemitite pyrite ore, problem is it is not elemental iron, I do not see how the electrolisis in caustic electrolyte idea would work, even if you tried to convert reduce it to iron in the cell, can you give some more detail of this idea and how you feel it may work?

 

[Geo]

as unpopular as it is, milling and (the illegal)mercury is one sure way of getting it all. warning: mercury is very toxic and should not be handled by anyone that has not studied the effects of mercury poisoning on people.i do not promote its use in any way, just stating that as a collector of gold, it really cant be beat. anyone who reads this and thinks its a good idea, let me inform you before you try. free standing gold is not very likely to stick to mercury. i wont go into details about how to make it work, just take my word for it that its more to it than just pouring mercury into a sample of dirt and getting gold back out.

 

[jeneje]

Cell idea, magnetite hemitite pyrite ore, problem is it is not elemental iron, I do not see how the electrolisis in caustic electrolyte idea would work, even if you tried to convert reduce it to iron in the cell, can you give some more detail of this idea and how you feel it may work?

butcher, my thinking was if you roast the black sands at high heat for 30minutes or longer it would change the structure of the magnetite hemitite then fracture the sand into a weak NaOH solution decant and add the fracture into cell if this would have any effect on the iron and free the gold to recover and process.
Ken

 

[jeneje]

Butcher, here is what I am thinking about trying with the black sand concentrates. I know that there is no way to chemically dissolve the sand safety. So if I can remove as much iron as possible before leaching the gold I may be able to obtain more micro gold dust.

Classify the concentrates to at least 100 mesh size.
Heat concentrates to red hot temperature and hold for at least 30 minutes.
Fracture the sand into a mild NaOH solution.
Decant the solution (saving it for another use).
Put the fractured concentrates into a cell with caustic electrolyte.
After reaction is done, if any, remove the concentrates and wash well.
Put the concentrates in a reaction vessel and add a mix of HNO3 and water to remove any silver or palladium. Decant, wash and then process with AR to recover any gold.

I don’t know if this will help to remove the iron and release the gold or not. I will have to do research on making the cell for this trial. There are a lot of questions to be answered before trying, like what type of cathode, anode, amps, electrolyte mixture to name a few I’m sure there are more but its something to experiment with.
Ken

 

[butcher]

Grinding to fine powder and roasting to oxidize the material, I understand that part.

I know that the black rust can be converted to Iron, when electrolysis of a rusted iron object (antique), in a sodium hydroxide solution as the cathode, but the yellow rust is not converted to iron in this process, it is too far oxidized.

How are you going to make the oxidized powder conductive (like a bar of metal would be), and attach electrically to the power supply? and I do not see how the oxidized powder would convert to iron, unless your plan was to oxidize it further, but I still cannot see how you can do this in an electrolytic cell.

If you can get the black sands ground fine enough, and was able to get the iron compounds all roasted to iron hydroxide (I think it would be difficult to convert all of the forms of iron compounds), (also there could be several deadly gases in the roasting process, including arsenic), iron hydroxide is not soluble worth a darn in acids and gold could be leached without dissolving much of the iron, this sounds easy, but in reality it is not.

In a leaching process not only do we have the problem of iron but also the many forms of compounds it is in, and converting these iron compounds in these black sands and ore, and converting these compounds safely into a form of iron that we can either dissolve the iron from the values or convert the iron to a form that we can dissolve values without attacking the iron compound, these different iron compounds are terribly hard to convert all into one form, dangerous also if your not aware of dangers involved, normally not much value involved for all of the work and costs, many difficulties in acid leaching.

Then there is the smelting process, unless your a large company and your goal is to make iron and collect a little bit of gold in the process, I do not see where the cost would be worth it with black sands, I can see where removing free gold from black sands can be worth processing, but not the tiny bit that is locked up in it, at least from what I have tried so far or learned so far.

 

[jeneje]

Grinding to fine powder and roasting to oxidize the material, I understand that part.

I know that the black rust can be converted to Iron, when electrolysis of a rusted iron object (antique), in a sodium hydroxide solution as the cathode, but the yellow rust is not converted to iron in this process, it is too far oxidized.

How are you going to make the oxidized powder conductive (like a bar of metal would be), and attach electrically to the power supply? and I do not see how the oxidized powder would convert to iron, unless your plan was to oxidize it further, but I still cannot see how you can do this in an electrolytic cell.

If you can get the black sands ground fine enough, and was able to get the iron compounds all roasted to iron hydroxide (I think it would be difficult to convert all of the forms of iron compounds), (also there could be several deadly gases in the roasting process, including arsenic), iron hydroxide is not soluble worth a darn in acids and gold could be leached without dissolving much of the iron, this sounds easy, but in reality it is not.

In a leaching process not only do we have the problem of iron but also the many forms of compounds it is in, and converting these iron compounds in these black sands and ore, and converting these compounds safely into a form of iron that we can either dissolve the iron from the values or convert the iron to a form that we can dissolve values without attacking the iron compound, these different iron compounds are terribly hard to convert all into one form, dangerous also if your not aware of dangers involved, normally not much value involved for all of the work and costs, many difficulties in acid leaching.

Then there is the smelting process, unless your a large company and your goal is to make iron and collect a little bit of gold in the process, I do not see where the cost would be worth it with black sands, I can see where removing free gold from black sands can be worth processing, but not the tiny bit that is locked up in it, at least from what I have tried so far or learned so far.

Butcher, i really don't know much about black sand, here is what i have done and this part i do know works. I started a test yesterday with a teaspoon of concentrates - done a hard boil in a lye solution for 15 minutes. let cool, decanted it, boiled again in tap water for 15 minutes, decanted and filtered the water then added a 6 to 1 AR mix and waited at first there were no reaction as the day progressed and the heat of the sun(i guess) heated the solution a small reaction started and it tested for gold. (I have attached the pic of the test here). I agree with you about the cell and compounds but i also think if you are in a rich area for gold the doing a lye boil and a boil in water before leaching will help to release the small partical of gold and enhance the yeild.

To try and remove all the iron is a waste of time, but removing as much as possible before leaching does help.

Ken

 

[butcher]

I like the violet color, I believe you leached free gold in the concentrates, getting the gold out of the bond with iron inside the black sands as a compound with iron oxides would be much more difficult.

Keep up the good work anytime you get that violet color in your test tube your doing good.

 

[jeneje]

I like the violet color, I believe you leached free gold in the concentrates, getting the gold out of the bond with iron inside the black sands as a compound with iron oxides would be much more difficult.

Keep up the good work anytime you get that violet color in your test tube your doing good.

I agree with that the compounds in iron are better left to the professional refiner... :lol: . I to think it was free gold in the concenrates, but the lye boil i think helped to remove the contaimates left by the river.

I do like to try other things butcher, but to remove the gold from black sand proves interesting to say the least... :lol: so for now i am happy with the free gold.

The violet color does look so good, as a newby i am glad to see that color. :mrgreen:
Thanks for the encouragement Butcher.
Ken

 

[Geo]

one thing to consider when dealing with free standing gold in creeks and streams. even though gold is considered stainless because it doesnt tarnish, it still gets a film or a coating of organic material (oil,tar,tree sap) and it all conspires to keep you from being able to reclaim it. many people think it terms of soap and some even use Tarn-x to clean the gold so it can be recovered. i know from experience that Tarn-x will make fine gold (like flour gold) float out of your pan. anyone who has ever used it can tell you that small bits of debris like Mica and quartz and even black sand will float after being treated. the best way to remove that kind of stuff is to roast the sand. it serves two purposes. (1) it removes organics and (2) if you dump the sand while it is at the dull red stage into cold water, the bits of sand that has trapped gold within it will bust releasing the gold that was trapped inside. sorry, i like to rant sometimes. :lol: