# Chlorine leach



## want2ride (Aug 8, 2011)

i am wondering if anyone tried to do a chlorine leach in a batch type system. we have some micron gold that might require crushing. It seems that there is at least a bit of limestone in this gravel glacier deposit. 

I have never done this anything like this before. I need to be able to have a system that can have less long term liability than cyanide would have. What kind of information do you need me to give you to help me out?


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## solarsmith (Aug 8, 2011)

as allways an assay is in order for any one that wants to process ore for profit... other wise there are a lot of leaches that will take metals out of ore.. most do not like any thing with carbon. My question is does limestone have carbon? thanks BRYAN IN DENVER COLORADO


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## Reno Chris (Aug 9, 2011)

Chlorine is not viewed by regulators, insurance folks, etc. as being significantly less toxic than cyanide. Chlorine is a deadly poison - its use in war is outlawed by the Geneva Convention. 

Other issues -
1) Glaciers do not concentrate gold.

2) Micron sized gold does not concentrate in placer gravel deposits.


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## want2ride (Aug 9, 2011)

I am aware that glaciers do not concentrate gold, but they aparently took some good gold bearing rock from Canada and deposited it in the northern US and it picked up some limestone along the way. Has been assayed, i don't want to give out specifics, but it should be good enough to do a batch system as long as i don't have a couple thousand into chemicals per ton. 

The micron gold is not concentrated, it is locked up in rocks and is not visible except under good magnification. Some of the rocks are pretty large others are not. we know what rocks have it and what don't. even without sorting (which is only doable with the big rocks) it should be doable. 

i guess i should start with some bucket sized batches and work from there.


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## solarsmith (Aug 10, 2011)

if its more than 20 oz per ton you have gold ore concentrate and can sell it as is to a lot of diferant people.
if less you can concentrate using a floatation system or
concentrate with a gravity system, or any combination of the two.
I have 0.59 oz per ton and will be testing to see what works best..
I been reading about ssn leach and will be trrying it soon.
gold to day was 1800+ per oz . wow

BRYAN IN DENVER COLORADO 303 503 4799


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## Reno Chris (Aug 10, 2011)

> if less you can concentrate using a floatation system or
> concentrate with a gravity system, or any combination of the two.



Cant float it unless the gold is in a sulfide or telluride (original poster wont say).
Can't gravity concentrate it if the gold is micron sized as the original poster mentioned. 

One thing about chlorine leaching is that it requires acidic conditions - not necessarily strong acid, but at least mildly acidic. 
Under basic conditions, the chlorine will convert to hypochlorite and chlorides. 
Limestone is a very powerful acid neutralizer, and may consume a lot of acid, depending on how much you have.

Bucket scale testing would be a good idea before investing lots of $$$$$$ in any system.


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## solarsmith (Aug 11, 2011)

oxide ore will still float and so will free gold . gold is hydrophobic and more so with the right reagent (pre treatment) thats why every one allways tells any one trying gravity concentrating to add jet dry to offset golds natural tendancy to float. placer gold has been sucsefully recovered in the 90%s in the alaska area.
Bryan In denver colorado


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## Reno Chris (Aug 11, 2011)

Technically, you are right that gold will float. However, no one recovers free gold by flotation (except in a lab) because its practically speaking impossible. In a pan some gold will float - but if you stir the water with your finger it will break the surface tension and the gold will sink. In a normal froth flotation cell, the turbulence is huge and holding gold in the froth is very difficult. There is no reagent which will hold gold strongly on the bubble surface like sulfides can be held in the froth. So practically speaking, I am right - floating gold is not practical (which is why no one does it commercially).

Of course placer gold can be recovered - but the original poster stated his gold was micron sized - that 1/1000th of a milimeter. You can't even see gold of that size without a microscope, and it cannot be recovered by any gravity methods as you would in a normal placer. Commercially, micron sized gold is recovered by leaching with cyanide.


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