# Poly metallic sulphide ore-Australia



## Anonymous (Apr 17, 2009)

I am a new member and firstly I would like to thank you in advance for your thoughtful and knowledgable response.

I have had quite a find of late and have taken a tenement out on the overlying area.Basically I have discovered a high grade sulphide ore body with 1 surface reaching outcrop of around 600m x 200m,of which I am currently sampling.

At the moment i am trying to unlock the gold values and I am making good progress.

About my process:
- crushing to a fine powder,using a keenes sample crusher
-seperating on a keenes shaker table
-seperating the magnetics from non magnetics
-roasting the cons on high heat for 1 hour,to drive off the sulphides.
-leaching in a SSN
-precipitating with T-6 and bringing the Ph back up to 4-7 with DISTILLED WATER,(it gets abit funky there,feedback,opinions appreciated)
-then doing another leach in a chlorine based,hydrochloric acid leach.
-filtering
-and then firing.

My leach bins are set up as follows,I have 2 x 100lt bins sitting on top of one another with the base of the first one lined with filter cloth with perferations in the bottom of that bin.There is also an oxygenator feeding O2 into this bin this is the bin were i place my cons.
In the second bin I have a recirc pump and my leach solution that is pumping into the first bin and is constantly filtered through my cons in the top bin.

At this point I have only leached about 50kg of cons,with some success in fact with my last attempt a brown sludge was captured in my final filtering.The problem is with firing,I was using borax and soda ash as a flux and would burn my paper filters(carbon) with my precips using a torch, I had no collecter metal and ended up with a heavy bead of flux!! But no visible gold,I was a bit pissed by then so i threw it all away after crushing and panning and there was some visible gold but not much.

This time around i will be using .999 silver as a collector and hopefully will get a better result.

I have attched assay results of some cons samples and photo's of the ore that I am sitting on.

If the next leach is successful,i will be stepping up production and if anyone has some plans for hammer mills or ball mills that are low cost that would be appreciated.i could even send you some ore samples for a collection.

Thanks Matt,in the Pilbara


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## Anonymous (Apr 17, 2009)

Page 1 of 1
200 Mary Street, Richmond, Victoria 3121 T: 03 9429 1899
F: 03 9429 4866
ANALYTICAL DIVISION
Date Incoming: 28 Jan 2009 Focus Reference: Inv12177
LAB281092
Client:
Ag 21.88
Al 7211.12
As 382.09
Au 864.80
B
Bi
Ca 3116.55
3.44
Co 51.07
14.22
Cu 128.22
108545.00
Hg 9.58
Mg 2453.30
Mn 178.65
Mo 2.30
Ni 91.50
P 229.72
Pb 65.32
Pd
Pt
Rh
Ru
Sb 3.84
Se
Sn
Te 6.78
Ti 939.19
W
107.77
ICP – OES finish for 31 elements.
Sample: 1.06800 grams
Undissolved: 0.49570 grams
Focus Metals Pty. Ltd. ABN 51 007 788 150
E-mail: [email protected]
Matt Chimenti
all results in ppm's unless otherwise noted
n.d
n.d
Cd
Cr
Fe
Ir n.d
n.d
n.d
n.d
n.d
n.d
n.d
n.d
Zn
Aqua Regia dissolution, with the undissolved solids filtered out followed by


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## Anonymous (Apr 17, 2009)

have you got a good recipe??


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## semi-lucid (Apr 17, 2009)

> roasting the cons on high heat for 1 hour,to drive off the sulphides.





> and be veeery careful with the arsenic......



I would think most of the arsenic is going up in smoke during that roast. After which it will come down on the surrounding countryside. Is this not correct? Wouldn't you would need a collector in your smoke stack to collect and dispose of it in a safe manner?

John


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## Anonymous (Apr 17, 2009)

i have only roasted about 100kg of cons at this point,and there has not been a whole lot of consideration in regards to the As.
The apparatus i use to roast is basically an old beer keg with a hatch cut into it that has gas burners underneath it.
What i will do is run a flue from this oven into a drum of water hopefully this will capture the toxins (As).This water will be then disposed of properly. 

Thanks John


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## aussco999 (Apr 19, 2009)

Hey Matt:

Well, this sounds like an interesting project on a very large ore body. I’m working on a similar commercial sized project in Mexico, with an oxide/sulfide ore too. We are getting some very good extraction result, because we also did the proper homework before starting the project.

I have a few questions/comments about your process first, and then maybe I can pass along some helpful hints we are doing that might benefit you.

The crushing, grinding and concentrating of the ore is all standard stuff, but do you have a better idea at about what temperature you are roasting the cons? A high heat doesn’t mean much to me, as saying a red heat. Tests have shown that the optimum roast temperature on many arsenic and/or antimony gold ores can be as low as 450 C, but no higher than 595 C. Heating the cons higher than that causes many problems (such as, gold locked up in re-crystallized hematite) and no leach (acid or base) will touch the gold.

Why did you pick SSN for a leach? This a very powerful leach, but not very selective unless you control the pH and ORP carefully. And, you lost me on the T-6 precipitant. Maybe I know it by another name or it’s mentioned somewhere else here on the forum and I’ve not read that far yet. Can you tell me what is the chemical ingredients?

Can you tell me the reason for the second chlorine leach, and was it done again on the cons or the precipitants from the SSN leach? If the SSN was used as a pre-leach, wouldn’t a single acid leach accomplish the same thing?

There can many firing problems when you don’t know what metals are in the mix. If you are going to use a collector, I would recommend lead (Pb) over silver, as it’s cheaper, often easier to get, and all the precious metals are soluble in it. Just don’t use car wheel weights as they contain to much antimony, which will make the gold brittle.

I’ve not used a torch (only poured from a kiln), so you will have to check with Harold, Steve or some others, but if you want to go the direct smelt route again, try adding a few grams of saltpeter (potassium nitrate) to your flux formula. It’s a heavy-duty oxidizer and will convert most base metals to an oxide during the smelt, moving them up into the slag, but won’t bother the gold.

And, here are a few IF’s for you. IF your ore body is as large as you say and goes to a decent depth, and IF you can become it’s new owner or take control of it, and IF you can effectively collect a concentrate, and IF your concentrates contain an economical amount of precious metals,,, then looking for plans to build any cheap crushing, grinding and recovery equipment just won’t cut it. 

You shouldn’t take on such a big project on a hobby scale. It would then be time to find the Big Boys and make some real money for all your hard work. Also, if that is a future possibility, take some representative samples across the vein, from several locations, and send them out for a certified analysis. An unbiased third party assay is the only thing the Big Boys will look at.

Good luck on your project and keep us informed of your progress.

John


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