# Grinding Your Ground Roasted Concentrates AGAIN !



## DarkspARCS (Aug 10, 2020)

Greetings everyone!

I wanted to share an experience Ive had that taught me a good lesson in extraction efficiency that others may find helpful when they discover that they have the same attitude towards crushing and grinding your ore that I once did, which is what this is all about...

ATTITUDE...

In Astrophysical terms, attitude isn't just a state of mind but more importantly a state of position that a spacecraft possesses when calculating orbital insertion. In simple terms, WRONG ATTITUDE, GAME OVER...

Our attitude towards our process when metallurgical extraction is concerned can be explained in exactly the same manner. A disrespect for the chemicals we use, the tonixs involved, and the temperatures required can spell a GAME OVER scenario for us as well.

The attitude towards GRINDING our ores not just can BUT WILL make an important difference in how much gold one will see a result of when milling.

My process used to be pan down the crushed ore (-20 mesh + -), roast it to powder, then separate the iron with a magnet...

Then my partner came along and showed me a big step I was skipping which showed me a better return on the gold extracted from the roast, which is the REGRINDING of those roasted concentrates...


When Ive finished roasting my concentrates the roast took the -20 mesh refractory concentrates Ive worked down to about a -100 + - mesh as the hot ore will further break down the covalent bonds the sulphides arsenides and tellurides my ores possess.

I roast my ores in an iron gold pan, mixed with uniodized salt and several 9" iron nails. Iron is important in the roasting process but something that isn't spoken of much is the encapulation iron oxides will do with the micron gold content. The iron will encapsulate those gold particles and then keep ahold of that gold when magnetically separating the roasted concentrates.

Many of the publications and patents Ive reviewed regards industrialized processes include REGRINDING the roasted cons again... and in a different part of their process lines again and again!!! I ignored that feature ... Believing chemicals will take care if that for me, which they will BUT THAT COMES AFTER THE GRIND AND THE ROAST... The magnetic separation of the iron is the important part being discussed here, and REQUIRES that the roasted concentrates be ground again beforehand, so that the oxides that have encapsulated the gold will be properly broken back down and the gold free to remain behind when running that magnet through the roasted cons.

This grinding is critical, and this is the method my partner showed me he uses to perform this regrinding of roasted concentrates...




I call it the "Simes method of regrinding iron- encapsulated roasted gold concentrates". Thats a process I will cover in more detail soon. The important thing to take from this is that a method that specifically gives a process necessary to achieve best results shouldnt always be ho hummed like it was with me, because there's a reason why its mentioned there...

Regrinding ore seemed so time consuming and like an unnecessary step but it isnt, which we find out later on down the line. Its a good thing I saved those concentrated roasted iron oxides Id separated with a magnet... I will eventually return to them and regrind them...=)


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## cosmetal (Aug 11, 2020)

*"Simes method of regrinding iron- encapsulated roasted gold concentrates". Thats a process I will cover in more detail soon."*

Looking forward to your further elaboration. I am particularly interested in your grinding method.

I have always been fascinated by black sands concentrates. When I had my placer claims, I built my own Miller table with two silver-plated copper plates that I "filmed" with mercury (yes, I knew what I was doing and had a mercury trap at the end of the table to catch any free mercury). When I first finished building it, I ran water over it overnight to check for leaks. In the morning, I was amazed at how gold colored the mercury film had become. The plates were coated with micro gold that was within our water. I lived in Placerville at that time - the epicenter of the 1849 gold rush.

All my black sand cons were from our dredges. Unfortunately, I never ground or roasted the cons. I now live in Sacramento and I am literally surrounded by black sands from the old-time, dragline bucket dedging operations. At the current price of Au, I am getting very "twitchy" to attack some of those tailings.

Peace and health,
James


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## Dwf (Sep 1, 2020)

Thanks for sharing!
I find this very interesting, and will definitely be trying it. 
Can you further explain how you do your roast? I haven’t heard of this method with salt and iron nails. 
Also, how are you regrinding your concentrates? 
I was thinking of building a small ball mill that would fit on my work bench. 

Thanks again!


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## Junior2021 (May 26, 2022)

DarkspARCS said:


> Greetings everyone!
> 
> I wanted to share an experience Ive had that taught me a good lesson in extraction efficiency that others may find helpful when they discover that they have the same attitude towards crushing and grinding your ore that I once did, which is what this is all about...
> 
> ...


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## Junior2021 (May 26, 2022)

OLÁ boa noite 


Obrigado por postar conhecimento importante. Muito interessado nos detalhes. Acredito que seja isro Encapsular o ouro no ferro através da queima intensa do Minério o sal seria um redutor? Depois liberar o ouro e passar para o processo químico? Muito interessante. Parabéns aguardo detalhes.
obrigado.


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## Alondro (May 26, 2022)

I am finding a similar thing with the black sands I'm recovering from my hot spot in NJ for gold dust and small flakes. The iron oxide forms a shell around many tiny gold particles. I'm currently doing a roast followed by long-term soak in conc HCl to dissolve away the iron oxide. It appears to release a tremendous number of additional gold particles. Once the process is complete, I'll do a confirmation dissolve and drop.

But, not all black sands will show this. Black sands from a sandpit down the road from me showed NO gold at all. They were almost entirely just hematite, magnetite, and some galena. The only way to be sure is to test a sample, and fortunately this is a cheap method.


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## minero74 (May 27, 2022)

Good afternoon Guys
Thank you sharing all the knowledge you have.
I will regrind my concetrate again after roasting


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## goldshark (Aug 3, 2022)

Still waiting to hear back on the grinding technique. Is a ball mill acceptable with steel balls, or should one use some bull quartz for grinding media? I would think the steel balls may produce too much Iron oxide. At least too much FeO until they wear a bit. Would a Bico plate grinder be the method of choice?


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## dkbinco (Sep 26, 2022)

Hey guys, did we ever hear back on grinding method or about nails and salt.


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## Alondro (Sep 26, 2022)

goldshark said:


> Still waiting to hear back on the grinding technique. Is a ball mill acceptable with steel balls, or should one use some bull quartz for grinding media? I would think the steel balls may produce too much Iron oxide. At least too much FeO until they wear a bit. Would a Bico plate grinder be the method of choice?


A pre-ore-grind with just the balls and a few worthless rocks will knock off all the iron oxide rust from the balls in a short time. It's easy enough to do.


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## dkbinco (Sep 27, 2022)

I am waiting on an assay, and I know I will roast, but a post roast is interesting to me I am new and reading and studying and learning before I start all this. I have gathered stuff to do this, but don't understand the salt and nails unless to break down iron oxides, but the slimes method looks like a floatation thing of some kind?????


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## goldshark (Oct 2, 2022)

It would be interesting to assay the slimes. Perhaps the roast only penetrates a certain amount of mils, relative to the roasting time. I.E., on courser material, the core doesn't get exposed to the necessary Oxygen. Roast, grind, reroast. Classify, classify, classify. I guess you have to find what the logistics are for the most economical recovery.


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## dkbinco (Oct 7, 2022)

I have some ore down to 150 mesh or 200 microns I think, after roasting, I am still courious as to the method of this second grind without contaminating it again. Anyone have any thoughts?


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