# My gold containing Red Mud???



## NoIdea (Aug 29, 2011)

Evening All – a long time ago, before finding this grail of PMG refining forum, I did some experimenting, dissolving base metals with heated sulphuric acid (battery acid), bubbled with air. 

The material used came from all sort of PMG containing electronic scrap, pins, pyrolized green CPU’s, etc. 

The dissolving took, for what seemed like forever. Every now an again (24hr to 36hrs) I would vigorously stir the mix, wait 2 or 3 seconds, and then decant. Add more acid to the digester for further digesting; the decanted liquid was left to settle. After settling the green/blue clear layer was decanted (this was used in later digestions), leaving behind a mud, this mud was air dried in batches; the dried batches were bulked together and stored till now.

I have slowly reconstituted the above dried material with very dilute HCl acid, back to a mud. This was done by multiple digests, as the dried material was as hard as rock, decanting the light grey suspension into a settling container. After digesting around half of the dried material, and collecting the subsequent mud, treating the mud with hot HCl, settling, decanting, repeated three times, washing was done three times using the same process of settling and decanting.

The mud was air dried and incinerated, this is a before and after picture of the mud. The pile to the left is the dried mud and that to your right is the mud after incinerated.



With a large pinch of the incinerated mud, I digested it in small amount poor-mans AR, diluted the cloudy solution with 4x water, filtered, and re-filtered through the same filter until a clear light yellow solution was obtained. 

The cotton bud to the left was stannous chloride test of the solution and the bud to the right was the solution after adding ferrous sulphate.

Just wondering if anyone else has ended up with the same colour of incinerated material?

My first thought was iron contamination??

Cheers

Deano


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## butcher (Sep 2, 2011)

Funny you asking, I have some red mud similar looking , that has been baffling me, I believe mine to be Iron salt, have not confirmed it yet, but the darn stuff does not seem to want to dissolve in any acid I try, somewhere I red one of the Iron compounds when heated strongly become hard to dissolve in acids.

now If I can find a source for thiocyanate to test my theory.


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## shaftsinkerawc (Sep 2, 2011)

Did the photo get posted backward? The pile on the left looks smaller than the one on the right which is reddish? I would think after incineration that it would get smaller? One of my gold drops from AR had a reddish tint to it on the first pass. Tried to rinse with Hcl thinking iron staining but no reaction. Waiting to give it a second refining. awc


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## NoIdea (Sep 7, 2011)

Hi Yah - Sorry the picture is for comparison only. I have since treated the, now red powder, with Poormans AR and now I have gold in solution but the red mud is still there.

Interesting Very Interesting 8) 

Cheers 

Deano


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