# PGM black precipitation with iron/steel



## Slaughlin79 (Oct 24, 2018)

Zinc is surprisingly expensive for such an abundant metal and shipping makes it that much more. So since I can get just about as much steel of different grades as I want and know that it will precipitate pgms I was wondering if it will cause any problem? Thanks


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## FrugalRefiner (Oct 24, 2018)

You don't mention what type of solution you're precipitating from.

If it's a typical acid solution, I would recommend copper over iron. Copper will only cement out precious metals and mercury. Iron will precipitate a whole host of other metals if they are present.

Dave


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## snoman701 (Oct 24, 2018)

Zinc flour is $4 / lb in a 50 lb bag from lmines....it's simple, it's effective, and you don't have to worry about your pm's getting adhered to it, as its 100% put in to solution. 

If you only need a pound, it's like $11 on eBay.



Sent from my iPhone using Tapatalk


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## Lino1406 (Oct 25, 2018)

Using iron will result in "rust" which contaminates and is hard to get rid off. Aluminum
is preferred (I combine using sheets, foils and powder) and is much faster than zinc. Of course
zinc has the lowest cleanliness drawbacks.


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## Slaughlin79 (Oct 26, 2018)

Sorry guys and thank y’all for the replies,I hadn’t thought anyone had commented so thank you. I will look into the zinc powder. And the solution is HCl Bleach and 15 percent h2o2. Absolutely no nitric whatsoever as I’m trying to not have to use any. I’m trying to make this go round profitable because I spent way more than I made processing some gold but it was also my first time to do it seriously. 

You mention that it will rust but can’t I just soak in some heated HCl or should I just listen and not use it?

I tried aluminum on a batch and after all the platinum fell am solution test no more for pgm’s I let it settle. After I siphoned off the waste and washed the rest. On re- dissolving there was quite a bit of some fluffy brownish material that would not dissolve. I’ve actually got it on a hot plate almost boiling adding h2o2 and HCl and oh just won’t dissolve and I’m at a loss of what it could be. The solution was clear as crystal when I added aluminum so all of this dropped from solution and I would think it is a metal slat but then again?

I’m obviously still a novice but no matter how much I read and search there’s just some things for the life of me I can’t find answers to. Thanks again and I really do appreciate the help from everyone on this site


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## Slaughlin79 (Oct 26, 2018)

This is the mystery precipitate from the aluminum.

And to the precipitate with copper suggestion I did try that and it’s like stuff just doesn’t have the same laws in my yard. I actually did what was suggested by a site member and got an air pump and fed air bubbling from. The bottom and actually I feed the hose all the way the a coiled up piece of copper tube that I drilled any holes through and there is absolutely no black sediment on the bottom after shutting down air letting sit for a week. I don’t understand why. The solution tested strong for platinum and palladium “test started red to brown to a pretty yellow-blue-green just like Hoke talks about. Now the tests shows a hint of reddish orange with stannous but even after sitting for weeks now there is no sediment,just a jet black solution from all the copper it soaked up. As the HCl was used up light green copper chloride would began to form on vessel wall and I would add to dissolve. 

I’m wondering and I know this might be a dumb thing get but I wonder if the solution is just thick because it doesn’t have the consistency of water anymore and the platinum is just suspended but Not in colloidal form?


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## Slaughlin79 (Oct 27, 2018)

This is a better picture. It came out looking very green in reality it has a greenish tint with orange. I know I have copper in it. Any ideas?


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## Lino1406 (Oct 27, 2018)

You should reduce volume, by adequate filtration, even drying and start all over again


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## Slaughlin79 (Nov 3, 2018)

Okay I guess not.


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## Slaughlin79 (Nov 3, 2018)

Lino I don’t think it was anything but trash even though that doesn’t explain how it magically appeared but I’m not not even going to worry about it. It will be thrown away bc I’m not keeping it around for someone to accidentally get into. But thanks


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