rusty
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- Sep 15, 2010
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resabed01 said:rusty said:Looking good resabed01, whats next to do.
Wet everything down with a layer of water, mag the fine iron filings out.
You can leave the water to use for your dilute nitric leach, 50/50 water acid when going after the silver and any palladium there could possibly be in there.
Filtering is going to slow you down a tad, try wicking.
Use distilled water on that silver rinse, the distilled water is free of minerals looking to grab some along the way.
I'm using HCL to convert the silver nitrate to silver chloride, then going the scrap iron route to convert this into metallic silver.
Once your satisfied all the silver nitrate has been wicked from the concentrates, proceed to go for the gold using the leach of your choice.
A word of caution, those finely divided powders react violently to acids, I add the acids to my cold and concentrates let the acid work on the cons for a half an hour or more before adding more acid, string at this next addition then when I'm satisfied the acids have taken up some of the metals I add the heat with a very slow paddle speed.
The heavy metals will form a layer under the insoluble mud, so be careful string as not to bring up to much metal into the hot acid at once or you'll have a boil over.
Here's a boil over I had this afternoon, caused by to much paddle speed for too long a duration. You'll not be so lucky should you have a boil over, the reactor saved the day. Didn't loose a gram of values.
Thanks for the advice Rusty. Magnetic seperation was the first thing I did. From the total I pulled out almost 10% of the solids that were magnetic. Some small trace amounts still exist but I don't think there will be enough to cause problems. I'll give it another water wash and go over it with the magnet again before I start leaching. I think my biggest enemy here will be tin. I wanted to do a HCL leach first to remove tin, aluminum and anything else that wants to hitch a ride with the HCL. After that, incineration again before moving onto nitric acid.
Before I start any leaches I want to find a suitable vessel that will be large enough to prevent boil overs as I expect a fairly rowdy reaction. Four litres would be enough, maybe more. I know the coffee pots won't work in this case.
Give yourself plenty of headroom, start with the amount of acid you figure is needed for the job then add a teaspoon full of concentrates periodically. Once each teaspoon full has settled down add another.
My recent boil over reactor had 4 liters of material plus the leach so figure that I had 6 liters of headroom not counting above the level mark and the lid cavity.