Separate Al2O3 from a bag of mixture?

[Mebing]

I have a bag of what was told to be Al2O3. However I think it's not 100% and may contain other stuff like Aluminium or maybe sand. It was taken from an aluminium smelter as waste. What experiments can I carry out to find out the % amount of Al2O3 in the bag? And after finding out, if possible, how to separate Al2O3 from the rest of the stuff?

 

[donmackenzie]

ICP-MS analysis should be able to give you an answer, but you'd probably have to send it out. As for a quick experiment you can do in-house, I don't have any suggestions.

Anybody else? I'd be interested to know myself...

 

[pmureiko]

I believe this will work. Take a sample of solids and use nitric acid to dissolve the alumina. Rinse and dry the remainder, with the difference being sand.