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Chemistry / How to get silica from diatomaceous earth?
« on: 08/06/2011 04:36:25 »
I'm trying to get relatively pure SiO2 from diatomaceous earth, which according to Wikipedia (http://en.wikipedia.org/wiki/Diatomaceous_earth) is primarily SiO2, Al2O3 and FexOy. H2SO4 would remove the FexOy, but I'm wondering if it would pull the Al2O3 into solution. I suppose I could use HNO3, but I would rather not use it on something like this. Are there any other methods for purifying the silica?