In recent days, economic internet web pages has been announced that a new very cheap procedure to obtain high purity silicon from sand will end the use of oil as energy source.
could you be so nice to mention the internet economic information your found?.
I have found several papers claiming on simple processing production of "pure" Si from sand, but the question is what is "sand" as said by Karem? Some claims concern with removing of Fe, some other with removing of alcali metals etc...