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How to extract calcium from its salts

June 3, 2014

Q. Hello

I am a general chemist (currently working in organic synthesis) with some knowledge of electrochemistry, which is also a hobby.

I am interested in the simplest way to liberate calcium from its salts.

I know it is done in industry by electrolysis of CaCl2 at high temperature. I would like to use a much lower temperature and avoid chlorine.

Would it be wise to attempt electrolysis of mixed fused nitrates or would that be too dangerous? I understand that some eutectics melt below 150 °C. but have also read that calcium can explode in contact with some salts such as carbonate (with is less oxidizing than nitrate) but nitrates seem to have the lowest melting points in general.

Alternatively, I have tried plating Ca from organic solutions, for example perhaps it can be plated from a dipolar aprotic solvent such as pyridine or THF. But with Ca there are usually solubility problems and conductivity problems- unlike the case with univalent ions such as lithium. (I have successfully liberated Li from LiCl04 in acetonitrile and from LiAlH4 in THF.)

Sincerely, Ansel

Ansel Wald
Hobbyist and organic chemist - Bothell, Washington USA