How to purify sodium chloride table salt that contains sodium ferrocyanide I wish to obtain pure sodium chloride crystals from ordinary table salt.  But all proprietary table salts seem to contain the anti-caking agent sodium ferrocyanide which I should like to remove.
Don't.  Ferrocyanide is a good way of tying down cyanide ions so they don't do their usual bad things to you.  Trying to purify the salt could release the cyanide ions.