Abstract
The anode graphite used in the electrolysis of sodium chloride solution is attacked and therefore the procedure of the electrolysis is greatly affected. In this case, sulphate ions contained in the solution permeate into graphite lattices and bring about swelling and breaking down of the graphite. The more the graphitic degree develops, the severer the action is. Natural flake graphite has good electric conductivity and other good point, although it has bad point that causes the phenomenon above described and contains large quantities of impurities. Many attempts to remove these impurities have been made, but the procedures are difficult and impractical. Today ores having high carbon content are refined several times with oil floatation, and consequently the carbon yield is very low.
Applying the swelling phenomenon above mentioned, we have succeeded in the purification of natural graphite in high yield by the use of oxidation reagents and oil floatation.
