PURPOSE: To produce a non-aq. liq. contg. high purity chlorine dioxide by adding a non-aq. liq. to an aq. chlorite soln., adding an acid soln. to the aq. phase and agitating them.

CONSTITUTION: An about 25% aq. soln. of a chlorite (e.g. sodium chlorite) is prepd. and diluted with water to about 0.5-12.5 wt.% concn. The desired amt. of a non-aq. liq. (e.g. an aliphatic org. liq. such as hexane) is added to the diluted soln. to prepare two liq. phases, that is, aq. and non-aq. phases. The desired amt. of an acid soln. (e.g. an about 15-37% hydrochloric acid soln.) is added to the aq. phase and the acid is reacted with the chlorite to form chlorine dioxide. At this time, chlorine is formed as a byproduct. Since chlorine is soluble in the non-aq. phase, a part of the formed chlorine is brought into contact and reaction with the chlorite in the aq. phase by vigorous agitation of further form chlorine dioxide. The two phase are then agitated to extract and dissolve the chlorine dioxide in the non-aq. phase and the objective high purity chlorine dioxide almost free from chlorine and water-soluble ionic salts is obtd.