Solubility data for the KCl + K(2)CrO(4) + H(2)O system at 30 degrees C, 60 degrees C, and 90 degrees C were determined, and the phase diagrams were constructed. In addition, the crystalline areas in the phase diagrams were analyzed and discussed. On the basis of the solubility data, a method of separating potassium chromate from the KCl + K(2)CrO(4) + H(2)O system in a new, cleaner process of producing potassium chromate was evaluated.