SYNTHESIS OF ARDEALITE (Ca2(SO4)(HPO4)･4H2O) USING SONOCHEMISTRY

Abstract

Double salt which is the regularity of their crystal structure has higher physical and chemical properties than single salt or solid solutions. The purpose of this study is to synthesize ardealite (Ca₂(SO₄)(HPO₄)･4H₂O) with double salt by irradiating ultrasound to the reaction field. Since the amount of ultrasonic cavitation depends on the output (W) of the ultrasonic irradiation device, the output conditions (50 W, 150 W, and 600 W) were investigated. In X-ray diffraction measurements, it confirmed that phosphate-substituted calcium sulfate, a random solid solution of phosphate and sulfate ions, is formed at low power (50 W), and ardealite is formed at 150 W and 600 W. At 150 W, each peak attributed to ardealite was also observed in the infrared absorption spectra and differential thermal analysis. In the optimum output of 150 W, an amplitude of 20% (3.76 μm) and an irradiation time of 1 hour were the optimum conditions for the synthesis of ardealite.