The sedimentation behavior and scale inhibition mechanism of CaCO₃ particles freshly precipitated from equimolar Na₂CO₃ and CaCl₂ solution after electromagnetic treatment were studied by measurement and analysis of Zeta potentials, surface free energy and theoretical work of adhesion. It was found that the absolute value of Zeta potential of CaCO₃ decreased by about 5 mV, and the sedimentation rate of particles sped up after electromagnetic treatment. The surface free energy of CaCO₃ particles formed after electromagnetic treatment is 31.59 mJ•m^－2 which decreased by about 30%, and the Lifshitz-van der Waals component are 43.53 mJ•m^－2 and 25.50 mJ•m^－2 for the untreated and treated particles respectively, showing that CaCO₃ particles became more thermodynamically stable after treatment. The theoretical work of adhesion between electromagnetically treated CaCO₃ particles and 316L stainless steel in aqueous solution was lower than that of the untreated samples, and deposition of the electromagnetically treated CaCO₃ on the surface of stainless steel was less.

Key words: electromagnetic water treatment, antiscale, calcium carbonate, Zeta potential, surface free energy, theoretical work of adhesion