Abstract: How to effectively control the growth behavior of gypsum crystal in solution system has become one of the urgent problems to be solved in desulfurization industry， and the effective information of crystal growth process can’t be detected online timely and effectively. In this work， molecular dynamics simulation (MS) was used to calculate adhesion energy， face-center distance and area of specific plane of gypsum crystal， to determine morphologically dominant crystal planes and surface structure， and to theoretically study the interaction mechanism between sodium chloride and the main growth planes. The effect of sodium chloride on the crystal morphology of gypsum was obtained through experiments， which was compared with the results of MS. Results showed that sodium chlorides have varied effects on each crystal planes of gypsum crystals， which further changing the crystal morphology of gypsum. The simulation results are consistent with the experiment. MS can provide a theoretical support for morphology control of gypsum crystals.

Key words: gypsum crystal; solution system; crystals growth behavior; solvent effect; molecular dynamics