The main tasks of kinetic research of mineral dissolution chemical reactions in various solvents are shown. Kinetics of antimonite interactions with a sodium sulfide solution depending on various factors (reagent concentration, experiment duration, temperature) is studied. The research were carried out on the monodisperse particles with dimension –0,104 + 0,074 mm possessing average superficial energy (activity), it allows to get average specific speed. Quantity of antimonite ions, which has passed from antimonite firm phase into a solution, increases with increase of experiment duration up to 1000 second and with rise of temperature in range of 298–328 K and concentration of Na₂S from 0,05 to 1 molar. Kinetic law of antimonite (Sb₂S₃) dissolution depending on the listed factors is established. Following kinetic parameters are defined: speed constant, specific speed, reaction order and activation energy of dissolution process.