In this study, the dissolution of stibnite, Sb2S3, which is an antimony ore, in HCl solutions was investigated, taking into consideration the effect of particle size, acid concentration, stirring speed, solid-to-liquid ratio, and temperature. It was observed that the dissolution rate increased with increasing temperature and with decreasing particle size and solid-to-liquid ratio, while no pronounced effect of stirring speed was observed. Using the experimental data, we attempted to establish a kinetic model for the dissolution of the ore in HCl solutions. Employing graphical and statistical methods, the following kinetic model including the effect of the above choosen parameters was established to represent the dissolution process -In(1 - X) = 9.79 x 10(-10). (D)(-0.908)(C)(10.600)(S/L)(-0.321)e(-6244/T) t, where X is the conversion fraction of the mineral, D is the particle size, C the acid concentration in weight percent, and S/L is the solid-to-liquid ratio in grams per milliliter. The activation energy for this dissolution process was calculated as 52 kJ mol(-1).