The role of ore properties (density, particle size, and mineralogy) in thickening process was studied in this research. The shaking table was used to prepare the sample for the tests. The tailings were continuously fed on the table by gravity to separate the tailings in three products as slime, middling and coarse particles. The solid density and particle size of the samples were different. To study the effect of mineralogical properties, the sedimentation behavior of the feed and middling samples were tested. The results showed that the free settling velocity of the feed (2–6 mm/s) was less than that of the middling sample (18–23 mm/s), and the compressibility of middling (density: 0.63–0.86 Mg/m³) was more than that of feed (density: 0.33–0.47 Mg/m³). This was due to the amount of clay reduction in the middling sample. The sedimentation behavior of the slime and the coarse samples were also compared in order to study the effect of particle size and density. The settling velocity of the slime and the coarse particles was obtained as 0.1-0.4 and 26 mm/s, respectively, and the maximum underflow density were obtained as 0.35 and 1.57 Mg/m³, respectively. Therefore, the particle size and density reduction reduced the thickener performance. In order to study the effect of particle size, the sedimentation behavior of the slime and coarse samples were compared, and it was obtained that the settling velocity and underflow density increased with the increasing in the particle size.