The increased efficiency of the sedimentation tanks at refineries to the technical and economic reasons are important, therefore the feasibility of increasing the efficiency of sedimentation tanks by modeling and optimization of the tanks, is necessary. In this study, using thin layer plates in mineral sedimentation tanks have been investigated in the laboratory practice and by using mathematical modeling, feasibility and efficiency of the actual volume of the tanks equipped with the usual conditions in the sedimentation tanks, have been compared. Results indicate that efficiency is the same and equal Е = 53% ,Time required for settling tanks equipped with thin layer plates in comparison with conventional tanks, equal to 2.64, is lower. The maximum flow rate in tanks equipped with thin layer plates in comparison with conventional tanks, equal to 1.6, is increased. Thin layer plates, improvements the process of mineral sedimentation significantly, this is based on increasing surfaces of sedimentation, the laminar flow, reducing the level of suspended solids from settling and removal of short connections inside the tank, is based.