The objective of the research consisted in comparing the operation efficiency of a separator provided with fixed screens mounted to the shoe and the one fitted with spring-mounted screens, determination of the impact of the basic kinematics parameters on the separation efficiency. Analysis was also carried out regarding the use of cylindrical spring-mounted screens and flat spring-mounted screens. The process of mass movement on the screen surface was examined also including the movement upward, downward and throwing up. The values characteristic for the separation process were output (capacity) of screens and the impurity separation degree. The analyzed kinematic parameters included: screen shoe vibration amplitude, screen vibration amplitude, screen inclination angle, screen vibration operation angle, own vibration frequency, kinematics limits coefficient. As a result, the mathematical models of separation were determined regarding the unit efficiency and the impurity separation degree. Next calculation based on these equations determined the value of the following parameters: Ap=1, 2, A=8 mm, K=2, 3, for which qF=0.72 kg∙s-1∙m-2, E=0.87. The parameters of springs ensuring proper modulus may be determined with the monogram or formula (20). According to the conducted experiments qF screen capacity depended on the straight-line basis on Ap spring stiffness, A screen shoe vibration amplitude and it increased as qF and Ap values increased. The increase was less evident in case of ω and ε value increase. Whereas the non straight-line basis and significant increase followed as the values of α and K parameter increased. Impurity separation degree E increased initially and next decreased as increase followed of spring stiffness Ap, and along with screen hopper vibration amplitude increase. This increase was less evident in case of ω frequency and ε angle increase. Separation of impurities significantly decreased in case of α and K parameter increase.