A corrected model describing transport processes for multicomponent mixtures in electric field is proposed. This model is more consistent compared to the other models of this sort used for simulations of electrophoresis in the case of concentrated solutions. The main idea underlying the model is in accounting for the motion of a solvent. Usually the concentrations of solutes are considered small compared to that of a solvent and the equation describing its motion is not considered. This automatically leads to the violation of momentum balance and, hence, to the defects of the model itself. In the model presented in the paper by means of redefining the mass fluxes the balance of momentum is satisfied automatically while the equations governing the evolution of the system look more symmetric and simple. This model allows us to discover some fine effects in evolution of the mixture and clarify the essence of some conservation laws (conservation of the Kohlrausch function) arising in the simplified mathematical models describing electromigration phenomena.