A model is developed based on experimental and theoretical analysis for the description of the Montan wax extraction process. This paper focuses on Graefe extraction, a standard methodology in brown coal industry, which is used to estimate the maximum yield of available wax. Using the results of Graefe extraction, the equilibrium curve and transfer coefficient can be identified by means of a global optimization algorithm Molecular-Inspired Parallel Tempering (MIPT). Another aim of the work is to predict the yields of Montan wax extracted by a percolation-column extraction, which contains 100 times the amount of brown coal as it is used in Graefe extraction.