This thesis is a kind of study and concise overview of present approaches for modelling granulation processes. Scrutinized are models for scaling the granulation process, in fact the procedures that are lead for the purpose of right selection of the macroscopic properties for the operation of a larger scale granulator (pilot and/or commercial) that will result in targeted collective attributes, identical to those that are gained in a small scale granulators (laboratory ones). Additionally, considered are approaches that are nowadays modelling tools for processes of physical conversion of substance by granulation. In analyzing the models for simulating the outcome of the particulate process of granulation, focus is given to the usage of mechanistic approach by concept of population balance. Process of physical conversion of TiO2 nanostructured substance in a collective of a more appropriate dispersity state is modelled with mechanistic approach using population balance. In this thesis, modelling approach implies testing the applicability of a 1-D discretized population balance with Size-Independent Kernel (SIK) coalescence model for simulating real changes of the property of particulate system (particle size distribution) during granulation process. Modelling of the granulation process is carried out using sequential procedure. Attained results are compared with those of a previous research, brought by using non-sequential modelling procedure. Used approach might indicate the contributions of underlying mechanisms in the granulation process. By optimization method, that connotes minimizing the overall sum of squared errors, characteristic process parameter, coalescence rate constant is estimated. Thus, for the sequential approach, kinetic of physical conversion of TiO2 nanostructured substance in a stochastic fluid-bed environment is quantified.