Molecular modeling is the technological know-how of representing molecular systems numerically and simulating their behavior with the equations of quantum and classical physics. using pc programs, polymer scientists may want to at once generate and obtain molecular facts which incorporates geometries, energies, digital houses, spectroscopic houses, and bulk homes. Molecular modelling covers a good sort of theoretical and computational methods want to represent the structure of molecules, ions and/or particles. They can be classified—according to the length and time scale of the modelling matter—from electronic to continuous levels. Considering solute/solvent systems, there are three main categories for molecular modelling: implicit methods, integral equations and classical density functional theory, and explicit methods. Thus, so as to present the most idea of every class of methods available in chemical engineering field, this work comprehends three methods: Poisson Boltzmann equation, classical density functional theory, and molecular dynamics simulation. Finally, scale integration is presented as a strategy for efficient modelling and simulation. Molecular modelling (MM) is yet one more approach providing valuable insight into the mechanism of ion–mineral surface interactions on an atomistic level. Molecular dynamics (MD), Monte-Carlo and geometry optimisation are the foremost commonly used simulation techniques. In these methods’ equilibrium structures of sorbed species and their energies are derivsed supported inter-atomic interaction energy calculations consistent with the laws of physics