Viscosity of oxide melts is one of the fundamental physicochemical properties that plays a crucial
role in important technological and natural processes like slag flow, slag/metal separation, volcano
eruptions etc. However, many oxides melt at extremely high temperatures and are highly corrosive
in the liquid state, which makes experimental measurement of melt viscosity by traditional
experimental techniques a difficult and expensive, if not unachievable, task. In this case it might be
useful to employ other methods of viscosity determination such as modelling or simulation. In the
present paper the shear viscosity coefficients of selected pure refractory oxides (CaO, MgO, Al2O3
and others) have been simulated at temperatures above their melting points via the classical
molecular dynamics and compared to the available viscosity data (eg experimental viscosities, other
model predictions) collected by the authors. The simulation has been carried out using the noncommercial
molecular dynamics simulation package LAMMPS and the Born-Mayer-Huggins
potential, which parameters for the selected oxides were taken from the literature. Several viscosity
calculation techniques (the Stokes-Einstein and Green-Kubo equations, the so called Einstein
relations, and the non-equilibrium molecular dynamics methods) have been applied to ensure a more
reliable viscosity calculation. It has been demonstrated that the simulated viscosity of the selected
melts agrees with the available experimental data. It has also been shown that the simulated
viscosity of a number of the oxide melts investigated is close to that calculated by phenomenological
viscosity models, which supports viscosity extrapolation from the corresponding binaries and
ternaries, if no experimental data is present for unary systems. In general, it has been demonstrated
that the molecular dynamics simulation could provide a reasonable estimation of viscosity if no other
viscosity data is available.