High-temperature centrifugation: Application to mesophase pitch

A laboratory high-temperature centrifuge capable of operating up to 500°C at centrifugal accelerations of 600 g has been designed and constructed. The apparatus has been particularly useful in separating the isotropic and anisotropic phases in mesophase pitches and quantitatively determining phase contents. The efficiency of phase separation was determined for a petroleum mesophase pitch as a function of temperature and centrifugal acceleration. Effects of gas evolution, sphere coalescence and intraphase precipitation were also observed.