Detailed knowledge of solid-liquid phase transitions is not only of academic interest but is also important for industrial-process applications, such as the use of high-pressure crystallization as a separation method. In previous reports, we have studied solid-liquid phase equilibria of several binary-systems containing aromatic compounds, using our unified solid-liquid-vapor equation-of-state (EOS), and demonstrated that our EOS method can be successfully applied to such systems. However, the procedure of analyses is rather complicated and not necessarily straightforward. In this report, we develop a much simpler model for condensed-phase behaviors. The model is based on our previously reported hard-sphere EOS. Successful applications to real compound systems are demonstrated. (c) 2004 Elsevier Ltd. All rights reserved.