Gasification is an important method of converting coal into clean-burning fuels and high-value industrial chemicals. However, gasifier reliability can be severely limited by rapid degradation of the refractory lining in hot-wall gasifiers. This paper describes an integrated approach to provide the experimental data and engineering models needed to better understand how to control gasifier operation for extended refractory life. The experimental program includes slag viscosity testing and measurement of slag penetration into refractories as a function of time and temperature. The experimental data is used in slag flow, slag penetration, and refractory damage models to predict the limits on operating temperature for increased refractory life. A simplified entrained flow gasifier model is also described to simulate one-dimensional axial flow with average axial velocity, coal devolatilization, and combustion kinetics. The goal of this experimental and model program is to predict coal and oxidant feed rates and to control the gasifier operation to balance coal conversion efficiency with increased refractory life.