The High-Temperature Materials Laboratory (HTML) focuses on evaluation of the temperature-dependent physical properties of ash and other ceramic materials, including viscosity, thermal conductivity, surface tension, thermal stability, strength, and corrosivity. Several furnace systems are available for testing with any atmosphere up to temperatures of 1700°C.

Research Activities

One of the key difficulties in the development of advanced pressurized fluidized-bed combustion (PFBC) and integrated gasification combined-cycle (IGCC) systems is the need to remove particulates at high temperatures and pressures. HTML research on these advanced combustion systems has included examination of ash deposition behavior, mechanisms of strength development, and surface reactions, all at elevated temperatures under combustion atmospheres.

Power generation facilities in the eastern United States have started blending western U.S. coals with the local eastern coals in attempts to reduce sulfur emissions. The HTML is active in determining the ash deposition and strength development rates of the blended coals as the resulting ash deposits and sinters inside a combustion process.

Laboratory Capabilities

• Viscosity measurements of ash slags in oxidizing or reducing environments in the range of 10–3000 poise. Slag viscosity is measured with a rotating-bob viscometer as the temperature drops from 1500°C to freezing temperature. Accuracy is ±5%.
• Strength measurements of ash deposits or ceramic materials at up to 1500°C
  • Compressive strength
  • Creep
  • Tensile strength
• Sintering propensity of powdered materials in corrosive environments
• Chemical analyses of surfaces
• Measurements of coal slag and vapor-phase corrosion rates against structural ceramic materials
• Thermal expansion properties of ceramic materials up to 1600°C.