A study was undertaken to design, construct, characterize, and demonstrate a new facility for determination of reaction rates of large coal particles at elevated pressures, A cantilever balance attachment (CBA) was designed, fabricated, and utilized in conjunction with the existing high-pressure controlled profile (HPCP) reactor. Large particle (8 mm diameter) combustion experiments of Utah HVBB coal at both atmospheric and elevated pressures were performed to demonstrate the facility’s capabilities. Measurements were obtained of particle mass loss rate and surface temperature coupled with a video record for visual observation.