[en] This paper presents the results of glass formulation development and melter testing to identify high waste loading glasses to treat high-Al high level waste (HLW) at Hanford. Previous glass formulations developed for this HLW had high waste loadings but their processing rates were lower that desired. The present work was aimed at improving the glass processing rate while maintaining high waste loadings. Glass formulations were designed, prepared at crucible-scale and characterized to determine their properties relevant to processing and product quality. Glass formulations that met these requirements were screened for melt rates using small-scale tests. The small-scale melt rate screening included vertical gradient furnace (VGF) and direct feed consumption (DFC) melter tests. Based on the results of these tests, modified glass formulations were developed and selected for larger scale melter tests to determine their processing rate. Melter tests were conducted on the DuraMelter 100 (DMIOO) with a melt surface area of 0.11 m² and the DuraMelter 1200 (DMI200) HLW Pilot Melter with a melt surface area of 1.2 m². The newly developed glass formulations had waste loadings as high as 50 wt%, with corresponding Al₂O₃ concentration in the glass of 26.63 wt%. The new glass formulations showed glass production rates as high as 1900 kg/(m².day) under nominal melter operating conditions. The demonstrated glass production rates are much higher than the current requirement of 800 kg/(m².day) and anticipated future enhanced Hanford Tank Waste Treatment and Immobilization Plant (WTP) requirement of 1000 kg/(m².day).