Physical and thermal properties and leaching characteristics of a hydroretorted beneficiated eastern US oil shale in different processing stages

Abstract

In connection with storage in embankments, tests were conducted to determine the physical and thermal properties and leaching characteristics of samples of beneficiated and thermally processed Alabama shale, including permeability, compressibility, compactibility, consolidation, shear stress, cohesion, thermal conductivity, and liquid and plastic limits. Tests were conducted on samples of unprocessed, hydroretorted, hydroretorted and combusted (H&C), and hydroretorted and agglomerated (H&A) beneficiated shale. The results show that the physical properties of unprocessed and thermally processed beneficiated shale differ considerably, but that none of the thermally processed shale samples exhibits toxicity as assessed by the US EPA toxicity characteristic leaching procedure (TCLP). Combustion and agglomeration reduce the amounts of metals leached during TCLP tests. Overall, storage of unprocessed and spent beneficiated shales in embankments will not result in significant environmental impact through leaching.