The influence of oil-shale mineral constitution on the amounts of Na2O, Al2O3, and SiO2 extractable from pyrolyzed oil shale using hot water and hot caustic solvents has been examined. Samples of oil shale from two drill cores and one composite sample from the Colony mine were split and studied by X-ray diffraction methods to determine their bulk mineralogy. Oil yield data were obtained for these samples by conventional Fischer assay analysis and samples of the spent oil shale were studied by X-ray diffraction to determine the changes which resulted from pyrolysis. The amounts of Na2O, Al2O3, and SiO2 extractable from 31 spent oil-shale samples were determined using hot distilled water, hot 0.1M KOH, and hot 0.5M KOH as solvents. Extractable Al2O and SiO2 were also determined for the 31 spent oil-shale samples using hot 0.1M NaOH and hot 0.5M NaOH.
Correlation of the relative abundance of analcime--Na[Al, Si2O6]. H20-- in raw oil-shale samples with the amounts of Na2O, Al2O3, and SiO2 extracted from pyrolyzed oil shale demonstrates that analcime contributes significantly to all of these elements after it has been subjected to pyrolysis. Because of the large contribution of SiO2 extractable from pyrolyzed analcime-bearing oil shale using caustic solvents, there may be significant problems in obtaining leachates high in Al2O3content and low in SiO2 content where analcime is present with dawsonite--NaAl(OH)2CO3. This consideration is important to assessment of potential aluminum resources in oil shale. In addition, the concentrations of water soluble Na2O, Al2O3, and SiO2 in analcime-bearing pyrolyzed oil shale are expected to be significantly greater than from oil shale which is free of analcime and dawsonite and this factor reflects the importance of oil-shale mineralogy to aspects of spent shale disposal
