CHARACTERIZATION OF SHALE OIL SOLIDS REMOVED BY THE HIGH-GRADIENT MAGNETIC SEPARATION TECHNIQUE.

The high-gradient magnetic separation (HGMS) technique has been previously shown to remove solid particles successfully from several types of shale oil. The nature of the separated solids was investigated in this study, principally by thermomagnetic measurements. Several phase transformations were identified in the magnetization profiles as a function of temperature. These transitions varied depending on the particular sample, although the low-temperature behavior was qualitatively similar for all the solids. The bulk mineralogy and elemental composition of the solids were similar to those of the oil shales prior to retorting. Relatively large concentrations of iron sulfides were identified.