Compaction and Related Properties of Retorted Oil Shale

AS part of a project to demonstrate the feasibility of retorting oil shale by the Paraho vertical retort process, laboratory and field tests were per formed to determine the physical and chemical properties of retorted oil shale for use as criteria for the design of full scale disposal systems. The material which exits from the retort is classified as a non‐plastic silty gravel. The material can be compacted to about 90 to over 100 pcf (1,440 to $1\text{,}600\mathrm{kg}/m^3)$ depending upon the degree of compactive effort applied. The addition of moisture from the dry state does not improve densification appreciably. When moistened to about optimum moisture and highly compacted, the material is classed as impervious and the material gains strength with time from cementing action. The retorted shale, so treated, can be used to construct stable, impervious retaining structures and impervious linings in valleys for holding the main disposal de posit and provide ground water protection.