Recovery of oil from oil shale

Recovery of oil from oil-bearing carbonates

Recovery of oil from oil-bearing limestone

Recovery of oil from tar sands

Recovery of oil from tar sands

Recovery of retorted shale from an oil shale retorting process

Recycle classifier for retorting oil shale

Recycling aerated scavenged middlings to conditioning step of ho

Reduction in pour point of shale oil

Refrigerator oil composition

Regeneration of ZnC12

Removal of nitrogen and sulfur from oil-shale

Rerefining of used motor oils

Retorting oil shale with iron oxide impregnated porous pellets

Retorting process

Retorting process for hydrocarbonaceous solids

Retorting process utilizing a flexible, helical shaped conveyor

Separating organic material from tar sands or oil shale

Separating spent mineral matter from heat carriers

Separation and recovery of heat carriers in an oil shale retorti