Abstract: This invention is a process for mining an underground formation of coal having high oxygen content by contacting the coal with a heated basic aqueous solution for a time sufficient to dissolve at least a portion of the coal formation to produce a coalate. Periodically or continuously, some of the dissolved material is removed to facilitate or improve access to the coal formation. The dissolved coal or coalate is then treated with a regenerating agent to recover basic aqueous solution from the coalate.

Abstract: This invention is a process for treating an underground formation of coal by contacting the coal with a basic aqueous solution for a time sufficient to disintegrate at least a portion of the coal formation. Subsequently, at least some of the disintegrated material is removed to create permeability in the coal formation. The coal is then treated with a heat carrying fluid to recover energy values from the coal. Another aspect of this invention is a process for slurry mining coal which comprises contacting the coal with the basic aqueous solution for a time sufficient to disintegrate the coal and form a slurry, then conveying said slurry to a receiving terminal.

Abstract: Shale oil can be produced from a naturally fractured and leached subterranean oil shale formation by reacting the formation components with a hot aqueous alkaline liquid to form and distribute clay-like materials which can be water-swollen to form a flow barrier along or around a selected portion of the oil shale formation. Such flow barriers can guide or confine fluids that are injected and produced to recover shale oil.

Abstract: In producing shale oil by circulating hot fluid into and out of a rubble-containing cavern within a subterranean oil shale, plugging is avoided by permeating a portion of oil shale, consolidating a permeated portion, inflowing fluid outside the consolidated portion, and outflowing fluid from within the consolidated portion so the fluid is filtered through the consolidated portion.