Expansion of the Commercial Output of Estonian Oil Shale Mining and Processing

Abstract

Economic and ecological preconditions are considered for the transition from monoproduct oil shale mining to pofyproduct Estonian oil shale deposits. Underground water, limestone, and underground heat found in oil shale mines with smallreserves can be operated for a long time using chambers left after oil shale extraction. The adjacent fields of the closed mines can be connected to the operations of themines that are still working. Complex usage of natural resources of Estonian oilshale deposits is made possible owing to the unique features of its geology andtechnology. Oil shale seam development is carried out at shallow depths (40-70 m) in stable limestones and does not require expensive maintenance. Such naturalresources as underground water, carbonate rocks, heat of rock mass, and underground chambers are opened by mining and are ready for utilization. Room-and-pillar mining does not disturb the surface, and worked oil shale and greenery wasteheaps do not breach its ecology. Technical decisions and economic evaluation arepresented for the complex utilization of natural resources in the boundaries of minetake of the “Tammiku“ underground mine and the adjacent closed mine N2. Ten countries have already experienced industrial utilization of oil shale in small volumes for many years. Usually oil shale deposits are not notable for complex geology of the strata and are not deeply bedded. Thus complex utilization of quite extensive natural resources of Estonian oil shale deposits is of both scientific and practical interest.