The paper deals with utilization of oil shale mining waste rock in Estonia. Crushed waste rock is utilized as an aggregate in civil engineering in frostfree environmental conditions and in road building in unbound mixtures where required resistance to fragmentation LA ≤ 35%. This study determines areas of utilization of waste rock and shows that waste rock aggregate produced using selective mining or selective crushing technology is usable in civil engineering in partially saturated conditions and in unbound mixtures where aggregates require resistance to fragmentation LA ≤ 30%. Waste rock is usable for backfilling the already mined areas.

The paper deals with risk management problems in Estonian oil shale mines. Investigations are focused on application of the method to determination of the quality of geological data. Various factors relevant to mining technology in Estonian oil shale deposit have been determined. For risk estimation, the empirical and judgmental approaches and the event tree were used. They allow determining the probability of the occurrence of geological features and its influence on the mining process. Analysis of obtained results showed that it is necessary to elaborate special methods for determination of the geological conditions in the mining area. The obtained information affords specialists to improve the quality of geological information and consequently the mine work efficiency. The analysis shows that the used method is applicable in conditions of Estonian oil shale industry. The results of the investigation are of particular interest for practical purposes.

The paper deals with risk analysis/assessment problems in Estonian oil shale industry. Investigations are focused on application of these methods for railway transport from mine to consumer. Various factors relevant to oil shale transport have been determined. For risk estimation an empirical approach, the event/fault tree is used. It allows to determine probability of deviations of the process duration from the mean value for different pathways. The obtained information affords specialists to improve the quality of the railway transport. The analysis shows that the used method is applicable in conditions of Estonian railway systems. The results of the investigation are of particular interest for practical purposes.