Microelements in Estonian and Green River (U.S.A.) oil shales: a quantitative comparison

Due to the deficiency and high price of crude oil and gas in all countries, more and more attention is shifted to the use of local fuels. As a rule, the local fuel is less energy-rich and needs special technology for utilizing, including rather expensive devices for cleaning the flue gases. In some countries, including the U.S.A. and Estonia, oil shale belongs to the local fuels. The technological properties of Estonian and USA oil shales have been studied and are compared with each other. In the present paper the results describing the content of macro- and microelements of these oil shales are presented. Since the ash content of shales is high, the data about elements in the ash is presented. Using the method of neutron activation analysis, 38 elements were measured in Green River and Estonian oil shale samples, including some ashes of these shales. The analysis of these data is based on a comparison of the enrichment coefficients for the respective elements against the Clark values. The low metal content of oil shales has once again been established. The American oil shale and its products are often rich in various metallic and nonmetallic elements. The Estonian oil shale and its products are remarkably rich in Cl and Br, reflecting the formation of this shale in the sea