Geological and Environmental Engineering | Article | Published 2021-12-25
The paper considers an analysis of the current status of available oil shale reserves in the Republic of Uzbekistan, an overview of oil shale fields is presented. The paper highlights peculiar characteristics of oil shales, which enable us to consider them as a promising source of mineral raw materials for various industries that are of current interest. The paper provides a detailed description of the geochemical features of Uzbekistan oil shales, which contain not only hydrocarbons but also rare-earth and platinum-group metals. A case study enabled the determination of the chemical composition of Baysun and Sangruntau oil shales. Analysis was conducted using Elan DRCII IСP mass spectrometer to determine the composition and distribution of metals in oil shales. Analysis revealed the presence and content of elements, such as Мо, Re, V, Ni, Te, U, Pt, Pd, Au, Ag, Se, As, Cd, Sb, Bi, as well as rare-earth metals. Baysun shales exhibited higher Те, Аu, Cd, Hg, V, U content, and Clarke concentrations, while Sangruntau shales contained more Se, Mo, Au, and Re. Different laboratory methods were used to determine metal content in Sangruntau shales. Literature analysis has demonstrated that some authors pay serious attention to the adsorption of metals by organic matter, clays, apatite, Ferrum oxide, and others. They propose two borehole mining methods: in-situ coal gasification and in-situ metal leaching. Comparative analysis revealed the advantages and disadvantages of in-situ coal gasification and in-situ metal leaching technologies. Mineralogical and geochemical studies provided important results and conclusions. Palaeogene Sangruntau and Baysun oil shales were found to differ substantially from their world analogs in terms of Mo, V, U, Re, Bi, Sb, Cd, Ni, Se, Fe, Tl, Au, Ag, Cu, Zn, Pb, Pd, Pt, Hg and rare-earth metal content. Comprehensive development of metal-bearing oil shales in the Republic of Uzbekistan presents apparent interest for expansion of fuel and energy balance as well as radioactive and rare-earth metal stocks.