Rare earth element-bearing coals from the Russian Far East deposits

摘要: Abstract Coal seams up to 10 m in thickness with high rare earth element (REE) concentrations (300–1000 ppm) were detected some of the Russian Far East deposits. This paper reports on REE composition coals from a number The REE-bearing are subdivided into three geochemical types. Studies distributions across coal seams, examination gravitation fractions and SEM-EDX studies have revealed that enriched contain mainly as sorbed forms (by organic matter clay particles) fine-grained authigenic minerals. formed in: (1) erosion-tectonic depressions wide-spread weathering crusts their basins; (2) volcano-tectonic grabens which accumulation occurred simultaneously bimodal volcanism. In former case, thought originate borderland; second chambers subalkaline magma. material mostly during peat stage, due mineralized water coming basins. contents (up 1.0% even more) combustion wastes, low LREE/HREE ratios considerable estimated resources — all place among new very promising mineral for Y heavy lanthanoids by-products.