Rare elements and non-ferrous metals in the paleogene brown-coal deposits of the Zeya-Bureya sedimentary basin (Amur Region, Far East): accumulation models, enrichment conditions and criteria for assessment of resource potential (a review)

A model has been developed for deposition of rare earth elements with yttrium, trace elements, and non-ferrous metals in platform and activated structures of the Upper Amur region. Genetic types of lanthanide enrichment are considered; lanthanides are shown to concentrate non-uniformly in coal seams and in coal combustion products. Light rare earth elements predominate in coals. The capacity of peat and coal for metal extraction from aqueous solutions was proven. Criteria for a preliminary assessment of coal as a raw material for lanthanides were considered and prospects for their identification were analyzed.