Comprehensive utilization and chemical properties of rare earth mineral

This paper introduces comprehensive utilization and chemical properties of rare earth mineral.The overall characteristics of rare earth elements(REEs) in rocks and wall rocks inside rare earth area are rather similar with each other,therefore REEs in rocks and wall rocks are basically consistent.Light rare earth elements(LREEs) in Silicalite that formed in faulted basin is more concentrated than LREEs in silicalite that formed in ancient South-China remnant ocean basin and on the fringe of Yangtze block.Silicalite that formed in tectonic extension phase is silicalite of hydrothermal origin,and its rare earth assemblage model shows relatively depleted light rare earth and positive Eu anomaly;Silicalite that formed in tectonic stability phase is silicalite of sedimentary origin,and its rare earth assemblage model shows relatively concentrated light rare earth and weak negative Eu anomaly.The rare earth mineral products mainly occur in Bayan Obo Fe-Nb rare earth mining area.The area is one of the primary production bases of rare earth in China and its reserve of the rare earth accounts for over 90% of the total reserve of rare earth in China.Rare earth or alkaline-earth metal elements can be added in the steel smelting in order to produce several heat-resisting intermetallic compounds inside the magnesium matrix and inhibit grain boundary glide and dislocation,thus it can improve the heat-resistance of steel products.Rare earth dissolved in steel can improve its high-temperature oxidation resistance,inhibit recrystallization,refine crystalline grain and inhibit aliquation of surface active elements on grain boundary,thus it can improve the comprehensive mechanical performance of the steel.