The Occurrence Characteristics And Leaching Rules Of Different Weathering Degree Rare Earth Ores

In recent years,China vigorously strengthen the rare earth mining integration and management because of rare earth is a kind of non-renewable strategic resources.China pay great attention to the protective mining of rare earth resources so that the right of mining plunged by half.Lots of rare earth mine which have been mined so many times and the weakly weathered lean rare-earth which being neglected by mining the rich and abandoning the poor had to be re-developed and utilized.Therefore,It is an urgent need to strengthen research and improve the utilization of limited resources.But much of the research is focused on the metallogenic regularity and leaching rule about different weathering crust in different regions.However,researching on the migrating rules of REE and the leaching rule of different weathering degree of rare earth ore in the same weathering crust have more practical value to the leaching process.Particle size distribution and REE contents of different weathering degree of rare earth ore in the same weathering crust were analyzed in this paper.The core samples phase composition were analyzed by XRD and FTIR.Different existing states of rare earth were extracted and separated by using sequential extraction method.Different existing states of rare earth distribution patterns were detected by means of ICP-MS and then analysis migrating rules of REE.In this article column leaching conditional experiments on the fully weathered rare earth and semi-weathered rare earth and mixed full-half weathered rare earth were introduced respectively.In addition,leaching kinetics test was carried out.The results show that the coarse fraction yield of partly and smaller partly weathering layer of RE ores is higher than the completely weathering layer.With the weathering degree reducing,the quartz and clay minerals contents decreased,the microcline and mica content increased,ion phase rare earth proportion decreased,colloidal state and mineral phases increased.With the particle reducing,ion phase rare earth proportion increased,mineral phases decreased,colloidal state evenly distributed.Four major effects of Rare Earth Distribution Patterns is tested owing to the research of different phases RE partition of different layers of rare earth,and prove that the phenomenon of Cerium depletion is because the Cerium have oxidized and turned Colloidal phase RE and Mineral phase RE.According to the comparison of two kinds of rare earth leaching conditions,we can improve the leaching result through reducing the leaching agent pH and current velocity,increasing concentration and liquid to solid ratio.Semi-weathered rare earth: pH=4,leaching agent concentration 4%,liquid-solid ratio 1:1,velocity 4mL/min,leaching rate 86%,rare earth concentration 0.18g/L,Al3+ concentration 0.017g/L.Semi-weathered rare earth leaching kinetics indicate that,when leaching agent concentration>1.5%,reaction controlling step for extraction kinetics is internal diffusion by the static leaching process.When leaching agent concentration<3%,reaction controlling step for extraction kinetics is hybrid control and When leaching agent concentration>3%,reaction controlling step for extraction kinetics is internal diffusion by the dynamic leaching process.