Spatial Distribution Of Rare Earth And Leaching Agent In Ionic Rare Earth In-situ Leaching Mining Tailing Area Based On GIS

Gannan ion type rare earth ore mining process has been developed from the initial pool leaching and heap leaching process for now the process of in-situ leaching, ammonium sulfate is used as leaching agent, after mining, tailing area has a large number of residual rare earth elements and leaching agent in soil, which lead to serious chemical pollution in mining area and surrounding farmland soil.This paper used the ionic rare earth in-situ leaching mining tailing in Longnan zudong,Ganzhou city of Jiangxi province as research area, the content characteristics of residual rare earth elements, leaching agents SO42-, NH4+and secondary substance NO3-in tailings area were analysed by the traditional statistical method, the spatial variability of residual rare earth, leaching agent and secondary substances were researched by the statistical analysis and GIS, and through Kriging spatial interpolation(Kriging), the spatial distributions of residues rare earth and leaching agents in soil were studied, the scientific basis for tailings management ways of high efficiency and low cost will thus be provided. The experimental results showed as follows:(1) From the mean content of rare earth elements in soil, the content of rare earth Y was337.65mg/kg, it was obviously higher than that of other rare earth elements, then the rare earth tailings was explained to be rich in yttrium. The coefficient of variation were moderate variation to the content of rare earth elements in soil except La; interpolation results showed that in the research area, distribution of light rare earth content varies irregularly, while the distribution of heavy rare earth content is roughly similar, the distribution of low value area area tend to be located in southern direction, high content area tend to be located in the northern direction, showing a gradually increasing trend from south to north.(2) The p H of tailings soil was relatively stable between 3.58 ~ 4.77, showing strong or very strong acidic property,the coefficient of variation was less than 10%, which belonged to weak variability;While the overall content of organic matter in soil belongs to extremely short of grade. The variation coefficient of SO42-, NH4+, NO3-were between 10% ~ 100%, which belonged to moderate variability, it showed that the difference of pollutant content in different sampling points and dispersion is larger. Correlation analysis showed that soil residual leaching agent SO42-, NH4+, NO3-exhibit a negative correlation with soil p H,whereas NH4+ and NO3- exhibit a positive correlation with SO42-, NH4+ exhibit a positivecorrelation with NO3-; interpolation results showed that the content of SO42-, NH4+, NO3- in tailings soil had a basically similar distribution trend of gradually increasing from north to south.