Abstract:
In the late 1960s, China's ion-type rare earth ore was first discovered and mined in Ganzhou, Jiangxi Province. In the long-term mining process, it has a continuous impact on the ecological environment of the mining area and the surrounding water and soil. In this paper, the soil geochemical survey and risk assessment of the ion-type rare earth ore in Southern Jiangxi Province and its surrounding areas were carried out.The results showed that the content of heavy rare earth in soil was significantly higher than that of light rare earth, and the content of Y was 7.2 times of the national background value (22.90 μg/g), accounting for the highest proportion.The
Igeo mean of geo-accumulation index evaluation showed that 77.44% of HREE and 99.55% of Sm were non-pollution to medium pollution, and 95.92% of LREE was non-pollution.Except for Pb at mild to moderate pollution levels, As, Cd, Cr, Cu, Hg, Zn and Ni were all non-polluting. Compared with the pollution risk screening value of agricultural land, the exceeding rate of heavy metals in the samples was 7.35%, and the ecological risk of heavy metals in the soil was low.The statistical results show that there is a good correlation between rare earth content and heavy metal pollution. The geological background of granite weathering crust dominates the control of rare earth and heavy metal Pb, which means that the higher the content of heavy rare earth is, the greater the Pb pollution may be. Therefore, it is necessary to pay attention to the geochemical characteristics and distribution of Pb elements in mine soil remediation, and adopt reasonable remediation technologies and means.