某稀土矿山辐射环境调查分析

Investigation of the radiation environment in one rare earth mine

通过对我国南方某离子型稀土矿山大气的X-γ辐射剂量率、Rn-222及其子体监测,地表水、地下水、土壤、生物样和地表水底泥取样放射性核素分析,调查和了解了该稀土矿山的辐射环境现状。监测结果表明该稀土矿开采对矿区内水库、地下水、土壤和水库底泥造成了一定放射性影响,其中矿区水库Th-232、总α和总β超过对照点较多,矿区内堆浸渣场、水冶车间、地浸采场及其周边地下水和土壤中U-235、Ra-226、Th-232、总α和总β略高于对照点,矿区内生物样和矿区附近其他地表水底泥未见明显的放射性影响。稀土浸出母液中有Rn-222及其子体释放,母液导流沟附近氡子体浓度略超过环境本底值,随着大气扩散、稀释作用,其它监测点的氡子体浓度均在本底值范围之内。有关部门应加强稀土开采监管,避免稀土开采对环境造成辐射影响。

Through monitoring of X-γ radiation dose rate,the concentration of radon and its daughters in air and analysis of radionuelide＇s concentration of surface water, ground water, soil and biological samples as well as samples from under earth of surface water, the current situation of the radiation en- vironment at the rare earth mine is investigated. The results of monitoring show that mining of rare earth ore has caused light radioactive contamination of reservoir,groundwater and soil area and reser- voir sediment in mining area. The concentrations of Th-232, total α and β in reservoir are much higher than that at the control point. The concentrations of Th-232, Ra-226, Th-232, total α and β in groundwater and soil of some places such as mine heap leaching residue field, hydrometallurgical workshop, in-situ leaching mining field and its surroundings are slightly higher than that of the con- trol points. The mining of rare-earth ore has no obviously radiological impact on biological samples and the nearby other bottom sediment of surface water. Radon and its daughters were released from the rare earth leached solution. The concentration of radon and its daughters near diversion channel are higher than the environmental background value. With diffusion and dilution in air, the content of radon and its daughters in other monitoring points are in the range of background value.