不同覆盖物抑制铀尾矿氡析出的效果

对5种不同覆盖物（红土、砂、废石、砂与红土混合物、废石与红土混合物）降低铀尾矿氡析出的效果进行了现场实验研究。结果表明,不同覆盖物的效果存在较大差异,在相同覆盖厚度条件下,氡析出率降低系数是红土〉红土与废石混合物〉红土与砂混合物〉废石〉砂。表面氡析出率随覆盖物厚度增大而减小,氡析出率降低系数的对数与覆盖厚度成正比,所得到的各种覆盖物的拟合线性方程可用来评价覆盖效果。建立了各种覆盖物覆盖厚度估算的经验公式。综合考虑降氡效果、经济成本、生态环境效应,废石与红土混合物是该地区铀尾矿库最佳覆盖物。

An Exploration on the Effectiveness of Suppression of Radon Exhalation from Uranium Tailings by Using Different Cover Materials

The effectiveness of reducing radon exhalation from uranium tailings by using five different cover materials,including laterite,sand,waste rock,mixture of sand and laterite,and the mixture of waste rock and laterite,were investigated experimentally at a uranium tailing impoundment,a uranium mine in Guangdong Province,China.The cover effectiveness of these selected materials are different,under the same thickness conditions,and the attenuation coefficients of radon exhalation rates are according the order of laterite > mixture of waste rock > mixture of sand and laterite > waste rock > sand.The radon exhalation rate decreases with increasing thickness of cover layer.The logarithmic of attenuation coefficients of radon exhalation is proportional to the thickness of covers.The equations of fitting line are obtained for every cover materials which can be used to evaluate the cover effectiveness.The empirical equations to estimate the cover thickness are established for the five abovementioned covering materials.Considering the effectiveness of reducing radon,economic cost,and environment,the mixture of waste rock and laterite is a favorable cover material to reduce the radon exhalation from the uranium tailings to the atmosphere in this area.