【摘要】 为了研究不同掺合料及掺量铀尾砂固化体孔隙特征与氡析出率之间的关系,分别采用15%、20%和25%的粉煤灰、矿渣粉或矿渣粉+粉煤灰对铀尾砂进行固化处理。采用核磁共振技术测量固化体试样的孔隙特征,并采用RAD7测氡仪测量试样的累积氡浓度,得出不同固化体试样的氡析出率。结果表明,随着掺合料掺量增加,核磁共振T₂分布曲线向左偏移,峰值幅度降低,试样内部孔隙逐渐演化为小孔径孔隙;固化体试样的氡析出率与孔隙度均随掺合料掺量增加而逐渐降低,氡析出率与孔隙度之间呈正相关关系,25%掺量矿渣粉固化体试样的氡析出率与孔隙度最低,分别为0.136 Bq/（m²·s）和9.83%;掺量相同时,孔隙度与氡析出率最低的为矿渣粉固化体试样,其次为粉煤灰+矿渣粉固化体试样,最后为粉煤灰固化体试样。研究结果可为实际工程中的铀尾砂固化处理提供理论参考依据。更多还原

【Abstract】 In order to explore the relationship between the pore characteristics and radon exhalation rate of uranium tailings solidified by using different admixtures at a different amount, experiments on solidification treatment were performed by respectively using fly ash（FA）, slag powder（GGBS） or slag powder plus fly ash at an amount of 15%, 20%, and 25%, respectively. Then, the pore characteristics of the solidified uranium tailings sample were measured by using nuclear magnetic resonance technology（NMR） and the radon exhalation rates of different solidified uranium tailings were obtained by measuring the cumulative radon concentration of the sample with a Radon meter（RAD7）. It is found that with an increase in the amount of admixture, the NMR T₂ distribution curve shifted to the left and the peak amplitude decreased; the inner pores of the sample gradually evolved into small pores; and the radon exhalation rate and porosity of the solidified sample gradually decreased. It is shown that a positive correlation exists between the radon exhalation rate and porosity, and the solidified sample with 25% of slag powder presents the lowest radon exhalation rate of 0.136 Bq/（m²·s） and the lowest porosity of 9.83%. With the same amount of admixture, the sample solidified with slag powder presents the lowest porosity and radon exhalation rate, followed by the sample solidified with fly ash plus slag powder and the solidified one with fly ash. The research results can provide a theoretical reference for the solidification treatment of uranium tailings in practical engineering.更多还原