爆破后压入式通风独头巷道内氡的运移模型

为有效指导铀矿井下独头巷道的通风设计，基于质量守恒定律和置换通风理论，首先建立了描述爆破后压入式通风独头巷道内抛掷空间和风流末端氡活度浓度随通风时间变化的计算模型，利用该模型得到了达到氡活度浓度限值条件的最短排氡通风时间的确定方法；然后分析了不同参数对风流末端氡活度浓度以及最短排氡通风时间的影响。结果表明，爆破后，独头巷道风流末端氡活度浓度在一定通风时间内保持不变，之后瞬间增至峰值，最终逐渐衰减至稳定；在其他参数一定的情况下，风流末端氡活度浓度开始剧增的时间随巷道长度的增加而减小，随风量增加而增大；风流末端氡活度浓度衰减速率随风量的增加而增大；风流末端氡活度浓度峰值随掘进面铀品位的增加而增大；最短排氡通风时间随巷道长度和掘进面铀品位的增加而增大，随通风量的增加而减小。

Transport Model of Radon in Blind Roadway with Forced Ventilation after Blasting

In order to guide the design of ventilation in the blind roadway under uranium mine ,based on the theories of mass conservation and displacement ventilation , the calculation models for the variation of radon activity concentration with ventilation time after blasting in the throwing‐space and in the wind end were firstly built .With the models ,the calculation method of the theoretical shortest ventilation time for elimina‐ting radon in the blind roadway which meets radon activity concentration limit was obtained ,and the influences of different parameters on the activity concentration of radon in the wind end and the shortest ventilation time to eliminate radon were both analyzed .The results show that after blasting radon activity concentration in the wind end suddenly rises up to peak value after keeping stable for certain ventilation time ,and it finally decays gradually to steady value .With other parameters unchanged ,the start moment that radon activity concentration suddenly rises up decreases with the increase of the length of the blind roadway ,but increases with the ventilation volume .The decay speed for radon activity concentration in the wind end increases with the ventilation volume .The peak value of radon activity concentration increases with the uranium grade of the driving face .The shortest ventilation time to eliminate radon increases with the length of the blind roadway and the uranium grade of the driving face ,and decreases with the increase of the ventilation volume .