Improvement Of Radon Reduction Method By Ventilation In A Uranium Mine

With the increasing mining depth and productivity requirements of uranium mines,the problems of radon reduction,ventilation adjustment and inefficiency exist in the later stage of mine production of extractive ventilation system.Simply depending on the increase of air volume can not improve the underground working environment.Therefore,it is necessary to carry out research on radon reduction technology with different ventilation modes according to the characteristics of uranium mines in China.With the increase of effective air flow rate,the radon concentration in underground mining face of a typical extraction ventilation shrinkage old mine has not decreased significantly.In this paper,the present situation and practical problems of radon removal by ventilation in this uranium mine are analyzed.Based on the present production situation,the related parameters of the mine are measured and analyzed,and the radon source is investigated.The radon in three different ventilation modes,i.e.exhaust ventilation,pressure-pumping mixing ventilation and pressure-pumping ventilation,is carried out by combining the local static method and the whole roadway dynamic method.Through the comparative experiment of precipitation rate,the improvement scheme of radon reduction by ventilation was put forward.The three-dimensional model of mine ventilation system is established by Ventism software,which verifies the feasibility of the adjustment scheme of the ventilation system.The improved detection and analysis show that the radon concentration in the underground of the uranium mine with the pressure ventilation system is 88% lower than that of theextraction type,and the qualified rate of radon concentration in the mine is 30% higher,which significantly improves the underground working environment.The improved scheme of radon reduction by ventilation proposed in this paper has achieved good results in radon reduction and energy saving.The results show that the withdrawal ventilation system is not suitable for shrinkage old mine,and the radon exhalation rate of rock wall under the condition of pressure ventilation is lower than that under the condition of withdrawal ventilation.The results provide a theoretical basis for the future adjustment of ventilation system in uranium mines and the design of ventilation system in new mines.