Experimental Study On Influence Of Pressure Gradient And Temperature On Radon Exhalation From Porous Emanium Medium

Uranium resources buried in the shallow seam are being gradually exhausted since itstarted in1960s, so more and more uranium mines have been being faced with thechallenge of deep mining. Radon permeation will be serious in the ventilation network dueto its different pressure distribution and the increasing of goaf, changing the amount ofradon of ventilation space. To studying on the radon transport in surrounding rock is ofgreat practical significance and application value to the adjustment of pressure inventilation network and the design of controlling radon exhalation and attenuating radonconcentration.Supported by the National Natural Science Foundation“The nonlinear simulation andstudy on the distribution of radon and its daughters in uranium ventilation network”(project number:1107571),The surrounding rock is simplified as porous emaniummedium, an apparatus for measuring the radon permeation and emanation in porousmedium is developed，and the variation law of radon exhalation rate under differentpressure state with pressure gradient and different medium temperature is studied by usingthe apparatus. In summary, this dissertation includes the following main contents:（1）Experimental study of the radium content of uranium tailings and the porosity ofradium. An apparatus for measuring the radon permeation and emanation in porousmedium is developed based on the similarity principle of model test, it has been succeed inthe test of pressure control and temperature measurement.（2）To this apparatus, the results show that the radon exhalation rate on highpressure side decreases exponentially with the increase of pressure gradient and the radonexhalation rate on low pressure side increases linearly when the pressure gradient is less than827.6Pa/m,the results are in line with the theoretical calculating value. The radonexhalation rates tend to be stable with the continued increase of pressure gradient. Incomparison, the effect of medium temperature is relatively small. Meanwhile, the increaseof pressure gradient can increase the radon exhalation rate of the whole medium to someextent.