The Applied Research Of Radon Measurement By Activated Carbon For The Exploration In The Sandstone-type Uranium Deposit In Yili Basin

Most of the sandstone type uranium deposits are originated in the meso-cenozoicbasin in china,which had the characteristics of larger buried depth,the smallerscale,scattered distribution.The instruction of the sandstone type uranium deposits are notobvious in the surface,so it is difficulity to look for the interlayer oxidation zonesandstone-type uranium deposits.For a long time, the looking for this kind of uraniummostly depend on the drilling method to area the geochemical zone of the interlayeroxidation zone sandstone-type uranium deposit,because of the high cost and the lowefficiency,it was restricted the prospecting process of the uranium deposit.In the presentane future,geophysical method is one of the important methods at looking for the interlayeroxidation zone sandstone-type uranium deposits in north China，and the radonmeasurement by activated carbon is one of the most widely used method,but how toinprove the prospecting effect of radon measurement by activated carbon,delineate theuranium metallogenic target areas rapidly and accurately,we need research further both intechnology method and anomaly interpretation.At first,we studied the main influencing factors of the radon measurement byactivated carbon by physical simulation,field test and fitting.mainly discusses how thefactors of the embedded depth of adsorber,the buried time,the soil moisture,the surfacevegetation,the rain conditions and the surface topography impacted the radon concentrationin the the radon measurement by activated carbon.The results showed that:when theactivated carbon adsorber buried in50cm,less effect on the radon concentrationmeasurement;usually the adsorber buried underground for more than five days,the radonconcentration could reach saturation;the soil moisture was smaller,the results of radon concentration measurement were better;the more vegetation in the surface,the poorer theeffect of radon concentration measurement; the anomalous of radon concentration couldchange when the topography conditions were different in the surface.It is helpful to choosethe best way of working in the practical work and get better detection result thoughstudying and mastering the basic rule of these factors which impacted on the radonconcentration.This paper in the southern margin of Yili basin, its gold mining area has carried outactive carbon measuring radon, combined with the known geological situation, to discussthe corresponding relation between the uranium mineralization belt and the anomaly ofradon concentration in this area,the result shows that the most of the uraniummineralization belts was in the low anomaly zone which surrounded by the high anomalyradon concentration.To establish the basic principle for selecting the uranium ore body byradon concentration anomaly,that is the basis of the low radon concentration areasurrounded by high radon concentration anomaly to delineate the ore prospect area.Appliedthe above principle to the anomaly interpretation of the radon concentration measuring byactive carbon method,and determined the location of the interlayer oxidation-reductionfront line better,selected the mineralization rake area of uranium,and had a good effect inprospecting.