Study On The Treatment Of Covering Soil For The XX Uranium Waste Dump In Western Inner Mongolia

Uranium is a special type of strategic mineral resources.After many years of uranium geological exploration work in the western part of Inner Mongolia,a large amount of untreated radioactive uranium ore waste stones have been left,resulting in radioactive pollution,which still has a negative impact on the local environment.In response to this situation,the government invests funds in governance.Many years of research and management practices at home and abroad have proven that in-situ coverage is the most effective method for suppressing the leaching and shielding of gamma radiation on the surface of uranium waste rock,and the commonly used covering material is soil.In order to make the design and construction of the treatment project reasonable and effective use of governance funds,it is necessary to carry out trials on the treatment of overburdened uranium ore wastes in the western part of Inner Mongolia to find the minimum thickness of the earth covering,to minimize the investment in governance,and to maximize the effect of governance.In this study,we selected the remaining waste rock piles of the XX uranium deposit in the western part of Inner Mongolia as the research object to carry out coverage research.Using the local sandy sub-clay as covering material,we carried out coverage tests with the degree of compaction greater than 0.9 and approximately equal to 0.7.The research shows that in order to achieve the goal of radioactive pollution control,the XX uranium waste dump in Western Inner Mongolia needs to be covered with six layers of sandy sub-clay,and the minimum thickness of the design is 85 cm.And it is proved that the degree of compaction has an effect on the rate of surface radon excavation after waste rock piled over the soil.The higher the degree of compaction,the lower the radon exhalation rate;the degree of compaction has little effect on the gamma radiation shielding effect;Under the influence of background radiation,there is an upper limit?environmental background value?of the shielding effect of the thickness of the covering soil on the gamma radiation.When the upper limit of the shielding effect is reached,the increase of the thickness of the covering soil has no effect on the shielding effect of the gamma radiation.The thickness of the covering soil needs to comprehensively consider factors such as strontium precipitation,?-radiation,overburden erosion,vegetation restoration,etc.,so that a certain thickness of the soil can effectively suppress the precipitation of strontium and shield?-radiation.At the same time,vegetation restoration can be carried out to maintain the soil cover.The effect is stable.The mathematical relationship between the thickness of the cover and the effect of suppressing the precipitation of the enthalpy is a quadratic polynomial,which can be solved by the cover measurement method.This relationship can quickly derive the effect of multi-layer coverage of the same covering material to suppress the precipitation of waste rock piles,in order to further determine the coverage.The layer thickness provides the basis.The study pointed out that after the uranium waste dump was covered and stabilized,the influence of meteorological factors on the gamma radiation dose rate was not obvious.Among the meteorological factors,the temperature and wind speed are directly proportional to the radon exhalation rate,and the air pressure and air relative humidity are inversely proportional to the radon exhalation rate.The radon released rate is greatly affected by temperature and relative humidity of the air,and is less affected by wind speed and air pressure.Based on the diffusion principle of helium and the attenuation principle of?-rays penetrating the material,this study deduces the relationship between the thickness of the overburden,the enthalpy of precipitation,and the gamma radiation dose rate.According to the relevant requirements of the state,the formula(i.e.X_min=?X?=67.53 ln??0.74?+9.27)for the minimum thickness of the XX uranium deposit in the western Inner Mongolia is designed.The main methods and precautions for the treatment of the uranium waste dump are discussed,which provides a reliable reference for the treatment of similar uranium geological waste dump in western Inner Mongolia.