The Study Of Distribution Characteristics Of Uranium In Typical Field Of Uranium Mine And Formation Mechanism

This paper select the typical sites of uranium mine areas, mainly to study thedistribution characteristics of uranium in shallow uranium tailings and paddy soil, and theadsorption mechanism of paddy soil for uranium, and to analysis these, draw thefollowing main conclusions:(1)Through the acid leaching of tailings sand samples, found that the leachingamount increase with time stretch, get the leaching amount of uranium in tailings sand ofdifferent depths. Results show that the leaching amount of uranium in tailings sand ishigher than other layers, the highest amount is up to25.62mg/g. This distribution may bedue to the oxidation, rainwater leaching and migration of uranium.(2)After sampling paddy soil by cross and snake-like and processing it, found that thedistribution characteristics of uranium content in paddy soil is that with the depth of thesoil increased uranium content gradually decreased, and the uranium content of topsoil isabout2-6times of deep soil layers. Shown that the migration distance of uranium in soil isshort, the main cause is maybe adsorption of uranium on soil is good.(3)In the experiment of adsorption mechanism for uranium on paddy soil throughexperiment of the single factors pH value, consumption of soil, adsorption time, initialconcentration of uranium solution, temperature and orthogonal experiment. When pHvalue is4.5, rice paddy soil consumption is0.06g, adsorption time is90min, the initialconcentration of uranium is1mg/L, the amount of paddy soil adsorption of uranium is themost.(4) Using isothermal equation of Langmuir and Freundlich to describe the adsorptionof paddy soil of uranium, fitting to correlation coefficients are0.98and0.83. Fittingeffect of Langmuir equation is better than Freundlich equation, so adsorption of paddysoil of uranium belongs to monolayer physical adsorption.(5) Analysis adsorption of paddy soil of uranium by adsorption kinetics, correlationcoefficient of quasi-first-order kinetics equation curve and quasi-second-order kineticequation curve are0.9947and0.9689, so adsorption of paddy soils of uranium belongs toquasi-first-order kinetics. (6)Evaluation of paddy soil pollution caused, found that the average of single factorpollution index of uranium content of surface soil in paddy field under the condition ofthe two background values is greater than1, reached a slight pollution level. the averageof single-factor pollution index of uranium content in other layers soil is less than1, in asafe level.(7) Main points of innovation: By sampling and laboratory analysis typical sites ofuranium mining site, preliminary analysis the distribution characteristics of uranium ofshallow tailings, discover the distribution characteristics, influencing factors and theformation mechanism of uranium by the tailings leaching water irrigation in paddy soil,innovative research of the impact of uranium mine environment.