Study On The Influence Of Surfactant On The Seepage Characteristics Of Sandstone In Low Permeability Uranium Deposit

Environmental geotechnical engineering is a new subject in the field of geotechnical engineering.In-situ leaching of uranium has the advantages of low cost,simple process,low environmental damage and high resource utilization.Uranium is not only an important nuclear energy resource,but also a strategic resource for national defense and security.It plays an important role in China and even in the world.Most of the proven sandstone type uranium resources in China are characterized by low permeability,poor uranium taste and easy to cause pore plugging during in-situ leaching.According to these characteristics,it is of practical significance to study the influence of surfactant on the seepage characteristics of low-permeability uranium ore sandstone.In this paper,through the static leaching test(Add ore and solution to the conical flask and shake well before static),the best surfactant is selected from three kinds of surfactants to improve the uranium leaching rate,and the optimal surfactant is used to carry out the percolation test of horizontal cylinder uranium sandstone,and the percolation law curve under the action of different fluids is obtained.The main research contents and conclusions are as follows:(1)The results show that 0.1g/L SDS and 0.5g/L SDBS are the best for uranium leaching.By the 4th day,most of the leachable uranium in uranium ore has been leached,and the content of uranium leached from the5 th to 7th days is very small.According to the concentration and time curve of uranium leaching,the leaching time of surfactant concentration gradient test is12 hours.(2)Seven concentration gradients of SDS and SDBS were set up to conduct the concentration gradient test.It was found that there was an optimal concentration point of uranium in each surfactant.Through comparison,it was determined that 0.5g/l SDBS had the best promoting effect on uranium leaching,which could be used as later percolation test.(3)No matter whether surfactant is added into the solution or not,the permeability coefficient of uranium ore increases first and then decreases.However,the permeability coefficient of ore without surfactant in the early stage of leaching is higher than that of ore with surfactant.The permeability coefficient of two ores in the middle stage of leaching is nearly the same.The permeability coefficient of ore without surfactant in the later stage of leaching is lower than that of ore with surfactant the permeability coefficient of the activator ore.(4)In the early stage of leaching,both uranium ores are from unsaturated to saturated.The diffusion ability of the solution with surfactant is stronger than that without surfactant.