Study On The Permeability And Expansibility Of Alkali Solution And Ion Solution Of Gaomiaozi Bentonite

The nuclear waste repository in China initially set the buffer / backfil l material for Gaomiaozi sodium bentonite,its high expansibility and low permeability to meet the deep repository requirements,due to the complex environment deep disposal system of high alkaline and heat and various io nic salt solution,buffer / repository physical and chemical changes in the external environment of the backfill material directly affects the safety of nuclear waste repository.Therefore,it is necessary to evaluate the physical and chemical changes of Gaomiaozi bentonite in high alkalinity,thermal e nvironment and salt solution environment.In this paper,through the test a nd analysis of variation of GMZ-1 a series of physical and chemical prope rties,discusses the physical and chemical properties in high alkaline ionic salt solution and thermal environment and environmental conditions of Gao miaozi bentonite,the specific contents are as follows:(1)The effect of alkaline solution under different concentrations of G aomiaozi bentonite liquid plastic limit,free swelling ratio,swelling perfor mance and permeability test,explore the influence of alkali solution on th e properties of the bentonite.The results showed that the alkali solution o f Gaomiaozi bentonite liquid plastic limit,the free expansion rate and exp ansion has great influence on the performance and permeability,and with t he concentration increasing,the influence degree of enhancement.(2)The salt solution for different ion species of Gaomiaozi bentonite liquid plastic limit,free swelling ratio,swelling performance and permeabil ity test,explore the effects of different ions on the properties of the bento nite.The results show that the ion in the solution,with the increase of m etal ion price,the influence on the performance of Gaomiaozi bentonite de creased.(3)Based on the expansion and permeability test of distilled water an d alkaline solution at different temperatures,the law between the change o f temperature and the properties of bentonite was explored.The results showed that the reaction became more intense with the increase of temperatur e.Conclusion: montmorillonite alkaline solution of GMZ bentonite has ce rtain dissolution and dissolution,with the increase of concentration,ionic s alt solution sodium,potassium,calcium,magnesium,iron,aluminum ion an d GMZ-1 of ion exchange,reducing swelling of bentonite the increase of i ts permeability,is not conducive to the buffer / backfill sealing materials,test temperature on Bentonite hydration and dissolution have played a catal ytic role,accelerate the testing speed,enhance the degree of reaction.