Measurement Of Mechanical Parameters And Calculation Of Critical Injection Strength Of Ion-absorbed Rare Earth Ore Body

There is no uniform standard for the intensity of liquid injection of in-situ leaching of rare earth mine,only operated by the experience that may cause landslides.The study of the mechanical parameters and distribution of the ore body,the parameters of the constitutive model,and the application of the mechanical parameters and the distribution types to the calculation of the intensity of liquid injection of the mine are of great significance to the economic and safety of insitu leaching process.Based on statistical regularity method to test soil mechanic parameters are both accurately and economical quick.In a rare earth mine southern Jiangxi province,6 measuring points were arranged and each measuring point had 3 test holes.Through pressuremeter test and borehole shear test,pressuremeter modulus,deformation modulus,compression modulus,cohesion and internal friction angle of ion-absorbed rare earth ore body were obtained.And the spatial variability of the mechanic parameters in ore body was analyzed by classical statistics method and geology statistics method.With assuming that the test value of mechanic parameters are truth value and the acceptable error of engineering is 15%.The optimal testing scale and the number of measuring points were analyzed by classical statistics method and geology statistics method.With the relationship between the pressure and displacement in pressuremeter test,the ore body's Duncan Chang model parameters were figured out by finite element back analysis method.With the mechanical parameters,topographic parameters of the mine,the critical injection intensity simulated by GeoStudio.The results shows that:1.The cohesion and the pressuremeter modulus of ore body in test block are strong variation,variation coefficient of the cohesion is 0.48 and variation coefficient of the pressuremeter modulus is 0.36,the extreme pressure is medium variation,variation coefficient of the extreme pressure is 0.212,the internal friction angle is weak variation,variation coefficient of the internal friction angle is 0.067.2.In this ore block,the test result can efficiently estimate the mean and the variation coefficient of ore body's cohesion and pressuremeter modulus by arrangement 5 measuring points uniformly in 45 m scope.3.Duncan Chang model parameters of the ore body are k=1331.7,n=2.775,r_f=0.516,k_b=563,m=0.154,c=22.2,?=31.7.4.The critical injection intensity of this ion-absorbed rare earth mine is 0.41m~3/d each injection well.