Experimental Research And Application Of The Effect Of Ore Leaching Agent Concentration On Ion Rare Earth Ore Body Strength Parameters

At present,the in-situ leaching technology is used for mining the ionic rare earth ores.Under the condition of improper control of liquid injection intensity,this technology is easy to cause shallow landslide.In this paper,the thickness of the sliding layer in the double electric layer on the surface of ore body particle is calculated under the condition of mixed electrolyte and single electrolyte.The influence of ammonium sulfate solution of the stage injecting ammonium sulfate solution and injecting supernatant on the thickness of sliding layer in the surface electric layer of ore body particles are analyzed.The effect of layer thickness on the stability of ore body aggregates during the injection of ammonium sulfate solution and supernatant are analyzed.The reasons of the influence of ammonium sulfate solution on the shear strength parameters of ore body in the stage of injecting ammonium sulfate solution and injecting supernatant are analyzed.The main conclusions are as follows:(1)For the ammonium sulfate solution injection stage and the supernatant injection stage,when the concentration of the ammonium sulfate solution increased from 0 mol/L to0.16 mol/L,the fractal dimension of the ore body decreased from 2.09 and 2.18 to 1.98 and 1.98,respectively.The content of fine particles in the body decreases,the coarse particles increase,and the ore body particles reunite.During the injection of ammonium sulfate solution and the supernatant,when the concentration of ammonium sulfate solution gradually increased from0.16mol/L to 0.28mol/L,the fractal dimension of the ore body increased from 1.98 and 1.98 to2.09 and 2.11 respectively.That was,the content of fine particles in the ore body increases,the coarse particles decrease,and the particles of the ore body disperse.(2)For the ammonium sulfate solution injection and the supernatant injection stage,when the concentration of the ammonium sulfate solution is lower than the critical concentration,as the concentration of the ammonium sulfate solution increases,the thickness of the electric double layer on the surface of the ore body particles decreases rapidly.The viscous ore body particles were agglomerated,the lubrication effect and the overall cementation between the ore body particles were weakened,the ore body shear strength parameter cohesion c was reduced,and the internal friction angle?is increased.When the concentration of the ammonium sulfate solution was above the critical concentration,with the increase of the concentration of the ammonium sulfate solution,the thickness of the electric double layer on the surface of the ore body particles increases slightly,the ore body particles with viscosity were dispersed,the lubrication between the ore body particles and the overall cementation function were strengthened,the cohesive force c increases,and the internal friction angle?decreases.(3)When considering the effect of ammonium sulfate solution on the strength of the ore body,the critical injection strength of the mine calculated by the model is 0.72m~3/d during the injection of ammonium sulfate solution,and the critical injection strength of the mine calculated by the model is 0.68m~3/d.during the supernatant injection phase;without considering the influence of the concentration of the leaching agent,the critical fluid injection strength calculated by the model is 0.74m~3/d.