浸矿剂浓度对离子型稀土矿体抗剪强度参数的影响

The Influence of Leaching Agent Concentration on the Shear Strength Parameters of Ion-adsorption Rare Earth Ore

原地浸矿过程中离子型稀土矿体与浸矿剂发生离子交换和水化作用等,导致矿体颗粒成分、级配和矿体强度发生改变,从而影响矿山边坡的稳定性,甚至会造成山体滑坡等一系列工程问题。黏聚力、内摩擦角是影响矿体抗剪强度的主要参数,通过Zeta电位测定试验、颗粒级配测定试验以及直剪试验,分析出不同浓度的浸矿剂硫酸铵溶液浸矿对离子型稀土矿样双电层厚度、颗粒级配和抗剪强度参数的影响规律。试验结果表明:浸矿作用下,对粒径小于0.075 mm的矿样,当硫酸铵溶液浓度小于2%时,随着溶液浓度增大,矿样颗粒间黏聚力减小,内摩擦角增大;当硫酸铵溶液浓度在2%~3.5%之间时,随着溶液浓度增大,矿样颗粒间黏聚力增大,内摩擦角减小。

In the process of in-situ leaching, ion exchange and hydration occur between ion-adsorption rare earth ore-body and leaching agent, which result in changes of ore-body particle composition, gradation and ore-body strength, thus affecting the stability of mine slope and even causing a series of engineering problems such as landslide. Cohesion and internal friction angle are the main parameters affecting the shear strength of ore-body. Through zeta potential test, particle size distribution test and direct shear test, this paper analyzes the influence of different concentration of leaching agent ammonium sulfate solution on the double electric layer thickness, particle size distribution and shear strength parameters of ion-adsorption rare earth ore samples. The experimental results show that: under the action of ore leaching, for ore samples with particle size less than 0.075 mm, when the concentration of ammonium sulfate solution is less than 2%, the cohesion between particles decreases and the internal friction angle increases with the increase of solution concentration;when the concentration of ammonium sulfate solution is between 2% and 3.5%, the cohesion between particles increases and the internal friction angle decreases with the increase of solution concentration.