Soil−water characteristics of weathered crust elution-deposited rare earth ores

风化壳淋积型稀土矿的土水特性

The permeability of the weathered crust elution-deposited rare earth ores directly affects the efficiency of in-situ leaching.The soil−water characteristic curve(SWCC)is an important constitutive relation for calculating the permeability of ore body,which is related to many factors.Soil−water characteristic tests of rare earth ore samples considering different factors were carried out by using the pressure plate instrument.Effects of dry density,particle size and solution leaching on water holding behavior and the mechanism were investigated.The experimental observations indicate that with the decrease of dry density,the pore ratio increases gradually,and the saturated water content increases.Under the same matric suction,the water content decreases gradually with the increase of particle size,thus decreasing water holding capacity of ore accordingly.In the same water content,matric suction is inversely proportional to particle size.Under the same matric suction,the water content of ore samples after leaching is less than that of the ore samples before leaching,indicating that solution leaching can decrease water holding capacity of ore.

风化壳淋积型稀土矿的渗透特性直接影响原地浸矿的浸出效率。土水特征曲线是研究矿体渗透特性的重要基础,与许多因素具有关联性。为了研究不同因素对矿体土水特征曲线的影响,采用压力板仪进行土水特性试验,分析干密度、粒径和溶浸对稀土矿体土水特性的影响及其作用机理。结果表明,随着干密度的减小,孔隙率增大,矿体饱和含水量增加。采用同一基质吸力时,随着粒径的增加,矿体含水率逐渐减小,矿体持水能力降低。在相同体积含水率情况下,基质吸力与粒径大小成反比。采用同一基质吸力时,溶浸后矿体含水量比溶浸前矿体含水量降低,说明溶浸使得矿体持水能力减小。