| Abstract: | In order to reveal the permeability rule of leaching agent solution and the effects of anions in the leaching process of weathered crust elution-deposited rare earth(RE) ores, the effects of ammonium concentration, temperature, particle size and porosity on the permeability were discussed in detail with(NH_4)2_SO_4, NH_4Cl and NH_4NO_3 as the leaching agent. It was found that the permeation velocity of ammonium salts increased linearly with the increase of hydraulic gradient. The seepage of ammonium salts solution in the RE ores followed Darcy's law and displayed a laminar flow. The properties of the leaching agent solution and RE ores were the main factors that affect the permeability of RE ores. With the decrease of ammonium concentration and increase of temperature, the viscosity of solution decreased and the permeability coefficients of RE ores increased. And the effects of temperature on the viscosity and permeability were larger than ammonium concentration. The permeability of RE ores became worse with the decrease of particle size and porosity, and the particle size played a more important role compared with porosity. The permeability coefficient of RE ores increased and the viscosity of ammonium salts solution decreased in the order of(NH_4)_2SO_4, NH_4Cl and NH_4NO_3, implying that the penetrating power of anions increased in the order of SO_4~(2-), Cl~- and NO_3~-. The results may play a vital role in improving the permeability of weathered crust elution-deposited RE ores. |
