风化壳淋积型稀土矿铵盐浸出过程中稀土离子和铝离子分布规律研究

为揭示风化壳淋积型稀土矿浸矿过程中稀土阳离子(RE^(3+))及杂质铝离子(Al^(3+))的迁移分布规律,本文分别用硫酸铵、硫酸铵与甲酸铵混合浸取剂对风化壳淋积型稀土矿进行模拟浸取实验,测定并计算不同浸取阶段、不同矿层中各种状态下的RE^(3+)和Al^(3+)含量变化。结果表明:矿土和孔隙中的RE^(3+)和Al^(3+)含量随着浸取的进行而减少,迁移状态的RE^(3+)和Al^(3+)含量随浸取程度加深而增大,浸取剂对RE^(3+)的浸出效果优于对Al^(3+)的浸出效果。矿土中的RE^(3+)和Al^(3+)在浸润开始时的第四层矿体中含量最多,孔隙中RE^(3+)含量在第四层矿体中100%浸润时最多,迁移状态的RE^(3+)和Al^(3+)含量随着浸取程度以及矿层深度的加深而增大,其峰值集中在最后阶段的第四层矿体中。浸润阶段发生反吸附,但对后续浸出过程没有明显影响。硫酸铵与甲酸铵混合浸取剂对Al^(3+)的浸出有良好的抑制效果。

Pore structure characteristics of the relative water-resisting layer on the top of the Ordovician in Longgu Coal Mine

In order to study the permeability and water-resisting ability of the strata on the top of the Ordovician in Longgu Coal Mine, this paper tested the permeability and porosity of the strata, investigated the fracture and pore structure features of the strata, and identified the main channels which govern the permeability and water-resisting ability of the strata. The permeability of the upper, central and lower strata shows as 2.0504 × 10^-3-2.782762× 10^-3, 4.1092 × 10^-3 -7.3387 × 10^-3 and 2.0891 ×10^-3-3.2705 × 10-3 μm^2, respectively, and porosity of that is 0.6786-0.9197%, 0.3109-0.3951% and 0.9829-1.8655%, respectively. The results indicate that： （I） the main channels of the relative water-resisting layer are the pore throats with a diameter more than 6 μm; （2） the major proportion of pore throats in the vertical flow channel and the permeability first increases and then sharply decreases; （3） the fractures occurring from the top to 20 m in depth of the strata were filled and there occurred almost no fracture under the depth of 40 m; and （4） the ratio of turning point of the main flow channel in the strata on top of Ordovician can be used to confirm the thickness of filled water-resisting lavers.