风化壳淋积型稀土矿稀土离子的吸附特性及其溶质运移规律

发布时间：2018-10-09 19:41

【摘要】：研究风化壳淋积型稀土矿体的吸附特性,以及浸矿过程中稀土离子在浸矿液中的溶质运移规律,对于提高原地浸矿稀土浸取效率具有重要意义。本文首先通过筛分获得不同粒径的稀土矿样,测试各粒径矿样的离子相稀土品位、比表面积、表面形貌以及矿物成分等,分析稀土离子在矿体中的吸附特性;然后对不同孔隙比矿样进行室内常水头柱浸试验,分析孔隙比对资源浸取率和浸矿周期的影响,并依据穿透曲线计算滞留因子、水动力弥散系数。研究结果表明:(1)矿样所含的主要矿物质有高岭石、电气石、钾长石、石英、白云母、石榴子石等,六种矿物总含量高达94.82%;不同矿物成分的粒度有明显的差异,随着矿样粒径的减小,高岭石和白云母的含量增加,矿样的稀土离子吸附量与高岭石等黏土矿物的含量成正相关。(2)基于稀土离子在矿体颗粒表面凹坑的单位面积吸附量与孔径和粒径成对数正态分布,建立了稀土离子吸附量与矿体颗粒表面凹坑孔径之间关系的分析模型,运用该模型计算得到赣南信丰某矿山矿样的有效吸附孔径为2.0~20.0 nm。(3)不同孔隙比矿样的稀土资源浸取率均在90%左右;孔隙比较大的矿样较易穿透,浸矿周期较短,尾矿中铵根离子的残留率较高;延长顶水注液时间,可有效降低铵根离子残留率。(4)不同孔隙比矿样的溶质穿透曲线延迟性不同:孔隙比较大,矿样较易穿透,穿透曲线明显左移;无反应的硫酸根离子的穿透曲线较参与离子交换与吸附解吸作用的铵根离子的左移。在水力梯度为1.1的条件下,当采用第一种注液方式时,不同孔隙比矿样的滞留因子计算值均为1.16。
[Abstract]:It is of great significance to study the adsorption characteristics of weathered crust leaching rare earth ore bodies and the solute migration of rare earth ions in leaching solution for improving the leaching efficiency of in situ leaching rare earths. In this paper, rare earth mineral samples with different particle sizes were obtained by sieving. The ionic rare earth grade, specific surface area, surface morphology and mineral composition were measured, and the adsorption characteristics of rare earth ions in ore bodies were analyzed. The influence of the porosity ratio on the leaching rate and the leaching period was analyzed, and the retention factor and hydrodynamic dispersion coefficient were calculated according to the penetration curve. The results show that: (1) the main minerals in mineral samples are kaolinite, tourmaline, potassium feldspar, quartz, Muscovite, pomegranate, etc. The contents of kaolinite and Muscovite increased with the decrease of ore size. The amount of rare earth ions adsorbed by ore samples is positively correlated with the content of clay minerals such as kaolinite. (2) based on the logarithmic normal distribution of the adsorption amount per unit area of rare earth ions on the pits on the surface of ore bodies, the pore size and pore size of rare earth ions are logarithmic normal distribution. An analytical model of the relationship between the adsorption capacity of rare earth ions and the pore size of pits on the surface of ore bodies has been established. By using this model, the effective adsorption pore size of the ore sample of Xinfeng mine in south Jiangxi is 2.0 ~ 20.0 nm. (3) the leaching rate of rare earth resources of the samples with different void ratios is about 90%, the ore samples with large porosity are easy to penetrate and the leaching period is shorter. The residual rate of ammonium ion in tailings is higher, and the residual rate of ammonium ion can be effectively reduced by prolonging the injection time of top water. (4) the delay of solute penetration curve of mineral samples with different void ratios is different: the porosity is large, the ore sample is easy to penetrate, The breakthrough curve was obviously shifted to the left, and the breakthrough curve of the non-reactive sulfate ion was higher than that of the ammonium ion involved in ion exchange and adsorption and desorption. When the hydraulic gradient is 1.1, the calculated values of the retention factors of the samples with different void ratios are 1.16 when the first liquid injection mode is adopted.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD865

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