【作者】 黄颖；

【导师】 胡世丽；

【作者基本信息】 江西理工大学 ， 建筑与土木工程（专业学位）， 2017， 硕士

【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。更多还原

【Abstract】 To grasp the adsorbing characteristics of weathered crust elution-deposited rare earth ores and solute transport process of rare earth ions in leaching solution are of great significance for improving leaching rate of in-situ leaching mining.Firstly,various grain-sizes of weathered crust elution-deposited rare earth ore samples were obtained by sieving,and testing ionic REO grade,specific surface area,surface morphology and mineral composition etc of various ore samples,the adsorbing property for rare earth ions in the ore body was analyzed.Then through indoor column leaching experiments for the ore samples of different void ratio were carried out under constant head,the effect of void ratio on leaching rate and leaching cycle the ore resources was analyzed;and retardation factor and coefficient of hydrodynamic dispersion based on breakthrough curve were calculated.The results show that:(1)The mineral compositions of Xinfeng’s rare earth ore mine from southern Jiangxi province are kaolinite,k-feldspar,quartz,tourmaline,muscovite and garnet,and the total mass proportion of these 6 main mineral components reaches 94.82%.But the granularity of different mineral composition is obviously different,and the quality proportion of kaolinite and muscovite increases in small grain-size of rare earth ore.And the adsorption capacity of rare earth ion is positively correlated to the proportion of clay minerals such as kaolinite.(2)Based on that the adsorption capacity of rare earth ions in the concavities on the surface of ore bodies is a log-normal distribution with the aperture and grain-size,the model to analyze the relationship between the adsorption quantity of rare earth ions and the aperture of surface concavities is established.Then by using the model,the effective pore size of adsorption for Xinfeng’s rare earth ore mine in southern Jiangxi province is calculated to be 2.0~20.0 nm.(3)The leaching rate of rare earth resources for ore samples which are of different void ratios is about 90%.The larger void ratio of the ore sample is easier to penetrate,and its leaching cycle is shorter and residual rate of NH4+ is higher.Prolonging injecting time of underscreen water can effectively reduce the residual rate of NH4+.(4)For the ore samples of different void ratio,solute transport breakthrough curve is of different delay: the ore sample is easier to penetrate because of its larger void ratio,and its curve obviously shifts to the left;compared with NH4+ which participates in ion exchange and adsorption desorption,the breakthrough curve of the unreacted SO42-moves to the left.When the hydraulic gradient is 1.1 and using the first liquid injection mode,the retardation factor of ore samples which are of different void ratios is 1.16.更多还原