离子型稀土毛细上升影响因素及其规律研究

发布时间：2018-03-06 17:00

本文选题：离子型稀土　切入点：毛细损失　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：离子型稀土是我国特有的矿产资源,属于保护性开采矿产资源,目前广泛采用原地浸工艺进行开采。本文以离子型稀土原地浸开采过程中的毛细损失现象为工程背景,期望最大程度减小因毛细损失导致的资源浪费和环境污染,在自制毛细试验装置的基础上,以寻乌某矿的离子型稀土为研究对象,对离子型土毛细上升影响因素及其规律进行研究。试验交换液分别为清水、浓度为3%和5%的硫酸铵溶液。四种离子型稀土土样的最大粒径分别为4.75 mm、1.18 mm、0.6 mm和0.3 mm。得到如下结论:(1)清水在离子型稀土中发生毛细上升时,随土体最大粒径的增加,最大毛细上升高度逐渐减小,毛细渗透系数逐渐增加。最大毛细上升高度与毛细渗透系数呈负相关性。相同土样的毛细渗透系数小于饱和渗透系数。毛细上升速率随时间的增加先快速下降、后缓慢发展。(2)当土样最大粒径不同时,硫酸按溶液的浓度对毛细上升的敏感性也不同,最大粒径为4.75mm 土样受其影响较小,而最大粒径为0.3mm、0.6mm、1.18mm时表现较为敏感。从减小原地浸工艺毛细损失的角度,建议选取浓度为3%的硫酸铵溶液。(3)交换液的重力对毛细上升起阻碍作用,也是导致同时间段毛细上升高度和水平扩散距离不相等的决定性因素。原地浸工艺配制注入液时,在不影响稀土离子交换效率的情况下可适当提高注入液浓度,以减小毛细损失程度。(4)基于土柱含水率分布呈线性变化的假定,通过理论分析认为毛细入渗率与毛细速率和含水率呈正相关性变化。毛细过程中水力变化和能量转换是导致毛细现象的根本原因,二者在毛细上升过程中的彼此牵制转化,缩小了水力梯度而最终使毛细作用趋于稳定。
[Abstract]:Ionic rare earth is a unique mineral resource in China, which belongs to the protective mining. At present, the in-situ leaching process is widely used for mining. This paper takes the phenomenon of capillary loss in the process of ion type rare earth in-situ leaching as the engineering background. Expecting to minimize the waste of resources and environmental pollution caused by the loss of capillary, based on the self-made capillary test device, the ion rare earth of Xunwu Mine is taken as the research object, The influencing factors and their regularity of capillary increase in ionic soil were studied. The maximum particle sizes of the four ionic rare earth soil samples are 4.75 mm ~ 1.18 mm ~ (0.6 mm) and 0.3 mm 路m ~ (-1) respectively. The conclusion is as follows: when the capillary size of the water increases in the ionic rare earth, the maximum particle size increases with the increase of the maximum particle size of the soil. The rising height of the maximum capillary decreases gradually, The capillary permeability coefficient of the same soil sample was smaller than that of saturated permeability coefficient. The capillary rising rate decreased rapidly with the increase of time, and the capillary permeability coefficient increased gradually, and the capillary permeability coefficient was negatively correlated with the capillary permeability coefficient of the same soil sample, and the capillary permeability coefficient of the same soil sample was less than that of the saturated permeability coefficient. When the maximum particle size of soil sample is different, the sensitivity of sulfuric acid to capillary increase is different according to the concentration of solution, and the maximum particle size of 4.75mm soil sample is less affected by it. However, the maximum particle size of 0.3mm ~ 0.6mm ~ (-1. 18 mm) is more sensitive. In order to reduce the capillary loss of in-situ leaching process, it is suggested that the gravity of the exchange solution with concentration of 3% ammonium sulfate solution. It is also a decisive factor leading to the inequality of capillary height and horizontal diffusion distance in the same time period. When the injection solution is prepared by in-situ leaching process, the concentration of the implanted solution can be appropriately increased without affecting the exchange efficiency of rare earth ions. In order to reduce the degree of capillary loss, it is assumed that the distribution of soil column moisture content changes linearly. Through theoretical analysis, it is concluded that the capillary infiltration rate is positively correlated with capillary rate and moisture content, and that hydraulic change and energy conversion are the fundamental reasons leading to capillary phenomenon. It reduces the hydraulic gradient and finally stabilizes the capillary action.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD865

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