离子型稀土原地浸矿导流孔周渗流规律试验研究

发布时间：2018-03-31 06:43

本文选题：原地浸矿　切入点：导流孔　出处：《江西理工大学》2017年硕士论文

【摘要】：目前,对导流孔周渗流规律理论研究不足,缺乏相应的技术指导,导致只凭经验布置导流孔,造成部分浸出液无法回收,同时因裂隙渗漏,导致相当部分浸出液流失,使得稀土回收率低,给矿区生活带来极大的危害和污染。故研究导流孔周渗流规律,对计算原地浸矿母液回收率具有重要意义。本文利用原地浸矿室内模型试验,分析单个和密集导流孔周渗流规律。首先,利用单个导流孔周水平方向孔隙水压力分布规律和导流孔收液率与底板渗漏量关系分析单个导流孔周渗流规律;其次,运用分形理论,推导出单个导流孔周水平方向孔隙水压力分形分布表达式,并将实测单个导流孔孔周孔隙水压力分布运用该式拟合,确定分形参数;最后,利用不同间距、不同初始水头条件下,密集导流孔周水平方向孔隙水压力分布规律、导流孔收液率的控制过程和孔周水平方向和竖直方向水力梯度变化规律来分析密集导流孔周渗流规律,综合考虑水平与竖直方向水力梯度之比对收液率的影响,为合理确定孔间距提供参考。结论如下:(1)单个导流孔周水平方向孔隙水压力分布规律为在导流孔两侧形成大致呈对称状的降落漏斗,靠近导流孔孔隙水压力值较低,远离导流孔孔隙水压力值较高,离导流孔越近孔隙水压力值下降越快,且很快接近导流孔,底面曲率很小,水面线较为平缓,确定单个导流孔影响范围为22cm。(2)根据分形理论,假设水沿水平方向进入导流孔的通道为普遍存在的2分叉分形树状网络结构,基于Hagen-Poiseuille方程,提出单个导流孔周水平方向孔隙水压力分形分布表达式及其分形参数计算方法,室内模型试验表明该计算公式有效可行。(3)随初始水头增加,描述树状分叉网络的各级圆管分形参数长度比逐渐增加,且增加幅度越来越小;但是各级圆管的直径比和初级母管长度逐渐减小,并渐趋稳定,各级圆管直径比的稳定值为0.84。(4)影响导流孔收液率的根本因素是水力梯度,分析不同间距条件下,密集导流孔周水平和竖直方向水力梯度变化规律,综合考虑导流孔周水平与竖直方向水力梯度之比对收液率的影响,得出当水平-竖直水力梯度之比达到2.26时,收液率达到最大值为73.7%。
[Abstract]:At present, the theoretical study on the percolation law around the diversion hole is insufficient and the corresponding technical guidance is lacking, which leads to the arrangement of the diversion hole only by experience, which results in the partial leaching fluid being unable to be recovered, and at the same time, due to the leakage of the fissure, a considerable part of the leaching fluid is lost.The recovery rate of rare earth is low, which brings great harm and pollution to the life of mining area.Therefore, it is of great significance to study the percolation law around the diversion hole for calculating the recovery rate of in-situ leaching mother liquor.In this paper, in situ leaching laboratory model tests are used to analyze the percolation law around single and dense diversion holes.Firstly, the distribution of pore water pressure in the horizontal direction around a single diversion hole and the relationship between the liquid recovery rate of the diversion hole and the leakage amount of the bottom plate are used to analyze the percolation law around a single diversion hole; secondly, the fractal theory is used to analyze the percolation law around a single diversion hole.The fractal expression of pore water pressure distribution in horizontal direction around a single diversion pore is derived, and the fractal parameters are determined by fitting the measured pore water pressure distribution around a single diversion hole.Under different initial water head conditions, the distribution of pore water pressure in the horizontal direction around the dense diversion hole, the control process of the fluid recovery rate of the diversion hole and the variation of the hydraulic gradient in the horizontal and vertical direction of the orifice are analyzed to analyze the percolation law around the dense diversion hole.The effect of the ratio of horizontal and vertical hydraulic gradient on the recovery rate is considered synthetically, which provides a reference for the reasonable determination of pore spacing.The conclusion is as follows: (1) the distribution of pore water pressure in the horizontal direction around a single diversion pore is characterized by the formation of a roughly symmetrical drop funnel on both sides of the diversion hole, the lower pore water pressure near the diversion hole, and the higher pore water pressure far away from the diversion hole.The closer the pore water pressure is to the diversion hole, the faster the pressure decreases, and the closer it is to the diversion hole. The curvature of the bottom surface is very small and the water surface line is relatively smooth. The influence range of a single diversion hole is determined to be 22 cm. 2) according to fractal theory,Assuming that the channel of water entering the diversion hole along the horizontal direction is the universal two-bifurcation fractal tree network structure, based on the Hagen-Poiseuille equation, the expression of the fractal distribution of pore water pressure in the horizontal direction of a single diversion hole and the calculation method of its fractal parameters are presented.The indoor model tests show that the formula is effective and feasible. With the increase of the initial water head, the ratio of fractal parameter length to fractal parameters of the tree-like bifurcation network increases gradually, and the increasing amplitude is smaller and smaller.However, the diameter ratio and the primary length of the tube are gradually decreasing, and gradually stabilizing. The stable value of the diameter ratio of the different grades is 0.84.40)) the hydraulic gradient is the fundamental factor affecting the liquid recovery rate of the diversion hole, and the hydraulic gradient is analyzed under different spacing conditions.The variation of hydraulic gradient in the vertical and horizontal direction of the dense diversion hole is studied. Considering the influence of the ratio of the horizontal to the vertical hydraulic gradient, it is concluded that when the ratio of horizontal to vertical hydraulic gradient reaches 2.26,The maximum recovery rate was 73.7%.
【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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