原地浸矿改变稀土矿石工程性质及诱发滑坡机理初步研究

发布时间：2018-03-07 06:43

本文选题：原地浸矿　切入点：离子型稀土矿床　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：离子型稀土矿床是我国独特的珍贵资源,然而它的开发利用却带来了严重的环境问题。现行的原地浸矿工艺虽然不同于已经淘汰的池浸、堆浸工艺,毋须进行“搬山”运动,较好地保护了植被,减少了水土流失,也提高了资源回收率,但取而代之的是边坡稳定性的问题。原地浸矿常常诱发滑坡灾害,直接影响矿山安全生产和经济效益,还可能毁坏农田,甚至造成人员伤亡和财产损失,因而引起社会的广泛关注。目前对原地浸矿诱发滑坡的机理虽有一定研究,而且大多认为原地浸矿造成边坡土体局部液体过饱和,改变了土体的物理力学性质,使其强度大大降低,是滑坡形成的主要原因。但前人对滑坡成因的分析,往往是在矿山现场观察的基础上进行一般性推理分析,对浸矿过程是否以及如何改变稀土矿石的物理力学性质,最终导致滑坡,缺少实验研究资料的支撑。论文以原地浸矿已经诱发多处滑坡的赣南乡标稀土矿为研究对象,在野外地质调查的基础上,从原地浸矿采场1#滑坡的新鲜滑动面上,采用掏洞的方式,按2m深度间距,在采取了一组尾矿样品,在距离该滑坡直线距离不足100m处采取了稀土原矿样品。样品在阳光下放置数日直至风干后,进行了化学成分、矿物成分、粒度成分、密度、液限、塑限、膨胀性、力学性质等主要工程性质试验研究。研究表明尾矿样品与原矿样品相比,化学成分、矿物成分、粒度分布、结构以及力学性质等各项工程性质均发生了显著改变。分析认为浸矿过程中强烈的化学反应改变了稀土矿石的结构,导致浸矿后稀土矿石强度大大降低。研究发现,尾矿样品颗粒粒度分布随深度呈现出明显的变化规律,并清楚地表明粒径介于3~0.031mm颗粒向深部发生了大量迁移,并造成了孔隙阻塞。据此分析,是由于孔隙阻塞引起局部矿体中土体接近饱和,进一步降低了稀土矿石的强度,从而诱发了1#滑坡。
[Abstract]:The ion rare earth deposit is a unique precious resource in China, but its exploitation and utilization have brought serious environmental problems. Although the present in-situ leaching process is different from the eliminated pool leaching and heap leaching technology, there is no need to carry out the "mountain moving" movement. Better protection of vegetation, reduction of soil and water loss, and improvement of recovery rate of resources are replaced by the problem of slope stability. In situ leaching often induces landslide disasters, which directly affect mine safety and economic benefits. It may also destroy farmland and even cause casualties and property losses, which has caused widespread concern in society. Although there is some research on the mechanism of in-situ leaching induced landslides, Most of them think that the in-situ leaching causes the local liquid supersaturation of the slope soil, which changes the physical and mechanical properties of the soil, greatly reduces the strength of the soil, and is the main reason for the formation of the landslide. On the basis of mine site observation, general reasoning analysis is often carried out to determine whether and how to change the physical and mechanical properties of rare earth ores during the leaching process, which eventually leads to landslides. The paper takes Gannan standard rare earth deposit which has already induced many landslides in situ leaching as the research object, on the basis of field geological investigation, from the fresh sliding surface of the in situ leaching pit 1# landslide. A group of tailings samples were taken according to the distance of 2m depth, and rare earth raw ore samples were taken at a distance of less than 100 m from the landslide. The samples were placed in the sun for a few days until the air dried, and the chemical composition was carried out. The main engineering properties, such as mineral composition, particle size composition, density, liquid limit, plastic limit, swelling property, mechanical property and so on, are studied. The results show that the chemical composition, mineral composition and particle size distribution of the tailings sample are different from those of the raw ore sample. The structure and mechanical properties of rare earth ores have been changed remarkably. It is considered that the strong chemical reactions during the leaching process have changed the structure of rare earth ores, resulting in a great decrease in the strength of rare earth ores after leaching. The particle size distribution of tailings shows obvious variation with depth, and clearly indicates that the particle size is between 30.031mm and 30.031mm, which leads to pore blockage. It is due to pore blockage that the soil mass in the orebody is nearly saturated which further reduces the strength of the rare earth ore and thus induces the 1# landslide.
【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】：TD854.6;P642.22

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