离子型稀土矿浸出前后工艺矿物学研究

Technological Mineralogy of Ion-Type Rare Earth Ore before and after Leaching

为了研究离子型稀土矿浸出前后的工艺矿物学,以柱浸实验为基础,通过X射线衍射仪(XRD),矿物解离分析仪(MLA),傅利叶交换-红外分析仪(FT-IR), X射线荧光分析仪(XPS),扫描电镜(SEM)等多种测量手段对稀土原矿与浸出尾矿的表面组成和结构进行对比分析。研究结果表明:离子型稀土矿主要由高岭石、钾长石、石英、金云母、褐铁矿等矿物组成,稀土含量仅含0.12%左右;浸出过后Al, RE, Fe, O元素相对含量下降, K, Si元素含量相对上升; Al减少的主要原因是高岭石、褐铁矿、金云母等矿物与浸出剂发生溶解反应造成的,浸出后矿体结构遭到破坏; Fe减少的主要原因是部分氧化铁胶体被溶解以及浸出过后离子型稀土矿中的水合铁离子进入到了溶液中。钾长石、石英等矿物在浸出过程中基本不参与反应;元素N在稀土原矿中主要以有机物的形式存在,浸出后稀土矿中发生了离子交换反应,大量N元素以-NH_2键存在于尾矿中,有机态N大量减少,有机态N的减少会破坏矿体的胶结体结构,使矿体中团聚体的稳定性降低,进而使矿体的整体稳定性下降。Al, Fe等元素随着矿体的部分溶解而进入到溶液中,使浸出液含有杂质。本实验进一步完善了稀土浸出理论,并为稀土浸出以及矿山防护提供了理论依据。

In order to study the process mineralogy of ionic rare earth ore, the surface composition and structure of ionic rare earth ore before and after leaching were investigated using column leaching and different experimental techniques, such as X-ray diffraction(XRD), mineral liberation analyzer(MLA), infrared spectroscopy(FT-IR), and X-ray photoelectron spectroscopy(XPS). The results showed that the ionic rare earth ore was mainly composed by kaolinite, orthoclase, quartz, limonite and some other minerals, and the content of rare earth was about 0.12%. The relative content of Al, RE, Fe and O decreased after leaching, while some elements such as K and Si had a increase in their relative content. The main reason of the decrease of Al was due to the dissolution reaction between minerals such as kaolinite, limonite and leaching agent, and thus the structure of the ore body was partially destroyed after the leaching. The reason for Fe decrease was that part of the iron oxide colloid was dissolved and the hydrated iron ions in the ionic rare earth ore were leached into the solution after the leaching. Minerals such as orthoclase and quartz did not participate in the reaction during the leaching process. Elemental N existed mainly in the form of organic matter in the rare earth ores. After leaching, ion exchange reaction took place in the rare earth ores. A large amount of N was present in the tailings with-NH2 bonds, and the amount of organic N was greatly reduced. The reduction of the organic N destroyed the structure of the cemented body of the ore, which reduced the stability of the aggregates in the ore and further reduced the overall stability of the ore body. The partially dissolution of the ore made Al, Fe and other element into the solution, which made the leachate contain impurities. This experiment further perfected the theory of rare earth leaching, and provided theoretical basis for rare earth leaching and mine protection.