南方离子型稀土尾砂的高岭土分选研究

发布时间：2018-04-04 18:20

本文选题：离子型稀土尾砂　切入点：分选　出处：《景德镇陶瓷学院》2015年硕士论文

【摘要】：经过三十多年的开采,我国南方离子型稀土尾砂堆积成山,造成了严重的生态环境问题,因此稀土尾砂的有效利用具有十分重要的意义。本文以江西赣南某离子型稀土尾砂为研究对象,进行系统的矿物特性分析,探讨该尾砂分选出高岭土的可行性并进行了选矿试验研究,并对稀土尾砂进行漂白除铁工艺进行研究,成功从南方离子型稀土尾砂中分选出了符合陶瓷工业TC-3标准的高岭土。对稀土尾砂进行系统的矿物特性分析。采用化学成分分析测定稀土尾砂的化学成分；采用X射线衍射分析和MLA工艺矿物学分析测定尾砂的矿物组成和主要矿物的赋存状态；采用筛分分级得出尾砂在不同粒度下的粒径分布,并且对部分粒级采取差热分析和扫描电子显微形貌分析。得出以下结论：尾砂的主要化学组成为：SiO272.13%、Al2O317.69%、Fe2O31.93%、TiO20.33%。主要矿物为石英、高岭石、长石、黑云母和白云母,含铁矿物组要为钛磁铁矿、褐铁矿、黄铁矿、钛铁矿。尾砂中高岭石呈鳞片状微晶集合体；石英粒度粗细不等；磁铁矿呈粒状,粒度变化较大；多数褐铁矿呈粉尘状分布于高岭石中；钛铁矿呈粒状,粒度较微细。差热分析结果表明尾砂中主要成分为石英,高岭石含量较少。SEM结果表明粗颗粒(+0.45mm)尾砂为石英,随着粒级的减少,呈现粒状团聚体,-10um粒级呈2um左右片状及少量针管状,其主要矿物为高岭石。对稀土尾砂进行重、磁选试验考察稀土尾砂的分选可行性并且确定其分选工艺流程。采用摇床对尾砂进行重选分离试验,结果表明通过重选可以将尾砂中的高岭石和石英分离；采用高梯度磁选机对尾砂进行磁选试验,尾砂中的含铁矿物在磁场强度为0.6T时可以有效除去,除铁率达45.08%。通过摇床、高梯度磁选的试验结果确定工艺流程采用“一粗两精”分选工艺,粗选采用螺旋溜槽,一次精选采用050水力旋流器,二次精选采用025水力旋流器,水力旋流器得到的产品通过高梯度磁选机进行磁选。分选出了A1203品位29.32%、Fe203品位0.84%、Ti02品位0.06%的高岭土,产率为20.56%,A1203回收率为38.14%。采用还原—络合法对-325目的稀土尾砂进行除铁漂白,讨论了pH、反应温度、保险粉用量、漂白时间、加药次数、草酸用量等工艺条件对稀土尾砂除铁漂白效果的影响,结果得出在漂白除铁工艺条件为：pH值为3、反应温度50℃、保险粉用量3%、反应时间60min、加药次数4次、草酸2.5%时,Fe203含量从2.11%降低到1.43%,白度从57.7提高至72.3。
[Abstract]:After more than 30 years of exploitation, the ion type rare earth tailings have accumulated into mountains in southern China, which has caused serious ecological environmental problems. Therefore, the effective utilization of rare earth tailings is of great significance.In this paper, an ionic rare earth tailings in south Jiangxi Province are taken as the research object, the mineral characteristics of the tailings are analyzed systematically, the feasibility of separating kaolin from the tailings is discussed, and the ore dressing experiments are carried out.The bleaching and iron removal process of rare earth tailings was studied, and kaolin conforming to the TC-3 standard of ceramic industry was successfully separated from the southern ionized rare earth tailings.The mineral characteristics of rare earth tailings were systematically analyzed.The chemical composition of rare earth tailings was determined by chemical composition analysis, the mineral composition and the occurrence state of main minerals were determined by X-ray diffraction analysis and MLA process mineralogical analysis.The particle size distribution of tailings under different particle sizes was obtained by sieving and classifying, and the differential thermal analysis and scanning electron microscopy (SEM) were used to analyze some of them.The main chemical composition of the tailings is: 1% SiO272.13) Al _ 2O _ 3 17.69 and Fe _ 2O _ (31.93) and TiO _ (20.33).The main minerals are quartz, kaolinite, feldspar, biotite and Muscovite. The iron-bearing minerals are ilmenite, limonite, pyrite and ilmenite.Kaolinite in tailings is a scale-like microcrystalline aggregate; quartz is of different grain size; magnetite is granulated and its particle size varies greatly; most limonite is distributed in kaolinite as dust; ilmenite is granular with fine particle size.The results of differential thermal analysis show that the main component in the tailings is quartz, and the content of kaolinite is less. The results show that the coarse grain (0.45mm) tailings are quartz. With the decrease of grain size, the grain size of granular aggregates is about 2um flake and a small amount of needle-tube, and the content of kaolinite is less than that of kaolinite.Its main mineral is kaolinite.The separation feasibility of rare earth tailings was investigated by gravity and magnetic separation tests and the separation process was determined.The results show that the kaolinite and quartz in tailings can be separated by gravity separation, and the high gradient magnetic separator is used to separate tailings.The iron bearing minerals in the tailings can be effectively removed when the magnetic field intensity is 0.6 T, and the iron removal rate is up to 45.08.Through the test results of shaking bed and high gradient magnetic separation, the process flow is determined to be "one thick and two fine" separation process, the coarse selection is made of spiral chute, the first cleaning is 050 hydrocyclone, the second cleaning is 025 hydrocyclone,Hydrocyclone products through high gradient magnetic separator for magnetic separation.The kaolin with a grade of 29.32 and 0.84% Ti02 and 0.06% of grade A1203 was selected and the recovery rate of A1203 was 20.56% and the recovery rate was 38.14%.The effect of pH, reaction temperature, dosage of insurance powder, bleaching time, times of adding drugs and amount of oxalic acid on the bleaching effect of rare earth tailings on iron removal was discussed by using reduction-complexation method to remove iron from the tailings of rare earths, such as pH, reaction temperature, dosage of insurance powder, bleaching time, dosage of oxalic acid and so on.
【学位授予单位】：景德镇陶瓷学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD926.4

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