德昌尾矿稀土资源回收利用研究及新型羟肟酸类捕收剂的合成

发布时间：2018-09-01 13:33

【摘要】：稀土元素是在新能源、新材料和尖端科技等领域应用日益广泛,具有“工业味精”的美誉,是不可再生的重要战略资源。受技术水平和生产条件的限制,稀土矿回收技术指标较低。尾矿中还有许多稀土矿物没有得到回收。这些尾矿的流失,既造成资源的浪费,又构成了污染矿山外部环境的隐患。随着德昌稀土大规模生产不断进行,对尾矿进行二次开发利用其中的多种有价元素,可产生极为可观的经济效益和社会效益。本文以研究德昌大陆槽稀土尾矿中的稀土回收方案和新型羟肟酸类捕收剂的合成为主要研究内容。详细的研究了尾矿的性质,考察了磨矿工艺条件,并进行了稀土尾矿浮选试验。主要结果如下:经尾矿筛分分析可知:稀土尾矿试样中47.6%的矿物粒度大于100目,78.02%的矿物粒度大于200目。通过XRD衍射组分分析:尾矿中的主要稀土矿物为氟碳铈矿,脉石矿物主要为石英、长石、方解石、萤石、石膏、天青石和伊利石,少量的重晶石、方铅矿等其它矿物。4,4-二羟基联苯与干冰、三氯苯制备4,4-二羟基-3,3-联苯二甲酸,产率55.07%;向盐酸羟胺的氢氧化钠溶液中滴加4,4-二羟基-3,3-联苯二甲酸二甲酯溶液,得目标产物4,4-二羟基-3,3-联苯二甲羟肟酸,产率49.66%。采用核磁共振、红外光谱、质谱、元素分析对目标产物的结构进行了表征,确定合成了目标产物。3-羟基-2-萘甲酸甲酯和盐酸羟胺的氢氧化钠溶液可制备H205,产率74%,并采用核磁共振氢谱对目标产物的结构进行了表征,确定合成了目标产物。在磨矿条件试验中主要考察的因素为:磨矿时间、矿浆浓度、助磨剂种类及用量。通过试验得出:最佳磨矿时间为10 min,适宜矿浆浓度为70%;助磨剂添加量依次为:1.25 kg/t、1.05 kg/t、0.75 kg/t、0.75 kg/t;-200目粒级含量分别增加了12.25%、6.5%、5%、4.75%。其中,六偏磷酸钠的助磨效果最好。在助磨剂对稀土尾矿浮选影响的试验中,硅酸钠添加量为0.75 kg/t时,精矿中的Ce O2品位较清水选矿时提高了0.82%,其它助磨剂皆有不良影响。通过抑制剂、活化剂种类和用量试验;测定稀土精矿的Ce O2含量和稀土回收率,并通过XRD衍射半定量分析了浮选精矿的矿物组分。试验结果显示:硅酸钠、碳酸钠、氯化铵、氟化钠的最佳添加量分别为1000 g/t、500 g/t、500 g/t、300 g/t,Ce O2品位分别为8.52%、5.25%、5.09%、5.62%、,回收率分别为54.90%、80.11%、91.97%、85.54%。在捕收剂种类及用量对浮选效果影响的试验中,三种捕收剂的捕收能力为:3-羟基-2-萘甲羟肟酸4,4-二羟基-3,3-联苯二甲羟肟酸水杨羟肟酸;选择性为:羟肟酸4,4-二羟基-3,3-联苯二甲羟肟酸3-羟基-2-萘甲羟肟酸。精选试验中,以水杨羟肟酸为捕收剂,硅酸钠、碳酸钠、氯化铵、氟化钠为调整剂,矿浆p H=9,通过一次粗选、两次精选可得到Ce O2品位为31.47%的合格稀土精矿。
[Abstract]:Rare earth elements are widely used in the fields of new energy, new materials and cutting-edge science and technology, and have the reputation of "industrial monosodium glutamate", which is an important non-renewable strategic resource. The technical index of rare earth ore recovery is low due to the limitation of technical level and production conditions. There are also many rare earth minerals in the tailings that have not been recovered. The loss of these tailings not only causes the waste of resources, but also constitutes the hidden trouble of polluting the external environment of mines. With the continuous large-scale production of rare earths in Dechang, the secondary development and utilization of various valuable elements in tailings can bring about considerable economic and social benefits. In this paper, the scheme of rare earth recovery and the synthesis of new hydroxamic acid collector in rare earth tailings of Dechang continental trough are studied. The properties of tailings were studied in detail, the grinding process conditions were investigated, and the flotation tests of rare earth tailings were carried out. The main results are as follows: according to the analysis of tailings, the mineral particle size of 47.6% of rare earth tailings is more than 100 mesh and 78.02% is more than 200 mesh. The main rare earth minerals in the tailings are fluorocarbon cerium, the gangue minerals are quartz, feldspar, calcite, fluorite, gypsum, celadite and Illite, and a small amount of barite. Galena and other minerals, such as galena, 4-dihydroxy biphenyl and dry ice, trichlorobenzene is used to prepare 4- 4- dihydroxy-3-, 3-biphenyl dicarboxylic acid in the yield of 55.070.The sodium hydroxide solution of hydroxylamine hydrochloride is added to the solution of dimethyl biphenyl dimethyl 4-dihydroxy-3-tetrachloroic acid by dripping into the sodium hydroxide solution of hydroxylamine hydrochloride. The target product 4o 4-dihydroxy-3 o-3-biphenyl dimethyl hydroxamic acid was obtained in 49.66% yield. The structure of the target product was characterized by NMR, IR, MS and elemental analysis. H205 was prepared in the solution of sodium hydroxide of methyl 3-hydroxy-2-naphthyl formate and hydroxylamine hydrochloride. The structure of the target product was characterized by nuclear magnetic resonance spectroscopy (NMR), and the target product was synthesized. The main factors investigated in grinding condition test are grinding time, pulp concentration, type and amount of grinding aids. The results show that the optimum grinding time is 10 min, the optimum pulp concentration is 70 and the content of grinding aids is increased by 12.25% 1.25 kg/t,1.05 kg/t,0.75 kg/t;-200 and 4.75% respectively. Among them, sodium hexametaphosphate is the best grinding aid. In the experiment of the effect of grinding aids on the flotation of rare earth tailings, when the amount of sodium silicate was 0.75 kg/t, the grade of Ce O 2 in the concentrate increased by 0.82%, and the other grinding aids had a bad effect. The content of Ce O 2 and the recovery rate of rare earth in rare earth concentrate were determined by depressant, activator type and dosage test, and the mineral components of flotation concentrate were semi-quantitatively analyzed by XRD diffraction. The results show that the optimum addition amount of sodium silicate, sodium carbonate, ammonium chloride and sodium fluoride is 1000 g / t ~ (500) g / t ~ (3) ~ (3) g / t ~ (3) C ~ (2) and 5.09 ~ 5.25 ~ (5.25) ~ (5.25) ~ (5.62) O _ 2, respectively, and the recovery rate is 54.9080.11 ~ 91.97% ~ 85.54, respectively. In the experiment of the effect of collector type and dosage on the flotation effect, the collecting ability of the three kinds of collectors was as follows: 1. 3 hydroxyl-2-naphthyl hydroxamic acid 4-4-dihydroxy-3-biphenyl-dihydroxamic acid-salicylhydroxamic acid; The selectivity of hydroxamic acid was 4- dihydroxy-3-biphenyl-dimethoxime acid, 3-hydroxy-2-naphthyl hydroxamic acid. In the cleaning test, using salicylhydroxamic acid as collector, sodium silicate, sodium carbonate, ammonium chloride and sodium fluoride as adjuvant, pulp pH _ (9) can be obtained by one rough separation and two times cleaning. The qualified rare earth concentrate with Ce O _ 2 grade of 31.47% can be obtained.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD923

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