金属锑真空提纯及高纯锑的制备研究

【作者】 黄占超；

【导师】 杨斌；

【作者基本信息】 昆明理工大学 ， 有色金属冶金， 2003， 硕士

【摘要】 我国是产锑大国，锑的储量居世界首位。但是我国除锑锭外，其它锑品的种类极少。许多国家进口我国的粗锑，经过深加工后又返销到我国，从中获得了巨额利润。因此，对粗锑进行深加工和发展锑品的种类对我国经济发展尤为必要。 随着高新技术的发展，高纯金属的用途越来越广，4N、5N、6N金属锑被得到了广泛应用并且具有很高的经济价值。但是由于生产工艺的限制，其产量很难提高，而且对工艺的各种控制环节有很高的技术要求。对此情况，本文提出了采用真空蒸馏的方法来制备4N以上的金属锑，并从理论上进行分析，通过实验进行研究得到了制取4N锑的工艺条件。 按照高纯锑的标准分析了原料中十四中杂质元素的含量。首先进行了真空蒸馏热力学分析，根据各种杂质与锑的沸点不同，可以初步判断锑可以和各种杂质进行分离。在此基础上对不同温度下锑和十四中杂质的纯物质饱和蒸气压进行比较，将锑中的杂质分为纯物质饱和蒸气压比锑高即比锑易蒸发的杂质和纯物质饱和蒸气压比锑低即比锑难蒸发的杂质。根据各自纯物质饱和蒸气压的不同，理论上分析可以将锑和其它杂质分离。判断锑能否与杂质进行分离的另外一种方法是利用锑及杂质形成的二元系分离系数β进行判断。以锑为主体金属，分析锑分别与十四种杂质形成的二元系分离系数、相图以及气液相平衡图，从中得到在真空蒸馏的条件下锑可以分别与十四种杂质分离。其次进行动力学分析，动力学中影响低沸点易蒸发杂质从锑中蒸发的环节有四个：杂质从锑液中向锑液表面扩散、锑液表面杂质的蒸发、杂质气体在真空炉内残余气体中的扩散及杂质气体的冷凝，对于主体金属锑影响其蒸发的是上面后三个环节。根据实验条件分析，影响低沸点杂质与锑分离程度的主要环节是杂质在锑液中的扩散。在分析真空蒸馏的同时将区域提纯进行了理论分析，证明利用区域提纯技术可以在真空提纯的基础上制备纯度更高的金属锑。 根据真空提纯热力学和动力学进行实验研究。首先通过内热式真空炉进行砷锑分离研究，经过三种不同方案的实验研究证明控制好一定的真空度和温度可以将砷锑分离。在此基础上进行公斤级外热式真空炉实验研究。此实验也采用三种方案：第一种是控制低真空度使砷及易蒸发杂质从金属锑中蒸发出来，使锑及难蒸发杂质残留，从而达到分离；第二种是将气体通入锑液中进行搅拌，促进砷及易蒸发杂质在锑液中的扩散及增大它们的蒸发量，让锑及难蒸发的杂质残留；第昆明理1一人学硕卜学位论文摘要三种是提高真空度使锑与砷及易蒸发的杂质同时蒸发，通过不同的冷凝温度分别将砷及易蒸发杂质与锑在冷凝段分离，而难蒸发杂质残留在柑锅里。从而通过一次真空蒸馏就可以将易蒸发、难蒸发杂质与锑分离，得到产品锑。实验研究表明第叹种方案可以达到实验目的，先升冷凝端温度并控制温度在773K，再升加热端温度并控制加热温度在923K一1023K，真空压力<ZOPa，就可以得到产品 4N金属锑。更多还原

【Abstract】 The yield of antimony ranks our country the first in the world. But the production of antimony is only a few except antimony ingot. Many foreign countries gain huge profit through importing Chinese crude antimony and selling to China again by further processing. So further processing crude antimony and developing new kinds of antimony are very necessary to Chinese economic development.With the development of high technology, the use of high purity metals are more and more wide, such as 4N, 5N, 6N antimony, which have high economic values. However, on account of the technological restriction of high purity antimony, the increase of high purity antimony yield is difficult. There are strictly technological requirements to domination process in the procedure. So a new method of preparing 4N antimony by vacuum distillation is brought forward in the dissertation. The theoretic analysis is done, and new technology of preparing 4N antimony is obtained through experiment study.According to the standard of high purity antimony, the content of fourteen impurities in the raw material is analysed. Firstly, the thermodynamics analysis is carried through. According to different boiling point, we can predict that the antimony can be separated from the impurities. Then the vapour pressures of pure substance of antimony and impurities are compared under different temperature. The impurities in the raw material are classified through vapour pressures of pure substance. One kind is more volatilizable than antimony, the other is much more difficult to evaporate than antimony. According to different vapour pressures of pure substance the antimony can be separated from the impurities. At the same time another criterion which can judge the feasibility to separate the antimony from the impurities, is separation coefficient . The antimony is looked as chief body, separation coefficient, phase diagram, and gas-liquid equilibrium composition diagram of antimony-based binary alloy are analysed. The results show that antimony can be separated from the impurities under vacuum condition, too. Secondly, the kinetics study is carried through. There are four restriction processes which influencethe impurities’ evaporation from the antimony. The first process is the impuritiesdiffusion from the inside of the liquid antimony to the surface. The second is the impurities’ evaporation on the liquid antimony surface. The third is the diffusion of impurities gas in the residual gas of vacuum furnace. The last is the condensation of impurities gas. According to the experiment condition, the impurities diffusion from the inside of liquid antimony to the surface is a main process, which greatly influences the separation between antimony and impurities. Then the zone refine is also discussed, and shows that zone refine can produce higher purity antimony on the basis of vacuum distillation.According to the thermodynamics and kinetics analysis of vacuum distillation, the experiment research is carried through. The first is separation of antimony and arsenic by inner-heating vacuum furnace. Three kinds of experiment show that the antimony can be separated from the arsenic under definite temperature and pressure. Then the kilogram level experiments are gone along by outer-heating vacuum furnace. Three methods are adopted. The first method is that it makes the arsenic and low boiling-point impurities evaporate from the liquid antimony, and make the antimony and high boiling-point impurities remain. The second method is that the gas is inflooded the liquid antimony in order to stir the liquid. It can accelerate the diffusion of arsenic and low boiling-point impurities in the liquid and increase the evaporation quantity, but the antimony and high boiling-point impurities would be remained. The third method makes the antimony, arsenic and low boiling-point impurities evaporate simultaneously by lowering the pressure in the vacuum furnace. The arsenic and low boiling-point impurities can be separated from the antimony by different condensat更多还原