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综述了目前氧化铝碳热还原法及碳热还原-卤化法炼铝的研究进展,重点总结了上述炼铝法的机理及研究现状,讨论了金属铝的制备方法及其影响因素,并指出了制约上述各炼铝法金属铝直收率提高的影响因素。结果表明:常压及真空直接碳热还原法炼铝过程,由于氧化铝碳热还原过程生成的碳化铝,导致碳化铝、氧化铝和金属铝三元系在高温下相互熔解,以致气相不能分离,致使铝的提取率较低,且难以与渣相分离。真空碳热还原-硫化法炼铝存在低价硫化铝歧解得到的产物金属铝与硫化铝(Al2S3)的分离困难,且硫化铝易吸水潮解,生成剧毒物质H2S,造成环境污染;真空碳热还原-氯化法炼铝,虽产物金属铝与冷凝物氯化铝易于分离,但该法存在氯化铝对设备的腐蚀及含六个结晶水的氯化铝脱水处理问题,若能克服上述问题,则该过程就存在连续化作业的可能;而真空碳热还原-氟化法炼铝过程存在机理研究不清及炉型结构设计不合理,从而导致产物金属铝的直收率不高。
The current research progress of alumina carbothermal reduction method and carbothermal reduction-halogenation method is summarized. The mechanism and research status of the above-mentioned aluminum precipitation method are summarized. The preparation methods of aluminum and its influencing factors are also discussed. Restricting the above aluminum refining aluminum straight-line yield factors. The results show that the aluminum carbides, aluminum oxides and metallic aluminum ternary systems are melted at high temperature by atmospheric pressure and vacuum direct carbothermal reduction process, and the gas phase can not be separated due to the formation of aluminum carbide by carbothermal reduction of alumina , Resulting in a lower extraction rate of aluminum and difficult to separate from the slag phase. Aluminum carbides and aluminum sulphide (Al2S3) are difficult to separate due to the low-price aluminum sulphide disintegration in vacuum carbothermal reduction-sulphurization process, and aluminum sulphide is easy to absorb water and deliquesce to generate highly toxic substance H2S, resulting in environmental pollution. Vacuum carbon Thermal reduction - aluminum chloride process, although the product of aluminum and aluminum chloride condensate easily separated, but the existence of the law of corrosion of aluminum chloride and equipment containing six water crystallization of aluminum chloride dehydration problems, if we can overcome The above problems, then the process there is the possibility of continuous operation; and vacuum carbothermal reduction - fluorination aluminum refining process is not clear mechanism and the unreasonable design of the furnace structure, resulting in the product straight aluminum aluminum yield is not high .