摘要
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 latest development in aluminum production by alumina carbothermic reduction and by carbothermic halite in vacuum was tentatively reviewed.The discussion centered on the mechanisms responsible for the Al extraction,and the major limitations of the vacuum Al extraction technologies.In the case of Al extraction in air or in vacuum by alumina carbothermic reduction,the formation of Al3C4 at high temperature resulted in a molten mixture of Al3C4-Al2O3-Al,leading to a very low Al extraction rate in gaseous phase from the slag.In Al extraction by carbothermic-sulfide,it is rather difficult to separate Al from Al2S3,and Al2S3produces poisonous H2S after water absorption.Although it is fairly easy to extract Al from condensed AlCl3 by carbothermic-chloride,serious AlCl3 corrosion of the vacuum furnace and dewatering of AlCl3-6H2O remain to be big challenges.We suggest that Al yield may be considerably increased by fully understanding the possible mechanisms of Al extraction in carbothermic-chloride technique and by optimizing the vacuum furnace design.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2011年第6期765-774,共10页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金重点资助项目(u0837604)
高等学校博士学科点专项科研基金(20095314110003)
关键词
真空
碳热还原
碳热还原-卤化
炼铝
Vacuum
Carbothermic reduction
Carbothermic-halide
Aluminum production
