真空条件下铋金属蒸气气相形核及冷凝实验研究

A Study on Vapor Phase Nucleation and Condensation of Bi Metal Vapor in Vacuum

随着铋应用范围的不断扩大,其需求量逐年递增,且因无毒不致癌的特性逐渐有取代铅、锑、汞等有毒金属的趋势.然而,铋行业规模小,冶炼及精炼技术水平低,装备落后,无法满足健康发展的要求.本文采用真空冷凝法,研究真空条件下铋金属蒸气的冷凝条件及形核规律.通过理论计算分析发现,当系统压力为1 Pa,温度为698. 4℃时,有利于铋的挥发及蒸气的冷凝,冷凝温度在500~700℃之间;结合理论计算开展蒸气冷凝实验研究,结果表明,在系统压强为1 Pa左右时,铋蒸气的冷凝温度区间为527. 3~753. 2℃,冷凝方式为滴状冷凝,冷凝过程为"非自发形核".

With the continuous expansion of the scope of application of bismuth,its demand has been increasing.In addition,bismuth tends to gradually replace toxic metals such as lead,antimony,and mercury due to its non-toxic and non-carcinogenic properties. However,the bismuth industry has a small scale,low level of smelting and refining technology,and backward equipment,which hinders its development. In this paper,the vacuum condensation method is used to study the condensation conditions and nucleation laws of bismuth metal vapor in vacuum. Through theoretical calculation and analysis,it is found that when the system pressure is 1 Pa and the temperature is 698. 4 ℃,it is conducive to the volatilization of bismuth and the condensation of vapor. The condensation temperature range is between 500 and 700 ℃. The theoretical study of vapor condensation is conducted. It is shown that when the system pressure is about 1 Pa,the condensation temperature range of bismuth vapor is 527. 3~ 753. 2 ℃. The condensation method is droplet condensation. The condensation process is "non-spontaneous nucleation".