论文部分内容阅读
用固体吸附法提取超纯SiCl_4,同用石英精馏塔提纯SiCl_4,其原理是不相同的.从原理上讲,精馏法是靠SiCl_4与各种杂质氯化物的沸点不同来实现分离的.先将低沸点的氯化物放掉,再将SiCl_4逐步精馏出来,最后留下的是高沸点.此种方法,对于去除非极性的重金属氯化物,效果是显著的.但是,它对去除极性杂质氯化物,却表现了较大的局限性.例如,它对去除PCl_3、BCl_3、FeCl_3等杂质氯化物,就是比较困难的.原因是,这类极性杂质氯化物有可能形成络合物,它们的挥发度又是同SiCl_4接近的,即使再精馏多次也不能达到理想的效果.
The solid adsorption method for the extraction of ultra-pure SiCl_4, with the use of quartz distillation column purification SiCl_4, the principle is not the same .From the principle, the distillation method is based on SiCl_4 and various impurity chlorides boiling point to achieve separation. The first low-boiling point chloride released, and then SiCl_4 step by step out, leaving the final high-boiling point.This method for the removal of non-polar heavy metal chloride, the effect is significant.However, its removal For example, it is more difficult to remove chloride such as PCl_3, BCl_3 and FeCl_3 because the polar impurities such as chloride may form a complex Their volatility is again close to that of SiCl 4, which can not achieve the desired result even if the distillation is repeated several times.