精密分馏

1.precisionfractionaldistillation  

精的英语翻译：

essence; extractive; perfect; refined; skilled; spirit
【医】 anima

密的英语翻译：

close; dense; intimate; meticulous; secret; thick

分馏的英语翻译：

【化】 fractional distillation; fractionation; fractionation by distillation
selective evaporation