Purification of tellurium by single-run multiple vacuum distillation technique

摘要

5N5(99.9995%)purity Te was achieved by multiple distillation technique under a dynamic vacuum of approx5 X 10~(-3)Torr using an exploratory setup made of quartz tube.The impurity analysis of the purified Te done by an inductively coupled plasma optical emission spectrometry(ICP-OES)confirmed the reduction of total impurity content from 87 to 4 ppm upon three successive distillations in a single experimental run.Major trace impurities in tellurium such as Al,Ag,Pb,Cu,Bi,Ni,Fe,Mn and Mg were reduced effectively.The analysis results are discussed with reference to vapour pressures(p_v)of impurities.The evaporation rate(W_e)and mean free path(A)are calculated under experimental conditions of vacuum level,distillation temperature(T)and system dimensions.