Based on the purification theory of zone refining

tellurium was purified for 16 zone passes by self-prepared zone refining furnace.The results show that under protection of high pure nitrogen

with the output power of induction coil of 13.0

12.5and 11.5kW

respectively

and the zone movable speed of 1.5

2

.0mm·min-1 as well as zone length of 25

5

0mm

the impurities content is reduced from1.41×10-2%to 2.8×10-4%.The contents of eleven kinds of impurities are reduced sharply

and compared with each original content

it can be decreased by 3orders of magnitude at most and 1order at least

respectively.Finally

the purity of tellurium reaches from 4Nto 6N.