Removal of Tellurium out of Molten Iron

Abstract

The co-existence of a small amount of tellurium seems to improve deoxidation of steel with aluminum.The practical realization requires a subsequent treatment upon which the residual tellurium must be removed out of steel. The three experimental examinations led to the following conclusions:
1) Ar stream can fast rid molten iron of tellurium. 40%-50% of tellurium was taken away for 20 min. under the present experimental conditions. The rate satisfies the general kinetic equation for vaporization of alloying elements.
2) Rare earth metal is the most suitable substance to be added for the present aim, i. e. the removal of tellurium at low oxygen potential.
3) A flux of CaF₂-CaCN₂ mixture is applicable instead of expensive REM. The mixture with a composition ratio of 1:1 succeeded in reducing the residual concentration of tellurium to about 20 ppm (rd. 90% reduction of tellurium) during 20 min. treatment with little change in the concentrations of oxygen, carbon and nitrogen in the melt.