硫化亜鉛のカーボン還元

抄録

The direct reduction of ZnS by C and CaO and catalystic effect of Na₂CO₃, Na₂SO₄ and Fe₂O₃ were studied by the thermogravimetry and measurement of the generated CO and CO₂ in the temperature range 900-1100°C. The mechanism of the direct reduction was investigated by thermodynamic data and characterizing the residues at various conditions of the direct reduction by x-Ray diffraction and XMA.
The overall reaction of direct reduction is represented by the equation (1).
ZnS+CaO+C=ZnO+CaS+CO...(1)
It is conside-red that the equation (1) is divided into the following three elementary reactions and the equation (2) is the ratedetermining reaction of direct reduction.
ZnS+CaO=ZnO+CaS...(2)
ZnO+C=Zn+CO...(3)
ZnO+CO=Zn+CO₂...(4)
The small amount of addition of Na₂CO₃, Na₂SO₄ and Fe₂O₃ (about 1 wt%) to samples of direct reduction is very effective for activating the direct reduction due to accelerating the equation (2).