減圧アーク加熱を用いたAl-1.2%Zn合金溶湯からの亜鉛の除去

抄録

  A technique to remove zinc from aluminum alloy melts using vacuum arc heating was investigated. Zinc removal treatments for 4.6 kg of Al-1.2%Zn melt were carried out using a prototype zinc removal/recovery device which has a low-vacuum heating chamber for rapidly heating melt by arc discharge and a high-vacuum recovery chamber for promoting zinc evaporation. Melt temperature increased rapidly when the pressure of heating chamber was controlled at 600 Pa. In the heating chamber, zinc and aluminum evaporated perhaps due to the high-temperature of the arc discharge. Effective zinc removal in the recovery chamber occurred by controlling the pressure less than 60 Pa. Argon gas injection into the melt in the recovery chamber enhanced the zinc removal efficiency. Zinc concentration after the zinc removal treatment with the argon gas injection was about 0.02%.