|
Vol.54, No.2, 104 ~ 113, 2016
|
| Title |
| Study of the Thermal Reduction Behavior of Dolomite by the Pidgeon process |
| 백의현 Ui Hyun Baek , 이병덕 Byeong Deok Lee , 이기우 Ki Woo Lee , 한길수 Gil Soo Han , 한정환 Jeong Whan Han |
|
|
|
| Abstract |
| This study examined methods to increase the production of Mg crown and minimize the amounts of solid impurities using the thermodynamic commercial package Factsage. A thermodynamic calculation was carried out to predict the degree of reduction of Mg vapor depending on the operating parameters through a single-stage calculation method involving the use of the CaO/MgO molar ratio, ferrosilicon/ dolime mass ratio and the pressure and temperature during the Pidgeon process. The results indicate that the CaO/MgO molar ratio was 1.4~1.5 to increase the degree of the reduction of Mg vapor in a non- equilibrium state. The thermodynamic calculations were designed to examine the effect the ferrosilicon had on specific ferrosilicon/dolime ratios. A good effect was observed between 25 and 30%. Moreover, it was determined that the optimum operating conditions which offer a high purity level of magnesium and reduce the degree of vapor was the case 5 (1200 ℃, 0.1 ~ 0.01 torr). In addition, the distribution of solid impurities in the Mg crown was calculated by a multi-stage calculation method while decreasing the temperature. Solid impurities existed as compounds in the Mg crown depending on the condensation temperature range in retort. The compound was composed of Mg2Si under 700 ℃ and CaAl2 under 500 ℃, also FeAl3, MnB under 400 ℃. A comparison of the thermodynamic calculations and experimental results regarding the types of impurities were in good agreement.(Received July 2, 2015) |
|
|
| Key Words |
| Mg crown, intermetallics, solidification, recovery, computer simulation |
|
|
 |
|
