Tian Y.,National Engineering Laboratory for Vacuum Metallurgy |
Tian Y.,Kunming University of Science and Technology |
Tian Y.,State Key Laboratory Breeding Base of Complex Non ferrous Metal Resources Clear Utilization in Yunna |
Yang B.,National Engineering Laboratory for Vacuum Metallurgy |
And 15 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2013
The behavior of MgO in Mg extraction by carbothermic reduction in vacuum was studied in thermodynamic theory. The impacts of reduction conditions, including the pressure and temperature, on the reaction pathway and reduction temperature were theoretically calculated and experimentally evaluated. The condensate and slag were characterized with X-ray diffraction. The calculated results show that the MgO reduction with carbon easily occurs in vacuum, and the reduction temperature drops down with a decreasing pressure. At a pressure ranging from 30 Pa to 100 Pa, the main reaction MgO (s) +C (s) =Mg (g) +CO (g) starts at 1573 K; and the indirect reaction MgO (s) +CO (g) =Mg (g) +CO2 (g) never occurs. The experimental results reveal that at 1553 K and a pressure of 30~100 Pa, metallic Mg coexists with carbon and un-reacted MgO in the C-coated condensate, possibly because of the reverse reaction, Mg (g) +CO (g) =MgO (s) +C (s). No magnesium carbides were observed in the slag.