Reduction characteristics of molybdenum trioxide with aluminum and silicon

• Published in: Rare metals Vol. 37; no. 7; pp. 621 - 624
• Main Authors: Zhu, Hang-Yu, Gao, Rong, Jin, Wu-Tao, Qiu, Long-Wu, Xue, Zheng-Liang
• Format: Journal Article
• Language: English
• Published: Beijing Nonferrous Metals Society of China 01.07.2018; Springer Nature B.V
• Subjects: Aluminum; Biomaterials; Calcium carbonate; Chemical reduction; Chemistry and Materials Science; Energy; Intermetallic compounds; Materials Engineering; Materials Science; Metallic Materials; Molybdenum; Molybdenum disilicides; Molybdenum oxides; Molybdenum trioxide; Nanoscale Science and Technology; Physical Chemistry; Reduction (metal working); Silicon; Sublimation; X-ray diffraction; Molybdenum trioxide; Reduction; Silicon; Aluminum; Metallothermic
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-015-0536-z

Thermodynamics for reduction of molybdenum oxides by aluminum and silicon were calculated, and the results show that reduction reaction is feasible at a certain temperature region. Compared to the presence of CaO or CaCO 3 , reduction products of molybdenum trioxide with aluminum and silicon at various temperatures were detected by X-ray diffraction (XRD). Results show that molybdenum trioxide is reduced by aluminum or silicon step by step, and the intermediate product is MoO 2 . At 1000 °C, molybdenum trioxide could be reduced to metal Mo by aluminum, and in the presence of CaO, metal Mo as the reduction product appears even at 800 °C. In contrast, silicon could barely reduce molybdenum trioxide to metal Mo even at 1200 °C. In the presence of CaO or CaCO 3 , reducibility of silicon increases significantly, and the reduction products are metal Mo and MoSi 2 . Altogether, CaO or CaCO 3 performs two major roles in reduction process: restraining sublimation of MoO 3 and decreasing the temperature of reducing MoO 3 to metal Mo.