METHOD FOR ROASTING OF MOLYBDENUM CONCENTRATE AND MIDDLINGS Russian patent published in 1998 - IPC

FIELD: metallurgy of rare metals; technology of roasting of molybdenum concentrate and middlings. SUBSTANCE: air is supplied to charging zone of furnace in space above material, i.e. to top part of charging zone. Air is discharged through tuyere belt located in the lower part of charging zone. In furnace charging zone provision is made of gas and material motion in the same direction. Temperature of effluent gases is not less than 600-700 C. Gas filtration through layer of hot material provides for complete combustion of organic substances with partial oxidation of molybdenite. Full oxidation of molybdenite and high degree of driving-off of rhenium and osmium into gas phase are ensured in the lower part of furnace operated under standard conditions. EFFECT: higher efficiency; provision of full combustion of organic matter and higher degree of recovery of osmium and rhenium. 2 cl