Processing of spent molybdenum-bearing catalysts from petrochemical synthesis

Abstract

Technologies for processing spent molybdenum-bearing catalysts from petrochemical production are reviewed. The degree of molybdenum-trioxide extraction from the spent catalysts is presented for different technologies. Pyrometallurgical and hydrometallurgical methods, when used individually, do not ensure the required molybdenum-trioxide extraction. The pros and cons of direct alloying of steel with spent catalysts through the slag phase are outlined. The processing of hydrometallurgically treated catalysts to obtain slag mixtures for steel refining is described. An optimal multistage processing method for the catalysts is considered. By that means, waste-free processing of the spent catalysts is possible. On that basis, calcium molybdate may be used instead of ferroalloys for steel treatment in the ladle–furnace unit.