The invention discloses a method for extracting
molybdenum,
nickel,
vanadium and ferrum from polymetallic black-shale paragentic minerals, comprising the following steps of: ball-milling the polymetallic black-shale paragentic minerals, and then adding into a pressure kettle for
oxygen pressure leaching to obtain leach liquor containing
ferrous sulphate,
molybdenum trisulfate acyl, vanadic acid and
nickel sulfate and leach residues containing
molybdic acid sediments; adding
ammonia water into the leach liquor to extract the
vanadium; then carrying out reextraction to obtain
ammonium vanadate; generating sediments containing the
molybdenum and the ferrum and a solution containing the
nickel; filtering to obtain
nickel carbonate; carrying out warming alkaline leach on the leach residues containing the
molybdic acid sediments and the sediments containing the molybdenum and the ferrum; filtering to obtain an alkaline leach solution containing the molybdenum and filter residues containing the ferrum; after resin absorbs the molybdenum, eluting, acid-precipitating, filtering,
drying and calcining to obtain
molybdenum trioxide; and acid-dissolving, reducing and filtering the filter residues containing the ferrum to obtain green
vitriol. The invention prevents the
pollution of
smoke gases, such as
sulfur dioxide and the like in environment and has low production cost and high
recovery rate of molybdenum, nickel and by-products of the
vanadium and the ferrum.