Mineral processing method

A mineral processing method comprising:

• a conditioning step of adding a disulfite to a mineral slurry containing a copper mineral and a molybdenum mineral;
• and
• a flotation step of performing flotation using the mineral slurry after the conditioning step so that a raw material mineral included in the mineral slurry is separated into a floating ore having a weight percent of the molybdenum mineral higher than a weight percent of the molybdenum material in the raw material mineral and a precipitating ore having a weight percent of the copper mineral higher than a weight percent of the copper material in the raw material mineral, wherein
• the mineral slurry is obtained by mixing a mineral and seawater, and
• a pH of a liquid phase of the mineral slurry is 4 to 6.