The invention discloses a method for cooperatively treating
chromium-containing waste water by a
pelletizing process. The method comprises steps as follows: Cr<6+> in the
chromium-containing waste water is reduced into Cr<3+>, and Cr(OH)3 precipitate is formed; the reduced
chromium-containing waste water is mixed with
zinc-containing dust, and a
zinc and chromium contained mixture is obtained, andfirst
zinc and chromium contained pellet is prepared by a first
pelletizing process; the zinc-containing dust is mixed uniformly with
industrial water, a zinc-containing mixture is obtained, the first zinc and chromium contained pellet coated with the zinc-containing mixture is prepared by a second
pelletizing process, a zinc-containing
coating layer is formed, and a second zinc and chromium contained pellet is prepared; the second zinc and chromium contained pellet is sent to a rotary
hearth furnace for reduction, and a metallized pellet is prepared; and the metallized pellet is added to
blast furnace ironmaking components for
smelting, and chromium in the metallized pellet is completely melted into molten iron. According to the method for cooperatively treating the chromium-containing waste water by the pelletizing process, the chromium-containing waste water produced in a steel and
iron plant can be 100% consumed in the
plant, outsourcing treatment is not needed, and the method hasenvironment-friendly and
social benefits while realizing reducing and harmless treatment.