The invention discloses a method for producing low-
sulfur molten iron in one step by melting and reducing
copper slag. The method is characterized in that the method includes the following
processing steps that: the high-temperature molten
copper slag is first reduced by
reducing agent in a high-temperature reduction furnace, wherein, when the reduction reaction of iron is nearly finished, a certain amount of additive, which is theoretically calculated, is added in a melting bath based on the existing
slag system in the reduction furnace, a jet gun is inserted into a slag-iron interface to blow
carbon monoxide into the melting bath when the additive is completely molten, the blowing time is 30min to 40min, and desulphurization reaction is almost finished. The melting bath is kept still, and when slag and iron are completely separated, the high-temperature low-
sulfur molten iron and the slag are respectively discharged out of a tap hole and a slag hole. In addition, after high-temperature
flue gas passes through a secondary
combustion chamber, a residual heat boiler recovers residual heat from the
flue gas, dust is collected from the
flue gas by
cyclone, and the
flue gas is washed. By sufficiently utilizing the high desulphurization of the refined slag and blowing the
carbon monoxide, the invention solves the defect that the content of
sulfur in the molten iron produced by melting and reducing the
copper slag for ironmaking is high; the
processing flow is short, the emission of
pollutant is less, and moreover, the applicability is high.