| 摘要 |
PROBLEM TO BE SOLVED: To recover zinc while sufficiently raising zinc concn. without executing pre-treatment of agglomeration or the like, by adding pre-melt slag produced in an iron-making process in a specified range when the zinc is separatively recovered by blowing zinc-containing dust containing not less than a specified value of the zinc into molten iron. SOLUTION: When the zinc is separatively recovered by blowing the zinc- containing dust containing >=0.5 mass% zinc into the molten iron, the pre-melt slag produced in the iron-making process is added at 1-10 kg/ton of the molten iron to recover the zinc. At least one kind among blast furnace slag, molten iron desiliconized slag, molten iron dephosphorized slag and decarburized slag, is suitable to be used for the pre-melt slag. Silicon concn. in the molten iron before executing the separatively recovering treatment, is made to >=0.2 mass% or carbon concn. in the molten iron before and after this treatment, is made to 3.4-4.8 mass%, and the silicon concn. in the molten iron after the treatment is made to >=0.03 mass% and thus, it is desirable to raise the zinc concn. in the dust. |
