Method for treating zinc-iron-containing dust and sludge

The invention provides a method for treating zinc-iron-containing dust and sludge. The method comprises the following steps of: (1) material preparation, namely performing calculation according to components of different dusts and sludge to ensure that the excess coefficient of free carbon in the materials reaches 1.0 to 1.4; (2) material mixing, namely uniformly mixing the materials and drying natural particle materials or cold bound pellets to be sent to a storage bin for later use; (3) material feeding, namely adding dust and sludge into an empty molten iron tank after molten iron is just poured from the molten iron tank and preheating the dust and sludge materials by using waste heat of the empty molten iron tank; (4) zinc and iron separation, namely recovering zinc-containing smoke by using dust-collection equipment; and (5) material melting, namely further reducing the dust and sludge materials by using high-temperature molten iron in a blast furnace casting process and melting the reduced materials, and mixing the melted materials and blast furnace molten iron to form molten iron for a converter. The zinc-iron-containing dust and sludge can be recovered by using conventional equipment without adding a reducing agent or a catalyst, or needing any special equipment, and has the advantages of convenience and operability, short process, low cost and good effect; and the recovery rate of iron reaches over 90 percent, and the recovery rate of zinc is more than 95 percent.