Process of recycling iron oxides and plastics in steelmaking

A process of recovering metallic iron values in waste iron oxide dust from an off-gas stream from a steelmaking furnace, comprising wet cleaning the off-gas to form a wet sludge comprising iron oxide dust, drying the sludge by heating the sludge under conditions such that a mixture of dried sludge and particulate thermoplastic added to the dried sludge has a temperature sufficient to soften and melt the thermoplastic, agglomerating the iron oxide-thermoplastic mixture into a particulate form suitable for introduction into a steelmaking furnace, adding the particulate mixture to a steelmaking furnace, and combusting the plastic binder.

A process of recovering metallic iron values in waste iron oxide dust from an off-gas stream from a steelmaking furnace, comprising wet cleaning the off-gas to form a wet sludge comprising iron oxide dust, drying the sludge by heating the sludge under conditions such that a mixture of dried sludge and particulate thermoplastic added to the dried sludge has a temperature sufficient to soften and melt the thermoplastic, pelletizing a water-insoluble thermoplastic material, adding the thermoplastic pellets to the dried sludge, agglomerating the hot mixture into a particulate form suitable for introduction into a steelmaking furnace, adding the particulate mixture to a steelmaking furnace, and combusting the plastic binder.

A process of recovering metallic iron values in waste iron oxide dust from an off-gas stream from a steelmaking furnace, comprising dry cleaning the off-gas and separating a hot iron oxide dust fraction having a temperature sufficient to provide a temperature of about 300.degree. F. to about 500.degree. F. when mixed with the balance of the dry iron oxide and a water-insoluble thermoplastic material in a proportion of at least 1 part by weight of plastic to 5 parts by weight of iron oxide, pelletizing the thermoplastic material, adding the thermoplastic pellets to the iron oxide dust, agglomerating the mixture into a particulate form suitable for introduction into a steelmaking furnace, adding the particulate mixture to a steelmaking furnace, and combusting the plastic binder to reduce the iron oxide to metallic iron.

A process of recovering metallic iron values in waste iron oxide dust, comprising collecting the dust in dry form, adding the dry dust together with particulate water-insoluble thermoplastic material to a high shear mixer, mixing the dry iron oxide dust and the thermoplastic material in the mixer to a temperature sufficient to soften and melt the thermoplastic material to provide a binder for the iron oxide dust, extruding the hot mixture through a forming die and cooling and forming the extrudate into the form of discrete bodies suitable for introduction into a steelmaking furnace, adding the discrete bodies to a steelmaking furnace, and combusting the binder in the presence of oxygen in the furnace.