Method for reducing oxidic slags and dusts using inductively heated furnace
A method for reducing oxidic slags and dusts possibly loaded with organics uses an inductively heatable coke bed extending in the axial direction and having a temperature gradient. Reaction gas is sucked off in an axial region of the coke bed between two induction bodies and metal regulus and slag melt are tapped on the lower end. An inductively heatable shaft furnace chargeable with a lumpy coke bed for the reduction of metallic slags is made of an electrically insulating refractory material, has an adjustable temperature gradient includes at least one cooled induction body on the head side, a suction connection in an axial region where the prevailing temperature exceeds the condensation point of the substances to be removed, located below the cooled induction body on the head side, and an opening for tapping metal regulus and slag melt is provided on the lower end of the furnace.
1. A method for reducing oxidic slags and dusts using an inductively heatable coke bed extending in an axial direction and having a temperature gradient, comprising the steps of:
drawing off reaction as by suction in at least one axial region of the coke bed positioned below a head-side induction body arranged in a vicinity of a cold charging end of the coke bed, wherein said drawing off of the reaction as is performed from two or more axially consecutive annular spaces arranged in the axial direction of the coke bed, and
tapping a metal regulus and slag melt at a tap end of the coke bed,
wherein said head-side induction body is operated at a frequency of 20-120 kHz, and a tap-end induction body arranged in a vicinity of the tap end of the coke bed is operated at a frequency of 1-10 kHz.
2. A method for reducing oxidic slags and dusts using an inductively heatable coke bed extending in an axial direction and having a temperature gradient, comprising the steps of:
drawing off reaction as by suction in at least one axial region of the coke bed positioned below a head-side induction body arranged in a vicinity of a cold charging end of the coke bed, wherein said drawing off of the reaction as is performed from two or more axially consecutive annular spaces arranged in the axial direction of the coke bed, and
tapping a metal regulus and slag melt at a tap end of the coke bed,
wherein volatile halides and CO are drawn off from a first one of said annular spaces positioned adjacent the charging end, and metal vapors are drawn off from a second one of said annular spaces.
3. A method according to claim 2 , wherein the metal vapors comprise Zn vapor with CO.
4. A method for reducing oxidic slags and dusts using an inductively heatable coke bed extending in an axial direction and having a temperature gradient, comprising the steps of:
drawing off reaction as by suction in at least one axial region of the coke bed positioned below a head-side induction body arranged in a vicinity of a cold charging end of the coke bed, wherein said drawing off of the reaction as is performed from two or more axially consecutive annular spaces arranged in the axial direction of the coke bed, and
tapping a metal regulus and slag melt at a tap end of the coke bed,
further comprising the step of adding acidic additives to the slags and dusts to lower the slag basicity.