PRODUCTION OF LOW-HYDROGEN STEEL

PURPOSE:To prevent the increase in the cost of equipment and ingot production and to obtain a low-hydrogen steel by charging auxiliary raw materials for steel making in a dry state into a refining furnace after calcination to perform refining and adding dry quicklime to the inside of a ladle in the end period of tapping to chill suspended slag. CONSTITUTION:The sintering raw material mixed with ore powder, quicklime, etc. is calcinated in a sintering tray 3 engaged with a drum 2 of a sintering machine 1 and is discharged continuously from a discharge part 4. The raw material is crushed and sized by a crusher 6 past a chute 5 and is temporarily stored in a receiving hopper 7. The material is then passed through the conventional sintered ore supply route 10 or auxiliary raw material take-out chute 11 by a dampler 9 provided to a change-over chute 8 and is charged into a hermetic vessel 15 made by welding, for example, a steel plate 14 into a box shape, lining the welded plate with refractories 12 and providing a discharge port 13. The cap 16 of the port 13 is thereafter closed and the inside is maintained dry by the sensible heat of the sintered or in a high temp. or hot state itself. The material is carried in this state into a steel making plant where the sintered ore is charged to the auxiliary raw material supply hopper of, for example, a converter and the material is fed out and added to the inside of the converter if necessary.