ARC FURNACE FOR THE MELT REDUCTION OF FINELY-DIVIDED IRON OXIDE MATERIAL

摘要

For the melt reduction in a DC electric arc furnace of iron oxide material of such a fine grain size that it can be blown about by the action of an electric arc, a hearth for the iron melt used, is provided with an outer wall and a roof down through which an arcing electrode extends with its tip positioned to form an arc with the melt, the electrode having a lengthwise passage through which the fine-grained oxide material, together with equally fine-grained particles of carbonaceous material, are fed to the tip. This prevents substantial loss of the materials by their being blown away from the arc. The arc, unshielded by the flow of materials, can produce from the space radiation damaging to furnace linings. To prevent the effect of such radiation, at least the electrode tip is surrounded by a coke bed floating on the melt and retained by a partition depending from the roof symmetrically around the electrode, down to a level spaced above the melt level, the lower portion of the coke bed closing the space between the partition and the melt. The partition forms an outer space within the wall and under the roof and to which the reaction gases can flow via the interface between the coke bed and the melt and possibly through the particles of coke, to this outer space, the latter having means for exhausting the gases. The coke bed permits the arc to operate while acting as a barrier against the arc radiation, while the coke bed at the same time permits the reaction gases to flow under the bed to the outer space for discharge from the apparatus, the bed shielding the furnace construction above, against the heat of the discharging gases.