Channel type induction furnace

A method of operating a channel type induction furnace to produce liquid metal, the channel type induction furnace including a shell lined with refractory material, the shell including a floor having a wall extending from the floor to form a hearth;

• and at least one induction heater associated with the channel type induction furnace and communicating with the hearth by a throat in the floor, the throat including throat passages having a down-passage serving as an inlet to the at least one induction heater and at least one up-passage serving as an outlet from the at least one induction heater, the throat passages complementary shaped and configured to channels in the channel type induction heater and each of the throat passages in fluid communication with a complimentary shaped and sized channel;
• wherein the furnace floor is inclined downwards from an operative rear of the hearth towards an opposing operative front of the hearth;
• wherein the wall at the front of the hearth includes a bottom section and a top section to form a front wall, with the front wall bottom section extending further into the hearth than the front wall top section, and the front wall bottom section terminating in an upper edge in abutment with the front wall top section;
• wherein the down-passage includes an inlet in the floor at a location proximate the base of the front wall;
• wherein at least one of the up-passages having an outlet in the floor at a location in abutment with the base of the front wall bottom section and with the front wall bottom section being provided with a vertical slot extending upwards above the at least one of the up-passages through it and opening onto the upper edge of the bottom section;
• and wherein the induction heater is located proximate the front wall, the method comprising:
• preparing a feed material comprising a metallic oxide and a reductant;
• charging the feed material into the furnace onto the inclined furnace floor proximate a rear wall at an operative rear of the hearth;
• and
• operatively allowing the feed material to accumulate on the floor and to extend into the liquid metal bath, to undergo carbo-thermic reduction through radiation from heat of combustion of gases, for the feed material to melt and join the liquid metal bath, with the gases originating from heating of the feed material and optionally also from fuel, preferably gas, introduced into free space above the liquid metal bath and feed material.

A steelmaking apparatus, comprising:

• an iron furnace;
• and
• a refining furnace;
• wherein the iron furnace includes a channel type induction furnace provided with a liquid iron transfer conduit extending from the iron furnace fore-hearth to the refining furnace, to produce liquid iron from an iron containing feed material, contain the liquid iron as a pool in the iron furnace hearth, and to transfer slag-free liquid iron from the pool to the refining furnace by means of the liquid iron transfer conduit;
• and
• wherein the channel type induction furnace of the iron furnace includes a shell lined with refractory material, the shell including a floor having a wall extending from the floor to form a hearth;
• and at least one induction heater associated with the channel type induction furnace and communicating with the hearth by a throat in the floor, the throat including throat passages having a down-passage serving as an inlet to the at least one induction heater and at least one up-passage serving as an outlet from the at least one induction heater, the throat passages complementary shaped and configured to channels in the channel type induction heater and each of the throat passages in fluid communication with a complimentary shaped and sized channel;
• wherein the furnace floor is inclined downwards from an operative rear of the hearth towards an opposing operative front of the hearth;
• wherein the wall at the front of the hearth includes a bottom section and a top section to form a front wall, with the front wall bottom section extending further into the hearth than the front wall top section, and the front wall bottom section terminating in an upper edge in abutment with the front wall top section;
• wherein the down-passage includes an inlet in the floor at a location proximate the base of the front wall;
• wherein at least one of the up-passages having an outlet in the floor at a location in abutment with the base of the front wall bottom section and with the front wall bottom section being provided with a vertical slot extending upwards above the at least one of the up-passages through it and opening onto the upper edge of the bottom section;
• and wherein the induction heater is located proximate the front wall;
• a fore-hearth separate from the furnace hearth, the fore-hearth comprising a shell lined with refractory material, and having a floor with a wall extending from the floor to form the fore-hearth;
• wherein the fore-hearth communicates with the induction heater up-passage by passages opening into it in its floor;
• wherein the fore-hearth passages includes a down-passage serving as an outlet and an up-passage serving as an inlet to the fore-hearth from the at least one induction heater up-passage operatively to receive substantially slag-free metal from the induction heater;
• wherein the fore-hearth passages is complementary shaped and configured to the channels in the induction heater;
• and wherein the fore-hearth including a liquid metal overflow plug;
• wherein the refining furnace including a channel type induction furnace in fluid communication with the iron furnace fore-hearth through the liquid iron transfer conduit to receive liquid iron from the iron furnace fore-hearth, to convert the liquid iron to liquid steel and contain the liquid steel as a pool in the refining furnace hearth, and to transfer slag-free liquid steel from the liquid steel pool to the alloying container by a liquid steel transfer conduit, and the refining furnace being provided with a closable outlet to tap liquid steel from the refining furnace;
• wherein the channel type induction furnace of the refining furnace includes a shell lined with refractory material, the shell including a floor having a wall extending from the floor to form a hearth;
• and at least one induction heater associated with the channel type induction furnace and communicating with the hearth by a throat in the floor, the throat including throat passages having a down-passage serving as an inlet to the at least one induction heater and at least one up-passage serving as an outlet from the at least one induction heater, the throat passages complementary shaped and configured to channels in the channel type induction heater and each of the throat passages in fluid communication with a complimentary shaped and sized channel;
• wherein the furnace floor is inclined downwards from an operative rear of the hearth towards an opposing operative front of the hearth;
• wherein the wall at the front of the hearth includes a bottom section and a top section to form a front wall, with the front wall bottom section extending further into the hearth than the front wall top section, and the front wall bottom section terminating in an upper edge in abutment with the front wall top section;
• wherein the down-passage includes an inlet in the floor at a location proximate the base of the front wall;
• wherein at least one of the up-passages having an outlet in the floor at a location in abutment with the base of the front wall bottom section and with the front wall bottom section being provided with a vertical slot extending upwards above the at least one of the up-passages through it and opening onto the upper edge of the bottom section;
• and wherein the induction heater is located proximate the front wall.