EP0051607A1

EP0051607A1 - Metallurgical process and furnace

Info

Publication number: EP0051607A1
Application number: EP19810900995
Authority: EP
Inventors: Robert Nelson Rose
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-05-15
Filing date: 1980-05-15
Publication date: 1982-05-19
Also published as: AU7076881A; WO1981003342A1

Abstract

Four metallurgique (1 a 15 Fig. 1 et 2) ainsi qu'un procede de fusion, affinage et traitement de metaux et servant a la reduction de minerai par la combustion non stoechiometrique d'un combustible fluide et d'un gaz entretenant la combustion a l'interieur d'un bruleur a combustion interne (21 et 23, Fig. 1-4, detail aux Fig. 5-9) dechargeant au-dessous de la ligne du metal (11) dans un four possedant un fond (3) et des parois laterales (7a et 7b) refractaires ou en graphite et un toit (10) et possedant une entree d'alimentation (13) servant a introduire le materiau solide d'alimentation dans le four au-dessus du niveau du metal en fusion, ce four possedant une ouverture (15) permettant l'extraction du metal en fusion, et ce procede indiquant l'utilisation de bruleurs (21) a combustion interne s'etendant vers le bas au travers du toit du four avec leurs extremites de decharge (29 Fig. 5) sensiblement au-dessous du niveau du metal en fusion (11) et avec leurs autres extremites a l'exterieur du four, chaque bruleur possedant une chambre de combustion (26 Fig. 5) refractaire ou metallique et une chemise de refroidissement (27) entourant la chambre de combustion, l'orifice d'admission (65) du fluide de refroidissement et l'orifice de sortie (66) du fluide de refroidissement de la chemise etant situes a proximite de l'autre extremite du bruleur, a l'exterieur du four.Metallurgical furnace (1 to 15 Fig. 1 and 2) as well as a process for smelting, refining and treatment of metals and used for reduction of ore by the non stoichiometric combustion of a fluid fuel and of a gas supporting combustion inside an internal combustion burner (21 and 23, Fig. 1-4, detail in Fig. 5-9) unloading below the metal line (11) in an oven with a bottom (3 ) and refractory or graphite side walls (7a and 7b) and a roof (10) and having a feed inlet (13) for introducing the solid feed material into the furnace above the level of the metal in melting, this furnace having an opening (15) allowing the extraction of molten metal, and this method indicating the use of internal combustion burners (21) extending downwardly through the roof of the furnace with their ends discharge (29 Fig. 5) substantially below the level of the molten metal (11) and with their other ends outside eur of the furnace, each burner having a combustion chamber (26 Fig. 5) refractory or metallic and a cooling jacket (27) surrounding the combustion chamber, the inlet orifice (65) of the cooling fluid and the outlet orifice (66) of the cooling fluid of the jacket being located near the other end of the burner, outside the oven.

Description

METALLURGICALPROCESSANDFURNACE

The Field of the Invention The field of the present invention is in the melting, refining and processing of ferrous and non-ferrous metals, with or without a simultaneous alloying thereof with other metals and with or without the introduction of other ingredients into the molten metal to affect the composit¬ ion or characteristics of the end-product, and the field of the present invention is also in the reduction of ores of metals. The field of the present invention is more particul¬ arly the processing of metals and ores in such furnaces by supplying both the heat required for melting the metal or its ore and for keeping it molten and for supply¬ ing the reducing or oxidizing gas for the processing of the metal by submerged internal-combustion burners which dis¬ charge the hot products of combustion substantially below the level of the melt or "melt-line", thereby to agitate and stir and circulate the melt within itself so as to achieve a uniform composition and uniform characteristics throughout the finished end-product. The term "internal combustion burner" as used here^¬ in means a burner having a combustion chamber therein to which fuel and combustion-supporting gas are supplied, and in which internal-combustion chamber the combustion takes place and is substantially completed, and from the discharge end of which burner the hot products of combustion exit substantially below the level of the melt. As shown by Figure 1, none of the interaction between the fuel and oxygen takes place below the bottom of the pool of molten metal. The fuel and the combustion-supp₀rting-gas are supplied at a pressure substantially higher than the static pressure of the melt at the depth thereof at which the burner discharges the hot products of combustion. The word "oxygen" as used hereinafter is intended to encompass air as well as oxygen-enriched air and also oxygen alone and a mixture of oxygen and an inert gas , and the word "melt" is intended to encompass a pool of molten metal and also a molten pool of an ore thereof and also a pool of a mixture of molten metal and ore, and the phrase "metal source" is intended to encompass metallic feed-material and also an ore of the metal as a feed material.

Brief Summary of the Invention The present invention generally contemplates a furnace including a melt-down section at one end, and a lefining or processing section downstream thereof, preferably with a bridge-wall separating the two sections , such bridge-wall extending downwardly from the roof of the furnace and extending into the melt to a point substant- ially below the melt-level or "metal-line" so as to prevent unmelted metal pieces or particles from passing from the melt-down section into the refining or processing section. A material-feed is disposed above the melt-down section and a flue passageway extends through the upper portion of the bridge-wall which is between the roof of the furnace and the metal-line, and such flue-passageway extends into the end of the material-feed tower (or other material-feed means) near or adjacent to the metal-line in the melt-down section, so that the hot products of combustion which rise upwardly through the molten material in the refining and processing section and accumulate in said section above the metal-line will pass through such flue-passageway .(.in the bridge-wall) into the material-feed section or what is also the pre¬ heating section, so that such hot gaseous products of combustion will pass through such material-feed and pre- heating countercurrent to the movement of solid material pieces or particles and will pre-heat the same.

The material-supply and pre-heating section may be in the form of a flue tower, with downwardly-inclined cascading baffles extending inwardly from the sides thereof (as indicated in Figure 1) , or such material- feed and pre-hea.ting section or means may be a fluidized bed if the solid metal particles are sufficiently small so that the hot products of combustion passing there¬ through will keep the bed fluidized and moving towards the metal-line in the melt-down section, or such material-feed and pre-heating section or means may be an inclined rotary tubular section in which solid materials or particles will tumble and so feed or move towards the metal-line in the melt-down section. The aforementioned baffles in the tower-like or flue-like feed and pre¬ heating section are used primarily where the material to be melted is in theform of relatively small particles which can flow down through the staffered baffles. If the material to be melted is in the form of relatively large pieces, the baffles (shown in Figure 1) may be omitted. A suitable number of generally uniformly distributed lance-like internal-combustion burners are adjustably mounted in and extend through the roof of the refining or processing section of the furnace and are of sufficient length so that when they are adjusted for their submerged position, a substantial length of the burner will be submerged within the melt, and so that when they are retracted they may discharge the products of combustion at a point suitably above the metal-line, so as to melt any previously molten material which had solidified in the refining section during a shut-down of the furnace- operation without the molten metal having been first fully drawn off from the furnace.

One or more relatively short internal-combustion burners may be non- djustably mounted in and extend through the side-wall of the melt-down section of the furnace at a point substantially below the metal-line. Such side-wise mounted burners may have their discharge ends or noses flush with the inner surface of the wall in which they are mounted or such noses may be set back a slight, distance from such inner surface of the wall of the furnace. While such side-mounted burners are removably mounted, they need not be adjustable in relation to the furnace-wall unless there is need for projecting their noses a substantial distance into the melt and for retracting their noses at times.

Such side-mounted burners melt the incoming solid materials or particles thereof and help to keep the same molten. A molten-metal overflow or discharge opening is provided at the metal-line in a refining section of the furnace, preferably at the downstream end thereof, followed by a suitable spout if continuous operation of the furnace is desired. If the furnace is to be operated batch-wise, then a tape-hole is provided in the wall of the refining section of the furnace at or slightly below the floor-level thereof, through which the batch of the

m finished melt can be withdrawn;- such tap-hole being plugged for the next batch. By providing the discharge- opening and the spout above the melt- line or metal- line, molten metal may be drawn off by tilting the furnace. Brief description of the drawings

Figure 1 represents a somewhat schematic cross - sectional view of a furnace representing an embodiment of the present invention.

Figure 2 represents a vertical cross-sectional view on line 2-2 of Figure 1.

Figure 3 represents a top plan view of the furnace shown in Figure 1.

Figure 4 represents a fragmentary horizontal cross- sectional view on line 4-4 of Figure 1. Figure 5 represents a somewhat schematic longitudinal cross-sectional view of an embodiment of the internal- combustion burner.

Figure 6 represents a cross-sectional view on line 6-6 of Figure 5. Figure 7 represents a cross-sectional view on line

7-7 of Figure 5.

Figure 8 represents a cross-sectional view on line 8-8 of Figure 5.

Figure 9 represents a cross-sectional view on line 9-9 of Figure 5.

Figure 10 represents a fragmentary cross-sectional view on the circular line 10-10 on Figure 6; but shown in planar development.

Detailed description of the Invention In the embodiment illustrated by the drawings, the furnace includes a melt- down section 1 and a refining or processing section 2 downstream thereof. The melt- down section 1 and the processing section 2 have, in common, an imperforate refractory bottom or floor 3 (Figures 1 & 3) . The melt-down section 1 has a refractory end-wall 4 and side-walls 5-a and 5-b. Refractory end-walls 6-a and 6-b at the upstream end of the processing section^" 2

O PI extend from the side-walls 5- a & 5-b (respectively) of the melt- down s ection 1 to the refractory side-walls 7- a & 7-b of the processing section 2 , and the refractory end-wall 8 at the downstream end of the processing s ection 2 extends between the downstream ends of the side-walls 7- a & 7-b as indicated in Figures 1 , 2 , 3 & 4.

A bridge-wall 9 extends downwardly from the roof 10 of the pro cessing section 2 , between the ups tream end- walls 6- a & 6-b thereof , to a point subs tantially below the metal- line 11 , with the lower end 12 of the bridge- wall being sufficiently above the floor 3 to permit the free flow of molten metal from the melt- down section 1 into the processing or refining s ection 2 (Figures 1 & 2) and extends into the melt to a point sufficiently below the metal- line 11 (or sufficiently clos e to the floor 3 of the furnace) as to prevent unmelted pieces or particles from passing from the .melt- down section 1 into the refining s ection 2.

The roof 10 may be arched as indicated in Figure 2 • or it may be flat .

The ups tream end-walls 6- a & 6-b of the process ing section 2 and the bridge-wall 9 are formed in direct continuation of each other .

The material- feed and pre-heating tower and flue 13 extends upwardly from and may be formed in direct continuation of the end-wall 4 and s ide-walls 5- a & 5-b of the melt- down section 1 and the end-walls 6- a & 6-b of the proces sing section 2 and the bridge-wall 9 , as indicated in Figures 1 , 2 5c 3. A flue-opening 14 extends from the processing section

2 to the material- feed and pre-heating flue 13 through the bridge-wall 9 , from a point near the roof 10 in the processing s ection to a point in the material- feed and pre-heating flue 13 which is near the melt- line 11 , s o that the hot products of combus tion which accumulate in the processing section 2 (between the metal- line 11 and the roof 10) will flow into the bottom of the material-

_ GM feed and pre-heating flue 13 approximately at a point near where the solid metal or ore particles are delivered to the metal- line 11 in the melt- down section 1 , and so that the hot products of combus tion which s o come through the flue passageway or opening 14 will pas s outwardly through the material- feed 13 counter- current to the movement of the solid material pieces or particles , so as to pre-heat the s ame .

The lowermos t solid pieces or particles in the material- feed may be melted by the hot gases coming through the flue-pas sage 14 p lus the hot gas es of combustion issuing from the internal- combus tion burner or burners in the melt- down section 1 ( des cribed herein¬ after) . Opposite downwardly inclined baffles 17 & 18 extend inwardly from the opposite walls 19 6c 20 of the material- feed and pre-heating tower and flue 13 , in the manner indicated in Figure 1 , so as to cause the solid material to cas cade down through the material- feed and pre-heating • tower and flue 13 in such a way as to maximize the exposure of the solid material pieces or particles to the hot products of combus tion rising upwardly through the tower and flue 13.

A plurality of relatively long internal- combus tion burners 21 (one embodiment of which is shown in Figure 5) extend downwardly through the roof 10 of the refining or processing s ection 2 of the furnace and are adj us tab ly mounted thereto in generally gas-tight relation there¬ with by stuffing- gland- like collars or means 22 s chemati- cally indicated in Figure 1.

The burners 21 may be vertically adj usted and may be retracted upwardly (as shown in Figure 1) so that they dis charge the hot products of combus tion above the metal¬ line 11 and so that they may be extended downwardly and submerged in the melt , thereby to dis charge the hot products of combus tion substantially below the metal- line or in proximity to the floor of the furnace . The burners 21 are retracted if it is des ired to shut down the furnace with molten material left therein , which will solidify during the shut- down period . When the furnace is started up again after such shut- down period, the withdrawn burners 21 are s tarted up and made to fire or to dis charge the hot pro ducts of combustion above and in sufficient proximity to the upper surface of the theretofore solidified material , gradually to melt the same , and are then lowered into the molten material either in a single step or gradually as the material is melted, until they reach their fully submerged pos ition shown in Figure 1.

Some of the burners 21 may be withdrawn and rendered inoperative while others are submerged and operate , if less than all the burners 21 will provide sufficient heat to keep the materials molten and at a sufficiently high temperature for the refining , alloying , compounding or other process ing of the melt .

One or several short side-mounted internal combus tion • • burners 23 are extended through the side-wall or side- walls of the melt- down section 1 of the furnace , sub¬ stantially below the metal- line 11 , as indicated in Figures 1 & 4 to cause the hot products of combus tion dis charged from the burners 23 first to melt the incoming feed of solid material or particles and then to keep the materials molten in the melt- down section 1 and also to contribute to the hot products of combus tion rising upwardly through the pre-heating tower and flue 13. The submerged side- mounted burner or burners 23 are provided only when the furnace is either operated continuous ly without any shut¬ down while there is molten metal within the furnace above the level of the s ide-mounted burners 23 or where the furnace is operated batch-wis.e with a complete with¬ drawal of the molten material through the tap-hole 24 or where the- molten material is withdrawn through a tap-hole 24 to a point below the level of the s ide-mounted burners 23 if such withdrawal is for the purpose of a shut- down. The overflow-opening 15 in the downstream end-wall 8 of the furnace is at a point which determines the location of the metal-line 11 in the continuous operation of the furnace. - The spout 16 is carried by and extends outwardly from the end-wall 8 of the furnace to a sufficient distance so as to permit the metal flowing over the lip of the spout to be readily caught by a ladle, mold or other catchment vessel which may be used for receiving the finished molten metal. For batch-wise operation, the metal out-flow-opening 15 may be located substantially above the metal-line 11, and finished molten metal may be drawn off through the opening 15 by tilting the furnace about a suitable trans¬ versely-extending horizontal pivot or fulcrum beneath the floor of the furnace suitably located therealong, so as to permit the upstream end of the furnace to be raised (by a suitable hoist or hydraulic lift or the like) in relation to the downstream end of the furnace so as to tilt the furnace at an angle suitable for such drawing ^• off of finished molten metal. The tilting pivot or fulcrum may be beneath the steel structure supporting the bottom or floor 3 of the furnace or the tilting pivot or fulcrum or may be located at a suitable point substantially above the floor 3, but in such case the pivotation would be provided by two opposite co-axial trunions extending outwardly from the side-walls 7-a & 7-b (secured to the steel frame of the furnace in which the refractory bottom and walls are mounted) . If it is desired to tilt or rotate the furnace for drawing off the finished molten metal, the material-feed or pre-heating flue 13 would be materially shortened and the gases discharged there¬ from vented into a suitable hood beneath or connected to a suitable chimney or stack.

When the material to be fed to the furnace is in relatively small pieces or particles , it may be fed to the furnace by means of an inclined rotary-drum pre-heater, or if the particles are sufficiently small and generally uniform, the material may be fed to the furnace through a fluidized bed of such particles . In each case , the hot products of combus tion from the burners 21 & 23 pas s through such rotary drum and through such fluidized b ed. The herein des cribed metalurgical furnace may also be us ed for the processing of metals from a direct- reduction of the ores thereof and in continuation of such direct- reduction .

The feed-material may also b e sponge-iron or pre- reduced iron or other pre-reduced metals .

. I may also effect the direct reduction of ores of metals , as ,~±^'or instance , iron ores , by feeding the iron ore _^th oug the material- feed and pre-heating s tack 13 i oy feeding suitable small-particle crushed ore or suitable size pellets of the ore to the furnace , above the pool of molten iron , through a fluidized bed or through an inclined rotary pre-heating retort .

The small particle ore of the suitable- s ize pellets may be partly or subs tantially reduced in the fluidized bed, as , for ins tance , to a reduction of 65 to 85% of Fe or to a reduction of 85 to 90% of Fe , which partly reduced ore is then fed to the pool of molten iron beneath the dis charge end of the fluidized bed or inclined rotary- drum where it is further reduced by the below- mentioned reducing atmosphere , or the small-particle ore or pellets of ore may be only pre-heated in the fluidized bed or in the inclined rotary drum or reduced to a much les^"ser extent than above mentioned, and the so pre-heated ore or less er- reduced ore is then fed to the pool of molten iron beneath the dis charge end of the fluidized bed or inclined rotary drum where is is then further reduced.

I may provide the reducing atmosphere by supplying air (or other combus tion- supporting gas) through the supplying- pipe 67 of the internal combustion burners (21 and/or 23) at a rate which is sufficiently les s than the stoichiometric quantity thereof in relation to the fuel

¹ j * S. *-. _*

OMPI being fed to said burners, so that the gases issuing from the submerged discharge ends of the burners will be generally reducing gases, while still supplying sufficient heat needed for the reduction of the ore and/or for the fusion or melting of the reduced material. The inter¬ action between the fuel and oxygen of which the non- stoichiometric proportions thereof are capable is sub¬ stantially completed within the combustion-chamber 26 of the internal combustion burner shown in Figure 5. I may also provide a reducing atmosphere by injecting into the molten pool of metal or into the zone immediately above the metal-line thereof, additional gaseous fuel (or liquid fuel) , with or without a concurrent supply of steam mixed therewith. The so produced reducing atmosphere may be used by itself without the- aforemention¬ ed reducing gases from the internal-combustion burners or in conjunction with such burner-produced reducing gases, to augment the latter.

The term "non-circulating" in the claims is in contradistinction to a pool or bath of molten metal which circulated in a closed cycle in an annular or torroidal orbit about a vertical axis, as for instance, in the ring-hearth furnace disclosed in French patent 1,458,054. Figures 5 to 9 illustrate an embodiment of the internal-combustion burners 21 and 23;- the two (21 & 23) differing from each other only in their length beyond the combustion-chamber 26 thereof.

The burners (21 & 23) include a generally cylindri- cal outer metallic shell 27, whose discharge end 28 may be tapered inwardly towards the discharge end 29 of the burner. The shell 27 has an outwardly extending annual flange 30, perferably formed integrally therewith, to which the closure or head 31 is bolted by means of peripherally distributed bolts 32, so as to permit the periodic opening of the outer end of the shell 27 when it is desired to remove or replace the refractory lining thereof. A preferably pre-formed cylindrical refractory liner 33 is mounted within and supported by the shell 27. The liner 33 has a conical discharge end or nose portion 34 which may also be formed as a separate piece. The refractory liners 33 & 34 are fitted sufficiently close to the inner metal shells 35 & 36 so as to obtain a good heat-transference from the refractory liners to such metal shells.

An outer refractory closure disc 37 is provided across the outer end of the cylindrical refractory liner .33 so as to complete the refractory enclosure of the combustion chamber 26;- the refractory disc 37 being held in place by the head 31.

A cylindrical fuel-supply shell 38 extends through the head 31 and may be welded thereto by means of a suitable flange or stuffing-gland or the like (not shown) . The shell 38 extends inwardly from the head 31 to a distance sufficient to reach the inner surface of the refractory disc 37, and is provided with an in-turned - inner terminal flange 39. The outer end of the cylindrical shell 38 is provided with an in-turned flange 40. A cylindrical member 41 extends through the outer flange 40 of the fuel-shell 38 and is preferably welded thereto by a suitable fillet weldment (not shown) . The inner end of the cylindrical member 41 terminates at the inner periphery of the in-turned flange 39 and is preferably welded thereto. A suitable number and size of equi-distantly spaced fuel-exit holes 42 are provided in the in-turned terminal flange 39, either parallel to the axis of the burner or preferably inclined inwardly at a suitable angle, so as to discharge the fuel in a number of inwardly-directed jets.

The fuel discharge holes 42 are preferably also inclined tangentially so as to cause the jets of fuel issuing therefrom to create a swirling turbulence within the combustion-chamber conducive to rapid and complete combustion. The outer end of the cylindrical member 41 is closed by the closure member of disc 43 having a central opening therein. A gland-like collar 44 is welded to or formed integrally with the disc 43 (by casting or the like) . A high-temperature ceramic electrode-encasing rod 45 extends through the gas-pressure-tight stuffing-gland 44 and is adjustably supported therein, so that it can be extended into the cylindrical member 41 to the. desired extent for optimum ignition. A pair of ignition elect- rodes 46 & 47 are insulatedly embedded in and extend through the insulating ceramic rod 45, with their inner¬ most ends extending therebeyond and. angled towards each other to provide a spark-gap 48 in operative juxta¬ position to the fuel-jets issuing from the fuel-exit holes 42. Lead-wires 49 & 50 extend from the electrodes 46 & 47 to any suitable source of intermittent of continuous current of sufficiently high voltage to provide a suitable ignition spark at the gap 48.

The nose-section 51 of the burner may be long, as in the case of the burners 21, or may be very short, as in the case of the side-mounted burners 23. The nose- section 51 of the burner is surrounded by the inner metallic cylindrical shell 35 and conical nose-portion 36 thereof g-enerally parallel to the outer metallic shells 27 & 28;- providing an annulus-shaped space 52 between such inner and outer metallic shells. -The inner¬ most ends of the conical shell-portions 28 & 36 are bridged and connected by a transverse conical closure

53 welded to such innermost ends. Circumferentially spaced longitudinally extending radial divider plates

54 are provided in the space 52 between the inner metallic shell portions 35 & 36 and the outer metallic shell portions 27 & 28. The innermost portions 55 of the plates 54 angle inwardly to correspond to the angle of the conical shell-portions 28 & 36, and terminate at 56, short of the conical closure-member 53 so as to

ϋU EATT

OMPI leave the fluid-passageway between the ends 56 of such divider plates 54 adj acent the conical closure-member 53.

A cylindrical member 57 surrounds the outer end of the outer cylindrical shell 27 to form the annulus - shaped lower header- chamber 58 for the incoming or ..in- lowing coo lant and to form the upper annulus- shaped header chamber 59 for the outwardly flowing coolant .

The in- flow header- chamber 58 is bounded by the upper annulus -shaped dis c 60 and the lower annulus -shaped dis c 61. The out-flow header- chamber 59 is bounded by the upper portion of the cylindrical member 57 and the annulus -shaped dis c 60 and the annulus- shaped dis c or j:Λ- r~ -62 welded to the upper end of the cylindrical

" ^' shell 57. The upper ends, . alternating pairs of radial separators 54 extend through corresponding slots- 63 in the annulus -shaped dis c or ring 61 and are welded to the edges of such s lots and have their upper ends welded to the edges of s lots 64 in the annulus -shaped dis c or ring 60 . The s lots 63 & 64 alternate with each other . The liquid coolant , generally cold water , enters through the in-flow pipe 65 into the annulus - shaped header 58 , and from there the coolant flows downwardly between the outer shell ( 27 & 28) and the inner shell (36 & 36) , through alternating longitudinal passageways formed by the separator plates 54 , until they reach the lower ends of such shells , where the coolant f lows to the adj acent up-pass ageway (as indicated by the arrows in Figure 5) , which up -passageways dis charge into the upper annulus- shaped header 59 , from which the coolant flows outwardly through the out- flow pipe 66 (as indicated in Figures 5 to 9) .

Air or oxygen (or any suitable combus tion-supporting mixture) is delivered to the annulus - shaped space 66 between the outer air shell 41 and the ceramic electrode- holder 45 . Gaseous (or liquid) fuel is delivered to the generally annulus - shaped space 67 between the cylindrical shell 41 and the outer cylindrical shell 38 , as indicated in Figures 5 & .

If it is desired to use a liquid fuel (as, for instance, any suitable fuel oil), the ceramic electrode- bearing rod 45 is removed, and in its place a liquid- fuel nozzle-assembly is inserted with its atomizing nozzle-tip as approximately the same location as the gap 48 between the ends of the electrodes 46 & 47. When using such fuel-nozzle-assembly, the ignition for such atomized fuel-oil may be provided by any suitable manual ignition means or other suitable ignition means . In such event, the outer annulus-shaped chamber 70 and the supply-pipe 69 thereto may be eliminated or just closed off.

As used in the following claim, the term "processing¹ is intended also to include refining.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

Claims

Claims 1. A metalurgical process which includes maintain¬ ing a non-circulating melt-down pool in a furnace by interacting a fluid fuel and oxygen in a heat-insulating 5 refractory combustion chamber of an internal-combustion burner separate and distinct from the furnace and having its discharge below the metal-line and above the bottom of the pool of molten metal, the interaction between the fuel and the oxygen, of which the same are capable,

10 being substantially completed within said combustion chamber, and with none of the interaction between the fuel and oxygen taking place below the bottom of the pool of molten metal, and injecting into the melt-down pool substantially below its top and above its bottom the

15 resultant hot gases issuing from said combustion-chamber and passing such hot gases upwardly through the melt-down pool, and feeding material to be melted to said melt-down pool and passing the hot gases which have risen through the melt-down pool through said material-feed counter-

2_.0 current to the feeding movement thereof, thereby causing said melt-down pool to be augmented by the melting of such feed-material, causing the excess of melt to flow from said melt-down pool into a non-circulating processing pool in said furnace and interacting a fluid

25 fuel and oxygen in a heat-insulating refractory combustion chamber of an internal combustion burner separate and distinct from the furnace and having its discharge below the top and above the bottom of the melt in the processing pool, the interaction between the fuel and the oxygen,

30 of which the same are capable, being substantially completed within said combustion chamber, and with none of the interaction between the fuel and oxygen taking place below the bottom of the processing pool, and injecting into the melt in such non-annular processing-

35 pool substantially below its top and above its bottom the resultant hot gases issuing from said combustion- chamber and passing such hot gases upwardly through the

OMP y WIP melt in the pro cess ing-pool , and caus ing s aid hot gases which have ris en through said pro cessing-pool to merge with the hot gas es which have ris en through the s aid melt- down pool so as to pass therewith through the aforementioned material- feed, and drawing off metal from s aid pro cess ing- pool .

2. A metalurgical pro cess which includes maintain¬ ing in a furnace a non- circulating pool of molten metal having an oxide content and reducing its oxide content by incompletely burning a fluid ..fuel with oxygen in a heat- insulating refractory combustion- chamber of an internal combustion burπό'ϊr^{" "}s parate and dis tinct from the furnace and having its dis charge below the top and above the bottom of the pool of molten metal , the inter¬ action between the fuel and the oxygen, of which the same are capable , being subs tantially completed within said combustion chamber, and with none of the combus tion taking place vertically below the bottom of the pool of molten metal , and passing the hot products of such incomplete combustion upwardly through the pool of molten metal .

3. A metalurgical process which includes maintain¬ ing in a furnace a non-circulating pool of molten metal having an oxide content and reducing its oxide content by incompletely burning a fluid fuel with oxygen in the presence of steam in a heat-insulating refractory combustion-chamber of an internal-combustion burner separate and distinct from the furnace and having its discharge below the top and above the bottom of the pool of molten metal, the interaction between the fuel and the oxygen, of which the same are capable, being sub¬ stantially completed within said combustion chamber, and with none of the combustion taking place vertically below the bottom of the pool of molten metal and passing such hot products of such incomplete combustion upwardly through the pool of molten metal, with the oxygen supplied to the combustion-chamber of the burner being sufficient¬ ly less than the stoichiometric quantity thereof in relation to the fuel being fed to the combustion-chamber so that the gases issuing from the submerged discharge end of the burner will include reducing gases and will still supply sufficient heat for maintaining the metal in a molten condition.

4. A metalurgical process according to claim 3, in which the hot products of the incomplete combustion which have risen through the pool of molten metal are passed through the material being fed to pool of molten metal counter-current to the direction of the feeding travel thereof.

5. A metalurgical process according to claim 2, in which hot products of combustion which have risen through the molten metal are passes through the material being fed to the pool of molten metal counter-current to the direction of the feeding travel thereof.

6. A metalurgical process which includes maintain¬ ing, in a furnace, a non-circulating melt of a metal- source having a non-metallic content, and lessening its non-metallic content by chemically reacting therewith the unreacted content ofthe generally homogeneous hot gaseous products of generally uniform composition resulting from the non-stoichiometric combustion-reaction between a fluid-fuel and oxygen in a heat-insulating refractory combustion-chamber of an internal-combustion burner separate and distinct from the furnace and having its discharge above the bottom and substantially below the top of the melt, and with none of the interaction between fuel and oxygen taking.place below the bottom of the melt, and with the interaction between fuel and oxygen of which the non-stoichiometric proportions

IJURE thereof are capable being substantially completed within said combustion-chamber, and passing the resultant hot gaseous products of such non-stoichiometric combustion of generally homogeneous and uniform co po- sition upwardly through the non-metallic content of the melt and the unreacted content of the hot gases resulting from such non-stoichiometric interaction between fuel and oxygen, thereby to lessen such non-metallic content of the melt, and such hot gaseous products, of said non- stoichiometric combustion-reaction supplying sufficient heat for maintaining the metal in a molten condition.

7. A metalurgical furnace including a refractory bottom and side-walls and including a roof, and including feed-entrance means arranged for introducing solid feed material into the furnace from above the metal-line, and having an opening in a wall thereof for drawing off molten metal, and a coolant acketed internal-combustion burner having its lower portion extending substantially into the melt, from above, with the upper portion of said burner disposed above the metal-line and with the uppermost portion of said burner disposed outside the furnace and with the discharge nose of said burner submerged in the melt substantially below the metal-line.

8. A metalurgical furnace, having a melt-down section and a processing section and including a refractory bottom and side-walls and including a roof, and including feed-entrance means arranged for intro- ducing solid feed material into the melt-down section from above the metal-line and having an opening in a wall thereof for drawing off molten metal, and a coolant- jacketed internal-combustion burner having its lower portion extending substantially into the melt, from above, with the upper portion of said burner disposed above the metal-line and with the uppermost portion of said burner disposed outside the furnace and with the dis charge nose of said burner submerged substantially below the metal-line .

9. A metalurgical furnace, having a melt-down section and a processing section and including a refractory bottom and side-walls and including a roof, and including feed-entrance means arranged for intro- ducing solid feed-material into the- melt-down section from above the metal-line, and having an opening in a wall thereof for drawing off molten metal, a coolant- jacketed internal-combustion burner in said melt-down section and a coolant-jacketed internal-co bustion burner ^' in said processing section, said burners having their lower portions extending substantially into the melt, from above, with the upper portions thereof disposed above the metal-line and with the uppermost portions thereof disposed outside the furnace and with the dis- charge noses thereof submerged in the melt substantially below the metal-line.

10. A metalurgical furnace having a melt-down section and a processing section and including a refractory bottom and side-walls and including a roof, and including feed-entrance means arranged for intro- ducing .solid feed-material from above the metal-line, into the melt-down section, and having an opening in a wall thereof for drawing off molten metal, a coolant- jacketed internal-combustion burner in said processing section of the furnace, extending through the roof thereof and having its lower portion extending sub¬ stantially into the melt and with the uppermost portion thereof disposed above the roof of the furnace and with the discharge nose thereof submerged in the melt sub¬ stantially below the metal-line, and a coolant-jacketed internal-combustion burner extending through the side- wall of the melt-down section of the furnace and having its discharge nose below the metal-line in the melt-down section.

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11. A metalurgical furnace, according to any of foregoing claims 7 to 10, in which the internal-combustion burners are adjustable vertically and arranged to be optionally raised sufficiently to place the discharge- ends thereof above the metal-.line and to be lowered into the melt with their discharge ends substantially below the metal-line.

12. A metalurgical furnace according to any of foregoing claims 7 to 11, in which the metal draw-off opening is above the metal-line and which includes means for tilting the furnace to cause the molten metal to flow out through the draw-off opening.

13. A metalurgical furnace according to any of foregoing claims 7 to 12, having a non-circulating metal- flow-path therethrough.