EP0137618A2 - Procédé et appareil pour introduire du calcium dans un bain de fer fondu - Google Patents
Procédé et appareil pour introduire du calcium dans un bain de fer fondu Download PDFInfo
- Publication number
- EP0137618A2 EP0137618A2 EP84305326A EP84305326A EP0137618A2 EP 0137618 A2 EP0137618 A2 EP 0137618A2 EP 84305326 A EP84305326 A EP 84305326A EP 84305326 A EP84305326 A EP 84305326A EP 0137618 A2 EP0137618 A2 EP 0137618A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- wire
- nozzle
- lance
- molten
- calcium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 title claims abstract description 72
- 229910052791 calcium Inorganic materials 0.000 title claims abstract description 71
- 239000011575 calcium Substances 0.000 title claims abstract description 71
- 239000000463 material Substances 0.000 title claims abstract description 44
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000008569 process Effects 0.000 title claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims abstract description 70
- 239000002184 metal Substances 0.000 claims abstract description 70
- 239000011261 inert gas Substances 0.000 claims abstract description 46
- 239000012768 molten material Substances 0.000 claims abstract description 30
- 239000007789 gas Substances 0.000 claims abstract description 22
- 239000000203 mixture Substances 0.000 claims abstract description 11
- 230000008018 melting Effects 0.000 claims abstract description 8
- 238000002844 melting Methods 0.000 claims abstract description 8
- 238000003756 stirring Methods 0.000 claims abstract description 5
- 238000013019 agitation Methods 0.000 claims abstract description 4
- 238000011144 upstream manufacturing Methods 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 4
- 238000007711 solidification Methods 0.000 claims description 3
- 230000008023 solidification Effects 0.000 claims description 3
- 230000007704 transition Effects 0.000 claims description 3
- 230000001737 promoting effect Effects 0.000 claims 1
- 230000007246 mechanism Effects 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 2
- 238000011109 contamination Methods 0.000 abstract 1
- 239000000155 melt Substances 0.000 description 25
- 229910000831 Steel Inorganic materials 0.000 description 18
- 239000010959 steel Substances 0.000 description 18
- 239000000654 additive Substances 0.000 description 15
- 230000000996 additive effect Effects 0.000 description 15
- 239000002893 slag Substances 0.000 description 12
- 230000003247 decreasing effect Effects 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000005275 alloying Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000009628 steelmaking Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005253 cladding Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000011236 particulate material Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000010079 rubber tapping Methods 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910000882 Ca alloy Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 244000007645 Citrus mitis Species 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- ULGYAEQHFNJYML-UHFFFAOYSA-N [AlH3].[Ca] Chemical compound [AlH3].[Ca] ULGYAEQHFNJYML-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000001669 calcium Chemical class 0.000 description 1
- 229940043430 calcium compound Drugs 0.000 description 1
- 150000001674 calcium compounds Chemical class 0.000 description 1
- 229910021346 calcium silicide Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 238000005188 flotation Methods 0.000 description 1
- 239000010436 fluorite Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 239000011214 refractory ceramic Substances 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/10—Making spheroidal graphite cast-iron
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/068—Decarburising
Definitions
- This invention relates to the field of processing of molten metals, in particular to a process and an apparatus for adding refining or alloying ingredients to improve properties of a metal being processed.
- a ferrous melt is typically produced in a suitable furnace and then tapped into a ladle where it is treated with one or more ingredients for refining or alloying purposes.
- calcium to the molten ferrous material at this point as a refining agent for oxide inclusion flotation, oxide inclusion morphology modification, desulfurization, etc.
- the low density (relative to steel), volatility and reactivity of calcium severely complicate the task of providing a satisfactory process for its addition to the molten material in the ladle.
- molten metal In metal processing, and in particular steel processing, molten metal generally is separated from a quantity of slag which remains relatively solid and floats upon the surface of the molten metal.
- the slag is made up of various.lower- density impurities, quantities of oxidized metals and the like.
- the additive In order to feed an additive material into the molten metal, the additive must be placed below or caused to pass through the slag surface.
- additive materials intended to improve the properties of e.g. steel are typically relatively expensive and must be conserved. Any waste of a calcium-containing additive material, for example by the loss of material in the slag layer during addition, can have a major economic impact on the'producer and the product. It is therefore highly desirable to feed the calcium well below the surface of the molten metal to the point where it will be most effective, and to mix the molten metal to evenly distribute the calcium additive therein.
- U.S. Patent 4,154,604 discloses a method and apparatus for adding a wire to molten metal in a vessel through a refractory clad tube filled with pressurized inert gas.
- This patent does not, however, disclose the desirability of effecting the melting of wire constituents at a substantial distance from the lower tip of the refractory clad tube in or directly below a region of downwelling of the molten metal. In fact, such a result is physically precluded in the preferred embodiment disclosed in said patent by the close proximity of the lower tip of the tube to the bottom wall of the vessel.
- a novel process for adding calcium to a bath of molten ferrous material comprises feeding a calcium metal-containing wire having a lower density than said ferrous material downwardly through a refractory lance inserted into said bath while providing a sufficient flow of inert gas through said lance to maintain the interior of the lance essentially free of said molten ferrous material and to induce substantial recirculatory stirring of said molten material, with the disposition of the lance in said bath and the composition, cross-sectional dimensions and feeding rate of said wire being such that (a) said wire bends substantially towards the horizontal direction after exiting from the wire outlet of the lance and before fully decomposing, and (b) at least a major part of the desolidification of the calcium in said wire occurs by melting in or directly below a region of downwelling of said molten ferrous material at a depth below the surface of said bath at which the ferrostatic pressure is greater than the vapor pressure of calcium at the temperature of said molten ferrous material.
- the buoyancy of the wire resulting from its lower density than that of the melt, that causes it to bend.
- the wire outlet of the lance is positioned at a depth below the surface of said bath at which the ferrostatic pressure is greater than the vapor pressure of calcium at the melt temperature.
- This countercurrent flow of the rising calcium and circulating molten ferrous phases greatly enhances the degree of contact between the calcium and the molten ferrous material and further increases the calcium residence time in the bath. As a result, the efficiency of utilization of the calcium refining additive is substantially improved.
- Another advantage of the process of the present invention is that the inert gas flow rate in the lance can be varied independently of the wire feeding rate to optimize the internal melt circulatory stirring rate and the extent of slag/metal contact at the surface of the bath.
- the present invention also includes a novel apparatus for efficiently adding a processing element in the form of a wire directly into a quantity of molten material, said apparatus comprising a heat-resistant nozzle having an outlet disposable beneath the surface of. the molten material, means for feeding the wire into the nozzle, and means for concurrently injecting an inert gaseous medium into the nozzle together with the wire, thereby preventing closure of the nozzle by solidification of molten material therein while agitating the molten material by gas bubble agitation.
- a seal device having opposed, pressure-biased pistons engages the wire upstream (relative to wire feed) of the source of inert gas, which gas is fed together with the wire through a gas-tight conduit to the nozzle.
- a particular configuration of the bore of the nozzle maximizes the effect of the inert gas.
- a restriction in the flow path adjacent the outlet of the nozzle creates an area of increased gas velocity, whereby any irregularities which may occur in the feeding of wire do not give rise to the passage of molten metal into the interior of the nozzle.
- the novel apparatus of the invention is inexpensive, convenient in use, effective in starting, stopping and during use, and requires use of the least amount of additive necessary to achieve a given concentration in the processed metal.
- FIGS. 1 and 2 A suitable apparatus for use in feeding a calcium metal-containing wire 1 into a bath 2 of molten ferrous material, e.g. steel, contained in a ladle 3 (which is open to the atmosphere) is schematically depicted in FIGS. 1 and 2.
- wire 1 has a lower density than the molten ferrous material 2.
- the term "calcium metal-containing wire” means that such a wire is comprised at least in part of unalloyed elemental metallic calcium as a distinct phase.
- the wire may also contain distinct phases of calcium alloys (e.g. a calcium-aluminum alloy) or calcium compounds (e.g.
- the calcium metal-containing wire may be clad (e.g. with a steel cladding) or unclad.
- the calcium metal-containing core of the clad wire may itself be a wire or may exist in any other known form, e.g. a powder.
- a surface layer 4 of a basic synthetic slag containing e.g. lime and fluorspar is applied to the melt 2 prior to commencement of the wire feeding.
- the terms "depth below the surface of the bath", “depth below the surface of melt 2", etc. refer to the depth below the slag/ molten metal interface.
- wire I is fed into melt 2 downwardly through a refractory lance 5 inserted into the bath 2 of molten ferrous material.
- a flow of gas inert to the molten ferrous material e.g. argon
- This inert gas exits from the wire outlet 6 of lance 5 and rises as a multiplicity of bubbles 7 surrounding lance 5 to the surface of the melt.
- the pressure and flow rate of the inert gas must be sufficient to maintain the inner bore of the lance free of molten ferrous material and thus prevent blockage of the bore by solidification of said material.
- the inert gas pressure and flow rate should be sufficient to induce a substantial recirculatory stirring of the melt 2 in ladle 3 (note arrows in bath 2 in FIG. 1).
- the inert gas flow rate is not so high as to generate a large amount of turbulence on the surface of the melt as the bubbles 7 escape to the atmosphere.
- a preferred range for the flow rate of inert gas through lance 5 is from about 1.5 x 10 -5 to about 4 x 10 -5 standard ft. 3 /(min. ' lb. of melt). Since the inert gas in lance 5 is not relied upon to propel the wire 1 into the melt, its flow rate through the lance can be adjusted independently of the wire feeding rate.
- the inert gas pressure in lance 5 must, of course, be greater than the ferrostatic pressure at the wire outlet.
- refractory lance means that at least those outermost longitudinal portions of lance 5 that come into contact with the molten ferrous material 2 are made of a refractory material (e.g. alumina) that is resistant to physical or chemical change while subjected to such contact.
- lance 5 is straight and oriented in a vertical manner while wire 1 is being fed through it.
- lance 5 may also be tilted away from a vertical orientation during the wire feeding (but not horizontal).
- the lance may have a "dog-legged" shape.
- the lance is provided with a wire inlet and a wire outlet, with the wire inlet at a higher elevation during use than the wire outlet.
- the wire outlet is at the lower tip of the lance.
- the temperature of the molten ferrous material 2 in ladle 3 ranges from about 2800°F to about 3000°F. At these temperatures the vapor pressure of calcium is quite substantial. As discussed earlier, it is essential to the full success of the calcium addition operation that a major part (or all) of the desolidification of the elemental calcium metal in wire 1 occur by melting rather than by vaporization. Thus, this desolidification must occur below the critical depth in the melt, which is defined as that depth below the surface of the melt at which the ferrostatic pressure is equal to the vapor pressure of calcium (at the melt temperature). The critical depth may be readily determined as a function of temperature by using the chart provided in FIG. 3. The rightmost curve in FIG. 3 is a plot of calcium vapor pressure vs.
- the leftmost curve is a plot of ferrostatic pressure vs. depth below the surface of the melt.
- the vapor pressure of calcium is 1.57 atm.
- a ferrostatic pressure of 1.57 atm. is experienced at a depth of 2.8 feet, which is thus the critical depth at 2860°F.
- the term "disposition of the lance” or “lance disposition” contemplates both the depth of the lance in the bath and its position in horizontal planes through the bath (e.g. the plane of FIG. 2), as well as the orientation of the lance with respect to the vertical (i.e. the degree and direction of its tilt, if any, away from the vertical).
- the four variables of lance disposition, wire composition, wire cross-sectional dimensions and wire feeding rate are interrelated, so that a change in one of said variables may require that one or more of the remaining variables be readjusted to continue obtaining the results (a) and (b) set forth above.
- the lance be disposed so that its wire outlet 6 is positioned below the critical depth while the wire is being fed through the lance, as shown in FIG. 1.
- the wire outlet of ' the lance it is also possible to operate with the wire outlet of ' the lance somewhat above the critical depth. In this case, it may be necessary to increase the wire feeding rate, increase the wire diameter or switch to a clad wire in order to continue the practice of the present invention.
- the lance 5 be non-centrally disposed in the ladle 3, as viewed in horizontal planes such as the plane of FIG. 2.
- lance 5 is straight and vertically-oriented in the bath
- the wire outlet 6 of lance 5 is at the lower tip of the lance and is positioned below the critical depth D
- the distance between the longitudinal axis of the lance and the inner surface of the nearest ladle side wall is from about 1/6 to about 1/3 of the longest linear dimension of the bath (in horizontal planes)
- the temperature of the molten ferrous material 2 is from about 2800 °F to about 3000°F
- a preferred range for the wire feeding . rate in the practice of the present invention is from about 500 ft./min. to about 1000 ft/min.
- the temperature of the molten steel in the ladle was 2860 0 F, which corresponds to a critical depth of 2.8 ft.
- the wire bent substantially towards the horizontal direction. Complete decomposition of the wire occurred at a distance of about 10 feet from the lower tip of the lance.
- the molten steel in the ladle was tapped and cast into appropriate molds.
- the cast steel product contained 0.22 wt. % carbon, 1.36 wt. % manganese, 0.03 wt. % aluminum, 0.12 wt. % vanadium, 0.005 wt. % sulfur and 45 ppm calcium. 100% inclusion modification was observed.
- Example 1 The procedure of Example 1 may be repeated with the use of an unclad calcium metal wire. Operating equipment and conditions are substantially unchanged, except that an unclad 12 mm. diameter calcium metal wire is fed to the bath of molten steel for one minute at a rate of 800 ft./min. After exiting from the wire outlet at the lower tip of the lance, the wire bends substantially towards the horizontal direction. Complete decomposition of the wire occurs at a distance of about 10 feet from the lower tip of the lance.
- FIGS. 4 to 11 A preferred embodiment of the apparatus of the invention is illustrated in FIGS. 4 to 11.
- One or more processing elements for treating a molten metal product are disposed in, or otherwise form a part of, a wire 20. Such elements are hereinafter sometimes referred to as being in wire-form.
- the general objective is to convey the wire 20 from reel 22 to the quantity of molten metal 56 in rece p table 52.
- a feeding mechanism 24 draws the wire from the reel and advances the wire along a feed path.
- Inert gas is supplied to the gas-tight conduit, and a seal mechanism 30 located immediately upstream of the inert gas input prevents loss of inert gas around wire 20 in a direction backwards along the feed path.
- the nozzle 60 of the invention shown in detail in FIGS. 5 to 7, comprises a refractory ceramic casing 62, through which the calcium wire is conveyed in metallic conduit portions 66 and 70 to the ultimate outlet or discharge point 84.
- Refractory casing 62 may be made of alumina (A1 2 0 3 ) or any other suitable refractory material such as those used to line kilns and the like.
- the nozzle 60 may be raised and lowered with respect to the metal receptacle 52, or vice versa, by means of appropriate mechanical linkages.
- the metal receptacle 52 may be carried by a winch/conveying system, including yoke assembly 48.
- it may be preferable to raise and lower the entire feed mechanism as a unit, as shown in FIG. 11. In any event, it is beneficial to avoid flexing the conduit 44.
- the central wire-carrying portion of nozzle 60 includes a metallic conduit 66 leading to metallic conduit 70, through both of which the wire 20 is passed.
- the larger conduit 66 carries the wire to near the discharge opening 84 of nozzle 60.
- An enlarged bore 68 is formed at the end of large conduit 66, into which bore small conduit 70 is placed.
- Small conduit 70 and large conduit 66 are joined by threads, or by weld 72, or by other convenient means.
- the discharge end of the smaller conduit 70 at the extreme end of nozzle 60, has an elongated, gradually tapered funnel-shaped section 80 of decreasing internal diameter in the direction of flow.
- the narrower end 82 of the funnel-shaped section there is an abrupt increase in diameter, formed by a relatively short substantially cylindrical section 83 of substantially uniform diameter.
- this particular variation in diameter along the direction of wire travel has certain advantages.
- the cross-section is adapted to cooperatively prevent the molten metal 56 from running upwards into the nozzle.
- encroaching molten metal may solidify in the nozzle along the internal areas of conduits 66 and 70 and there bind the wire to the conduit.
- the inert gas passing outwards through the nozzle together with wire 20 agitates the metal 56, mixing the additive and the molten metal, thus providing for a more even distribution of the additive material.
- the inert gas also functions to keep the nozzle cool.
- the wire-form additive In order to add the wire-form additive to the molten metal 56 at a point well below the surface of molten metal, it is necessary to overcome substantial fluid pressure in the molten metal.
- the fluid pressure is, of course, a function of the depth below the surface of molten metal. The particular pressure will depend upon the particular metal, but will usually be quite substantial at a depth of one or two meters.
- the pressure of inert gas supplied must overcome this fluid pressure in order to prevent molten metal 56 from rising in the nozzle. Should any molten metal be permitted to run into the nozzle, wire 20 can immediately be seized and welded to a conduit wall as the molten metal solidifies.
- the additive material in the form of wire 20 melts after discharge into the reservoir of molten metal 56. Bubbles 88 of inert gas rise toward the surface of molten metal 56, agitating the molten metal and causing an overall flow therein, upwards adjacent the nozzle and downwards at other areas, namely around the periphery of the molten metal reservoir 52.
- conduit 70 The decreasing internal diameter of conduit 70 is intended to maximize the gas velocity immediately adjacent the ultimate outlet 84 of the nozzle.
- the gas at constant pressure, increases in velocity up to the restriction 82.
- an open cavity or chamber formed by the uniformly cylindrical section 83 of the bore serves to space the restriction 82 from the molten metal 56, further guarding against the entry of molten metal into the restricted orifice 82.
- seal mechanism 30 is provided to prevent a backwash of inert gas.
- Seal mechanism 30 comprises a housing having at least one pair of opposed pistons 32 having contoured sealing surfaces for slidably engaging the wire moving therebetween, which clasp the advancing additive wire 20 in a gas-tight fashion.
- the inert gas Downstream of the opposed pistons 32, the inert gas is fed from inert gas source 31 via conduit 33 to the area of wire 20, the wire now being enclosed in a gas-tight conduit 44 leading from seal 30 to the nozzle 60,
- a compressed air source 34 is preferably used to drive opposed pistons 32 against wire 20. Spring biasing, hydraulic pressure or the like are also possible.
- a manifold 36 may be used to equally distribute the air pressure of compressor 34 or other source.
- Opposed pistons 32 are slidably mounted in gas-tight cylinders, and sealed therein by means of resilient "0"-rings, for example two per piston.
- the equalization of gas pressure by means of manifold 36 results in equal pressure on opposed pairs of axially aligned pistons 32, at each stage thereof.
- Two stages or pairs of opposed pistons are shown, disposed in parallel relationship. It will be appreciated that the opposed pistons may likewise be mounted at right angles, or as otherwise desired.
- the pairs may also be operated independently such that one pair provides an atmosphere seal and the other pair provides an inert gaseous medium seal.
- the housing of seal unit 30 is preferably made of steel.
- the pistons 32, mounted in the cylinders of the housing, are made of a durable plastic material.
- the pistons may, for example, be made from or coated with teflon, nylon, or the like.
- a suitable control mechanism may be connected simultaneously to the pinch roller wire feed device 24 and to the inert gas pressure control 42.
- the gas control 42 should be left closed until the wire becomes engaged by opposed pistons 32 of seal 30.
- no particular gas pressure is required until the injector nozzle 60 is brought into proximity with the molten metal 56, or the slag 54 thereupon.
- the feeder and inert gas pressure control may be simultaneously activated, and the nozzle plunged into the molten metal. Melting additive and inert gas are discharged at the nozzle orifice, well below the slag/metal interface.
- FIG. 11 A preferred physical arrangement of the system is shown in,FIG. 11. Virtually the entire system is disposed upon a pivotally-mounted table l20, which-pivots on hinge 122.
- a hydraulic or pneumatic lifting device 124 is operable to lift and lower the table 120 about its pivot, thereby raising and lowering nozzle 60 with respect to the molten metal 56 in container 52.
- the lifting mechanism may likewise be incorporated under the common inert gas/wire feed control.
- the nozzle 60 is formed with a bore having, with respect to the direction of additive feed and inert gas flow, a substantially cylindrical section of substantially uniform diameter, followed by a tapered section of decreasing diameter terminating_ at an aperture having a radius only slightly larger than that of the wire and a second substantially cylindrical section of substantially uniform diameter larger than that of said aperture, whereby the wire remains spaced from the internal edges of the nozzle conduit adjacent the outlet.
- An abrupt transition between the tapered and second cylindrical sections creates a restricted diameter orifice with increased gas velocity therein, past which orifice the molten metal does not backflow.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT84305326T ATE35290T1 (de) | 1983-08-12 | 1984-08-06 | Verfahren und vorrichtung zum einbringen von calcium in eisenschmelzen. |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/522,754 US4481032A (en) | 1983-08-12 | 1983-08-12 | Process for adding calcium to a bath of molten ferrous material |
US522754 | 1983-08-12 | ||
US06/522,753 US4512800A (en) | 1983-08-12 | 1983-08-12 | Wire injection apparatus |
US522753 | 1995-09-01 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0137618A2 true EP0137618A2 (fr) | 1985-04-17 |
EP0137618A3 EP0137618A3 (en) | 1986-04-02 |
EP0137618B1 EP0137618B1 (fr) | 1988-06-22 |
Family
ID=27060927
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84305326A Expired EP0137618B1 (fr) | 1983-08-12 | 1984-08-06 | Procédé et appareil pour introduire du calcium dans un bain de fer fondu |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP0137618B1 (fr) |
JP (1) | JPH0347909A (fr) |
KR (1) | KR880000468B1 (fr) |
AU (1) | AU550957B2 (fr) |
BR (1) | BR8404033A (fr) |
DE (1) | DE3472274D1 (fr) |
DK (1) | DK386284A (fr) |
ES (3) | ES8700330A1 (fr) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001042517A1 (fr) * | 1999-12-06 | 2001-06-14 | Firma Caltex Gmbh | Procede permettant la production d'un fil d'injection |
EP2137326A1 (fr) * | 2007-04-02 | 2009-12-30 | Specialty Minerals Michigan Inc. | Insert de buse de canne d'injection de fils |
US7906747B2 (en) | 2004-06-10 | 2011-03-15 | Affival | Cored wire |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE456001B (sv) * | 1983-11-08 | 1988-08-29 | Bind O Matic Ab | Block samt sett att framstella detsamma |
DE3661841D1 (en) * | 1985-01-24 | 1989-02-23 | Vallourec | Process for treating liquid metals by a calcium-containing cored wire |
US4705261A (en) * | 1986-11-28 | 1987-11-10 | Pfizer Inc. | Wire injection nozzle |
FR2764905B1 (fr) * | 1997-06-23 | 1999-07-23 | Pechiney Electrometallurgie | Procede de traitement du plomb fondu par le calcium et fil a base de calcium pour ce traitement |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2577837A (en) * | 1949-10-29 | 1951-12-11 | Lothar R Zifferer | Introduction of magnesium into molten iron |
GB1219706A (en) * | 1968-05-13 | 1971-01-20 | Nippon Kokan Kk | A method for treating a molten metal |
US3729309A (en) * | 1969-03-07 | 1973-04-24 | Nippon Kokan Kk | Method for adding alloying elements to molten metals |
US3778250A (en) * | 1969-02-26 | 1973-12-11 | Jones & Laughlin Steel Corp | Method for treating metallic melts |
US3885957A (en) * | 1972-03-01 | 1975-05-27 | Thyssen Niederrhein Ag | Method for the desulfurization of a steel melt |
US4066248A (en) * | 1976-02-27 | 1978-01-03 | Fried. Krupp Gesellschaft Mit Beschrankter Haftung | Charging device |
US4094666A (en) * | 1977-05-24 | 1978-06-13 | Metal Research Corporation | Method for refining molten iron and steels |
US4154604A (en) * | 1976-07-28 | 1979-05-15 | Mannesmann Aktiengesellschaft | Feeding additives into the interior of molten metal |
JPS5713115A (en) * | 1980-06-26 | 1982-01-23 | Komatsu Ltd | Production of tough and strong free-cutting ca cast steel |
-
1984
- 1984-08-06 EP EP84305326A patent/EP0137618B1/fr not_active Expired
- 1984-08-06 DE DE8484305326T patent/DE3472274D1/de not_active Expired
- 1984-08-10 BR BR8404033A patent/BR8404033A/pt not_active IP Right Cessation
- 1984-08-10 ES ES535098A patent/ES8700330A1/es not_active Expired
- 1984-08-10 AU AU31783/84A patent/AU550957B2/en not_active Expired
- 1984-08-10 DK DK386284A patent/DK386284A/da not_active Application Discontinuation
- 1984-08-11 KR KR1019840004837A patent/KR880000468B1/ko not_active IP Right Cessation
-
1985
- 1985-08-01 ES ES545812A patent/ES8607407A1/es not_active Expired
- 1985-08-01 ES ES545813A patent/ES8607408A1/es not_active Expired
-
1990
- 1990-02-08 JP JP2029345A patent/JPH0347909A/ja active Granted
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2577837A (en) * | 1949-10-29 | 1951-12-11 | Lothar R Zifferer | Introduction of magnesium into molten iron |
GB1219706A (en) * | 1968-05-13 | 1971-01-20 | Nippon Kokan Kk | A method for treating a molten metal |
US3778250A (en) * | 1969-02-26 | 1973-12-11 | Jones & Laughlin Steel Corp | Method for treating metallic melts |
US3729309A (en) * | 1969-03-07 | 1973-04-24 | Nippon Kokan Kk | Method for adding alloying elements to molten metals |
US3885957A (en) * | 1972-03-01 | 1975-05-27 | Thyssen Niederrhein Ag | Method for the desulfurization of a steel melt |
US3885957B1 (fr) * | 1972-03-01 | 1986-12-16 | ||
US4066248A (en) * | 1976-02-27 | 1978-01-03 | Fried. Krupp Gesellschaft Mit Beschrankter Haftung | Charging device |
US4154604A (en) * | 1976-07-28 | 1979-05-15 | Mannesmann Aktiengesellschaft | Feeding additives into the interior of molten metal |
US4094666A (en) * | 1977-05-24 | 1978-06-13 | Metal Research Corporation | Method for refining molten iron and steels |
JPS5713115A (en) * | 1980-06-26 | 1982-01-23 | Komatsu Ltd | Production of tough and strong free-cutting ca cast steel |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN, vol. 6, no. 78 (C-102)[956], 15th May 1982; & JP-A-57 013 115 (KOMATSU SEISAKUSHO) 23-01-1982 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001042517A1 (fr) * | 1999-12-06 | 2001-06-14 | Firma Caltex Gmbh | Procede permettant la production d'un fil d'injection |
US7906747B2 (en) | 2004-06-10 | 2011-03-15 | Affival | Cored wire |
EP2137326A1 (fr) * | 2007-04-02 | 2009-12-30 | Specialty Minerals Michigan Inc. | Insert de buse de canne d'injection de fils |
EP2137326A4 (fr) * | 2007-04-02 | 2010-10-13 | Specialty Minerals Michigan | Insert de buse de canne d'injection de fils |
US8221677B2 (en) | 2007-04-02 | 2012-07-17 | Specialty Minerals (Michigan) Inc. | Wire injection lance nozzle insert |
Also Published As
Publication number | Publication date |
---|---|
ES545812A0 (es) | 1986-06-16 |
ES8607408A1 (es) | 1986-06-16 |
EP0137618B1 (fr) | 1988-06-22 |
JPH0369966B2 (fr) | 1991-11-06 |
DE3472274D1 (en) | 1988-07-28 |
ES8607407A1 (es) | 1986-06-16 |
DK386284D0 (da) | 1984-08-10 |
EP0137618A3 (en) | 1986-04-02 |
AU550957B2 (en) | 1986-04-10 |
DK386284A (da) | 1985-02-13 |
ES8700330A1 (es) | 1986-10-16 |
JPH0347909A (ja) | 1991-02-28 |
ES535098A0 (es) | 1986-10-16 |
KR880000468B1 (ko) | 1988-04-07 |
ES545813A0 (es) | 1986-06-16 |
BR8404033A (pt) | 1985-07-16 |
AU3178384A (en) | 1985-02-14 |
KR850001921A (ko) | 1985-04-10 |
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