US3881915A - Method for enhancing reduction of ores, oxides and melting of metals by magnetic forces - Google Patents

Method for enhancing reduction of ores, oxides and melting of metals by magnetic forces Download PDF

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US3881915A
US3881915A US306429A US30642972A US3881915A US 3881915 A US3881915 A US 3881915A US 306429 A US306429 A US 306429A US 30642972 A US30642972 A US 30642972A US 3881915 A US3881915 A US 3881915A
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metal
particles
oxide
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Priority to AU62358/73A priority patent/AU6235873A/en
Priority to BR882673A priority patent/BR7308826D0/en
Priority to NL7315424A priority patent/NL7315424A/xx
Priority to DE2356533A priority patent/DE2356533A1/en
Priority to IT5365973A priority patent/IT997735B/en
Priority to FR7340344A priority patent/FR2206385B2/fr
Priority to CA185,736A priority patent/CA992327A/en
Priority to AR25099673A priority patent/AR202638A1/en
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    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21BMANUFACTURE OF IRON OR STEEL
    • C21B13/00Making spongy iron or liquid steel, by direct processes
    • C21B13/0006Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
    • C21B13/0013Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state introduction of iron oxide into a bath of molten iron containing a carbon reductant
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B5/00General methods of reducing to metals

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  • Yet another feature and advantage of the invention resides in a method for conducting the off-heat and carbon monoxide produced as a consequence of the reaction in the molten metal stream back to the supply of oxide charge in order to pre-heat and partially reduce the charge.
  • the particle will have been sufficiently wetted” and heated so that it has either been partially reduced (in the case of an oxide) or melted (in the case of a particulate) before the magnetic hold on the particle is gone.
  • the particle may then well move toward the surface of the stream but the probability is that it will either have been reduced or melted before that time.
  • the stream is characterized by turbulent movement so that movement of the particle within the stream and beneath the surface may be described as randomly kinetic.” In that event it is highly unlikely that any particles would not be reduced or melted within the stream substantially instantaneously.
  • Recirculation of the metal on the conveyor refers to the movement of molten metal up an induction conveyor and then merely allowing the metal so elevated to slide back downwardly over the lower layer of metal which is continuously being moved upwardly by inductive current moving perpendicular to the direction of metal flow.
  • the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream.

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  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

A continuous reducing or melting method including the steps of: providing a substantially continuous moving molten metal stream, introducing into the molten stream a substantially continuous charge of metallic ores, or oxides or particulates which are magnetically attractive or which become magnetically attractive at a given temperature, the metal of the oxides or particulates being substantially the same as that of the molten metal stream, and utilizing a magnetic field to force the oxides or particulates into and beneath the surface of the stream and to so hold them at/or beneath such surface as long as they are magnetically attractive so as to thereby accelerate their dissolution or chemical reaction, the product of which adds further molten metal to the stream.

Description

United States Patent [191 Proler [4 May 6,1975
[76] Inventor: Sam Proler, 5106 Contour Pl.,
Houston, Tex. 77035 221 Filed: Nov. 14, 1912 21 Appl. No; 306,429
Related [15. Application Data [63] Continuation-impart of Ser. No. 161,905, July 12,
1971, abandoned, which is a continuation-in-part of Ser. No. 29,325, March 30, 1970, abandoned.
[52] US. Cl; [51] Int. C2112 5/52 [58] Field of Search 417/50; 75/93 R, 65, 135,
FOREIGN PATENTS OR APPLICATIONS 401,372 5/1969 Australia.................................75/12 327,687 4/1930 United Kingdom 75/11 Primary ExaminerL. Dewayne Rutledge Assistant Examiner-M. J. Andrews Attorney, Agent, or Firm-Bernard A. Reiter [57] ABSTRACT A continuous reducing or melting method including the steps of: providing a substantially continuous moving molten metal stream, introducing into the molten stream a substantially continuous charge of metallic ores, or oxides or particulates which are magnetically attractive or which become magnetically attractive at a given temperature, the metal of the oxides or particulates being substantially the same as that of the molten metal stream, and utilizing a magnetic field to force the oxides or particulates into and beneath the surface of the stream and to so hold them at/or beneath such surface as long as they are magnetically attractive so as to thereby accelerate their dissolution or chemical reaction, the product of which adds further molten metal to the stream.
46 Claims, 7 Drawing Figures FATENTEE MAY 6 I975 SHEEF 1 0F 4 FIG] 1 METHOD FOR ENHANCING REDUCTION OF ORES, OXIDES AND MELTING OF METALS BY MAGNETIC FORCES This application is a continuation-in-part of application Ser. No. l6l,905 entitled Another Method For Processing Metallic Ores And/Or Metallic Compounds," filed July l2, 1971, now abandoned; which in turn is a continuation-in-part of application Ser. No. 29,325 entitled Method For processing Metallic Ores And/Or Metallic Compounds, filed Mar. 30, 1970, now abandoned.
BACKGROUND OF THE INVENTION In the blast furnace production of hot metal" as it is commonly known, enormous quantities of raw materials are required, along with a significant capital investment for equipment, in order to produce the end product. In an effort to produce metallized iron more economically, numerous other reduction processes have been conceived. ln practically all of the reduction methods conceived, the iron ore which is used must be ground prior to its use in order to separate the gangue and thereby increase the iron content of the oxide. Extraction of such gangue of course improves the quality of the iron oxide, influences the particle size, and in general results in improvement of the overall quality of the particle. This process, commonly known as beneficiation" obviously becomes a factor which increases the cost of the product produced.
In addition to the method of producing hot metal from oxides in their natural state, certain methods have been conceived which may utilize the by-products of present day steel production. Some of these methods have been conceived so as to enable utilization of various forms of iron oxide which cannot otherwise be utilized in their by-product state. These by-products, such as BOF dust, are generated at a size that is too small for many of the present reduction methods. This fine material must, in order to be used in blast furnace for example, be sintered before it is suitable as a charge material. Although this material may be used in certain other types of processes and methods such as those disclosed in U.S. Pat. No. 3,157,489 to Wiberg, experiments indicate that certain deficiencies and problems exist when fine or small size charge material is introduced into molten metal in the manner suggested by this patent. Specifically, it is found that utilization of this fine material as a feed into a molten bath is ineffective because the fines do not go readily into solution due to their relatively light weight and slow wetting action. This is not to say that such oxides do not at all go into solution in a molten bath, but only that the rate of dissolution is relatively slow and that such rates cannot be accelerated by increasing the oxide introduction, because to do so would cause a freeze-up in the bath in the area of introduction. More specifically, it is found in the course of experimentation that the oxides tend to float on the surface and will not, particularly in a substantially static molten bath, go readily into solution.
ln addition to the presence of naturally occurring iron ores which commonly require beneficiation, and steel mill by-products such as BOF dust which commonly requires sintering and which are otherwise unusable because of their slow wetting action, there is known to exist in various areas of the world very high content iron ores in fine or in dust size particles. These reserves differ from the aforementioned iron ore with respect to the relative degree of iron content found in the ore.
With present known methods, relatively little use can be made of such dust size particles either in most reduction methods or in the conventional blast furnace without some type of preparatory processing such as sintering, pelletizing or briquetting. These and other similar size of charging materials cannot be used in the blast furnace because they tend to obstruct the necessary permeability required in blast furnace charges, and they cannot be efficiently and economically used in the molten bath reduction processes and methods because of their relatively slow wetting and dissolution times.
The charging materials referred to hereinabove, such as iron oxide and steel mill by-products such as blast furnace dust, BOF dust, mill scale and scarfer grit exist in extensive and readily available quantities throughout the world. For example, with reference to the hot rolling of carbon steel alone, it may be pointed out that from one-half to two percent of the weight of the ingot may be lost as mill scale during reheating and rolling. Further, during the reducing of ores in a blast furnace, the refining of pig iron and steel scrap in an open hearth furnace or a basic oxygen furnace, from one to two percent of the metal charge may be oxidized and then collected in pollution control equipment as iron oxide fumes. These by-products and the aforementioned unused and unusable natural oxides found in the particle state are therefore available in extensive quantities but are not used economically in blast furnace operations because of the necessity for intermediate processing such as sintering, pelletizing or briquetting; and they cannot be used in other reduction and melting methods because of the technical obstructions arising from the problems of wetting and slow dissolution. It is abundantly clear that intermediate processing such as sintering, pelletizing and briquetting for utilization of these oxides in the blast furnace is a less desirable alternative than reducing them in molten metal. This is inherently true because of the necessity to commit capital investment to the construction of sintering, pelletizing and briquetting facilities. It is estimated, for example, that the elimination of a sintering or pellet plant alone should result in a savings of ten to fifteen percent in both the capital and operating cost over plants requiring such facilities. Therefore, it becomes readily apparent that the factors of economics and simplicity dictate that effort and attention be directed to overcoming the known problems associated with the reduction of iron oxide-bearing material or melting of iron and steel particulates in molten metal so as to therefore enable utilization of the extensive natural quantities and by-products of these materials that exist around the world.
BRIEF SUMMARY OF THE INVENTION The present invention pertains to a method for substantially instantly and continuously making hot metal. More particularly the invention pertains, in its preferred embodiment, to a method for utilizing a substantially continuous moving molten metal stream as the vehicle for producing additional molten metal. This is accomplished by introducing into the stream, a substantially continuous charge of metal oxides or metal particulates, the metal of which is substantially the same as that of the molten metal of the stream; and utilizing the forces of magnetic attraction to draw the metal oxides or particulates into and beneath the surface of the stream and to so hold them there so long as they are magnetically attractive. The continuous movement of the molten metal stream away from the area of introduction presents a continuously new molten metal bath for the charge which is introduced. As a result, a number of specific advantages over presently known reduction and melting methods are clearly achieved. First, the possibility of freeze-up at the area of introduction of the charge is substantially eliminated because that area of the bath is continuously moving away and presenting a new molten metal area to receive the substantially continuous charge. Secondly, due to the inherent turbulence of the moving molten metal stream described hereinafter, the oxides or particulates are thoroughly mixed so as to promote and enhance their contact with the hot metal of the stream. Further, the existence of magnetic force fields emanating from beneath and through the stream not only attract and draw the oxides or particulates to and beneath the surface so as to thereby more rapidly induce wetting over the area of the oxides or particulates but, in addition, holds the oxides or particulates at or beneath the surface so long as they maintain their magnetic attraction. The combinative effect of the moving stream, its turbulent motion by comparison to a static bath, and the magnetic attraction which draws the charge into and beneath the surface not only significantly accelerate the dissolution and chemical reaction of the charge but also permits introduction of the charge on a substantially continuous basis. The product of the chemical reaction between the oxides and the stream constitutes the added molten metal to the stream while the by-products of the reaction, namely heat, carbon monoxide and slag are withdrawn in the manners described hereinafter, or through any conventional means. The appropriate reducing agent, such as carbon in the case of iron oxide, is appropriately introduced to the stream also, as may be any other desirable additives.
A principal advantage of the invention, therefore, resides in a method whereby molten metal may be produced in an economically efficient and continuous manner.
Another advantage of the invention resides in a method for maximizing the use of available heat in a molten metal stream to effect reducing or melting of a charge introduced thereto, this through the use of a turbulent stream and the utilization of a magnetic force field emanating from beneath the stream and through the body thereof.
A still further feature and advantage of the invention resides in a method of continuously reducing oxides and melting metal particulates in a single apparatus or unit.
Still another feature and advantage of the invention resides in a method for continuously reducing oxides and melting metal particulates in a single unit or producing apparatus which requires a relatively low capital investment.
Still another feature and advantage of the invention resides in a method for efficiently reducing iron oxides to molten iron.
Still another feature and advantage of the invention resides in a method for reducing an iron oxide charge to molten iron, on a continuous basis, and then continuously to steel, all in a single production unit.
Yet another feature and advantage of the invention resides in a method for conducting the off-heat and carbon monoxide produced as a consequence of the reaction in the molten metal stream back to the supply of oxide charge in order to pre-heat and partially reduce the charge.
Still another feature and advantage of the invention resides in a method for continuously reducing iron oxide and melting iron particulates and the like so as to produce molten iron without the necessity for such intermediate processing steps as sintering, pelletizing or briquetting.
Still another feature and advantage of the invention resides in a method for reducing metal oxides or melting metal particulates in a manner which substantially reduces the possibilities of pollution and other contaminating disadvantages commonly associated with such processes.
Yet even another feature and advantage of the invention resides in a method for enhancing reduction of metal oxides and melting of particulates through the use of magnetic attraction.
Still another feature of the invention is a method whereby molten metal may be turbulently moved to cause an improved stirring and mixing action within the metal itself so as to maximize homogeneity in the production of carbon and alloy steels.
These and numerous other features and advantages of the invention will be more clearly recognized and appreciated upon a reading of the following detailed description, claims and drawings wherein like numerals denote like parts in the several views, and wherein:
DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view, in substantially schematic form, showing a molten metal furnace where heat is introduced, and a closed loop trough and conveyor reactor system extending therefrom and back into the furnace.
FIG. 2 is a partial section and cutaway view of FIG. 1 along the plane 22 thereof.
FIG. 3 is an alternative illustrative arrangement of the invention, in which there is provided at least two cooperating furnaces each for introducing heat to the system, and each communicating with the other by two or more molten metal reactors.
FIG. 4 is an isometric view showing the concept of a moving molten metal stream and having therebeneath a magnetic field for attracting a charge into and beneath the surface of the molten metal stream.
FIG. 5 is an isometric view, in partial cutaway, showing an alternative form of the invention in which reduction and melting, or melting alone may take place in a static molten reactor, on a continuous basis.
FIG. 6 illustrates a cross-section view of a form of electromagnetic induction conveyor.
FIGS. 7a, b and c illustrate several exemplary forms of a cascade reactor such as may be used for reducing, melting, alloying and refining in any of the other illustrations herein.
DETAILED DESCRIPTION OF THE INVENTION The term oxides herein shall refer to the compound form of metals when combined with oxygen and which may be of magnetic character either at ambient or at other temperatures, such as for example a hematite. For exemplary purposes however, the invention shall be described with reference to the compound of iron oxide. For purposes herein the term iron oxide" shall particularly refer to iron oxides in their natural and in their man-made forms.
Natural iron oxides shall, for example, include iron oxides occurring in their natural elemental state and which are derived from the mining of iron ores. The term oxide" therefore, as used herein, shall include the respective ores from which the oxide thereof is derived.
Man-made oxides shall include all by-products and waste materials created as a consequence of metallurgical operations and including, such as for example with reference to iron, oxides produced in the burning in a BOF furnace, blast furnace, open hearth furnace (flue dust) and also scarfer grit, mill scale, and the like.
Man-made oxides may, if desired, further include all forms of pellets, briquets, sintered material, and other beneficiated or agglomerated forms of ores, particularly iron.
The term metal particulates or particulates shall include by-product or waste metal fragments from metal operations of all types which may be used as charge material for the method disclosed herein and may, for exemplary purposes only, consist of borings, punchings, shredded pieces, crushed turnings, clippings, shavings, and the like.
The term reactor herein shall refer to the apparatus for containing molten metal and which is exposed to a magnetic field.
The term particles shall refer generically to oxides and particulates and may be equated to the term charge.
The term reducing" in this method shall refer to the chemical reduction of the oxidation level in an oxide.
The term melting" in this method shall refer to process of heating a solid so as to impart sufficient kinetic energy to the molecules thereof as to cause them to overcome their crystal binding forces.
The most efficient and economical method for accomplishing rapid wetting and dissolution of oxides and particulates is to introduce such oxides or particulates over an extended area into a molten metal stream which is continuously moving past the area of introduction. More specifically, the stream should be characterized by continued and turbulent internal mixing, as opposed to the laminar type of flow normally characterizing conventional stream movement. The primary reason for this is that internal turbulence inherently increases and facilitates mass and heat transfer from the liquid molten metal to any solid which is introduced therein. The presence of a turbulent flow pattern is particularly desirable when the solid being introduced into the liquid is relatively light and therefore either tends to be thrown about or to float on the surface of the liquid. As explained earlier, this is essentially the case when relatively fine iron oxides or particulates are introduced into molten metal. Such fine particles do not normally rapidly wet since their entire surface area is not immediately exposed to the molten metal and as a consequence their rate of heat absorption is substantially slower than might be expected if the oxides and particulates were beneath the stream surface. Since the rate of heat absorption is thereby slowed, continued introduction of the feed or charge must be stopped or reduced, thereby reducing the ultimate rate of production.
The time period for dissolution of a solid particle in a molten stream, whether the particle be an oxide or a particulate, is largely determined by its relative size. Larger particles take longer time simply because there is greater mass to be heated. Once such particles are introduced to a stream, therefore, rapid dissolution of them in the stream dictates that their surface be entirely covered so as to thereby maximize use of the available heat developed by the stream. Because of the relatively slow wetting time, the movement of particles, whether they be relatively light oxides or relatively heavy particulates, is not characterized by the pattern of movement of the stream itself because the particles will not in a sense become a part of the stream. lf the particles could be drawn beneath the surface of the stream they would not only be exposed fully to the heat developed within the stream, if the same were molten metal, but the particles would take on a random kinetic movement of the turbulent stream itself thereby facilitating mixing and the transfer of heat through the mass of the particle, at a greater rate.
The characteristics of metals are such that their attraction to magnetic forces is reduced, and eventually eliminated, as the temperature of the metal increases. In the case of iron, for example, magnetic attraction is essentially nonexistent above a temperature of approximately 1,300F. Therefore, a magnetic force field may be effectively transmitted through molten iron. Should the force field come into contact with a particle, whether it be a metal oxide or a particulate, the temperature of which is less than the Curie Point, that is the temperature at which magnetic attraction is lost, the field will draw such particle into and beneath the surface thereof. Thereafter, the force of the magnetic field will remain effective in holding or suspending the particle within the molten stream until its temperature is raised to above the Curie Point. By this time the particle will have been sufficiently wetted" and heated so that it has either been partially reduced (in the case of an oxide) or melted (in the case of a particulate) before the magnetic hold on the particle is gone. Of course when such temperature is reached the particle may then well move toward the surface of the stream but the probability is that it will either have been reduced or melted before that time. This is particularly true if the stream is characterized by turbulent movement so that movement of the particle within the stream and beneath the surface may be described as randomly kinetic." In that event it is highly unlikely that any particles would not be reduced or melted within the stream substantially instantaneously. In addition, it is found that if the stream is continuously moved past an area where the particles, either oxides or particulates are being introduced, the rate of continuous introduction is substantially determined and influenced by the volume and rate at which the stream is moving. in addition it has been found that if the stream is moved continu ously in a closed loop manner, the particles, whether oxides or particulates, may be continuously introduced to the stream and continuously reduced or melted. in such a method it becomes obvious that heat will be lost in the course of movement and in the course of reduction or melting, and that it will be necessary to add heat, either intermittently or continuously, as needed in order to sustain the continuous reduction or melting of oxides r particulates within the moving molten metal stream.
It is recognized that when iron is heated to a high temperature it loses its ferromagnetism and is no longer strongly attracted by a magnet. The temperature at which any ferromagnetic material loses its magnetism is known as the Curie Point; it is 770C for iron and 350C for nickel, for example. The highest known Curie Point is l,l(l for cobalt. For some materials the Curie Point lies near the absolute zero of temperature. Substantially all materials that exhibit ferromagnetism are paramagnetic (are attracted by magnetic forces as opposed to repelled by magnetic forces) when they are heated above the Curie Point temperature. As the temperature continues to increase, the susceptibility decreases continually according to the Curie-Weiss law for strongly paramagnetic substances, unless there is a change in the phase structure of the material.
in accordance with the present invention, advantage is taken of the Curie Point phenomenon of molten metal, particularly with reference to iron, no matter whether it find origin in the oxide form or the particulate form, but assuming essentially that it is in either case in relatively small sizes such as explained earlier herein. This advantage is applied, in practical form, to the concept of the molten stream, preferably but not necessarily being characterized by an internal flow pattern designated as turbulent. In other words it is recognized that the invention, as described herein, is also feasible in a moving molten metal stream having an internal flow which may be described as laminar. Experimentation has shown that the forces of magnetic attraction which are to emanate from beneath the surface of the stream may be substantially equally as effective in either the turbulent or laminar flow. The relative strength, or density, of the magnetic field may however be varied in accordance with the depth of the stream, the relative size and mass of the oxide fines or particulates introduced to the stream and other such factors as may be found to influence the rate at which the charge, whether it be oxide or particulate, is introduced.
The manner of inducing the stream effect referred to herein may be accomplished in numerous ways. A most obvious manner to induce a streamlike flow to a liquid body is through the use of gravity, that is simply to allow the liquid to seek a lower level along a restricted path such as a trough. Therefore, it is contemplated that the method described herein shall be readily applied to any of the numerous types of furnaces or even a holding ladle, any of which is capable of being tapped into a downwardly directed trough to produce a stream of flowing molten metal. The method described hereafter may be practiced on any moving body of molten metal regardless of the manner in which such movement is induced. For example, movement may be induced through the use of the conventional electromagnetic induction conveyor. In one type of such conveyor, the mode of action correspondes to that of a linear induction motor, except that the solid metal plate secondary is replaced by the liquid metal layer in the conveying channel. The primary, known as an inductor, is in the usual design arranged underneath a conveying channel. A cross section of an exemplary channel conveyor may be visualized by reference to FIG. 6 wherein the laminated core 3 and the winding 5 of the inductor as well as the conveying channel 7 are shown. A layer of molten metal, herein refered to as a stream 9, is also shown. Such a conveyor induces a current density such that the current flow lines close in the layer of metal, so that the component of the current density transverse to the direction of travel generates the conveying action. These and similar conveyors exist in common use for regularly moving or conveying molten metals horizontally or up an inclined plane. Other means are known for inducing the flow of liquid such as a molten metal, in a stream. These other methods, such as vacuum pumping, along with those mentioned hereinabove may all be used with varying degrees of effectiveness in connection with the present invention.
The method of the present invention may be practiced with the use of any magnetic field, substantially without regard to the mode or manner by which such field is induced. It has been found feasible for example to dispose, in linearly parallel manner to the stream a permanent magnet beneath a trough or conveying channel through which hot metal is intended to pass.
By using the electromagnetic induction conveyor or other means, movement of hot metal up an inclined plane, or to a higher level, may be accomplished. l-lot metal moved to an elevated level may of course be returned by gravity to a lower level in a trough or channel. It may even be returned to the lower end of the conveyor itself; by recirculating the metal on the conveyor to a furnace from which the conveyor started (FIG. 1), and there may thus be established a closed loop, continuous hot metal circulating stream which may, as described and explained with reference to the drawings, be used as the vehicle for producing additional hot metal. Recirculation of the metal on the conveyor" refers to the movement of molten metal up an induction conveyor and then merely allowing the metal so elevated to slide back downwardly over the lower layer of metal which is continuously being moved upwardly by inductive current moving perpendicular to the direction of metal flow.
With reference to the closed loop method there is shown in FIG. 1 a top view of a furnace 11 containing a bath 13 of molten metal, such as hot metal characterized by a predetermined carbon content. Designed in the reactor is a slag outlet 15 disposed at an appropriate level and a hot metal outlet 17 disposed at also an appropriate level with respect to outlet 15. Outlet 15 is arranged in substantially linear relation with respect to the direction of movement of the moving molten metal stream 9 because the slag does not move entirely up the conveyor but only descends to its outlet 15. The stream 9 is characterized by an outlet channel 19a and a return channel 19b, the latter being positioned to reintroduce the hot metal back into the bath 13 in furnace 11. Hot metal in the induction conveyor may be moved at varying rates of up to 500 tons per hour or more. It is recognized of course that the conveyor may be designed to accomplish substantially any reasonable desired tonnage movement.
Appropriately positioned above the moving molten metal stream are the charging deflectors 23. Unlike prior approaches to the charging method, see US. Pat. No. 3,326,67l to H. K. Woemer, the charging deflectors 23 are intended to introduce oxides for reducion, or particulates for melting, over and extended surface area of molten bath or stream. Heretofore this was not feasible because movement of the stream could not be effectively and reliably promoted. Even introduction of the charge into a restricted area of hot metal was inhibited because of the probability that the temperature of the hot metal at the point of introduction of the charge might be lowered to a marginal point. In accordance with the present invention there is continuously exhibited a substantially new hot metal stream upon which the charge of oxide or particulate may be displayed.
Adjacent the furnace 11 is a reactor section R consisting essentially of trough, or in this example an electromagnetic induction conveyor 7 having laminated core 3 and windings 5, see FIG. 6. The conveyor induces movement of the metal upwardly as explained earlier and simultaneously imparts a magnetic field to the area above the trough position.
As a result, the oxide or particulate may be continuously introduced and reduction or melting may take place without interruption, without recharging, and without the necessity for intermediate steps, operations, or the like. It is only necessary to remove slag or other by-products from the operation while, at the same time, tapping off the product metal as may be desired.
In the drawing of FIG. 1 the bath 13 of molten metal is contained in furnace 11 which is adapted to supply heat either intermittently or substantially continuously to the bath 13 in order to maintain it at some predetermined temperature. Due to the continuous movement of molten metal from bath 13 through outlet 19a, and through reactor and upwardly to return 19b, a predetermined quantity of heat is lost. Therefore, and in order to maintain the stream 9 at the required temperature level, heat is added, as indicated above, by furnace 11 to the bath 13. Heat may be added instead, or in addition, to the stream also, if desired.
The introduction of oxide particles to stream 9 is best accomplished, as shown in FIG. 2, by the charging deflectors 23. The outlets distribute the charge of particles over an extended area of the stream preferably. This area generally corresponds to the area of the reactor itself, that is the area of the stream which is subjected to the forces of magnetism. It is feasible of course to consider introduction of particles over an area of the stream longer than that of the conveyor system, if, at the area of introduction there exists a magnetic field so as to force the particles into and beneath the stream and thereby enhance their reduction. Introduction of the charge through the stream may take place in any number of different ways and is significant primarily with respect to the surface area of stream over which the introduction occurs, for the reasons described above.
With reference now to FIG. 3 there is shown a dual furnace reactor arrangement. The dual reactors R1, R2 are disposed in substantially adjacent relationship to one another and are inclined oppositely with respect to one another. Although the reactors R1, R2 need not be in adjacent relationship as shown, but may be disposed in any desired manner extending from the furnaces, it is advisable that at least one conveyor move the molten metal in ascending manner from one to the other furnaces. It may therefore be recognized that the furnaces 11a, 11b may be disposd at different levels with repect to one another so that it is possible to utilize only one electromagnetic induction conveyor to elevate the hot metal to the upper furnace and, thereafter allowing a gravity trough to return the metal from the upper furnace to the lower furnace. In this manner it is of course feasible to dispose a magnet beneath the gravity return and thereby create a second reactor which derives its stream from the natural forces of gravity and magnetism. The conjunctive effect of the natural laws of gravity and magnetism, when combined with a stream of man-made molten metal thus produces a reactor means which, when used in accordance with the methods disclosed herein, serves as a vehicle for both reduction and melting, of oxides and particulates, respectively. It is to be recognized that the induction conveyor may be used to provide a continuously moving level closed loop (such as in circular path) stream. A further explanation of the declining stream reactor is set forth hereafter with regard to FIG. 4.
With further reference to FIG. 3 reactors R1, R2 are oppositely inclined so as to effectuate a continuous, closed loop processing system in which the furnaces 11a, 11b constitute the holding vessels for the molten metal which is the processing vehicle in each reactor R1, R2. Furnaces 11a, 11b also of course, serve as the means for introducing heat to the molten metal since, as may be expected, heat is lost through natural convection during the movement of the metal and is further lost in promoting either reduction or melting. It is feasible however to utilize the reactor area for introducing heat and to merely allow the furnaces lla, 11b to become mere holding or transfer vessels.
As shown in the embodiment of FIG. 3, the reactors R1, R2 are each of electromagnetic induction type, that is the magnetic forces are supplied from the cores and windings of the conveyor as opposed to a simple magnet of the permanent or electromagnetic specie. Disposed above each of the reactors and extending substantially over the entire surface area of the molten stream are a plurality of charging outlets 23 communicating with a charge supply conduit 43a and 43b. As indicated earlier, the charging outlets 23 are disposed substantially over the entire area of the magnetic field produced through the stream so as to thereby put to maximum utilization the continuously new molten metal that passes beneath the charge outlet. Due to this continuously moving molten metal stream the oxide or metal particulate, the metal of which is substantially the same as that of the molten metal of the stream, may be introduced from outlet 23 on a substantially continuous basis, and the forces of magnetic attraction emanating from beneath the stream draw the oxides or particulates into and beneath the surface thereof and so hold them so long as they are magnetically attractive. The continuous movement of the molten metal stream away from the area of introduction presents a continuously new, heated molten metal bath for the charge, thereby eliminating the possibility of freeze-up at the point of introduction, and also maintaining a continuous inherently turbulent medium in which the oxides or particulates are thoroughly mixed so as to promote and enhance their contact with the hot metal of the stream. The advantageous effect of the magnetic force field is maintained upon the particles until their Curie Point temperature is reached. At that time the drawing and holding effect becomes de minimus and, theoretically, the particles would buoy to the stream surface. However, as explained earlier herein, the particles have sufficiently wetted by the time the Curie Point is reached so that they have either been partially reduced (in the case of an oxide), or melted (in the case of a particulate) and, even if not, there is not sufl-icient oxygen remaining in the oxide to buoy it to the surface because of the interna random kinetic movement" of the turbulent stream itself. It is believed improbable even that sufficient oxygen remains within the oxide to buoy it to the surface even in a laminar flow stream. In the case of a particulate, the wetting effect has sufficiently occurred before the Curie Point is reached and the particulate has, at that time, already become a cohesive part of the stream, at least on the exterior surface of the particulate so that there exists an ample plastic liquid-liquid interface between the stream and the particulate to preclude separation from the stream. For example, in the case of a mill scale particle, experimentation has shown that the magnetic forces have drawn the particle substantially beneath the surface of the stream before the Curie Point (770C) is reached. Since reduction in the enclosed environment of the stream then is substantially instantaneous the particle has no opportunity to buoy to the surface before the Curie Point is achieved.
In the continuous method of FIG. 3, each of the furnaces Ila llb are characterized by a slag outlet 15a, 15b. The slag outlets are arranged at the lower level of the reactors R1, R2 since the slag would tend to accumulate thereat. Similarly, but at a somewhat lower level than slag outlets 15a, 15b, are the metal outlets 17a, 17b from which the product of the method is tapped.
In FIG. 4 is shown another variation in which the method hereof may be practiced. Here, such as for example in the case of hot metal being tapped from a blast furnace, there is provided a reactor R3 consisting of a trough 47 having disposed therebeneath a magnet arrangement 53, which may be either permanent or of electromagnet type. The stream 9 is obtained by gravitational forces and flows from furnace outlet 55 downwardly into the collecting vessel 57 of product hot metal 59. The product hot metal may be tapped at outlet 17c and the slag at another outlet (not shown). The charge particles are introduced through the charging outlets 23 and are immediately drawn into and beneath the surface of the stream 9 in the manner described hereinbefore.
In FIG. there is shown another apparatus for practicing the method of the invention. Here the reactor may constitute a furnace enclosure 110 which derives heat from an appropriate source which is operatred to either intermittently or continuously add heat to the system, as necessary. The molten bath 63 is disposed in proximate relation to reactor R4 which includes a permanent or electromagnet 53a. Oxide or particulate outlets 23 are disposed above the bath and in covering relation to the charging outlets to supply the oxide or particulate thereto. Appropriate metal and slag taps 17c, c respectively, are provided. Practicing the invention hereof in accordance with this apparatus results in a less turbulent stream, and of course also a slower moving stream than those described hereinabove. Here the characteristics of the stream are more laminar because movement of the stream corresponds to the rate of production emanating from metal outlet 170. The rate of production from metal outlet 17c may be increased however by substituting for magnet system 53a a horizontally disposed electromagnetic induction field, the movement of which is in a direction towards metal outlet l7c. In such case the rate of production will be influenced by such factors as the substantially continuous addition of heat to the stream, the feed rate of particles thereto, and the rate of movement of the electromagnetic induction field.
It will be recognized that the method of the invention may be practiced also in pursuit of the production of steel at varying carbon or alloy levels. For example, the hot metal outlet 17 of FIG. 1 may communicate via a trough or channel to a reactor which is adapted to receive iron oxide or other means for reducing the carbon content of the molten stream. In such arrangement a carbon reducing agent such as for example iron oxide (R3 0 may be introduced at a reactor area so that the magnetic field may facilitate the chemical reaction which produced carbon monoxide (CO) by drawing or forcing the agent more homogeneously and expeditiously into the molten metal than is otherwise possible. Removal of the carbon by an agent such as this produces a chemical reaction of endothermic character and it is therefore normally necessary to sustain such reaction by the addition of energy or heat to the stream. However, other types of agents, characterized as exothermic, may be used either alternatively or substantially simultaneously as the iron oxide in order to remove carbon. Such an agent, as an oxygen lance, my be played on the molten metal so as to produce carbon monoxide in accordance with conventional practice. It is contemplated that the exothermic agent may be employed substantially simultaneously, if desired, at the endothermic agent, for removing carbon from the stream, in order to thereby offset and/or equalize the heat loss resulting from the endothermic agent. It thus becomes feasible to conduct the carbon removal, without the continuous addition of heat to the molten metal stream while continuously producing steel, this after having started initially with iron oxide or other particles.
Each of the aforementioned steps for moving the molten metal via the channel or conveyor for processing molten iron to steel may be accomplished in a series of baths or holding vessels in order to sequentially reduce the carbon level to the desired steel chemistry. It is recognized that numerous arrangements of streams, reactors, holding vessels and furnaces and the like may be designed to accomplish varying volumes of steel production and steel chemistry. Therefore, it should be understood that the closed loop or continuous moving stream disclosed herein for the production of hot metal may likewise be used for the production of steel. Thus although it is suggested that one or more closed loop continuously moving hot metal streams may be tapped, such as at outlet 17 (see FIG. I) in order to supply one or more closed loop continuously moving molten metal streams for producing steel, as described hereinabove, such an arrangement constitutes only one of a multitide of different arrangements and designs which may utilize the concept of this invention. It will similarly be recognized that common fluxes, such as lime, may be added during any refining procedure and that other conventional practices will be employed in implementing the method hereof.
In each of the steps explained hereinabove, whether in the production of hot metal (iron) or in the production of steel therefrom, it should be understood that the reactors described herein may be used to both remove oxygen from metal oxides in order to produce hot metal, see FIGS. 1 through 6, and that the same type of reactors may be used to remove carbon from the hot metal thereafter so as to achieve a steel product of predetermined chemical characteristics. In the production of hot metal in a continuous or closed loop manner as described in FIG. 1 herein it will, as commonly known, be necessary to add carbon to the hot metal when producing more hot metal from a substantially continuous charge. ln refining the hot metal to steel in a subsequent closed loop stream which is fed, for example from tap 17 of FIG. 1, carbon may be removed through the use of either or both endothermic or exothermic agents as described above. In both the production of hot metal and the refinement thereof, beneficial results are achieved when the stream movement is characterized as turbulent and randomly kinetic. The stream should move at a relatively rapid but controlled rate. Slower movement of the stream of course reduces total production as there is presented less hot metal to the charged particles. With respect to the refining or alloying of hot metal, it will be recognized that these steps may take place while the stream is moving downwardly, such as by gravity, horizontally, or even upwardly, such as by using the aforementioned electromagnetic induction conveyor. The reactors to be used may take any number of forms such as a ladle, a channel or trough, the latter either in linear or in closed loop form. As with the production of hot metal from oxides, the production of steel may be continuous by utilization of the circular or closed loop trough. Such design enables substantially continuous and accurate monitoring of the chemical composition of the stream, thus permitting, when necessary, the advisable introduction of fluxing agents and the like.
Now with reference to FIGS. 7a, b, there is shown exemplary means for enhancing the turbulence of a moving molten metal stream. These exemplary designs constitute the basis for a cascading reactor and are characterized by an articulated surface arranged somewhat in the form of a step or steps which have therebeneath a plurality of magnets either permanent or electro for producing the magnetic force field described hereinabove. The cascading reactor may be utilized in connection with any application of the method as herein described, this including for example the reduction of oxides, the melting of particulates, and the production, alloying and refining of steel. in FIG. 7a the cascading means comprise a plurality of horizontal steps having the magnet disposed thereunder. The relative height of the steps may be varied in order to vary the turbulence imparted to the stream by its gravita tional fall from one level to the next. Introduction of oxides or particulates onto the step may be followed in accordance with the parameters outlined earlier herein. As may be visualized, the turbulent character of the cascading stream more quickly induces wetting of the particles thereby facilitating their reduction or melting. A somewhat reduced turbulence may be accomplished with the cascade of FIG. 71) wherein the steps recline on the surface and thereby provide a pool or bath on each step and in which the particles will tend to remain a somewhat longer time before being washed over and downwardly onto the subsequent step. During retention of the particle in the bath or pool it is subjected to substantial turbulence, therefore enhancing and improving the wetting time. In FIG. 7 there is shown a cascade of steps for accomplishing a somewhat different objective. Here the steps are sloped downwardly in order to impart various degrees of turbulence when this is desired. The latter cascade may be particularly appropriate to the melting of particulates such as shavings, boring, and tumings wherein continued movement of the charge is facilitated by the continuous assistance of gravity forces.
With regard to the melting of particulates it is recommended that the charge be submerged within the moving molten metal stream and that continuous but controlled charging take place so that subsequently charged particulates may tend to pile upon and bear down upon earlier charged particulates. Such earlier charged particlates are therefore maintained within the moving molten metal stream not only by the magnetic field but also by the weight of later charged particulates. Thus when the first charged particulates are heated above their Curie point and their magnetic characteristic is gone, they are maintained submerged within the stream due to the weight bearing upon them.
In further practice of the melting method herein it is contemplated that iron borings of approximately I inch or less in size and/or crushed steel shavings or turnings and steel borings, all of approximately 1 foot or less, may be charged to the moving molten metal stream over an extended area determined by the limits of the reactor. Movement of the stream through the charge may be enhanced by the cascade reactor design of FIG. 7c.
In practicing the method hereof, particularly in a closed loop apparatus such as illustrated in FIG. 3, a continuous tapping of product from outlets 17a, b may be achieved and the chemistry of the metal thereof may be accurately controlled by careful monitoring of well known parameters. Also, the rates and times of additions of charge, along with monitoring of hot metal temperature, both in the furnace and in the streams during addition of charge is of utmost importance in successfully practicing the method. All such monitoring and corrective measures will of course be related to and dependent on the type and size of particles introduced and the principal objectives of the introduction, that is melting, reducing or refining.
The advantages of the invention will, it is thought, have been clearly understood from the foregoing detailed description of the embodiments which have been elected as illustrations. Changes in the details of construction and of certain sequence in the method will suggest themselves and may be resorted to without departing from the spirit of the invention, and it is therefore my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.
Therefore, that which is claimed and desired to be secured by United States Letters Patent is:
l. The method for continuously processing metal particles having magnetic characteristics comprising the steps of:
providing a moving molten metal stream,
disposing a magnetic field substantially with lines of flux extending through the surface of the stream, said lines of flux extending substantially perpendicular to the surface of the said stream,
introducing into the stream a substantially continuous charge of metal particles which have magnetic characteristics so that the magnetic field forces said particles into and beneath the stream surface and continues to draw said particles downwardly and hold them beneath the stream surface so long as their magnetic characteristics exist, thereby enhancing exposure of the particles to the surrounding heat of the stream and facilitating their ultimate reduction. 2. The method of claim 1 wherein the particles are introduced over an area of the stream that corresponds to the area of magnetic field extending there beneath so that substantially all of the particles introduced to the stream are drawn beneath the surface thereof.
3. The method of claim 1 wherein the stream is characterized by the additional step of inducing turbulence into the stream so that the particles in the stream are distrained beneath the surface due to the magnetic forces and also are randomly kinetically mixed therewith so as to excite the speed of reduction.
4. The method of claim 1 wherein said particles are the oxide of a metal which is substantially the same metal as the metal of the stream,
the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide beomes a part of the stream,
continuously tapping product metal from the stream and by-products as may be desirable while continuously introducing said particles of oxide to the stream so as to provide a substantially continuous production of metal by using the stream itself as the medium for the chemical reaction which produces the metal and the by-product.
5. The method of claim 1 wherein the particles are the oxide of the metal which is substantially the same metal as that of the moving molten stream,
introducing to the stream a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream,
introducing to the stream a chemical agent to combine with elements in the stream so as to refine the flowing molten metal,
said stream consisting of molten iron and the agent introduced being iron oxide so that said agent is adapted to combine with carbon in the molten iron to produce carbon monoxide and more iron, thereby lowering the carbon content of the stream so as to produce steel, and
monitoring the stream in order to achieve the desirable chemical characteristics by selectively varying the agents and components introduced thereto. 6. The method of claim 1 including the additional step of closing the path of the stream so as to provide a continuous circulating closed loop means for processing metal particles, and introducing heat to the stream in order to maintain its continuous processing capabiltty.
7. The method of claim 6 where in the step of introducing heat to the stream is accomplished through the use of a furnace means,
disposing the said furnace in the path of the streams so that the stream flows into and out therefrom,
said furnace further being characterized by a reservoir bath of molten metal therein for feeding to and receiving from the metal of the stream.
8. The method for continuously processing metal particles having magnetic characteristics comprising the steps of:
providing a moving molten metal stream,
disposing a magnetic field substantially with lines of flux extending-through the surface of the stream,
introducing into the stream a substantially continuous charge of metal particles which have magnetic characteristics so as to thereby magnetically force said particles toward and beneath the surface of the stream and so hold them as long as the magnetic characteristics exist, thereby enhancing exposure of the particles to the surrounding heat of the stream, and moving the stream up an inclined plane while the particles are introduced thereto so as to thereby permit return of the stream to a lower level,
returning said stream from the upper end of said inclined plane, back to the lower end thereof so as to thereby provide a continuous circulating closed loop means for processing the metal particles, and
introducing heat to the stream in order to maintain its continuous processing capability.
9. The method of claim 8 wherein the step of adding heat to the stream includes provision for a furnace means disposed in the path of the stream so that the stream flows into and out therefrom,
said furnace further being characterized by a bath of molten metal therein for feeding to and receiving from the metal of the stream.
10. The method of claim 9 wherein the particles introduced are the oxide of a metal which is substantially the same metal as the metal of the stream,
the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream.
11. The method of claim 10 wherein the combined reducing agent and oxygen is removed and circulated to the charge prior to introduction so as to pre-reduce the particles thereof.
12. The method of claim 9 wherein the particles are particulates of a metal which is substantially the same metal as that of the moving molten stream so that the introduction thereof increases the metal of the stream.
13. The method of claim 10 wherein said magnetic field produces a flux which extends substantially perpendicular to the surface of the moving molten metal stream.
14. The method of claim 13 wherein the magnetic field flux originates from beneath the surface of the stream and is paramagnetic in specie so that said particles are attracted downwardly into the stream, therefore facilitating their reduction.
15. The method of claim 14 wherein the particles are introduced over an area of the stream substantially corresponding to the area of the magnetic field emanating from therebeneath.
16. The method of claim 15 including the additional step of substantially continuously introducing said particles of oxide to the stream so as to provide a substantially continuous addition of metal to the stream by using the stream itself as the medium for the chemical reaction which produces the metal and the by-products and,
tapping product metal and by-products, from the stream, as may be desired.
17. The method of claim 16 wherein the stream is characterized by the additional step of inducing turbulent fluid flow thereto in order to improve homogeneous and randomly kinetic mixing therein.
18. The method of claim 8 including the additional subsequent step of tapping a branch from the stream and introducing thereto a chemical agent to combine with elements therein so as to refine the flowing molten metal.
19. The method of claim 18 wherein the tapped stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the I molten iron to produce carbon monoxide, thereby lowering the carbon content of the stream so as to produce steel, and
monitoring the stream in order to achieve desirable chemical characteristics.
20. The method of claim 18 wherein refining of the tapped stream is, accomplished by the additional step, of introducing thereto an agent which produces an exothermic reaction.
21. The method of claim 8 including the additional subsequent step of tapping a branch from the stream and introducing thereto a chemical agent to combine with elements therein so as to refine the flowing molten metal.
22. The method of claim 21 wherein the tapped stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the molten iron to produce carbon monoxide, thereby lowering the carbon content of the stream so as to produce steel, and
monitoring the stream in order to achieve desirable chemical characteristics. 23. The method of claim 21 wherein refining of the tapped stream is, accomplished by the additional step, of introducing thereto an agent which produces an exothermic reaction.
24. The method for continuously processing metal particles having magnetic characteristics comprising the steps of:
providing a moving molten metal stream, disposing a magnetic field substantially with lines of flux extending through the surface of the stream,
introducing into the stream a substantially continuous charge of metal particles which have magnetic characteristics magnetically forcing said particles toward and beneath the surface of the stream and holding them beneath said surface as long as the magnetic characteristics exist, thereby enhancing exposure of the particles to the surrounding heat of the stream.
25. The method of claim 24 wherein the particles are particulates of a metal which is substantially the same metal as that of the moving molten stream so that the introduction thereof increases the metal of the stream.
26. The method of claim 24 wherein the stream is characterized by the additional step of providing turbulence inducing means therein so that particles in the stream are not only distrained beneath the surface by magnetic forces but are randomly-kinetically mixed therewith so as to excite the speed of production.
27. The method of claim 24 including the additional step moving the stream up an inclined plane while the particles are introduced thereto so as to thereby permit return of the stream to a lower level.
28. The method of claim 24 including the additional subsequent step of introducing to the stream a chemi- 18 cal agent to combine with elements therein so as to refine the flowing molten metal.
29. The method of claim 24 wherein the particulates are introduced in order to influence the chemical characteristics of the stream in a desired and predetermined manner.
30. The method of claim 29 wherein the field of magnetic flux extends substantially perpendicular to the surface of the stream.
31. The method of claim 24 wherein the particles are the oxide of a metal which is substantially the same metal as that of the moving molten stream,
the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream.
32. The method of claim 31 wherein the compound formed by the reducing agent and oxygen is removed and circulated to the charge prior to introduction so as to pre-reduce the particles thereof.
33. The method of claim 32 wherein said magnetic field flux extends substantially perpendicular to the surface of the moving molten metal stream.
34. The method of claim 33 wherein the magnetic field flux originates from beneath the surface of the stream and is paramagnetic in specie so that said particles are attracted downwardly into the stream, therefore facilitating their reduction.
35. The method of claim 32 wherein the particles are introduced over an area of the stream substantially corresponding to the area of the magnetic field extending therethrough.
36. The method of claim 35 including the further step of substantially continuously providing a stream of said moving molten metal, and substantially continuously introducing said particles of oxide to the stream so as to provide a substantially continuous addition of molten metal to the stream by using the stream itself as the medium for the chemical reaction which produces the metal and by-products.
37. The method of claim 36 including the additional step of introducing fluxing agents to the stream after the reduction is carried out.
38. The method of claim 37 including the additional step of tapping the molten metal from the stream, and of tapping by-product slag, both as desired.
39. The method of claim 31 including the additional subsequent step of introducing to the stream a chemical agent to combine with elements therein so as to refine the flowing molten metal.
40. The method of claim 39 wherein the stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the molten iron to produce carbon monoxide and more iron, thereby lowering the carbon content of the stream so as to produce steel, and
monitoring the stream in order to achieve desirable chemical characteristics.
41. The method of claim 40 wherein the carbon monoxide is used to preheat the charge fed to the stream.
42. The method of claim 39 wherein the agent introduced produces a chemical reaction with the stream which is exothermic in character.
43. The method of claim 42 wherein the exothermic reaction is produced by utilization of an oxygen lance as the agent.
20 46. The method of claim 45 wherein the relative magnitudes of heat used by and produced by the respective endothermic and exothermic reactions are substantially equal and the agents introduced for each such endothermic and exothermic reaction are introduced in respective magnitudes to accomplish such equal and offsetting, heat utilizations by the stream.
* II I l IO

Claims (46)

1. THE METHOD FOR CONTINUOUSLY PROCESSING METAL PARTICLES HAVING MAGNETIC CHARACTERISTICS COMPRISING THE STEPS OF: PROVIDING A MOVING MOLTEN METAL STREAM, DISPOSING A MAGNETIC FIELD SUBSTANTIALLY WITH LINES OF FLUX EXTENDING THROUGH THE SURFACE OF THE STREAM, SAID LINES OF FLUX EXTENDING SUBSTANTIALLY PERPENDICULAR TO THE SURFACE OF THE SAID STREAM, INTRODUCING INTO THE STREAM A SUBSTANTIALLY CONTINUOUS CHARGE OF METAL PARTICLES WHICH HAVE MAGNETIC CHARACTERISTICS SO THAT THE MAGNETIC FIELD FORCES SAID PARTICLES INTO AND BENEATH THE STREAM SURFACE AND CONTINUES TO DRAW SAID PARTICLES DOWNWARDLY AND HOLD THEM BENEATH THE STREAM SURFACE SO LONG AS THEIR MAGNETIC CHARACTERISTICS EXITS, THEREBY ENHANCING EXPOSURE OF THE PARTICLES TO THE SURROUNDING HEAT OF THE STREAM AND FACILITATING THEIR ULTIMATE REDUCTION.
2. The method of claim 1 wherein the particles are introduced over an area of the stream that corresponds to the area of magnetic field extending there beneath so that substantially all of the particles introduced to the stream are drawn beneath the surface thereof.
3. The method of claim 1 wherein the stream is characterized by the additional step of inducing turbulence into the stream so that the particles in the stream are distrained beneath the surface due to the magnetic forces and also are randomly kinetically mixed therewith so as to excite the speed of reduction.
4. The method of claim 1 wherein said particles are the oxide of a metal which is substantially the same metal as the metal of the stream, the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide beomes a part of the stream, continuously tapping product metal from the stream and by-products as may be desirable while continuously introducing said particles of oxide to the stream so as to provide a substantially continuous production of metal by using the stream itself as the medium for the chemical reaction which produces the metal and the by-product.
5. The method of claim 1 wherein the particles are the oxide of the metal which is substaNtially the same metal as that of the moving molten stream, introducing to the stream a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream, introducing to the stream a chemical agent to combine with elements in the stream so as to refine the flowing molten metal, said stream consisting of molten iron and the agent introduced being iron oxide so that said agent is adapted to combine with carbon in the molten iron to produce carbon monoxide and more iron, thereby lowering the carbon content of the stream so as to produce steel, and monitoring the stream in order to achieve the desirable chemical characteristics by selectively varying the agents and components introduced thereto.
6. The method of claim 1 including the additional step of closing the path of the stream so as to provide a continuous circulating closed loop means for processing metal particles, and introducing heat to the stream in order to maintain its continuous processing capability.
7. The method of claim 6 where in the step of introducing heat to the stream is accomplished through the use of a furnace means, disposing the said furnace in the path of the streams so that the stream flows into and out therefrom, said furnace further being characterized by a reservoir bath of molten metal therein for feeding to and receiving from the metal of the stream.
8. The method for continuously processing metal particles having magnetic characteristics comprising the steps of: providing a moving molten metal stream, disposing a magnetic field substantially with lines of flux extending through the surface of the stream, introducing into the stream a substantially continuous charge of metal particles which have magnetic characteristics so as to thereby magnetically force said particles toward and beneath the surface of the stream and so hold them as long as the magnetic characteristics exist, thereby enhancing exposure of the particles to the surrounding heat of the stream, and moving the stream up an inclined plane while the particles are introduced thereto so as to thereby permit return of the stream to a lower level, returning said stream from the upper end of said inclined plane, back to the lower end thereof so as to thereby provide a continuous circulating closed loop means for processing the metal particles, and introducing heat to the stream in order to maintain its continuous processing capability.
9. The method of claim 8 wherein the step of adding heat to the stream includes provision for a furnace means disposed in the path of the stream so that the stream flows into and out therefrom, said furnace further being characterized by a bath of molten metal therein for feeding to and receiving from the metal of the stream.
10. The method of claim 9 wherein the particles introduced are the oxide of a metal which is substantially the same metal as the metal of the stream, the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream.
11. The method of claim 10 wherein the combined reducing agent and oxygen is removed and circulated to the charge prior to introduction so as to pre-reduce the particles thereof.
12. The method of claim 9 wherein the particles are particulates of a metal which is substantially the same metal as that of the moving molten stream so that the introduction thereof increases the metal of the stream.
13. The method of claim 10 wherein said magnetic field produces a flux which extends substantially perpendicular to the surface of the moving molten metal stream.
14. The method of claim 13 wherein the magnetic field flux originates from beneath the surface of the stream and is paramagnetic in specie so that said partIcles are attracted downwardly into the stream, therefore facilitating their reduction.
15. The method of claim 14 wherein the particles are introduced over an area of the stream substantially corresponding to the area of the magnetic field emanating from therebeneath.
16. The method of claim 15 including the additional step of substantially continuously introducing said particles of oxide to the stream so as to provide a substantially continuous addition of metal to the stream by using the stream itself as the medium for the chemical reaction which produces the metal and the by-products and, tapping product metal and by-products, from the stream, as may be desired.
17. The method of claim 16 wherein the stream is characterized by the additional step of inducing turbulent fluid flow thereto in order to improve homogeneous and randomly kinetic mixing therein.
18. The method of claim 8 including the additional subsequent step of tapping a branch from the stream and introducing thereto a chemical agent to combine with elements therein so as to refine the flowing molten metal.
19. The method of claim 18 wherein the tapped stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the molten iron to produce carbon monoxide, thereby lowering the carbon content of the stream so as to produce steel, and monitoring the stream in order to achieve desirable chemical characteristics.
20. The method of claim 18 wherein refining of the tapped stream is, accomplished by the additional step, of introducing thereto an agent which produces an exothermic reaction.
21. The method of claim 8 including the additional subsequent step of tapping a branch from the stream and introducing thereto a chemical agent to combine with elements therein so as to refine the flowing molten metal.
22. The method of claim 21 wherein the tapped stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the molten iron to produce carbon monoxide, thereby lowering the carbon content of the stream so as to produce steel, and monitoring the stream in order to achieve desirable chemical characteristics.
23. The method of claim 21 wherein refining of the tapped stream is, accomplished by the additional step, of introducing thereto an agent which produces an exothermic reaction.
24. The method for continuously processing metal particles having magnetic characteristics comprising the steps of: providing a moving molten metal stream, disposing a magnetic field substantially with lines of flux extending through the surface of the stream, introducing into the stream a substantially continuous charge of metal particles which have magnetic characteristics magnetically forcing said particles toward and beneath the surface of the stream and holding them beneath said surface as long as the magnetic characteristics exist, thereby enhancing exposure of the particles to the surrounding heat of the stream.
25. The method of claim 24 wherein the particles are particulates of a metal which is substantially the same metal as that of the moving molten stream so that the introduction thereof increases the metal of the stream.
26. The method of claim 24 wherein the stream is characterized by the additional step of providing turbulence inducing means therein so that particles in the stream are not only distrained beneath the surface by magnetic forces but are randomly-kinetically mixed therewith so as to excite the speed of production.
27. The method of claim 24 including the additional step moving the stream up an inclined plane while the particles are introduced thereto so as to thereby permit return of the stream to a lower level.
28. The method of claim 24 including the additional subsequent step of introducing to the stream a chemical agent to combine with elements therein so as to refine the flowing molten metal.
29. The method of claim 24 wherein the particulaTes are introduced in order to influence the chemical characteristics of the stream in a desired and predetermined manner.
30. The method of claim 29 wherein the field of magnetic flux extends substantially perpendicular to the surface of the stream.
31. The method of claim 24 wherein the particles are the oxide of a metal which is substantially the same metal as that of the moving molten stream, the stream being characterized by a reducing agent therein so that a chemical reaction is created whereby the oxygen of the oxide combines with the reducing agent and the metal of the oxide becomes a part of the stream.
32. The method of claim 31 wherein the compound formed by the reducing agent and oxygen is removed and circulated to the charge prior to introduction so as to pre-reduce the particles thereof.
33. The method of claim 32 wherein said magnetic field flux extends substantially perpendicular to the surface of the moving molten metal stream.
34. The method of claim 33 wherein the magnetic field flux originates from beneath the surface of the stream and is paramagnetic in specie so that said particles are attracted downwardly into the stream, therefore facilitating their reduction.
35. The method of claim 32 wherein the particles are introduced over an area of the stream substantially corresponding to the area of the magnetic field extending therethrough.
36. The method of claim 35 including the further step of substantially continuously providing a stream of said moving molten metal, and substantially continuously introducing said particles of oxide to the stream so as to provide a substantially continuous addition of molten metal to the stream by using the stream itself as the medium for the chemical reaction which produces the metal and by-products.
37. The method of claim 36 including the additional step of introducing fluxing agents to the stream after the reduction is carried out.
38. The method of claim 37 including the additional step of tapping the molten metal from the stream, and of tapping by-product slag, both as desired.
39. The method of claim 31 including the additional subsequent step of introducing to the stream a chemical agent to combine with elements therein so as to refine the flowing molten metal.
40. The method of claim 39 wherein the stream is molten iron and the agent introduced is iron oxide which is adapted to combine with carbon in the molten iron to produce carbon monoxide and more iron, thereby lowering the carbon content of the stream so as to produce steel, and monitoring the stream in order to achieve desirable chemical characteristics.
41. The method of claim 40 wherein the carbon monoxide is used to preheat the charge fed to the stream.
42. The method of claim 39 wherein the agent introduced produces a chemical reaction with the stream which is exothermic in character.
43. The method of claim 42 wherein the exothermic reaction is produced by utilization of an oxygen lance as the agent.
44. The method of claim 39 wherein the agent introduced produces a chemical reaction with the stream which is endothermic in character.
45. The method of claim 44 wherein a second agent is introduced to the stream to produce a chemical reaction of exothermic character, said second agent being introduced at substantially the same time that the endothermic action is occurring.
46. The method of claim 45 wherein the relative magnitudes of heat used by and produced by the respective endothermic and exothermic reactions are substantially equal and the agents introduced for each such endothermic and exothermic reaction are introduced in respective magnitudes to accomplish such equal and offsetting, heat utilizations by the stream.
US306429A 1971-07-12 1972-11-14 Method for enhancing reduction of ores, oxides and melting of metals by magnetic forces Expired - Lifetime US3881915A (en)

Priority Applications (14)

Application Number Priority Date Filing Date Title
US306429A US3881915A (en) 1971-07-12 1972-11-14 Method for enhancing reduction of ores, oxides and melting of metals by magnetic forces
US391878A US3929465A (en) 1972-11-14 1973-08-27 Method employing barrier means to submerge particles in a molten metal stream
GB5110473A GB1452313A (en) 1972-11-14 1973-11-02 Method for enhancing the reduction of ores and oxides and the melting of metals using magnetic forces
AU62358/73A AU6235873A (en) 1972-11-14 1973-11-09 Metal oxides into and beneath the surface of molten metal utilizing the forces of magnetic attraction to draw
BR882673A BR7308826D0 (en) 1972-11-14 1973-11-12 PROCESS TO PROCESS CONTINUOUSLY METAL PARTICLES OF MAGNETIC CHARACTERISTICS
NL7315424A NL7315424A (en) 1972-11-14 1973-11-12
FR7340344A FR2206385B2 (en) 1972-11-14 1973-11-13
IT5365973A IT997735B (en) 1972-11-14 1973-11-13 IMPROVEMENT IN PROCEDURES FOR THE REDUCTION OF OXIDE ME TALLIFER MATERIALS AND FOR THE MELTING OF METALS WITH MAGNETIC FORCES
DE2356533A DE2356533A1 (en) 1972-11-14 1973-11-13 METAL MELTING METHOD
CA185,736A CA992327A (en) 1972-11-14 1973-11-14 Method for enhancing reduction of ores, oxides and melting of metals by magnetic forces
AR25099673A AR202638A1 (en) 1972-11-14 1973-11-14 METHOD TO IMPROVE THE REDUCTION OF MINERALS, OXIDES AND THE FUSION OF METALS BY MAGNETIC FORCES
JP12813673A JPS5645970B2 (en) 1972-11-14 1973-11-14
ES420548A ES420548A1 (en) 1972-11-14 1973-11-14 Method for enhancing the reduction of ores and oxides and the melting of metals using magnetic forces
BE156990A BE829822Q (en) 1971-07-12 1975-06-03 MINERAL TREATMENT PROCESS

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Cited By (3)

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Publication number Priority date Publication date Assignee Title
US4406695A (en) * 1981-05-07 1983-09-27 Gardner Herman E Process for producing alloy steel product or iron powder by furnacing ground iron or molten iron on a molten lead bath
US5964920A (en) * 1996-04-02 1999-10-12 Prolerflo Corporation Method and apparatus for reduction of metal particulates
US6659283B1 (en) 2001-05-17 2003-12-09 Wilson Greatbatch Ltd. Capacitor grade powders

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US3393997A (en) * 1965-07-10 1968-07-23 Kocks Gmbh Friedrich Method for metallurgical treatment of molten metal, particularly iron
US3576321A (en) * 1968-11-22 1971-04-27 Kocks Gmbh Friedrich Methods and apparatus for treatment of metal heats
US3576320A (en) * 1968-11-22 1971-04-27 Kocks Gmbh Friedrich Methods and apparatus for treatment of metals
US3612720A (en) * 1968-10-01 1971-10-12 Aeg Elotherm Gmbh Method of apportioning liquid metal in an electromagnetic conveyor trough
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US3393997A (en) * 1965-07-10 1968-07-23 Kocks Gmbh Friedrich Method for metallurgical treatment of molten metal, particularly iron
US3612720A (en) * 1968-10-01 1971-10-12 Aeg Elotherm Gmbh Method of apportioning liquid metal in an electromagnetic conveyor trough
US3576321A (en) * 1968-11-22 1971-04-27 Kocks Gmbh Friedrich Methods and apparatus for treatment of metal heats
US3576320A (en) * 1968-11-22 1971-04-27 Kocks Gmbh Friedrich Methods and apparatus for treatment of metals
US3692290A (en) * 1970-02-20 1972-09-19 Voest Ag Plant for continuously refining pig iron

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4406695A (en) * 1981-05-07 1983-09-27 Gardner Herman E Process for producing alloy steel product or iron powder by furnacing ground iron or molten iron on a molten lead bath
US5964920A (en) * 1996-04-02 1999-10-12 Prolerflo Corporation Method and apparatus for reduction of metal particulates
US6659283B1 (en) 2001-05-17 2003-12-09 Wilson Greatbatch Ltd. Capacitor grade powders

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