US3883997A - Process for producing high-grade metallic products from solid slags and high-grade metallic products - Google Patents

Process for producing high-grade metallic products from solid slags and high-grade metallic products Download PDF

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US3883997A
US3883997A US41211973A US3883997A US 3883997 A US3883997 A US 3883997A US 41211973 A US41211973 A US 41211973A US 3883997 A US3883997 A US 3883997A
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slag
iron
pieces
blast furnace
percent
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Richard D Burlingame
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CONNELL A DE Ltd PARTNERSHIP LP
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Luria Brothers and Co Inc
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Priority to US05412119 priority Critical patent/US3883997A/en
Priority to SE7412906A priority patent/SE411225B/xx
Priority to ZA00746615A priority patent/ZA746615B/xx
Priority to AU74826/74A priority patent/AU480091B2/en
Priority to GB4692874A priority patent/GB1448327A/en
Priority to DE2451775A priority patent/DE2451775C2/de
Priority to ES431757A priority patent/ES431757A1/es
Priority to FR7436414A priority patent/FR2249959B1/fr
Priority to SU742081513A priority patent/SU622415A3/ru
Priority to CA212,887A priority patent/CA1037720A/en
Priority to JP12704674A priority patent/JPS5534853B2/ja
Priority to US05/544,882 priority patent/US4044459A/en
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Assigned to CONNELL LIMITED PARTNERSHIP, A DE LIMITED PARTNERSHIP reassignment CONNELL LIMITED PARTNERSHIP, A DE LIMITED PARTNERSHIP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AVONDALE INDUSTRIES, INC., A DE CORP.
Assigned to AVONDALE INDUSTRIES, INC. reassignment AVONDALE INDUSTRIES, INC. MERGER (SEE DOCUMENT FOR DETAILS). Assignors: LURIA BROTHERS & COMPANY, INC., ORTNER FREIGHT CAR COMPANY, WABASH ALLOYS, INC., YUBA HEAT TRANSFER CORP.
Assigned to FIRST NATIONAL BANK OF BOSTON THE reassignment FIRST NATIONAL BANK OF BOSTON THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CONNELL LIMITED PARTNERSHIP, A DE. LIMITED PARTNERSHIP
Assigned to FIRST NATIONAL BANK OF BOSTON, THE reassignment FIRST NATIONAL BANK OF BOSTON, THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). APRIL 30, 1990 Assignors: CONNELL LIMITED PARTNERSHIP
Assigned to FIRST NATIONAL BANK OF BOSTON, THE reassignment FIRST NATIONAL BANK OF BOSTON, THE SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CONNELL LIMITED PARTNERSHIP
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/005—Separation by a physical processing technique only, e.g. by mechanical breaking
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • ABSTRACT Process for recovering high-grade blast furnace iron or other metal from pieces of blast furnace iron or such other metal and blast furnace slag having large amounts of such blast furnace slag, by tumbling a substantial number of such pieces to achieve a constant redistribution thereof while impacting at least a substantial portion of such pieces with a high velocity, relatively small diameter shot or grit which has a hardness which is greater than the hardness of the slag, thereby abrading the impurity, while leaving the body of non-impurity substantially intact.
  • a product comprising a large body of high-grade blast furnace iron or other metal and having a substantial number of superficial irregularities, crevices and fissures containing only a small amount of blast furnace slag adhered in said irregularities, crevices and fissures, the amount of blast furnace slag being no more than about ten percent by weight of the total product, and preferably no more than about two to three percent by weight of such product.
  • the invention relates to the field of iron and steelmaking, and the refining of other metals, and particularly relates to a process of recovering, from a blast furnace operation. high-grade metal having a substantial amount of impurity, and then removing the impurity to allow the metal commercially to be used.
  • slag means any material having a high degree of impurities. Iron slag," the precise composition of which can vary substantially, is produced in the production of blast furnace iron and typically will have an approximate composition of 38 percent by weight of calcium oxide, 13 percent of magnesium oxide, 36 percent of silicon dioxide, percent of aluminum oxide, 1.5 percent of sulfur, and minor amounts of other metallic oxides.
  • the liquid iron slag In all iron blast furnaces, the liquid iron slag must be flushed out every few hours. This iron slag is usually removed by allowing it to flow through a tap hole, known as a slag notch" or cinder notch," which is located high in the blast furnace at approximately the normal level of the slag. The molten iron slag is thus allowed to run out ofthe blast furnace every few hours, in order to prevent accumulation of undue amounts of the slag.
  • a typical blast furnace will produce approximately 3,000 tons of iron per day, and large blast furnaces may produce as much as l0,000 tons of iron per day or more. It is therefore quite common to experience a loss of from about to 100 tons per day of iron with the removal of the iron slag from the blast furnace. Iron, with an acceptably low level of impurities contained therein, as is found in normal blast furnaces, has a very substantial value. Thus, such losses of up to 100 tons of iron per day are obviously substantial and are desired to be minimized or eliminated completely.
  • the molten blast furnace iron slag is conveyed into one of two large, walled-in slag pits located right next to the furnace, where it is allowed to solidify and cool.
  • the slag pit contains primarily slag, having, however, substantial irregular-shaped masses of iron of widely varying size scattered throughout the slag, like raisins in a cake.
  • the amount of iron slag produced per ton of iron will vary substantially, and the amount of iron distributed throughout the slag pit is usually in the range from about two to five percent by weight of the total slag pit contents.
  • the iron distributed through the iron slag in the slag pit is the same as the regular blast furnace iron product, having a relatively low level of impurities and high economic value, if it can be separated adequately from the surrounding iron slag.
  • the slag from the blast furnace is then channelled to the other slag pit, which is then empty, having earlier been emptied by power shovels and trucks while the other slag pit was being filled.
  • These power shovels and trucks are moved over to the full pit, after a period of time has elapsed to allow solidification of the iron slag, and the trucks are filled by the power shovels with large chunks of slag from the slag pit, which are transported to a slag processing facility, generally located nearby.
  • blast furnace slag iron was separated from the pieces or iron slag by use of an electromagnet, to be recycled to an open hearth furnace.
  • blast furnace slag iron pieces are highly variable in their iron and iron slag content, but will frequently comprise about 60 to percent of blast furnace iron, having a low sulfur content of typically about 0.03 percent by weight, and 20 to 40 percent of iron slag, having a sulfur content of about I to 2 percent by weight.
  • Unimproved blast furnace slag iron is not suitable for basic oxygen furnace processing, because of the relatively short resi dence time of the iron in the basic oxygen furnace. This residence time is usually not adequate to achieve sufficient desulfurization of the relatively high sulfur content blast furnace slag iron pieces. Therefore, in any integrated steel mill having only basic oxygen furnace steelmaking production, the blast furnace slag iron pieces produced from the mills blast furnace slag are commonly accumulated in large stockpiles as a low grade form of scrap, too good to haul to the dump, but not good enough to charge, as is, into the steelmaking basic oxygen furnace. This scrap has had a very low economic value in the past because, in addition to its unsuitability for basic oxygen steelmaking, it could not be utilized in any other sector of the ferrous industries, such as in iron foundries.
  • the process of this invention involves the use of a shot blasting and tumbling machine, of a type well known in the art and more fully described below.
  • This machine is frequently used to clean loosely adherent sand from foundry castings.
  • this use does not entail the removal of a hard material, firmly attached to the iron, from minute fissures and crevices such as is involved in the process of this invention to remove almost all of the slag from blast furnace slag iron pieces.
  • the instant invention overcomes the shortcomings of prior art processes and products by providing a process for recovering relatively low sulfur content, low slag content blast furnace iron from a crude material, called blast furnace slag iron pieces, having a large amount of iron slag contained on the surface thereof and extending from the surface thereof into the body thereof through cavities, fissures and the like.
  • This process although disclosed to be utilized to remove blast furnace slag from blast furnace slag iron pieces, may also be utilized to remove slag impurities from other refined metals such as aluminum, zinc, copper and the like.
  • the slag and metal chunks are broken up into pieces, having sizes of up to a maximum dimension of about 2 or 3 feet, in order to make it possible to charge them into conventional shot blasting machines and, when most of the slag has been removed, to charge them into basic oxygen furnaces, electric furnaces, iron foundry cupolas and the like, for further use of the iron.
  • a typical piece will have a non-geometric shape and dimensions up to about 2 by 2 feet by 6 inches.
  • any given slag pit will produce blast furnace slag iron pieces having a wide variety of shapes and sizes, down to as little as about one-quarter inch.
  • the blast furnace slag iron pieces, or pieces of other metal and slag are first prepared into suitable sizes, by the use of wrecking balls or similar well-known techniques.
  • the pieces containing significant quantities of blast furnace iron or other metal to be recovered are then separated from the other, principally slag containing, pieces. In the case of iron, this separation may easily be effected by the use of an electromagnet.
  • the suitably sized pieces are then transported, as by trucks, conveyor belts, railroad cars, or the like to the slag processing unit.
  • the slag processing unit is a tumbling and shot blasting machine, ofa general type which is known in the art and commercially available.
  • this machine the charge of slagmetal pieces, such as blast furnace slag iron, are placed in a suitable location, such as in a container, wherein they are operated on by a conveyor, rotating and tumbling the mass of individual pieces about, in order to achieve a continuing redistribution of the pieces.
  • the pieces on at least one face of the tumbling mass are subjected to the impact of a continuous flow of relatively high velocity, hard pellets or similarly shaped particles, commonly called shot or grit.
  • Shot is relatively uniformly shaped, usually spherical, particles of metal, typically a relatively hard high carbon steel alloy.
  • Grit is similar to shot, but instead of being spherical, it has facets and sharp corners.
  • the hardness of the shot or grit must be substantially greater than the hardness of the slag, so that the shot or grit will erode the slag when the slag metal pieces are impacted with the high velocity shot or grit.
  • This shot or grit is impacted against the slag-metal pieces, using a relatively high velocity impeller, for taking large quantities of the shot or grit and impelling them against the slag-metal pieces at relatively high velocity.
  • This impact occurring relatively continuously, while continuously redistributing the slag-metal pieces, such as blast furnace slag iron pieces, throughout the mass of such pieces, allows the achievement of relatively uniform exposure of all surfaces of all of the slagmetal pieces to the impact of the shot or grit.
  • the precise slag content of the final product can be regulated by varying the conditions of the process, and particularly the size of the shot or grit, the amount of shot or grit used, the velocity imparted to the shot or grit, the duration of the shot blasting process, and the extent to which the shot blasting enclosure is filled with slag-metal pieces. To a lesser extent, some of the superficial removal of slag is dependent upon the amount of tumbling of the individual pieces which is achieved by the conveyor for these pieces.
  • the product of the invention is a body of metal, blast furnace iron when the process is applied to blast furnace slag iron pieces, comprising an irregularly shaped body, the dimensions of which may vary within wide limits from a fraction of an inch to approximately 2 or 3 feet, and which has a multiplicity of surface-exposed fissures and crevices throughout the body, these fissures and crevices being relatively free of slag, the individual pieces having a total slag content of up to about 10 percent by weight and preferably no more than about 2 or 3 percent by weight.
  • the shot or grit impacting the slag produces a large quantity of relatively fine slag particles. as a residue of the process. These particles may be utilized as a component of Portland cement or the like in order to realize some economic value from this otherwise useless slag.
  • Yet another object of this invention is to provide a process for removing from blast furnace slag iron pieces the majority of the slag to produce a product which has a slag content of no more than approximately percent by weight, and preferably no more than 2 or 3 percent by weight,
  • Still another object of this invention is to provide a slag removal process, capable of removing slag from highly irregularly shaped surfaces of metal, which is applicable to a wide variety of metals, including iron, copper, aluminum. zinc and the like.
  • a still further object of this invention is to provide a metal product having the purity of a blast furnace metal, and having a large degree of surface irregularities, such as fissures and crevices, which are substantially free of impurities, containing no more than about 2 percent by weight of the impurities.
  • FIG. 1 is a schematic representation, in perspective, of a tumbling and blasting machine which may be utilized in the practice of the process of this invention
  • FIG. 2 is a top plan view of a representative piece of blast furnace slag iron prior to treatment by the process of the invention
  • FIG. 3 is a cross-sectional view taken along 3-3 of FIG. 2;
  • FIG. 4 is a top plan view of the product of this invention, corresponding essentially to the raw material of FIG. 2 with a majority of the slag removed, so that the final slag content of the product is no more than about two percent by weight;
  • FIG. 5 is a cross-sectional view, taken along line 55 of FIG. 4.
  • the numeral 10 generally designates a representative blast furnace slag iron piece.
  • the piece illustrated which will have a maximum dimension of approximately 2 or 3 feet and a maximum thickness of approximately 6 inches, comprises a principal continuous phase of blast furnace iron, generally designated by the numeral 12, and an outer covering of slag, generally designated by the numeral 14.
  • the body of iron contains a large number of crevices and fissures, of varying depths, sizes and shapes. Many of these fissures which are generally designated by numeral 16, are substantially filled with varying amount of hard, tough,
  • FIG. 3 it will be seen that such portions of iron as are generally designated by numeral 12 are seen in FIG. 2 as being quite small and superficially exposed iron segments on the surface of piece 10.
  • FIGS. 4 and 5 the final blast furnace iron product of this invention is generally designated by numeral 18.
  • FIGS. 2 to 5 inclusive are intended merely to be general schematic representations of what a piece of blast furnace slag iron may look like before and after the process of this invention and do not correspond precisely to any given piece of material.
  • Pieces 10 are formed from a blast furnace when the molten slag, containing about 2 to about 5 percent of molten iron, is tapped off through the slag notch or cinder notch of a conventional blast furnace. That iron and slag mixture is flowed, in the molten state, into suitable slag pits, where it is allowed to harden. This pit material is broken up and removed to a slag processing facility, where relatively large chunks of iron and slag are broken down into substantially smaller blast furnace slag iron pieces, such as by the use of a wrecking ball.
  • a wrecking ball weighing at least 15 tons would be dropped onto the pieces of iron and slag from a height of at least feet.
  • This process shatters the slag into a large number of small pieces, from which the ironcontaining blast furnace slag iron pieces may be separated by the use of a suitable electromagnet which can be adjusted to separate out only pieces having a predetermined amount of iron. Therefore, although the slag pit contains a predominant amount of slag and a relatively minor amount of iron (2 to 5 percent), the blast furnace slag iron pieces which are removed at the slag processing facility will comprise only those pieces having some significant amount of iron.
  • the pieces which are utilized in the process of this invention will desirably have sizes of up to approximately 2 or 3 feet in maximum dimension, any larger pieces being impacted again with the wrecking ball, to reduce their size to a suitable handleable size.
  • the maximum size of these pieces is determined by the size of piece that can be charged into and efficiently processed in, a shot blasting machine and subsequently accommodated in a melting furnace.
  • blast furnace slag iron pieces having maximum dimensions of up to 2 or 3 feet, are then transported, as by conveyor, truck, or railroad car to the final processing facility.
  • FIG. 1 illustrates schematically one form of tumbling and shot blasting machine usable in the process of this invention, which is commercially available.
  • tumbling and shot blasting machine is sold by Wheelabrator-Frye Inc. under the Super-Tumblast trademark.
  • These machines which come in different sizes and capacities, essentially comprise an enclosed chamber in which a given quantity of material is charged, and in which the mass of pieces is tumbled while it is impacted by a recirculating, high velocity continuous stream of pellets of shot or grit, which are discharged downwardly onto the mass of rotating pieces.
  • the tumbling and shot blasting machine which is generally designated by numeral 20, is seen to comprise a housing 22in which is formed an enclosure 24 into which the pieces to be worked on are charged.
  • Enclosure 24 has a door 29 which can be opened for inserting and removing the pieces 10, and which is closed during the actual tumbling and shot blasting operation.
  • conveyor 26 which is an L-shaped conveyor, comprising individual metal slats 28, each of which has a plurality of circular apertures 30. Each of the apertures 30 has a diameter of approximately five-eighths inch.
  • the conveyor 26 is mounted for counterclockwise movement, during the shot blasting step, on a plurality of drive wheels 36 which are driven by a suitable drive motor (not shown). The conveyor direction is reversed to discharge finished product from the shot blasting machine.
  • the conveyor 26 has a vertical section and a horizontal section, forming an L shape. When the pieces 10 to be treated are loaded into enclosure 24, they are placed on top of the horizontal surface of the conveyor 26.
  • the drive motor for conveyor 26 may be reversible, so that it may be reversed to facilitate discharge of the finished pieces when door 29 is opened.
  • a typical drive speed for conveyor 26 is feet per minute.
  • throwing wheels or impellers Located in the upper portion of the housing are one or two rotatably mounted thrust members 32 called throwing wheels or impellers, the purpose of which is continuously to deliver large quantities of shot or grit. at high velocity, against the upper face of the mass of pieces 10 located in enclosure 24.
  • the two throwing wheels 32 are, in a preferred embodiment of the invention, rotated at approximately 3,600 rpm, and are each 15 inches in diameter.
  • the two wheels 32 may each be driven by a motor (not shown) of about 60 to about 75 horsepower, and each imparts to the shot a tangential velocity of approximately 19,000 feet per minute.
  • the throwing wheels will preferably deliver in the range from about 2,000 to about 4,000 pounds of shot per minute, if an enclosure 24 having a capacity to handle about 50 cubic feet of slag iron pieces 10 is used.
  • the design of the throwing wheels and their details are well known.
  • the shot is generally designated by numeral 34 and preferably comprises small, hard spherical balls, more fully described below.
  • the enclosure 24 is filled with pieces 10 only to a level of about four-tenths of the total height of the enclosure, thus occupying about 40 percent of the enclosure volume. It is this optimum volume which is occupied which is used to designate the machine capacity. Thus a 50 cubic foot machine contains material occupying 50 cubic feet, when it is forty percent filled. This design capacity is selected to give the optimum efficiency of the shot blasting operation, and other volumes may be used, but with less efficiency.
  • the shot 34 impacts the upper surfaces of the mass of blast furnace slag iron pieces 10 and, because of the substantial hardness and kinetic energy of the shot, abrades away the slag 14 in small pieces, generally on the order of less than several hundredths of an inch in size. Also, some larger pieces of slag are broken away from the pieces 10 by virtue of the impact of the various pieces 10 against each other as they are tumbled about enclosure 24 because of the movement of conveyor 26.
  • the movement of conveyor 26 effects a continuous tumbling movement and redistribution of the pieces 10 within enclosure 24, so that different pieces and different surfaces of each piece are continuously exposed to the direct impact of the high velocity shot 34, thereby to effect a uniform abrasion of the slag from the iron or other metal to be recovered.
  • the pieces of shot exit the enclosure 24 by passing downwardly through apertures 30 in the slats 28 of conveyor 26.
  • the apertures 30 are approximately five-eighths of an inch in diameter, and will also, therefore, pass appropriately small pieces of slag, and occasional small pieces of iron which may also be abraded in the enclosure 24. These small pieces of shot, slag and iron, all of which are necessarily less than five-eighths inch in maximum dimension, pass through the apertures 30 in the slats 28 and fall into enclosure 40 in the bottom of the unit 20, where they are transported by conveyor screw 38.
  • the conveyor 38 may be a screw conveyor or a shaking conveyor, which transports the combination of shot, slag and iron across a screen of fit-inch mesh (not shown).
  • the particles which are greater than onequarter inch in size remain on the screen, and constitute mostly slag particles and some iron.
  • These particles are then passed, by a suitable conveyor (not shown), past a magnetic separator, which recovers the highly magnetic materials, comprising both iron and slag, but having enough iron to merit recovery for subsequent recovery and reuse.
  • This air separator is located in the upper chamber 48. Because the slag is of substantially lower density than the shot (or grit), it is blown further away by the air stream and is blown into a ducting system (not shown) which transports the slag to a bag house. The heavier shot and smaller slag iron pieces are not blown as far as the larger slag pieces, and they fall into shot hoppers (not shown) in chamber 48.
  • shot hoppers have adjustable discharge openings, and they function to keep the throwing wheels loaded with shot.
  • slag particles which pass through the screen having a Ar-inch or less size, as well as the very fine slag collected in the bag house, could be used as a component of certain types of cement which normally incorporate blast furnace slag therein.
  • the structural details of the tumbling and shot blasting mechanism 20 are well known in the art and form no part of this invention.
  • the tumbling and shot blasting unit is of at least 50 cubic foot size, that is to say, the optimum working capacity of enclosure 24 is 50 cubic feet.
  • slag iron pieces In the operation of the process of this invention, it is first necessary to reduce the slag iron pieces to usable sizes of up to approximately 2 or 3 feet in maximum dimensions. A substantial number of these pieces, typically comprising a charge weighing about 5,500 to 6,000 pounds, when a 50 cubic foot enclosure 24 is used, are then placed in a suitable tumbling and shot blasting mechanism 20 for the purpose of providing a relatively continuous tumbling and agitation of the individual pieces.
  • the individual pieces are then subjected to the impact of a high velocity stream of small spherical steel shot or hard grit 34, having a flow rate in the range from about 2,000 to about 4,000 pounds per minute and a hardness which is substantially greater than the hardness of the slag and having a size which is in the range of up to about one-tenth of an inch, and is preferably in the range from approximately 0.025 inches to approximately 0.060 inches for a period in the range from about 10 to about 60 minutes. It has been found that the smaller particles, preferably about 0.039 inches nominal size, provide a more effective cleaning, in that they are better able to penetrate deeply into any crevices and fissures in the blast furnace slag iron pieces. It is to be noted that when shot is sold the individual particles usually cover a range of sizes around the specification size. Therefore, if 0.039 inch shot is specified, some of the pieces supplied will be somewhat less than 0.039 inches in diameter and some slightly greater than that size.
  • the shot consists of a high carbon steel alloyed with chromium, having about 1 percent carbon, and having a hardness of approximately 48 on the Rockwell C scale.
  • a desirable shot having these characteristics is sold by Wheelabrator-Frye Inc. under the designation S390.
  • the velocity imparted to the shot or grit and its flow rate may be varied within wide ranges, and the precise velocity and flow rate utilized will depend upon the size of the available drive motor for the throwing wheel and the time period within which it is desired to clean the slag from the iron.
  • the velocity imparted to the shot or grit, for a 50 cubic foot volume of charge will be in the range from approximately 10,000 to approximately 35,000 feet per minute, leaving the throwing wheel. It is most preferred to impart a velocity of approximately 19,000 feet per minute at the throwing wheel, when utilizing a 50 cubic foot machine. TI-Ie optimum flow rate for a 50 cubic foot charge would be about 3,000 pounds per minute.
  • EXAMPLE I Approximately 20,000 pounds of blast furnace slag iron having sizes of up to 2 or 3 feet in maximum dimensions and thicknesses of up to about 6 inches, were processed using the method of this invention.
  • the machine utilized for the processing was a 50 cubic foot Wheelabrator Super-Tumblast, having two 60 horsepower throwing wheels and utilizing steel shot having a 0.055 inch nominal diameter, and designated as 8-550 shot. This machine imparts approximately 19,000 feet per minute of linear velocity to the steel shot at the point of departure from the throwing wheel at a flow rate of about 2,400 pounds per minute.
  • the conveyor 26 was set at an operating speed of approximately 15 linear feet per minute.
  • the enclosure was loaded with approximately 4,200 pounds of the slag iron pieces, and in each of two other instances it was loaded with approximately 7,500 pounds of the slag iron pieces.
  • the 4,200 pound batch was inspected at various stages during the 15 minute blast period. After 5 minutes of processing, cleaning was well under way, but the product was not yet satisfactory. After minutes, the product was judged to be at least 90 percent metallic, and after minutes the material was at least 96 to 97 percent metallic.
  • the two 7,500 pound batches constituted grossly overloaded conditions for the 50 cubic foot Super- Tumblast, which really should not be charged with more than 5,500 to 6,000 pounds of slag iron for efficient processing. It was a matter of practical interest, however, to observe just how well the machine would do under these conditions.
  • the material was inspected after 30 minutes of processing, and it was found to be at least 96 percent metallic. After 40 min utes of processing, the product was at least 98 percent metallic.
  • Example II The only other significant difference in the test conditions between Example I and II was that in Example II, the shot diameter was 0.039 inches, compared to 0.055 inches in Example I.
  • process of this invention is equally applicable to the steel metallics magnetically extracted from the slag produced by basic oxygen furnaces, open hearth furnaces, and electric arc furnaces, and to iron metallics recovered from various foundry melting slags.
  • the product of this invention is a body of a relatively high purity metal, which may be blast furnace iron,
  • the product has an irregular surface having a substantial number of crevices and fissures. which are free of slag.
  • the total slag content of each piece being no more than about percent by weight and preferably being no more than about 2 percent by weight.
  • the iron product of this invention can be used in all forms of steel making. That is to say, the cleaned blast furnace iron can be used in making steel by any process, as well as in making iron castings. as a substitute for the cast iron scrap and pig iron normally used in making iron castings.
  • the ultimate composition of the product of this invention would most desirably be no less than about 98 percent iron and no more than 2 percent slag, and have a total of no more than up to approximately 0.05 percent by weight of sulfur. It is to be noted that this is to be compared with conventional blast furnace iron which has up to about approximately 0.05 percent sulfur maximum, and the slag from the blast furnace which has up to approximately 2 percent by weight of sulfur.
  • the reason why the sulfur content of the cleaned blast furnace iron produced by this process is about 0.05 percent or less, notwithstanding the relatively high sulfur content of the slag. is because the amount of slag is so low as to be virtually insignificant as a sulfur contributor.
  • process of this invention may be used to treat aluminum. brass. copper or other metals to remove slag from the crevices and fissures thereof.
  • steps (b) and (c) occupy a period in the range from about 10 to about minutes and said product contains no more than 3 percent by weight of said impurities.
  • steps (b) and (c) occupy a time period in the range from about 15 to about 40 minutes and said product contains no more than 5 percent by weight of said impurities.

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US05412119 1973-11-02 1973-11-02 Process for producing high-grade metallic products from solid slags and high-grade metallic products Expired - Lifetime US3883997A (en)

Priority Applications (12)

Application Number Priority Date Filing Date Title
US05412119 US3883997A (en) 1973-11-02 1973-11-02 Process for producing high-grade metallic products from solid slags and high-grade metallic products
SE7412906A SE411225B (sv) 1973-11-02 1974-10-14 Forfarande for att atervinna metall fran ett stycke av sadan metall och slagg
ZA00746615A ZA746615B (en) 1973-11-02 1974-10-17 Process for producing high-grade mettalic products from solid slags and high-grade mettalic products
AU74826/74A AU480091B2 (en) 1973-11-02 1974-10-29 Process for producing high-grade metallic products from solid slags and high-grade metallic products
GB4692874A GB1448327A (en) 1973-11-02 1974-10-30 Process of recovering metal from slag
ES431757A ES431757A1 (es) 1973-11-02 1974-10-31 Un procedimiento para la recuperacion de metales a partir depiezas del metal conteniendo escorias rigidamente adheridas.
FR7436414A FR2249959B1 (enrdf_load_stackoverflow) 1973-11-02 1974-10-31
DE2451775A DE2451775C2 (de) 1973-11-02 1974-10-31 Verfahren zur Rückgewinnung von Metall
SU742081513A SU622415A3 (ru) 1973-11-02 1974-11-01 Способ очистки металла от шлака
CA212,887A CA1037720A (en) 1973-11-02 1974-11-01 Process for producing high-grade metallic products from solid slags and high-grade metallic products
JP12704674A JPS5534853B2 (enrdf_load_stackoverflow) 1973-11-02 1974-11-02
US05/544,882 US4044459A (en) 1973-11-02 1975-01-29 High-grade metallic products

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US05/544,882 Division US4044459A (en) 1973-11-02 1975-01-29 High-grade metallic products

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JP (1) JPS5534853B2 (enrdf_load_stackoverflow)
CA (1) CA1037720A (enrdf_load_stackoverflow)
DE (1) DE2451775C2 (enrdf_load_stackoverflow)
ES (1) ES431757A1 (enrdf_load_stackoverflow)
FR (1) FR2249959B1 (enrdf_load_stackoverflow)
GB (1) GB1448327A (enrdf_load_stackoverflow)
SE (1) SE411225B (enrdf_load_stackoverflow)
SU (1) SU622415A3 (enrdf_load_stackoverflow)
ZA (1) ZA746615B (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044459A (en) * 1973-11-02 1977-08-30 Luria Brothers & Co., Inc. High-grade metallic products
US4368599A (en) * 1976-07-20 1983-01-18 Werner Hunziker Apparatus for transport and simultaneous surface-treatment of discrete commodities
US5341602A (en) * 1993-04-14 1994-08-30 Williams International Corporation Apparatus for improved slurry polishing
US5782677A (en) * 1997-01-14 1998-07-21 Kanouse; Richard C. Continuous process blast mill for finishing cast metal parts
RU2190027C1 (ru) * 2001-09-03 2002-09-27 Институт горного дела - научно-исследовательское учреждение СО РАН Способ переработки отходов железорудного производства
WO2005023429A1 (en) * 2003-09-09 2005-03-17 House Of Metals Company Limited Method for recycling aluminum alloy wheels
US20150251291A1 (en) * 2014-03-07 2015-09-10 The Boeing Company Method and system for vibratory finishing of composite laminate parts
US9541343B2 (en) 2015-01-21 2017-01-10 James A. Dodson Interchangeable chamber and barrel system
US10330416B2 (en) 2015-01-21 2019-06-25 Wolf Precision, Inc. Interchangeable chamber and barrel system
US12091605B2 (en) 2021-04-14 2024-09-17 Harsco Technologies LLC Demetallized slag for abrasives and/or roofing granules and related methods

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0813050A (ja) * 1994-07-05 1996-01-16 Nippon Chuzo Kk アルミニウム空缶の再生方法及び再生装置
US20060032328A1 (en) 2004-07-15 2006-02-16 Katsunao Chikahata Sintered valve guide and manufacturing method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2563084A (en) * 1948-05-01 1951-08-07 American Wheelabrator & Equipm Continuous tumbling mill
US2726815A (en) * 1952-06-25 1955-12-13 Heckett Engineering Inc Impact apparatus for cleaning metal scrap and the like
US3097451A (en) * 1963-07-16 Blast machine system and method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5133047B2 (enrdf_load_stackoverflow) * 1971-09-09 1976-09-17

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3097451A (en) * 1963-07-16 Blast machine system and method
US2563084A (en) * 1948-05-01 1951-08-07 American Wheelabrator & Equipm Continuous tumbling mill
US2726815A (en) * 1952-06-25 1955-12-13 Heckett Engineering Inc Impact apparatus for cleaning metal scrap and the like

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4044459A (en) * 1973-11-02 1977-08-30 Luria Brothers & Co., Inc. High-grade metallic products
US4368599A (en) * 1976-07-20 1983-01-18 Werner Hunziker Apparatus for transport and simultaneous surface-treatment of discrete commodities
US5341602A (en) * 1993-04-14 1994-08-30 Williams International Corporation Apparatus for improved slurry polishing
US5782677A (en) * 1997-01-14 1998-07-21 Kanouse; Richard C. Continuous process blast mill for finishing cast metal parts
RU2190027C1 (ru) * 2001-09-03 2002-09-27 Институт горного дела - научно-исследовательское учреждение СО РАН Способ переработки отходов железорудного производства
WO2005023429A1 (en) * 2003-09-09 2005-03-17 House Of Metals Company Limited Method for recycling aluminum alloy wheels
US20150251291A1 (en) * 2014-03-07 2015-09-10 The Boeing Company Method and system for vibratory finishing of composite laminate parts
US9541343B2 (en) 2015-01-21 2017-01-10 James A. Dodson Interchangeable chamber and barrel system
US10330416B2 (en) 2015-01-21 2019-06-25 Wolf Precision, Inc. Interchangeable chamber and barrel system
US12091605B2 (en) 2021-04-14 2024-09-17 Harsco Technologies LLC Demetallized slag for abrasives and/or roofing granules and related methods

Also Published As

Publication number Publication date
SE411225B (sv) 1979-12-10
SE7412906L (enrdf_load_stackoverflow) 1975-05-05
CA1037720A (en) 1978-09-05
JPS5079402A (enrdf_load_stackoverflow) 1975-06-27
DE2451775C2 (de) 1982-08-05
GB1448327A (en) 1976-09-02
SU622415A3 (ru) 1978-08-30
ZA746615B (en) 1975-11-26
DE2451775A1 (de) 1975-05-07
AU7482674A (en) 1976-05-06
FR2249959B1 (enrdf_load_stackoverflow) 1978-06-16
JPS5534853B2 (enrdf_load_stackoverflow) 1980-09-10
ES431757A1 (es) 1977-05-16
FR2249959A1 (enrdf_load_stackoverflow) 1975-05-30

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