Slag, Utilization Patents (Class 65/19)
  • Patent number: 4650510
    Abstract: The invention relates to a method for manufacturing heat-resistant and/or fire-resistant fibre materials, when the employed initial material is molten slag from metal processes. According to the invention, the slag holding furnace (5) is used for achieving an essentially even and continuous molten flow from the slag smelting furnace (3) into the mineral wool furnace (6). The invention also relates to an apparatus for realizing the method, wherein the holding furnace (5) is provided with at least one control device (12) which shifts the furnace (5) between the different filling positions in order to ensure an even and continuous flow of molten material.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: March 17, 1987
    Assignee: Outokumpu Oy
    Inventor: Frans H. Tuovinen
  • Patent number: 4545797
    Abstract: Inert slag is calcined and treated with aqueous base or acid to yield product characterized by high surface area.
    Type: Grant
    Filed: June 13, 1983
    Date of Patent: October 8, 1985
    Assignee: Texaco Inc.
    Inventor: Azza A. Elattar
  • Patent number: 4518498
    Abstract: A filtration apparatus comprised of a rotary drum having a plurality of internal vanes for conveying slag material is presented. The slag is conveyed upwardly by the vanes, after which is falls freely onto a conveyer belt passing longitudinally through the drum. Deflectors guide the slag during its fall onto the belt. The deflectors are divergent and inclined relative to the direction of movement of the conveyer belt. The rotatable drum is axially subdivided into a plurality of sections, the vanes of each section being angularly offset in relation to the vanes of adjacent sections. The filtering apparatus herein effects uniform charging of slag material onto the conveyer belt.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: May 21, 1985
    Assignee: Paul Wurth S.A.
    Inventor: Guido Monteyne
  • Patent number: 4494971
    Abstract: A method and apparatus are presented for granulation of molten slag for determining the flow of molten slag and adjusting the supply of granulation water in accordance with the flow of molten slag.
    Type: Grant
    Filed: November 17, 1982
    Date of Patent: January 22, 1985
    Assignee: Paul Wurth S.A.
    Inventors: Guido Monteyne, Marc Calmes, Robert Schmeler
  • Patent number: 4477349
    Abstract: A filtration apparatus comprised of a rotary drum having a plurality of internal vanes for conveying slag material therein therein is presented. The slag is conveyed upwardly by the vanes, after which it falls freely onto a conveyer belt passing longitudinally through the drum. Each vane consists of a retaining blade and a liquid permeable filtering blade spaced from the retaining blade. A deflecting means is positioned beneath the filtering blade. The deflecting means includes a deflecting plate associated with a support member. The support member and the retaining blade provide a supporting frame work for the rotary drum.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: October 16, 1984
    Inventor: Guido Monteyne
  • Patent number: 4414016
    Abstract: Apparatus for the pelletization of heat-liquifiable materials, such as metallurgical slags, consists of feed means for the molten material, these feed means depositing the material on a downwardly-extending feed plate over which it flows while it is mixed with water, if water is necessary to promote the expansion of the molten material and for control of the cooling. The material then flows on to a first rotating radially-vaned drum or rotor by which it is projected into the air for simultaneous cooling and pelletization. The feed means comprises flow control means such that any flow greater than a predetermined maximum is fed onto a second feed plate disposed above the first, from which the excess molten material flows on to a second rotating radially-vaned drum or rotor operative in like manner to the first. The flow control means may comprise for example a dam over which the excess material flows.
    Type: Grant
    Filed: May 13, 1982
    Date of Patent: November 8, 1983
    Assignee: National Slag Limited
    Inventors: Michael Orlander, Robert P. Cotsworth, Peter A. MacKenzie
  • Patent number: 4381938
    Abstract: Disclosed are methods of precisely operating an improved zone controlled multi-purpose blast furnace mainly by closely controlling gaseous inputs and outputs made through multiple openings in the side of the furnace. The energy can be partially or completely, directly or indirectly, obtained from low cost solid carbonaceous fuels used to produce hot metal, gases and slags, products. "Solution loss" is avoided when operating in a high hot metal production mode but the Boudouard reaction is efficiently employed when operating to produce gases and slags. Gas flows are regulated on the basis of information obtained from on-line samples and performance-impairing recycling alkali metals and zinc may be purged while in a volatile form.
    Type: Grant
    Filed: June 12, 1980
    Date of Patent: May 3, 1983
    Inventor: H. Bruce Claflin
  • Patent number: 4379714
    Abstract: A method for regulating the granulometric characteristics of the components in metallurgical slags comprising the step of imparting a vibration to the slag, after the separation of the slag from the metallurgical furnace while the slag is being cooled. The imparted vibration frequency and amplitude is adjustable and ranges respectively from 12 to 100 Hz and 0.2 to 5 mm and when circular vibration is imparted from 0.4 to 12 mm.
    Type: Grant
    Filed: December 18, 1981
    Date of Patent: April 12, 1983
    Assignee: Vish-Minnogeoloshki Institute
    Inventors: Stoycho M. Stoev, Shtelyana D. Dshendova, Kiril N. Stoyanov, Raycho V. Dochev, Tzvetan P. Krestev
  • Patent number: 4350326
    Abstract: Molten slag fresh from a smelting or refining furnace is ladled into a pan on a wheeled carriage and is thereby transported to a first heat recovery station, where water is heated by radiation from the slag while the latter is being agitated and granulated. On granulation the slag is conveyed as by a skip hoist to a second heat recovery station, where the residual heat of the slag is utilized to heat air by convection. The heated air is directed into a utility device such as a boiler, from which the cooled air is fed back to the second heat recovery station for reheating. Several embodiments are disclosed.
    Type: Grant
    Filed: February 2, 1981
    Date of Patent: September 21, 1982
    Assignees: Kawasaki Jukogyo Kabushiki Kaisha, Kawasaki Steel Corporation
    Inventors: Hiroo Fujii, Kiyoaki Tanaka, Masashi Nakamura, Ryuzo Okuno, Shigeyuki Hashizume, Hideo Katayama, Tsutomu Fujita
  • Patent number: 4328019
    Abstract: A method and apparatus for melting low-cost raw materials such as blast furnace slag, basalt, feldspar or electrophos slag in the formation of high temperature mineral wool insulation. The low-cost mineral stock material is fed in particulate form continuously to a preheater in which it is elevated to a temperature range of between 1500.degree. F. and 2000.degree. F. by forcing hot combustion gases through a vertical column of the particulate stock material. Volatiles such as water and carbon dioxide are thus removed from the stock material. The preheated stock material is distributed to the top of an electric melting furnace which is essentially sealed from atmosphere. A substantially homogenous, low viscosity liquid glass melt is continuously discharged from the furnace.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: May 4, 1982
    Assignee: Forty-Eight Insulations, Inc.
    Inventors: Robert Dejaiffe, Edward L. Kells
  • Patent number: 4305743
    Abstract: A method and system for quenching, drying, and elevating glass compositions comprising an incline reciprocating conveyor arranged to receive a stream of molten glass. The reciprocating conveyor has deep side and lower end walls in order to hold a pool of quenching liquid which is constantly replenished. The reciprocating action of the incline conveyor moves the quenched and shattered glass up out of the quenching pool to the higher end of the conveyor where it is drained and then delivered to a second conveyor. The second conveyor preferably comprises a helical vibrating conveyor surrounded by infrared heaters. The infrared heaters can be adjusted to supply just enough heat to the shattered glass on a helical vibrating conveyor surface to provide drying of the glass.
    Type: Grant
    Filed: August 1, 1980
    Date of Patent: December 15, 1981
    Assignee: The O. Hommel Company
    Inventors: Richard O. Hommel, Dominick Battistone, Jr.
  • Patent number: 4299610
    Abstract: A method and an apparatus for manufacturing a crystalline blast furnace slag, which comprises: endlessly connecting at prescribed intervals a plurality of rectangular metal cooling bodies each with a hollow for cooling water, to form a plurality of cooling grooves with a width at the top end thereof of from 40 to 80 mm corresponding to said prescribed intervals and a depth of from 100 to 300 mm and becoming narrower toward the depth thereof, each between two adjacent ones of said cooling bodies; continuously pouring a molten blast furnace slag sequentially into said plurality of cooling grooves in an atmosphere of an inert gas and/or a reducing gas, while moving said plurality of cooling bodies endlessly connected in circulation in the connecting direction thereof; and, circulating a cooling water through said hollows for cooling water of said plurality of cooling bodies during the pouring of said molten blast furnace slag into said plurality of cooling grooves, to cool said plurality of cooling bodies, there
    Type: Grant
    Filed: March 25, 1980
    Date of Patent: November 10, 1981
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Ryo Ando, Shigeru Araki, Hideaki Hoshi, Kazuyoshi Sato
  • Patent number: 4297119
    Abstract: An apparatus for vitrifying blast furnace slag, which comprises:an endless conveyor belt formed by endlessly connecting a plurality of rectangular cooling metal members, each of said cooling metal members having a plurality of narrow and deep cooling grooves on the outer surface thereof for rapidly cooling and solidifying a molten blast furnace slag into a vitreous blast furnace slag; a driving means for travelling said endless conveyor belt; a molten slag container, arranged above the upstream of the upper forwarding position of said endless conveyor belt, for pouring a molten blast furnace slag into said cooling grooves; a stripper arranged, in the upstream of the lower returning position of said endless conveyor belt, at a prescribed position adjacent to the back surface of said endless conveyor belt, for taking out a cooled and solidified vitreous blast furnace slag in said cooling grooves; and, a cooling means arranged at a prescribed position in the lower returning position of said endless conveyor belt
    Type: Grant
    Filed: December 4, 1979
    Date of Patent: October 27, 1981
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Ryo Ando, Kazuyoshi Sato
  • Patent number: 4289519
    Abstract: Molten slag is granulated with water to produce a granulated-slag/water sry that is fed into the bottom of a horizontally extending foraminous drum. This drum has radially inwardly extending vanes and is rotated to lift up the granulated slag and separate it from the water, discharging the slag onto a conveyor belt for storage or further use. The water running out of the slag slurry is recirculated for use in the initial granulation step for the molten slag stream.
    Type: Grant
    Filed: January 7, 1980
    Date of Patent: September 15, 1981
    Assignee: SIDMAR Maritieme Staalnijverheid NV., Siderurgie Maritime S.A.
    Inventor: Guido Monteyne
  • Patent number: 4277273
    Abstract: Disclosed is an installation for the treatment and handling of metallurgical slag which includes means for the disintegration of a flow of pyroplastic slag by mechanical impacts and cooling means for the cooling of the particles of slag formed by the disintegration. The installation comprises at least one perforated endless band positioned in the path of fall of the particles of slag projected by the disintegration means and cooled by the said cooling means. The installation also comprises an insulating enclosure positioned immediately above the perforated band and which contains the disintegration and cooling means, and means for trapping the ascending gaseous and/or solid by-products.
    Type: Grant
    Filed: June 22, 1979
    Date of Patent: July 7, 1981
    Inventors: Edouard Legille, Carlo Heinz
  • Patent number: 4268295
    Abstract: Apparatus and method for manufacturing crushed sands from blast furnace melted slags including maintaining molten blast furnace melted slags out of contact with water while cooling the molten slags to a temperature between 850.degree. C. to 1300.degree. C. and then rapidly cooling the cooled slags with water thereby producing coarse grain hard quality water processed slags.
    Type: Grant
    Filed: July 6, 1979
    Date of Patent: May 19, 1981
    Assignee: Nakayama Steel Works, Limited
    Inventors: Katsuji Yamamoto, Yuichiro Iwasaki, Akira Adachi, Toshiro Kawata, Keisuke Nagano, Seiichi Fujita, Mikio Harada
  • Patent number: 4213402
    Abstract: An ash removal system for a coal-fired boiler, where the temperature of the water in the ash hopper is maintained at approximately 140.degree. F. under all operating conditions of the boiler, by running cooling water through heat exchange surface positioned in the ash hopper. The cooling water, after picking up heat, is passed through heat exchange surface located outside of the ash hopper, before being introduced into the ash hopper. Some of the heated cooling water can be used as low level heating fluid around the plant site, if desired.
    Type: Grant
    Filed: December 8, 1978
    Date of Patent: July 22, 1980
    Assignee: Combustion Engineering, Inc.
    Inventor: Edward L. Kochey
  • Patent number: 4211552
    Abstract: A method and system for processing molten slag is characterized in that molten slag is first spread onto a slag receiving means which is substantially made of a steel plate of desired thickness and is tiltably mounted on the floor of a roofed slag processing factory and is subsequently air and water-cooled such that the slag is solidified and finally is water-quenched in a cooling water pit whereby the resulting solidified slag is of practical use which neither collapses nor produces dust.
    Type: Grant
    Filed: October 31, 1977
    Date of Patent: July 8, 1980
    Assignees: IRI-E Kosan Corporation, Nippon Steel Corporation
    Inventors: Yoshio Tanaka, Tatsuo Shibata, Tatsuo Matsuo, Tadao Takashima, Sankichi Hori
  • Patent number: 4209313
    Abstract: Molten blast furnace slag is quenched by a volume of water divided into two streams. The first stream is directed downwardly against the slag while the second stream is directed horizontally against the slag. The molten slag is broken down into relatively fine sand-like granules which are kept submerged in the water. The vapors formed during granulation are substantially free of detectable SO.sub.2 and the H.sub.2 S formed and vented to the atmosphere is insufficient to be a detriment to the surrounding environment.
    Type: Grant
    Filed: January 2, 1979
    Date of Patent: June 24, 1980
    Assignee: Bethlehem Steel Corporation
    Inventors: John D. Lynn, Gerald N. Carrick
  • Patent number: 4204855
    Abstract: Molten slag is granulated with water to produce a granulated-slag/water sry that is fed into the bottom of a horizontally extending foraminous drum. This drum has radially inwardly extending vanes and is rotated to lift up the granulated slag and separate it from the water, discharging the slag onto a conveyor belt for storage or further use. The water running out of the slag slurry is recirculated for use in the initial granulation step for the molten slag stream.
    Type: Grant
    Filed: April 11, 1979
    Date of Patent: May 27, 1980
    Assignee: SIDMAR Maritieme Staalnihverheid N.V. Siderurgie Maritime S.A.
    Inventor: Guido Monteyne
  • Patent number: 4179275
    Abstract: Molten metallurgical slags are expanded by contact with water in a liquid or vapor state by passing the molten slag along a prefoaming or expanding trough by delivering the slag to this trough via an intermediate trough which is shiftable along the prefoaming trough in order to vary the location at which the slag contacts the prefoaming trough and the expanding-agent film thereon in accordance with physical characteristics of the molten slag, especially its temperature and viscosity. From the pre-expanding or prefoaming trough, the partially expanded slag may be subjected to expansion by conventional means, e.g. a rotating drum which disperses the slag particles through the air so that they can be collected in a completely expanded, dry and solidified state.
    Type: Grant
    Filed: May 15, 1978
    Date of Patent: December 18, 1979
    Assignee: Acieries Reunies de Burbach-Eich-Dudelange S.A. Arbed
    Inventors: Paul Metz, Robert Schockmel, Roland Mersch
  • Patent number: 4171965
    Abstract: Slag sand is produced by first mixing a stream of molten slag with a quantity of between 0.5 m.sup.3 and 0.7 m.sup.3 of water per ton of slag to chill the slag while leaving it above the pyroplasticity threshold. Thereafter water at a rate of between 0.3 m.sup.3 and 0.4 m.sup.3 is added to the slag to stiffen the stream and this stiffened stream is fed to a drum rotating at a rate between 600 rpm and 1000 rpm to break it up into fine granules which are collected on a foraminous belt.
    Type: Grant
    Filed: April 18, 1978
    Date of Patent: October 23, 1979
    Assignee: ARBED - Acieries Reunies de Burbach-Eich-Dudelange S.A.
    Inventor: Robert Schockmel
  • Patent number: 4153440
    Abstract: Disclosed is a process for the treatment of metallurgical slag, the process comprising mechanical disintegration of a current of pyroplastic slag formed by initial cooling of a current of melting slag by means of water. This cooling comprises a first cooling phase taking place in the course of the flow of a continuous current of slag through an inclined channel into which a variable quantity of water is injected by pressure through the base, and a second cooling phase taking place during the largely free fall of the flow of slag onto a disintegration device. The initial slag cooling phase is accelerated or decelerated in accordance with the properties of the slag, and the intensity and/or duration of the mechanical disintegration is modified in accordance with the physical and granulometric properties of the slag required.A further aspect of the invention provides an installation for the performance of the process as set forth above.
    Type: Grant
    Filed: April 6, 1978
    Date of Patent: May 8, 1979
    Assignee: Paul Wurth S.A.
    Inventors: Edouard Legille, Paul Metz
  • Patent number: 4152131
    Abstract: A device for expanding slag and cinder comprises a channel for carrying molten slag and provided with a lip serving as a spreader to spread out the melt in the form of a thin sheet, the lip being cooled internally; an inclined hollow cooling element constructed in the form of one or more boxes staggered heightwise, and in which cooling water circulates under pressure; nozzles immediately downstream of the lip to feed the cooling water from the cooling element to spray the slag; and a rotating drum which throws the slag into the air before pellets or granules are collected in a sloping collector to remove the non-evaporated water.
    Type: Grant
    Filed: July 5, 1978
    Date of Patent: May 1, 1979
    Inventor: Francis Gagneraud
  • Patent number: 4147332
    Abstract: Molten slag discharged from a metallurgical furnace and flowing down from a slag trough is atomized by air jet into a primary heat-exchanger of rotary cylindrical type and hot slag granules thus obtained and air are caused to pass in a co-current therethrough so as to exchange the heat of the slag to the air flow to obtain a primary hot blast, then the hot slag granules discharged from the primary heat-exchanger are supplied to a secondary heat-exchanger connected to the primary heat-exchanger where the hot slag granules are brought into contact with a counter flow of cold air supplied from outside the system, or with a counter flow of a mixture of the above cold air and a part of the primary hot blast exhausted from the primary heat exchanger to effect heat-exchange and to recover a secondary hot blast.
    Type: Grant
    Filed: August 5, 1977
    Date of Patent: April 3, 1979
    Assignee: Pacific Metals Co., Ltd.
    Inventors: Kotaro Ishii, Masahiko Mitsutsuka, Tomoyuki Osada
  • Patent number: 4127399
    Abstract: The hot mixture of solid slag particles and water produced by contacting water with the molten slag released from a blast furnace is introduced into a tank equipped with an overflow and a filter at the overflow which permits a portion of the water and a minor fraction of slag fines to overflow. The major fraction of larger slag particles collects at the bottom of the tank and is pumped as a slurry containing the remainder of the heated water to a remote sedimentation zone where the slag particles and the water of the slurry are separated.
    Type: Grant
    Filed: August 29, 1977
    Date of Patent: November 28, 1978
    Assignee: Rasa Shoji K.K.
    Inventor: Nisaburo Oikawa
  • Patent number: 4115089
    Abstract: Expanded slag, especially blast-furnace slag of Thomas melts is made by passing the slag along a trough in which water is fed into a layer of the molten slag. The slag is then permitted to cascade downwardly along an inclined surface which is wetted with water and finally is dispersed by a rotating disintegration drum and curtain of finely divided water. The expanded slag has a lower density, a more complete expansion characteristic and a greater uniformity than conventionally produced expanded slags.
    Type: Grant
    Filed: October 21, 1976
    Date of Patent: September 19, 1978
    Assignee: Acieries Reunies de Burbach-Eich-Dudelange S.A. Arbed
    Inventors: Paul Metz, Robert Schockmel, Desire Nick, Paul Pfeiffer
  • Patent number: 4083717
    Abstract: The present invention relates to a process for the separation of three metallurgical phases by decantation.
    Type: Grant
    Filed: July 20, 1976
    Date of Patent: April 11, 1978
    Assignee: Metallurgie Hoboken-Overpelt
    Inventors: Pierre Lenoir, Andre L. Delvaux
  • Patent number: 4065281
    Abstract: Amber glass is made by melting a soda-lime glass-forming batch in which at least 1 percent of the silica content is provided by lignite fly ash.
    Type: Grant
    Filed: May 5, 1976
    Date of Patent: December 27, 1977
    Assignee: Research-Cottrell
    Inventor: Robert Edward Byrne
  • Patent number: 4046541
    Abstract: A process for quenching molten residue discharged from a furnace hearth, through a non-submerged taphole, including the steps of: (a) providing a vertical slag duct in sealed communication at the top with the taphole and sealed at the bottom by being immersed a substantial distance into water in a quench tank, (b) flowing the molten residue from the hearth by gravity down the central axis of said slag duct and quenching it in the water contained in the submerged portion of the slag duct, said water being at a temperature sufficiently high to prevent slag explosions, wherein the improvement comprises:Substantially reducing cooling of the tap and hearth areas of said furnace by removing hot fluid from said duct and replacing same with cooler fluid, thereby substantially preventing steam generated by quenching of said molten residue in the water contained in the submerged portion of said duct from entering said tap and hearth areas.
    Type: Grant
    Filed: May 26, 1976
    Date of Patent: September 6, 1977
    Assignee: Union Carbide Corporation
    Inventor: John Erling Anderson
  • Patent number: 4046323
    Abstract: A process for controlled slow cooling of non-ferrous smelting slags, such as copper slags, for the recovery of the non-ferrous metals contained therein by subsequent crushing, milling and flotation operations is disclosed. The process comprises the steps of pouring the molten slag into a ladle, allowing the slag to slowly cool and solidify in the ladle at least to the point where a shell is formed which is strong enough to withstand dumping from the ladle, dumping the slag from the ladle in a single piece, allowing the dumped slag to cool until its center is substantially solidified, and breaking the dumped slag in small pieces for further cooling, crushing, milling and flotation operations. Alternatively, the top of the slag in the ladle may be water cooled while the slag is allowed to slowly cool in the ladle until its center is substantially solidified. The slag is then dumped and subsequently broken in small pieces.
    Type: Grant
    Filed: May 12, 1976
    Date of Patent: September 6, 1977
    Assignee: Noranda Mines Limited
    Inventors: George C. McKerrow, Albert Pelletier, Christopher J. Newman
  • Patent number: 4046542
    Abstract: This invention relates to a method for granulating blast furnace slag, in which, by means of watersprays, slag which is supplied through a slag chute into an open explosion room, is first granulated, whereupon the water-granules mixture is transported to an open granulation pit and onto a dewatering bed, the dewatering granules being conveyed from said pit periodically.
    Type: Grant
    Filed: April 1, 1976
    Date of Patent: September 6, 1977
    Assignee: Hoogovens IJmuiden B.V.
    Inventor: Kees J. Schmidt
  • Patent number: 4029495
    Abstract: A supported catalyst contaminated with organic impurities or a mixture of such a catalyst and a flux is introduced into a rotary furnace, rocking furnace or gradient furnace and agitated and heated therein until sintered or transformed into a semi-melted state. After sintered or transformed into a semi-melted state, the mix is then solidified, cooled and pulverized. The heavy metal is recovered by gravity concentration or magnetic separation. Alternatively, the sintered or semi-melted mixture may be fused at a higher temperature to separate the components by difference in their specific gravities.
    Type: Grant
    Filed: August 3, 1976
    Date of Patent: June 14, 1977
    Inventor: Yoshiro Hirayama
  • Patent number: 4018588
    Abstract: A slag handling apparatus and method are disclosed wherein slag is received at an elevated temperature of about 3000.degree. F. and an elevated pressure of about 450 pounds per square inch and is handled so that it may be transported at atmospheric pressures and low temperatures of the order of 100.degree.-200.degree. F. The slag is sequentially fractured and ground by a grinder while descending downwardly through a column of water in a series of vessels.
    Type: Grant
    Filed: May 10, 1976
    Date of Patent: April 19, 1977
    Assignee: Ecolaire Incorporated
    Inventor: Charles R. Hardy, Jr.
  • Patent number: 3942966
    Abstract: A method of preparing a ceramic material comprising the steps of forming a mixture of crystallizable glass frit particles and a silicate binder having a melting point of between 950 and 1,100.degree.C, heating the mixture to melt the binder and to initiate crystallization of the crystallizable glass frit and cooling the heated mixture to room temperature.
    Type: Grant
    Filed: April 19, 1973
    Date of Patent: March 9, 1976
    Assignee: Karl Kristian Kobs Kroyer
    Inventors: Karl Kristian Kobs Kroyer, Tage Fredsted, Gunnar Brocks
  • Patent number: 3938975
    Abstract: A method for treating blast furnace slag comprising cooling and solidifying the slag discharged from the blast furnace with an aqueous solution containing not less than 0.003% ferrous sulfate and/or ferrous chloride.
    Type: Grant
    Filed: August 16, 1974
    Date of Patent: February 17, 1976
    Assignees: Nippon Steel Corporation, Hamada Heavy Industries Co., Ltd.
    Inventor: Takeshi Nagata