Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B3/00—General features in the manufacture of pig-iron
  • C21B3/04—Recovery of by-products, e.g. slag
  • C21B3/06—Treatment of liquid slag
  • C21B3/08—Cooling slag
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
  • C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
  • C21B2100/42—Sulphur removal
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/02—Physical or chemical treatment of slags
  • C21B2400/022—Methods of cooling or quenching molten slag
  • C21B2400/024—Methods of cooling or quenching molten slag with the direct use of steam or liquid coolants, e.g. water
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/02—Physical or chemical treatment of slags
  • C21B2400/03—Removing sulfur
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/02—Physical or chemical treatment of slags
  • C21B2400/032—Separating slag from liquid, e.g. from water, after quenching
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/05—Apparatus features
  • C21B2400/062—Jet nozzles or pressurised fluids for cooling, fragmenting or atomising slag
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/05—Apparatus features
  • C21B2400/066—Receptacle features where the slag is treated
  • C21B2400/072—Tanks to collect the slag, e.g. water tank
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/05—Apparatus features
  • C21B2400/066—Receptacle features where the slag is treated
  • C21B2400/074—Tower structures for cooling, being confined but not sealed

Definitions

• the invention relates to a method for granulating slag, in particular from a blast furnace and / or a smelting reduction plant, wherein a granulation-water mixture formed during granulation is fed to a granulation vessel and then to a dewatering plant in which the slag granules are dewatered, and wherein the Granulating resulting H 2 S-containing vapors and gases are at least partially condensed in a condenser in fluid communication with the granulation in the condenser by Eindusen of water.
• the hot slag originating from a blast furnace or smelting plant is converted into granules, such as e.g. by rapid cooling and crushing with water.
• the granulate-water mixture flows through a granulation vessel or via a channel to a dewatering plant.
• the slag sand is dewatered to about 12% and then sold as a finished product.
• the gas streams consisting of a steam-exhaust steam mixture, which are understood as exhaust air and pollutants such as H 2 S and SO 2 , conducted in a closed circuit and precipitated with calcium oxide-containing water in a condensing tower.
• the amount of air sucked or otherwise introduced into the system and the H 2 S quantities produced vary greatly during tapping and tapping Tapping depending on slag rate, slag analysis, water cycle volume, water temperature, wind speed, wind direction, shape and design of the granulation tube and other factors.
• the introduced into the system air leads in other areas of the system according to DE 35 1 1 958 C to a slight overpressure and passes through Granulatabsch- and other openings and on hoods in the atmosphere. With the air, however, the harmful gases in concentrations that are above the permitted limits escape uncontrolled into the atmosphere.
• the sulfur-containing waste gases are subjected to chemical gas scrubbing in a separate apparatus in the condenser tower by means of the injection of an alkaline aqueous solution before they are passed into the atmosphere.
• chemical gas scrubbing in a separate apparatus in the condenser tower by means of the injection of an alkaline aqueous solution before they are passed into the atmosphere.
• an additional chemical system and a resulting consumption of chemicals are necessary.
• the invention aims to avoid the above-mentioned problems and disadvantages and has as its object to provide a method and a plant for granulating slag, in which the H 2 S content of the resulting during the granulation gases and vapors without complicated installations in an existing Reliable system eliminated without additional chemical consumption or at least reduced below the permissible limit concentration. Furthermore, the escape of H 2 S-containing gases from other openings and leaks in the system should be avoided and the amount of air introduced into the system should be minimized.
• This object is achieved in a method for granulating slag according to the aforementioned type according to the invention in that H 2 S containing residual gases are derived below the water injection from the Kondensierraum and H 2 S is burned.
• the combustion of H 2 S to SO 2 is carried out in a combustion chamber.
• a combustion chamber Such can also be easily added to an existing system.
• the combustion exhaust gas is cooled with water and the SO 2 formed from H 2 S is precipitated.
• a further preferred variant is characterized in that the residual gases are led after discharge from the Kondensierraum in countercurrent to the hot slag and this H 2 S is burned to SO 2 , optionally with heat supply by means of a support flame.
• the granulating container is sealed gas-tight with respect to the drainage system.
• escape of the sulfur-containing gases and vapors formed substantially during the granulation process is prevented in the dewatering system, so that a large part of these gases and vapors is deposited by the injected water in the condenser.
• an overpressure is set in the granulating container and in the condenser space below the water injection. This is done by setting the water injection.
• the overpressure has the positive effect that the H 2 S-containing residual gases without forced delivery devices, such as fans and the like., To the downstream combustion point, ie combustion chamber or slag channel, are passed. In addition, the amount of air introduced through the granulator is reduced, and thus also the amount of air and H 2 S cargo discharged from the system.
• vapors and gases produced in the dewatering plant are passed into the condensation space above the water injection.
• These vapors and gases, some of which also contain sulfur, can be precipitated in the condenser space or fed to combustion as H 2 S-containing residual gases.
• a negative pressure is set in the condensing tower above the water injection.
• a gas barrier In the presence of a gas barrier is formed, for example, in the granulation tank downstream equipment through a gas line with the Kondensierraum on the Wassereindüsung from a negative pressure, which causes no vapors and gases uncontrollably escape from openings and leaks, but these vapors and gases in the Be condensed condensing.
• the guided by a suction effect in the Kondensierraum steam and gas quantity is preferably controlled by the amount of injected water and kept to a minimum. This minimizes the amount of H 2 S discharged with the air as well as the energy consumption of the system.
• a further preferred variant of the invention is characterized in that condensate formed in the condensing space and injected water are removed from the condensing space and supplied to the water separated in the dewatering plant, which is recycled for granulation and water injection.
• the amount of injected water is appropriately regulated depending on the slag rate.
• the slag granulating plant of the present invention comprises a slag chute for conveying the hot slag to a granulating apparatus, preferably a spray head, a granulating vessel arranged thereafter for receiving a granulated water mixture, a condensing means fluidly connected to the granulating tank, preferably one Condensation tower, with a water supply and a device for water injection, and a granular dewatering system, and is characterized in that in the condenser below the device for water injection a discharge for vapors and gases is provided, which communicates with a combustion chamber in line.
• the slag granulating plant comprises a slag chute provided with a suction hood for conveying the hot slag to a granulating apparatus, preferably a spraying head, a granulating container arranged thereafter for receiving a granulated water mixture, one with the granulating container fluidically connected condensing device, preferably a condensing tower, with a water supply and a device for water injection, and a granular dewatering plant, and is characterized in that in the condenser below the device for water injection a discharge for vapors and gases is provided between the the granulator and the suction hood opens into the slag trough.
• a water cooler for the combustion exhaust gases is provided after the combustion chamber or after the exhaust hood of the slag trough. This serves to cool the combustion exhaust gases and to wash out or precipitate the resulting from the combustion SO 2 .
• the slag trough comprises a burner for generating a support flame , which can be switched on depending on the slag trough temperature.
• the slag trough can be heated after a longer standstill to the required for the combustion of H 2 S temperature.
• a preferred variant of the system according to the invention is characterized in that the granulate dewatering plant comprises at least one dewatering device and a water basin, which are provided with a cover, and leads away from the cover a derivative of vapors and gases, which in the condenser above the device for Water injection opens.
• a gas barrier is provided between the granulation and the granular dewatering system.
• a means for collecting water and condensate is provided in the condenser below the device for water injection, from which leads away a derivative, which opens into the granular dewatering device, in particular the water basin.
• the granulate dewatering plant in particular the water basin, is preferably in line with the water supply of the condensing device and / or the granulator in combination.
• hot slag from a blast furnace and / or a smelting reduction plant is conveyed through a slag channel 1 in the direction of the arrow to a granulating device 2, for example a spray head, where it is cooled and crushed by the injection of water.
• the resulting granulate-water mixture passes through a granulating 3 into a granulating 4 and from there through a channel 5 in a granular dewatering system consisting of dewatering devices 6a and 6b, eg screw conveyors, drum filter, etc., and water basin 7a-7c ,
• the granules are dewatered and the slag sand in storage areas 8a and 8b stored.
• the water deposited in the water tanks 7a-7c is returned to the granulating device 2 via a line 9 after replacement of the losses and cooling in a cooling tower 24 as process water from the collecting tank 23 of the cooling tower 24.
• the sulfur-containing vapors and gases produced during granulation are precipitated in a condensing tower 10 arranged above the granulation container 4.
• a device 1 1 for water injection is arranged, which is supplied via a fed from the collecting tank 23 water supply 12 with calcium oxide-containing water.
• a means 13 for collecting water and condensate e.g. formed by water gutters, arranged, which is connected via a discharge line 14 with the water tank 7c.
• the non-condensed or precipitated, H 2 S-containing residual gases and vapors are withdrawn below the device 1 1 and above the means 13 via a discharge line 15 from the condensing tower 10 and fed to a temperature-controlled Brennsch ⁇ where a combustion of H 2 S to SO 2 takes place.
• the combustion exhaust gases are subsequently cooled in a water cooler (or scrubber) 17 fed by the water feed 12 and the SO 2 contained therein is washed out or precipitated.
• the purified from H 2 S and SO 2 exhaust gas is then passed into the atmosphere.
• the wash water is fed to the discharge line 14.
• the discharge line 15 (shown in dashed lines) opens in the slag channel 1, specifically between the granulating device 2 and a suction hood 18 provided above the slag channel 1.
• the residual gases are conducted in the slag channel 1 in countercurrent to the hot slag and H 2 S is SO 2 burned.
• the distance between the junction of the discharge line 15 in the slag channel 1 and the suction hood 18 ensures that the residual gases can be heated to the required temperature for the combustion of H 2 S and that enough time is available for combustion.
• a burner 19 is provided in the slag trough l for generating a support flame.
• the combustion exhaust gases are discharged via the exhaust hood 18 and optionally supplied to the water cooler 17 or an Enlstaubungsvorraum.
• the granulating 4 is compared to the channel 5 and subsequently completed with respect to the granular dewatering system with a gas barrier 20, which allows only the granulate-water mixture a transfer into the channel 5 and the dewatering system, but the vapors and gases in the granulation and retains in the condensing tower 10.
• the device 1 1 By the injection of water through the device 1 1 is in the lower part of the condensing tower 10, i. below the water injection, and generates an overpressure in the granulation 4. Due to this overpressure, the residual gases are fed without need of forced delivery devices via the discharge line 15 of the combustion chamber 16 or to the slag trough 1 and conveyed therethrough.
• the drainage devices 6a, 6b with the water basins 7a and 7b and the last water basin 7c are provided with covers 21a-21c, of which a discharge line 21 for in the dewatering plant resulting, possibly sulfur-containing vapors and gases leads away, above the device 1 1 in the Condensation tower 10 opens. In this way, harmful exhaust gases that do not already arise in the granulation 4 and rise from there into the condensing tower 10, also the cleaning and in particular the combustion are supplied.
• the derivative line 22 and the Wasserzu 12 measuring or control devices are provided so that the extracted from the drainage system steam and gas quantity regulated by the amount of water injected into the condenser 10 and kept to a minimum can.
• measuring instruments for determining the slag rate are provided in order to be able to regulate the injected water quantity and also the dependence of these.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Furnace Details (AREA)
• Manufacture Of Iron (AREA)
• Processing Of Solid Wastes (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

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ID=33136548

Family Applications (1)

Country Status (14)

Families Citing this family (12)

Family Cites Families (19)

• 2003
  • 2003-09-25 AT AT0152503A patent/AT412650B/de not_active IP Right Cessation
• 2004
  • 2004-09-17 DE DE502004002708T patent/DE502004002708D1/de active Active
  • 2004-09-17 ES ES04765337T patent/ES2280998T5/es active Active
  • 2004-09-17 EP EP04765337A patent/EP1664353B2/fr not_active Not-in-force
  • 2004-09-17 CN CN2004800278280A patent/CN1856583B/zh not_active Expired - Fee Related
  • 2004-09-17 BR BRPI0414805-3A patent/BRPI0414805A/pt active Search and Examination
  • 2004-09-17 PT PT04765337T patent/PT1664353E/pt unknown
  • 2004-09-17 WO PCT/EP2004/010442 patent/WO2005031008A1/fr active IP Right Grant
  • 2004-09-17 CA CA002539601A patent/CA2539601A1/fr not_active Abandoned
  • 2004-09-17 RU RU2006113925/02A patent/RU2355771C2/ru not_active IP Right Cessation
  • 2004-09-17 PL PL04765337T patent/PL1664353T5/pl unknown
  • 2004-09-17 KR KR1020067007716A patent/KR101186277B1/ko not_active IP Right Cessation
  • 2004-09-17 US US10/572,775 patent/US7600397B2/en not_active Expired - Fee Related
  • 2004-09-17 AT AT04765337T patent/ATE351927T1/de not_active IP Right Cessation
  • 2004-09-17 AU AU2004276445A patent/AU2004276445B2/en not_active Ceased
• 2009
  • 2009-08-28 US US12/549,832 patent/US8302430B2/en not_active Expired - Fee Related

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