A device and method for granulating high-temperature molten slag by using high-speed air flow

Abstract

The present invention is provided with second and third upper blower nozzles on the left and right side plates respectively, and the second and third upper blower nozzles face the front side plate. The high-speed airflows ejected by the second and third upper blower nozzles are in the reverse direction in the horizontal direction during the parabolic upward movement stage of the high-temperature molten slag particles, and are in the same direction in the height direction during the parabolic upward movement stage of the high-temperature molten slag particles. That is to say, reverse high-speed airflows are used to blow the high-temperature molten slag particles during the parabolic upward movement stage of the high-temperature molten slag particles. By the resistance of the high-speed airflows, thrust is increased to the high-temperature molten slag particles in the height direction, delaying the time for the molten slag particles to land. At the same time, resistance is increased to the high-temperature molten slag particles in the horizontal direction, reducing the landing distance of the molten slag particles in the horizontal direction. On the premise of ensuring that the molten slag particles are completely solidified before landing, the length of the equipment is reduced, realizing the miniaturization of the equipment. The problem that the equipment cannot be installed in the steelmaking workshop is solved, and at the same time, the problems of transportation safety and high energy consumption are solved.

Description

Technical Field

[0001] The present invention relates to the field of utilization of high-temperature molten slag waste, and specifically to an air pulverization method and device for high-temperature molten slag discharged from blast furnaces, converters, electric furnaces, etc., especially a method and device for granulating high-temperature molten slag by using a high-speed air flow. Background Art

[0002] The liquid slag produced in the steelmaking process of steel production accounts for more than 15% of the steel output, and can reach up to 20 - 40%. The initial temperature of the slag is about 1400 - 1700°C. It not only contains rich heat energy resources, but also during the molten slag treatment process, the slag produced by cooling can be used as building materials, steel shot materials for ship hulls, etc., and has high utilization value.

[0003] Currently, high-temperature molten slag is mainly treated by water quenching and slag smothering methods. However, the water quenching method has problems such as large water consumption, generation of a large amount of harmful gases, and insufficient heat energy recovery. The slag smothering method often has dangerous accidents such as steam explosions. In recent years, high-temperature slag granulation methods such as the centrifugal method and the air quenching method have emerged. The centrifugal method relies on the centrifugal force generated by the high-speed rotation of a turntable or a rotating cup to granulate high-temperature liquid molten slag. Its granulation effect is greatly affected by temperature and flow rate. If the high-temperature molten slag concentrates and impacts a certain part of the equipment, it will cause local overheating and damage of the equipment, and the equipment maintenance cost is relatively high. The air quenching method uses the high-speed air flow generated by a high-power granulating fan to blow and granulate high-temperature molten slag. Its process flow is as follows: the high-temperature molten slag is poured from the slag pot into the slag flow channel, and is blown into particles by high-speed air at the outlet of the slag flow channel. For the slag particles with a still semi-solid surface that fall nearby (usually within 8m), supplementary cooling is taken to avoid adhesion; the slag particles that fall far away have completely become solid and will not adhere. When there is a heat recovery device, the high-temperature slag particles enter it to recover their sensible heat. The cooled slag particles are sent to the storage and transportation system and transported to the users. The air quenching method has the advantages of the water quenching method, the slag smothering method, and the centrifugal method, can avoid the danger of explosion and water pollution, and can recover heat energy (when there is a heat recovery device), and avoid damage caused by local overheating of the equipment. It has a high market prospect.

[0004] In addition, in the air quenching method, compressed air is used as the medium. During air quenching, the molten and semi-molten slag particles fly forward with the compressed air. During the flying process of being broken, the compressed air has a strong oxidation effect on the high-temperature liquid steel slag. After air quenching, the FeO phase in the steel slag disappears, and the unstable phase containing FeO significantly decreases, while the stable phases of Ca2O3 and Fe2O3 increase. This cannot be achieved by any steel slag treatment method such as the water quenching method, the slag smothering method, and the centrifugal method. When using water to supplement cooling, the digestion reaction of CaO is strengthened. The granulation and cooling process basically eliminates the unstable phases in the steel slag, and the amorphous mineral phases on the particle surface significantly increase, improving the potential activity of the steel slag. In addition, due to the different surface tensions of molten steel and liquid steel slag, the air quenching process can achieve good separation of slag and iron. Both the solid slag and steel are in the form of spherical fine particles, and the situation of slag-wrapped steel will not occur. After air quenching, simple magnetic separation can separate the slag and iron. By adjusting the process parameters of the air quenching process, the average particle size of the air quenched slag can reach about 2 mm, and the particle size distribution range is relatively narrow, which can replace yellow sand as fine aggregate for concrete and can be directly used.

[0005] Although the air quenching method has the above advantages, the air quenching method also has the following disadvantages: The existing air quenching equipment has a large floor area and needs to be installed separately outside the steel production workshop. During operation, special vehicles are required to transport the steel slag from the steelmaking furnace to the air quenching equipment for operation. On the one hand, the transportation of steel slag is dangerous. On the other hand, the steel slag cools and hardens during transportation, resulting in difficult unloading. Third, before air quenching, the steel slag needs to be heated again until it becomes high-temperature liquid molten slag again, consuming a large amount of energy. Summary of the Invention

[0006] To solve the above technical problems, the present invention proposes a device for granulating high-temperature molten slag by using high-speed air flow, including a crane, a high-temperature molten slag container, a turntable, a molten slag diversion trough, an upper blower, and a molten slag granulation body. The upper blower is provided with nozzles. The molten slag granulation body is composed of a top plate, a bottom plate, a left side plate, a right side plate, a front side plate, and a rear side plate. A second upper blower nozzle is provided on the left side plate, and a third upper blower nozzle is provided on the right side plate. The nozzles are connected to the upper blower through pipes.

[0007] Preferably, the second upper blower nozzle is located at one-fourth to one-half of the distance from the front end of the left side plate. The angle between the second upper blower nozzle and the left side plate is 20 - 80 degrees. The second upper blower nozzle faces the front side plate, specifically, it has an upward inclination angle of 605 degrees towards the front side plate.

[0008] The third upper blower nozzle is located at one-fourth to one-half of the distance from the front end of the right side plate. The angle between the third upper blower nozzle and the right side plate is 20 - 80 degrees. The third upper blower nozzle faces the front side plate. Specifically, it has an upward inclination angle of 605 degrees towards the front side plate.

[0009] Preferably, at least one water atomizing nozzle is further provided on the top plate, and the water atomizing nozzle is connected to an external water pipe.

[0010] Preferably, the water atomizing nozzle is arranged on the center line of the top plate.

[0011] Preferably, a fourth upper fan nozzle is provided on the left side plate, and a fifth upper fan nozzle is provided on the right side plate.

[0012] Preferably, the fourth upper fan nozzle is located at a quarter to a half of the distance from the rear end of the left side plate, and the included angle between the fourth upper fan nozzle and the left side plate is 20 - 80 degrees, and the fourth upper fan nozzle faces the front side plate; the fifth upper fan nozzle is located at a quarter to a half of the distance from the rear end of the right side plate, and the included angle between the fifth upper fan nozzle and the right side plate is 20 - 80 degrees, and the fifth upper fan nozzle faces the front side plate.

[0013] Preferably, a feed port is provided on the front side plate. The high-temperature molten steel slag in the high-temperature molten slag container is poured into the turntable, and the high-temperature molten steel slag flows out through the molten slag diversion groove. The upper fan nozzle blows the flowing high-temperature molten steel slag at high speed, so as to blow the high-temperature molten slag into the molten slag granulator through the feed port. At the same time, the high-speed air flow pulverizes the high-temperature molten slag falling from the molten slag diversion groove by air.

[0014] Preferably, the high-temperature molten slag container is in a funnel shape.

[0015] Preferably, the second upper fan nozzle and the third upper fan nozzle are symmetrically arranged. The fourth upper fan nozzle and the fifth upper fan nozzle are symmetrically arranged. The second, third, fourth, and fifth upper fan nozzles are respectively connected to the upper fan through pipelines.

[0016] The present invention also provides a method for granulating high-temperature molten slag by using high-speed air flow, including the following steps: using high-speed air flow to pulverize the falling high-temperature molten slag by air to obtain high-temperature molten slag particles moving in a parabolic motion; using reverse high-speed air flow to blow the high-temperature molten slag particles during the upward stage of the parabolic motion of the high-temperature molten slag particles, and increasing the thrust of the high-temperature molten slag particles in the height direction and increasing the resistance of the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow.

[0017] Preferably, the present invention further includes a step of atomizing water spray for cooling; using high-speed air flow to pulverize the falling high-temperature molten slag by air to obtain high-temperature molten slag particles moving in a parabolic motion; using reverse high-speed air flow to blow the high-temperature molten slag particles moving in a parabolic motion, and increasing the thrust of the high-temperature molten slag particles in the height direction and increasing the resistance of the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow; atomizing water spray for cooling the high-temperature molten slag particles moving in a parabolic motion from the top, and while increasing the resistance of the high-temperature molten slag particles in the height direction, quickly cooling the high-temperature molten slag particles.

[0018] Preferably, the present invention further includes a step of performing secondary reverse purging during the stage when the high-temperature molten slag particles fall in a parabolic motion; secondary reverse high-speed air flow is used to purge the high-temperature molten slag particles during the stage when the high-temperature molten slag particles fall in a parabolic motion. By the resistance of the high-speed air flow, a thrust is added to the high-temperature molten slag particles in the height direction, and a resistance is added to the high-temperature molten slag particles in the horizontal direction.

[0019] Beneficial effects: The present invention is respectively provided with a second upper blower nozzle and a third upper blower nozzle on the left and right side plates, and the second upper blower nozzle and the third upper blower nozzle face the front side plate. The high-speed air flow ejected from the second upper blower nozzle and the third upper blower nozzle is in the reverse direction in the horizontal direction and in the same direction in the height direction as the stage when the high-temperature molten slag particles rise in a parabolic motion. That is to say, reverse high-speed air flow is used to purge the high-temperature molten slag particles during the stage when the high-temperature molten slag particles rise in a parabolic motion. By the resistance of the high-speed air flow, a thrust is added to the high-temperature molten slag particles in the height direction, delaying the time for the molten slag particles to land. At the same time, a resistance is added to the high-temperature molten slag particles in the horizontal direction, reducing the landing distance of the molten slag particles in the horizontal direction. On the premise of ensuring that the molten slag particles are completely solidified before landing, the length of the molten slag granulation body is reduced, and miniaturization of the molten slag granulation equipment is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the present invention;

[0021] Figure 2 is a schematic structural diagram of the molten slag granulation body. DETAILED DESCRIPTION OF THE INVENTION

[0022] As shown in FIGS. 1 and 2, a high-temperature molten slag granulation device using high-speed air flow includes a crane 1, a high-temperature molten slag container 2, a turntable 3, a molten slag diversion trough 4, an upper blower 8, and a molten slag granulation body 6. The upper blower is provided with a nozzle 5. The angle of the upper blower nozzle is adjustable, the position of the upper blower is adjustable, and the upper blower is connected to the upper blower nozzle through a pipeline; the crane 1 lifts the steel slag in the furnace and pours the molten steel slag into the high-temperature molten slag container 2. The high-temperature molten slag passes through the bottom of the high-temperature molten slag container, passes through the turntable 3 and the molten slag diversion trough 4 and then falls freely. During the falling process of the high-temperature molten slag, the air blown out at high speed by the nozzle 5 of the upper blower 8 is blown into the molten slag granulation body 6, and at the same time, the molten slag is also granulated by air extraction. The molten slag particles move in a parabolic motion in the molten slag granulation body 6. This process belongs to the prior art and will not be elaborated here.

[0023] The innovation of the present invention lies in that the molten slag granulation body is composed of a top plate 601, a bottom plate 602, a left side plate 603, a right side plate 604, a front side plate 605 and a rear side plate 606. A second upper blower nozzle 502 is provided on the left side plate 603, and a third upper blower nozzle 503 is provided on the right side plate.

[0024] Preferably, the second upper blower nozzle 502 is located at a position from one-fourth to one-half of the left side plate 602 away from the front end. The angle between the second upper blower nozzle 502 and the left side plate 603 is 20 - 80 degrees. The second upper blower nozzle 502 faces the front side plate, specifically, it faces the front side plate 605 at an upward inclination angle.

[0025] The third upper blower nozzle 503 is located at a position from one-fourth to one-half of the right side plate 604 away from the front end. The angle between the third upper blower nozzle 503 and the right side plate is 20 - 80 degrees. The third upper blower nozzle 503 faces the front side plate 605, specifically, it faces the front side plate 605 at an upward inclination angle.

[0026] In the present invention, the second upper blower nozzle 502 and the third upper blower nozzle 503 are respectively provided on the left and right side plates 603 and 604, and the second upper blower nozzle 502 and the third upper blower nozzle 503 face the front side plate, specifically, they face the front side plate 605 at an upward inclination angle. The high-speed air flow ejected from the second upper blower nozzle 502 and the third upper blower nozzle 503 is in the reverse direction in the horizontal direction during the parabolic upward movement stage of the high-temperature molten slag particles, and is in the same direction in the height direction during the parabolic upward movement stage of the high-temperature molten slag particles. That is to say, the reverse high-speed air flow is used to blow the high-temperature molten slag particles during the parabolic upward movement stage of the high-temperature molten slag particles. By the resistance of the high-speed air flow, thrust is added to the high-temperature molten slag particles in the height direction, delaying the time for the molten slag particles to land. At the same time, resistance is added to the high-temperature molten slag particles in the horizontal direction, reducing the landing distance of the molten slag particles in the horizontal direction. On the premise of ensuring that the molten slag particles are completely solidified before landing, the length of the molten slag granulation body 6 is reduced, realizing the miniaturization of the molten slag granulation body 6 equipment.

[0027] As Figure 1 shown, preferably, at least one water atomizing nozzle 7 is further provided on the top plate 601, and the water atomizing nozzle 7 is connected to an external water pipe.

[0028] Preferably, the water atomizing nozzle 7 is arranged on the center line of the top plate 601.

[0029] Preferably, there are 2 - 10 water atomizing nozzles 7. Preferably, at least one of the water atomizing nozzles 7 is located at the inflection point position of the parabolic movement of the high-temperature molten slag particles.

[0030] In the present invention, the high-temperature molten slag particles moving in a parabola are atomized and sprayed with water for cooling from the top. While adding resistance to the high-temperature molten slag particles in the height direction, the high-temperature molten slag particles are quickly cooled. Further realizing the miniaturization of the molten slag granulation body 6 equipment.

[0031] As Figure 2As shown, preferably, a fourth upper blower 504 is provided on the left side plate 603, and a fifth upper blower nozzle 505 is provided on the right side plate 604.

[0032] Preferably, the fourth upper blower nozzle 504 is located at a position from one-fourth to one-half of the left side plate 603 away from the rear end. The angle between the fourth upper blower nozzle and the left side plate is 20 - 80 degrees. The fourth upper blower nozzle 504 faces the front side plate, specifically, it faces the front side plate 605 at an upward inclination angle. The fifth upper blower nozzle 505 is located at a position from one-fourth to one-half of the right side plate 604 away from the rear end. The angle between the fifth upper blower nozzle and the right side plate is 20 - 80 degrees. The fifth upper blower nozzle faces the front side plate, specifically, it faces the front side plate 605 at an upward inclination angle.

[0033] In the present invention, secondary reverse purging is carried out during the stage when the high-temperature molten slag particles fall in a parabolic motion; secondary reverse high-speed air flow is used to purge the high-temperature molten slag particles during the stage when the high-temperature molten slag particles fall in a parabolic motion. By the resistance of the high-speed air flow, thrust is added to the high-temperature molten slag particles in the height direction, and resistance is added to the high-temperature molten slag particles in the horizontal direction. The landing time of the molten slag particles is further delayed, and the landing distance of the molten slag particles in the horizontal direction is reduced.

[0034] Preferably, a feed port is provided on the front side plate 605. The high-temperature molten steel slag in the high-temperature molten slag container is poured into the turntable. The high-temperature molten steel slag flows out through the molten slag diversion groove. The upper blower nozzle blows the flowing high-temperature molten steel slag at high speed, so as to blow the high-temperature molten slag into the molten slag granulator through the feed port. At the same time, the high-speed air flow air-crushes the high-temperature molten slag falling from the molten slag diversion groove.

[0035] Preferably, the high-temperature molten slag container 2 is funnel-shaped.

[0036] Preferably, the second upper blower nozzle 502 and the third upper blower nozzle 503 are symmetrically arranged. The fourth upper blower nozzle 504 and the fifth upper blower nozzle 505 are symmetrically arranged. The symmetrically arranged upper blower nozzles can reduce the deviation during the purging of the molten slag particles and prevent damage to the left and right side plates.

[0037] Embodiment 2:

[0038] The present invention also provides a method for granulating high-temperature molten slag by using high-speed air flow, including the following steps: using high-speed air flow to air-crush the falling high-temperature molten slag to obtain high-temperature molten slag particles in a parabolic motion; using reverse high-speed air flow to purge the high-temperature molten slag particles during the stage when the high-temperature molten slag particles rise in a parabolic motion. By the resistance of the high-speed air flow, thrust is added to the high-temperature molten slag particles in the height direction, and resistance is added to the high-temperature molten slag particles in the horizontal direction.

[0039] Preferably, the present invention further includes a step of atomizing and spraying water for cooling; the high-speed air flow pulverizes the falling high-temperature molten slag into air, obtaining high-temperature molten slag particles moving in a parabolic motion; a reverse high-speed air flow is used to blow the high-temperature molten slag particles moving in a parabolic motion, increasing the thrust of the high-temperature molten slag particles in the height direction and increasing the resistance of the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow; atomized water is sprayed from the top to cool the high-temperature molten slag particles moving in a parabolic motion, quickly cooling the high-temperature molten slag particles while increasing the resistance of the high-temperature molten slag particles in the height direction.

[0040] Preferably, the present invention further includes a step of performing secondary reverse blowing during the stage when the high-temperature molten slag particles fall in a parabolic motion; a secondary reverse high-speed air flow is used to blow the high-temperature molten slag particles during the stage when the high-temperature molten slag particles fall in a parabolic motion, increasing the thrust of the high-temperature molten slag particles in the height direction and increasing the resistance of the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow.

Claims

1. A method for granulating high-temperature molten slag by using high-speed air flow, characterized in that It includes the following steps: Using a high-speed air flow to air-crush the falling high-temperature molten slag to obtain high-temperature molten slag particles in a parabolic motion; Using a reverse high-speed air flow to purge the high-temperature molten slag particles during the ascending stage of their parabolic motion, increasing the thrust on the high-temperature molten slag particles in the height direction and increasing the resistance on the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow; Performing a secondary reverse purge during the descending stage of the parabolic motion of the high-temperature molten slag particles; using a secondary reverse high-speed air flow to purge the high-temperature molten slag particles during the descending stage of their parabolic motion, increasing the thrust on the high-temperature molten slag particles in the height direction and increasing the resistance on the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow, delaying the landing time of the molten slag particles again, and reducing the landing distance of the molten slag particles in the horizontal direction; It also includes a device for granulating high-temperature molten slag using a high-speed air flow. The device includes a crane, a high-temperature molten slag container, a turntable, a molten slag diversion trough, an upper blower, and a molten slag granulation body. The upper blower is provided with nozzles; the crane, the high-temperature molten slag container, the turntable, the molten slag diversion trough, the upper blower, and the molten slag granulation body are arranged at the outlet of the slag flow trough in the steelmaking workshop; The molten slag granulation body is composed of a top plate, a bottom plate, a left side plate, a right side plate, a front side plate, and a rear side plate. A second upper blower nozzle is provided on the left side plate, and a third upper blower nozzle is provided on the right side plate.

2. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 1, characterized in that: The second upper blower nozzle is located at one-fourth to one-half of the distance from the front end of the left side plate. The angle between the second upper blower nozzle and the left side plate is 20 - 80 degrees, and the second upper blower nozzle faces the front side plate; the third upper blower nozzle is located at one-fourth to one-half of the distance from the front end of the right side plate. The angle between the second upper blower nozzle and the right side plate is 20 - 80 degrees, and the third upper blower nozzle faces the front side plate.

3. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 1, characterized in that: At least 1 water atomization nozzle is further provided on the top plate, and the water atomization nozzle is connected to an external water pipe.

4. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 1, characterized in that: A fourth upper blower nozzle is provided on the left side plate, and a fifth upper blower nozzle is provided on the right side plate.

5. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 4, characterized in that: The fourth upper blower nozzle is located at one-fourth to one-half of the distance from the rear end of the left side plate. The angle between the fourth upper blower nozzle and the left side plate is 20 - 80 degrees, and the fourth upper blower nozzle faces the front side plate; the fifth upper blower nozzle is located at one-fourth to one-half of the distance from the rear end of the right side plate. The angle between the fifth upper blower nozzle and the right side plate is 20 - 80 degrees, and the fifth upper blower nozzle faces the front side plate.

6. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 1, characterized in that: A feed inlet is provided on the front side plate. The high-temperature molten steel slag in the high-temperature molten slag container is poured into the turntable, and the high-temperature molten steel slag flows out through the molten slag diversion trough. The upper blower nozzle blows the flowing high-temperature molten steel slag at a high speed, so as to blow the high-temperature molten slag into the molten slag granulation body through the feed inlet. At the same time, the high-speed air flow air-crushes the high-temperature molten slag falling from the molten slag diversion trough.

7. The method for granulating high-temperature molten slag by using a high-speed air flow according to claim 1, characterized in that It also includes a step of atomizing and spraying water for cooling: The high-speed air flow air-crushes the falling high-temperature molten slag to obtain high-temperature molten slag particles in a parabolic motion; Using a reverse high-speed air flow to purge the high-temperature molten slag particles in a parabolic motion, increasing the thrust on the high-temperature molten slag particles in the height direction and increasing the resistance on the high-temperature molten slag particles in the horizontal direction through the resistance of the high-speed air flow; Atomized water spraying is carried out on the high-temperature molten slag particles moving in a parabolic motion from the top, adding resistance to the high-temperature molten slag particles in the height direction while rapidly cooling the high-temperature molten slag particles.

Images