Molten slag granulation method and device

Abstract

A slag granulation method includes crushing slag to obtain slag granules, then cooling the slag granules to obtain granulated slag, and recovering the granulated slag. Also provided is a slag granulation apparatus for carrying out the corresponding slag granulation method, including a granulation mechanism used to granulate the slag to obtain crushed slag granules and a cooling mechanism used to cool the slag granules to obtain granulated slag.

Description

[Technical Field]

[0001] Technical Field The present application relates to the technical field of steel smelting, and in particular to a method and apparatus for granulating molten slag. [Background technology]

[0002] background Blast furnace molten slag is the molten residue discharged from a blast furnace during the smelting of pig iron. It consists mainly of CaO, SiO2, Al2O3, and MgO. It is one of the most abundant by-products produced in the metallurgical industry. Approximately 350 kilograms of blast furnace molten slag are produced per ton of iron. The tapping temperature can reach 1450-1650°C. The iron yield is (1260-1880) x 10 per ton of slag. 3 It contains 1000 kJ of sensible heat, which is equivalent to the calorific value of 60 kg of standard coal. There is great potential, economic viability, and practicality in recovering this waste heat. Under these circumstances, research into the recovery and utilization of waste heat from blast furnace molten slag has become a focus of attention in recent years.

[0003] Currently, most blast furnace molten slag treatments use a water quenching process. The molten slag is swept into the water slag by high-pressure water, and the high-grade sensible heat is transferred to the water slag or wastewater at approximately 80°C, losing its recovery value. Furthermore, processing one ton of blast furnace molten slag consumes 0.4 to 0.5 tons of water and produces a large amount of waste steam containing large amounts of pollutants such as H2S and SO2. Subsequent resource utilization (such as pulverization) requires drying 15 to 20% of the moisture in the water slag, which requires approximately 1,000 m3 of hot air at 500°C per ton of blast furnace slag. 3 It is necessary.

[0004] Because blast furnace slag has low thermal conductivity and its viscosity increases rapidly as its temperature decreases, heat transfer from blast furnace slag is slow, making waste heat recovery difficult. Rapidly refining blast furnace slag increases the heat transfer area and improves heat transfer efficiency, enabling rapid and efficient recovery of sensible heat from blast furnace slag. Rapid cooling of molten slag granules not only creates conditions for heat recovery, but also maintains the glass phase content and activity of the cooled slag granules, meeting the requirements for fine slag powder raw material and maintaining the existing route for slag resource utilization.

[0005] To date, the primary processes for rapid dry granulation of molten slag have been air granulation and centrifugal granulation. Air granulation has not been widely adopted for processing blast furnace molten slag due to its high noise level and tendency to generate slag wool. Only a few steel mills have adopted this method to process steel slag, which has good fluidity. Centrifugal granulation primarily uses a rotating disk or cup granulator, which disperses and breaks the molten slag into small droplets using centrifugal force and rapidly cools them, ensuring that the glass content and activity of the cooled slag granules meet the requirements for fine slag powder raw material. However, the centrifugal granulation process is still in the experimental exploration stage, and issues such as slag crust formation, uneven particle size of the granulated slag, and the tendency to generate slag wool remain, requiring further research and improvement.

[0006] Chinese patent application CN201410755689.9, entitled "High-Temperature Molten Slag Waste Heat Recovery System and Method," discloses a method and apparatus for granulating molten slag using a rotating disk and recovering heat from the high-temperature granulated slag through a waste heat boiler.

[0007] Chinese patent application CN201010566938.1, titled "Metallurgical Molten Slag Dry Granulation and Thermal Energy Recovery System," proposes a metallurgical molten slag dry granulation and thermal energy recovery system. Liquid molten slag is dry granulated by centrifugal rotation and air pulses. Sensible heat in the molten slag is transferred to hot air via the pulsed air and fluidizing gas. The heat from the hot air is then recovered by a waste heat boiler to generate low- and medium-pressure steam for turbine power generation.

[0008] Chinese patent CN101736101B, entitled "Semi-moist slag processing waste heat recovery power generation system and method," and Chinese patent CN102433401B, entitled "Molten slag rapid cooling dry granulation and sensible heat recovery power generation system and method," provide a solution that uses water mist as a base for air granulation, and uses a high-pressure water-air atomizing device to rapidly cool the molten slag and granulate it into small particles of glass phase, and then passes it through a fluidized bed or vibrating bed to recover waste heat from the hot granulated slag.

[0009] Currently, granulation of blast furnace slag mainly relies on the water cooling process, and simple air granulation processes are not suitable. Centrifugal granulation processes are still under development. Utilization of waste heat from blast furnace slag is limited to converting hot air / nitrogen into steam and generating electricity, which is inefficient. Summary of the Invention [Means for solving the problem]

[0010] overview To overcome the problems present in existing technology, the present invention provides various molten slag granulation methods and apparatuses that enable the safe granulation of blast furnace molten slag and selectively recover and utilize the heat generated during the granulation process for immediate or subsequent use.

[0011] A first aspect of the present invention provides a method for granulating molten slag, comprising crushing molten slag to obtain molten slag granules, then cooling the molten slag granules, and then recovering the resulting granulated slag.

[0012] Specifically, the granulation method of the molten slag can be carried out as follows.

[0013] The molten slag is subjected to jet granulation to obtain surface-hardened granules and steam, and then the surface-hardened granules are cooled in a swirling fluidized field to obtain solid slag granules.

[0014] In the present invention, unless otherwise specified, the term "jet" refers to a high-velocity mist fluid that is a mixture of gas and water. Water and compressed air are sprayed together to form a high-velocity mixture of gas and droplets with a particle size of 0.01 to 0.20 mm. The lower limit of the velocity of the gas-water mixture is 20 m / s, preferably 50 m / s, more preferably 70 m / s, and most preferably 90 m / s. Although an upper limit of the velocity of the water droplets is not usually specified, taking into account the power consumption of the device, the upper limit of the velocity of the water droplets may be 150 m / s, preferably 120 m / s.

[0015] Unless otherwise specified, the term "molten slag" used in this invention refers to blast furnace molten slag, whose discharge temperature is 1300-1500°C. In the molten slag granulation process of this invention, the molten slag is first crushed and granulated by a jet (high-velocity gas-water mixture). After contact with the jet, heat is partially transferred to the water droplets, and the surface of the molten slag solidifies within the fine water droplets, forming surface-solidified granules. Because the temperature of the granules is approximately 800-1000°C, the core of the granules remains molten, while the high-velocity water droplets absorb heat and form steam. The surface-solidified granules then enter a swirling flow field, where they undergo high-speed revolution and rotation. The orbital velocity of the granules in the swirling flow field is 5-25 rad / s, the orbital radius is 80-120 mm, and the rotational speed is 100-400 rad / s. The high-speed revolution and rotation of the granules promotes the separation and separation of the surface boundary layer, reduces the thickness of the boundary layer, and rapidly renews the heat transfer interface, thereby reducing the thermal resistance and improving the heat transfer efficiency. During this process, the granules are cooled by the surrounding atmosphere, forming solid slag granules.

[0016] In the present invention, the swirling flow field is provided by a cyclone separator, which increases the movement path of the molten slag and improves the heat exchange efficiency between the molten slag granules and the surrounding atmosphere, resulting in a better cooling effect than other cooling methods in the prior art.

[0017] According to one embodiment of the present invention, there is provided a method for the coupled utilization of molten slag waste heat recovery, comprising the following steps: 1) The molten slag is fed into the flow guide cover, and is then collided with and crushed by the mist fluid sprayed from the granulator, forming molten droplets with a particle size of 5 mm or less. The molten droplets fly directionally along the flow guide cover together with the mist fluid. During the formation and flight process, the molten droplets are cooled and solidified by heat exchange with the mist fluid, producing granulated slag of 1000°C or less (the shape of the granulated slag depends on its temperature; at this stage, the granulated slag is only surface-solidified and not completely dried into solid granules) and a gas flow of 300-600°C, which achieves the granulation and cooling solidification of the molten slag; 2) After the granulated slag and gas flow exit the flow guide cover, they directly enter the cyclone separator. The separation of the slag and gas is achieved under the combined action of centrifugal force and gravity. The separated granulated slag is cooled to 700-800°C and then exits the bottom of the cyclone separator. The separated gas stream passes through the cyclone separator and the overflow pipeline, and its temperature is reduced to 150-300°C after heat exchange with the cooling water in the spiral heat exchange pipeline in the overflow pipeline; after leaving the cyclone separator and the overflow pipeline, the gas stream enters the waste heat recovery device, where it further exchanges heat with the heat exchange pipeline carrying the cooling water, forming exhaust gas with a temperature of 130-150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag; The cooling water in the spiral heat exchange pipeline absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 1.2-1.6 MPa and 188-201°C, which enters the superheated steam generator and is further heated to obtain superheated steam of 1.2-1.6 MPa and 250-350°C; 3) The granulated slag coming out of the bottom of the cyclone separator enters the rotating bed and undergoes contact heat exchange with the heat exchange pipeline carrying cooling water, and is cooled to 150-300°C, then discharged into the slag bin for storage; The cooling water in the heat exchange pipeline of the rotating bed absorbs heat and vaporizes, then undergoes steam-water separation to generate saturated steam of 1.2-1.6 MPa and 188-201 °C, which enters the superheated steam generator and is further heated to obtain superheated steam of 1.2-1.6 MPa and 250-350 °C; 4) The granulated slag in the slag bin is conveyed to a gas jet mill, where it is impinged and pulverized into ultra-fine powder using the superheated steam obtained in steps 2) and 3); The pressure of the superheated steam drops to atmospheric pressure, and the temperature drops to 150-250°C. The steam then enters the waste heat recovery device, where it undergoes further heat exchange with the heat exchange pipeline carrying cooling water, forming exhaust gas at 130-150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag.

[0018] Preferably, the exhaust gas is purified by dedusting and desulfurization before being discharged.

[0019] Preferably, in step 1), the mist fluid is one or more selected from compressed air at 0.5 to 0.8 MPa, high-pressure water mist at 0.4 to 0.5 MPa, low-pressure steam at 0.4 to 0.8 MPa, or a mixture thereof.

[0020] Preferably, in step 1), the granulated molten droplets have a solidification rate of 80% or more for granules with a particle size of 2 mm or less after cooling and solidification.

[0021] Preferably, in step 3), the saturated steam is further heated in a superheated steam generator using natural gas or mixed coal gas generated during the steel smelting process.

[0022] Preferably, in step 3), the granulated slag in the slag bin is transported to a slag powder production line and granulated slag having a specific surface area of ​​420 to 440 m 2 / kg of slag powder is directly ground.

[0023] Preferably, in step 4), the ultrafine powder is 450 to 750 m 2 / kg specific surface area.

[0024] Of course, the method for the combined utilization of slag waste heat recovery of the present invention can also be implemented as follows. Specifically, according to another embodiment of the present invention, the method for the combined utilization of slag waste heat recovery includes the following steps: 1) The molten slag enters the flow guide cover, where it collides with and is crushed by the mist fluid sprayed from the granulator, and is granulated into molten droplets with a particle size of 5 mm or less. The molten droplets fly along the flow guide cover together with the mist fluid. During the formation and flight process, the molten droplets are cooled and solidified by heat exchange with the mist fluid, producing surface-solidified granulated slag (approximately 1250°C) and a gas flow at approximately 100°C, thereby achieving the granulation and cooling solidification of the molten slag; 2) After the granulated slag and gas flow through the flow guide cover, they directly enter the cyclone separator. Under the combined action of centrifugal force and gravity, the slag and gas exchange heat and separate. The separated granulated slag is cooled to 650-850°C and then discharged from the bottom of the cyclone separator. The gas stream is heated to 200-600°C by the slag granules in the cyclone separator, and then enters the waste heat boiler through the overflow pipeline.

[0025] 3) The gas stream is cooled to 150-300℃ through heat exchange in the waste heat boiler, and then enters the waste heat recovery device, where it is further heat exchanged with the heat exchange pipeline carrying cooling water, reducing the gas temperature to 130-150℃; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag; The cooling water in the waste heat boiler absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 1.2-1.6 MPa and 188-201°C, which enters the superheated steam generator, where it is further heated to obtain superheated steam of 1.2-1.6 MPa and 250-350°C; 4) The granulated slag coming out of the bottom of the cyclone separator enters the rotating bed, where it exchanges heat with the heat exchange pipeline carrying cooling water, is cooled to 150-300℃, and then discharged into the slag bin for storage; The cooling water in the heat exchange pipeline of the rotating bed absorbs heat and vaporizes, then undergoes steam-water separation to generate saturated steam of 1.2-1.6 MPa and 188-201 °C, which enters the superheated steam generator and is further heated to obtain superheated steam of 1.2-1.6 MPa and 250-350 °C; 5) The granulated slag in the slag bin is conveyed to a gas jet mill, where it is impinged and pulverized into ultra-fine powder using the superheated steam obtained in steps 2) and 3); The pressure of the superheated steam drops to atmospheric pressure, and the temperature drops to 150-250℃, then the steam enters the waste heat recovery device, where it further exchanges heat with the heat exchange pipeline carrying cooling water, forming exhaust gas with a temperature of 130-150℃; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag.

[0026] Another embodiment of the present invention provides a method for granulating molten slag using a blast furnace molten slag granulator with a high-speed steam nozzle. Water enters a pipeline, is pressurized by a water pump, and then enters a heat exchanger, where it is heated by heat from a waste heat recovery pipeline. The water is at a high pressure exceeding atmospheric pressure and a high temperature exceeding its boiling point at atmospheric pressure. After being ejected from the nozzle, the water instantly vaporizes at atmospheric pressure, forming a high-speed steam jet (e.g., 90-110 m / s) that collides with the molten slag flowing out of the slag chute. The high-speed jet cools the molten slag and breaks it into small granules, which then fall to the bottom of the molten slag granulator. After impinging on the molten slag, the mixed jet ejected from the nozzle becomes completely steam and flows out the top of the device as a waste heat resource for further use.

[0027] Preferably, the water entering the pipeline is pressurized by a water pump, and the pressure in the pipeline rises to 0.1-1 MPa; the temperature of the water in the heat exchanger is raised to 100-182°C by the heat from the waste heat recovery pipeline.

[0028] Another embodiment of the present invention provides a horizontal molten slag granulation process using gas-water mixing, in which a high-speed airflow provided by an air nozzle array component composed of gas nozzles is used to break up the falling molten slag and obtain molten slag granules; at the same time, the molten slag granules are rapidly cooled by spraying water mist through a line of gas-liquid two-fluid nozzles, and the molten slag granules are subjected to an auxiliary pressing force to more accurately fall into the rear slag granule recovery section.

[0029] Preferably, the high velocity gas stream has a velocity of 90 to 110 m / s.

[0030] A second aspect of the present invention provides a molten slag granulation apparatus comprising: A granulation mechanism for granulating molten slag to obtain crushed molten slag granules; and A cooling mechanism for cooling the molten slag granules to obtain granulated slag.

[0031] Specifically, the molten slag granulating apparatus can be configured as follows.

[0032] According to one embodiment of the present invention, an apparatus for implementing a method for the combined utilization of slag waste heat recovery is provided. Specifically, the apparatus for the combined utilization of blast furnace molten slag waste heat recovery provided by this embodiment includes: The flow guide cover has a cylindrical structure; preferably, the cross section of the flow guide cover is rectangular with an aspect ratio of 2:1 to 5:1; more preferably, an online metering device is installed at the inlet end of the flow guide cover; a granulator having its outlet end connected to the inlet end of the flow guide cover; A cyclone separator, wherein a material inlet is arranged on the side wall of the cyclone separator and a material outlet is arranged at the bottom of the cyclone separator; the material inlet is connected to the outlet end of the flow guide cover; an overflow pipeline, the lower part of which is inserted vertically into the cyclone separator, and a spiral heat exchange pipeline is disposed inside the overflow pipeline; a first steam-water separator, the first steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet; the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a spiral heat exchange pipeline in an overflow pipeline via a pipeline and a water pump, and the steam inlet is connected to an outlet end of the spiral heat exchange pipeline in an overflow pipeline; a waste heat recovery device, a gas inlet and a gas outlet are arranged on the shell of the waste heat recovery device, and a heat exchange pipeline is arranged inside the waste heat recovery device, and the gas inlet is connected to the outlet end of the overflow pipeline; a second steam-water separator, the second steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet and a steam outlet disposed therein; the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline in the waste heat recovery device via a pipeline and a water pump, the steam inlet is connected to an outlet end of the heat exchange pipeline in the waste heat recovery device via a pipeline, and the steam outlet is connected to the inlet end of the granulator via a pipeline; a rotating bed having a cylindrical structure, a heat exchange pipeline disposed inside the rotating bed, an inlet end of the rotating bed connected to a material outlet of the cyclone separator, an outlet end of the rotating bed connected to a slag bin, and a pressing device disposed on the rotating bed for rotating the rotating bed; a third steam-water separator, the third steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet disposed therein; wherein the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline of the rotating bed via a pipeline and a water pump, and the steam inlet is connected to an outlet end of the heat exchange pipeline of the rotating bed; a gas jet mill, a supply pipe, a gas inlet pipe, and a gas outlet pipe arranged on the shell of the gas jet mill; the supply pipe of the gas jet mill connected to a slag bin, and the gas outlet pipe of the gas jet mill connected to a gas inlet of a waste heat recovery device; a superheated steam generator, a gas inlet pipe and a gas outlet pipe arranged on the shell of the superheated steam generator, the gas inlet pipe of the superheated steam generator connected to the steam outlet of the first steam-water separator and the steam outlet of the third steam-water separator, and the gas outlet pipe of the superheated steam generator connected to the gas inlet pipe of the gas jet mill;

[0033] Preferably, a vibrator is positioned above the slag bin.

[0034] According to another embodiment of the present invention, there is provided a blast furnace molten slag granulation apparatus with a high velocity steam nozzle, comprising: A molten slag granulator body having a box-shaped structure, a slag chute for introducing molten slag is arranged on one side of the upper part of the molten slag granulator body, and a steam outlet passage is arranged on the upper part of the molten slag granulator body; a steam spray mechanism including a first control valve, a water pump, a second control valve, a pressure gauge, a heat exchanger, a thermometer, and a nozzle arranged in sequence along the pipeline; an inlet end of the pipeline connected to a water source; the nozzle arranged on a side wall of the molten slag granulator body on which the slag chute is arranged, the axial direction of the nozzle forming an angle with the axial direction of the slag chute, and the outlet of the nozzle facing the molten slag flowing out of the slag chute; and A waste heat recovery pipeline and a heat exchange fluid outlet pipeline are disposed in the heat exchanger; wherein a valve is installed in the waste heat recovery pipeline.

[0035] Preferably, the axial direction of the nozzle forms an angle of 30 to 60 degrees with the axial direction of the slag chute.

[0036] In this embodiment of the blast furnace molten slag granulation equipment with a high-speed steam nozzle, the blast furnace molten slag processing process uses a water pump to pressurize the water entering the pipeline and then direct it into a heat exchanger. The heat source from the waste heat resource recovery pipeline raises the water temperature in the heat exchanger, reaching a high-pressure state exceeding atmospheric pressure and exceeding its boiling point at normal pressure. After being ejected from the nozzle, the high-temperature, high-pressure water instantly vaporizes at normal pressure to form steam. The steam is ejected from the nozzle, forming a high-speed jet (e.g., 90-110 m / s) containing steam, which collides with the high-temperature molten liquid slag flowing out of the slag chute. The high-speed jet cools the liquid molten slag and breaks it into small particles, which fall to the bottom of the molten slag granulation equipment. After impinging on the high-temperature molten slag, the mixed jet ejected from the nozzle completely turns into steam and exits the equipment from the top as a waste heat recovery resource.

[0037] Preferably, the first control valve is an electrohydraulic gate valve.

[0038] Preferably, the water entering the pipeline is pressurized by a water pump, and the pressure in the pipeline is increased to 0.1-1 MPa; the temperature of the water in the heat exchanger is increased to 100-182°C by the heat source from the waste heat recovery pipeline.

[0039] According to another embodiment of the present invention, there is provided an apparatus for the aforementioned horizontal molten slag granulation process with gas-water mixing, comprising: The molten slag granulator body has a box-shaped structure, and the slag inlet is disposed at the top end of the molten slag granulator body; High-velocity air jet mechanism, including: a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and an air nozzle array component connected to one end of the gas transmission pipeline; a first control valve and a flow meter sequentially disposed on the gas transmission pipeline at the outlet end of the gas storage tank; wherein a pressure gauge, a gas inlet pipe, and a gas inlet valve are disposed on the gas storage tank; and Wherein the air nozzle array part includes a plurality of air flow nozzles and corresponding branch pipelines, and the branch pipelines are connected to the gas transport pipeline; the air flow nozzles are arranged on an upper part of one side wall of the molten slag granulator body; A spraying mechanism including a second control valve, a water pump, a third control valve, a pressure meter, a flow meter, and a plurality of gas-liquid two-fluid nozzles arranged in sequence along the water transport pipeline: the inlet end of the water transport pipeline is connected to a water source; the gas-liquid two-fluid nozzles are arranged at the top and bottom inside the molten slag granulator body, and the gas-liquid two-fluid nozzles are connected to the gas transport pipeline and the water transport pipeline via connecting pipelines.

[0040] Preferably, an angle of 0 to 20° is formed between the axial direction of the air nozzle array component and the horizontal direction.

[0041] Preferably, the width of the air nozzle array component is greater than the width of the slug inlet.

[0042] Preferably, the second control valve is an electrohydraulic gate valve.

[0043] Preferably, the molten slag granulator body is semi-closed, and a granule slag recovery section is disposed at the rear of the molten slag granulator body.

[0044] Preferably, the airflow nozzle is a supersonic nozzle.

[0045] In the above-mentioned equipment for horizontal molten slag granulation process with gas-water mixing: The high-speed air jet mechanism provides the main power for crushing and granulating the molten slag, and the spray mechanism provides the main heat exchange medium for crushing and granulating the molten slag. The molten slag granulation process takes place inside the molten slag granulator.

[0046] The compressor pressurizes the gas and sends it to a storage tank, where it is supplied to the air nozzle array at a stable pressure. A high-velocity airflow (e.g., a jet speed of 90-110 m / s) is then injected into the molten slag granulator, crushing the molten slag. At the same time, the water pump pressurizes the water in the water pipeline and sprays it through the gas-liquid two-fluid nozzle along with the airflow from the gas pipeline. The sprayed mist droplets collide with the granulated molten slag, rapidly cooling it and solidifying it into stable small particles.

[0047] According to another embodiment of the present invention, there is provided an apparatus for granulating molten blast furnace slag using a gas nozzle array, comprising: A molten slag granulator body having a box-shaped structure, a slag inlet and a steam outlet passage disposed at the upper end of the molten slag granulator body; High velocity air jet mechanism including: a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and a nozzle array connected to one end of the gas transmission pipeline; wherein a first control valve and a flow meter are sequentially disposed in the gas transmission pipeline at the outlet end of the gas storage tank; and a pressure meter, a gas inlet pipe, and a gas inlet valve are disposed in the gas storage tank; Here, the nozzle array includes a plurality of nozzles and corresponding branch pipelines, and each branch pipeline is respectively connected to a gas transport pipeline; the nozzles are arranged on one side wall of the molten slag granulator body.

[0048] Preferably, the apparatus further comprises: A nozzle atomization mechanism including a second control valve, a water pump, a third control valve, a pressure gauge, a flow meter, and a plurality of atomization nozzles arranged in sequence along the water transport pipeline; the inlet end of the water transport pipeline is connected to a water source; the atomization nozzles are arranged at the inner bottom of the molten slag granulator body and are arranged in at least two rows, with the spray direction facing the molten slag flowing in from the slag inlet.

[0049] Preferably, the apparatus further comprises a waste heat recovery system comprising: a heat exchange box, a supply port connected to the discharge port of the molten slag granulator body being arranged at the top of one side wall of the heat exchange box; a heat exchange gas outlet being arranged at the top end of the heat exchange box; a plurality of perforated floor plates being arranged along the height direction within the heat exchange box; a molten slag granule outlet being arranged at the bottom of the heat exchange box; a gas nozzle array disposed below a perforated floor plate on the inner bottom of the heat exchange box, the gas nozzles in the gas nozzle array being disposed opposite the perforated floor plate; or The waste heat recovery system employs a cyclone separator.

[0050] Preferably, the perforated floor plates are arranged in a vertical zigzag pattern within the heat exchange box.

[0051] Preferably, the cyclone separator comprises a separator body, and the gas-solid medium inlet connected to the outlet of the molten slag granulator body is located at the top of one side of the separator body; the air outlet is located at the top of the separator body, and the dust hopper is located at the bottom of the separator body.

[0052] Preferably, the nozzles in the nozzle array are one or more selected from a supersonic nozzle, an atomizing nozzle, or a gas-liquid two-fluid nozzle; preferably, the axial direction of the nozzles in the nozzle array is perpendicular to the side wall of the molten slag granulator body.

[0053] Preferably, the nozzles in the nozzle array are arranged in a plurality of rows and columns, or in an arc; preferably, the nozzles in adjacent columns are staggered in the vertical direction; more preferably, the number of nozzles gradually decreases or increases along the vertical direction.

[0054] Preferably, the nozzles in the nozzle array are gas-liquid two-fluid nozzles; correspondingly, the apparatus is also provided with a nozzle water supply mechanism, which includes a fourth control valve, a water pump, a fifth control valve, a pressure gauge and a flow meter arranged in sequence along the water transport pipeline; the inlet end of the water transport pipeline is connected to the water source, and the outlet end is connected to the inlet end of the gas-liquid two-fluid nozzle.

[0055] The compressor pressurizes the air and sends it to the air storage tank, which then directs the air through the pipeline and (supersonic) nozzle to the molten slag granulator body for granulation. The liquid molten slag is granulated inside the granulator body. The liquid molten slag is collided and crushed by the high-speed air stream (e.g., jet velocity of 90-110 m / s or more) ejected from the supersonic nozzle, and the granulated slag granules undergo rapid heat exchange and cooling, promoting the rapid formation of slag.

[0056] Compared with the conventional air quenching process and water quenching process, the device of this embodiment adopts a supersonic nozzle array to further improve the slag processing capacity, enhance the heat exchange effect of the slag granules through mist droplet spraying, and reduce the waste of water resources.

[0057] According to another embodiment of the present invention, the device is capable of cleaning falling slags by mist and granulating the slags, including: A molten slag granulator body, the molten slag granulator body having a box-shaped structure, a slag inlet disposed at the top end of the molten slag granulator body, and a slag granule recovery unit disposed at the rear of the molten slag granulator body; Gas nozzle array arranged on one side wall of the molten slag granulator body; An atomizing nozzle array is arranged at the inner bottom of the molten slag granulator body, and the spray direction is directed toward the molten slag flowing in from the slag inlet; A residual slag cleaning nozzle is disposed at the inner bottom of the molten slag granulator body, and the outlet of the residual slag cleaning nozzle faces the inner bottom of the molten slag granulator body and the slag granule recovery section.

[0058] Preferably, the axial direction of the gas nozzle array is perpendicular to one side wall of the molten slag granulator body.

[0059] Preferably, baffles are positioned on either side of the outlet of the gas nozzle array, and liquid / atomizing nozzles are installed outside the baffles.

[0060] Preferably, the residual slag cleaning nozzle is one or more selected from a water atomizing nozzle, a steam atomizing nozzle, a high-velocity gas flow nozzle, or a gas-liquid two-fluid nozzle.

[0061] The above device, further comprising: a high-speed air jet mechanism including a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and a gas nozzle array connected to one end of the gas transmission pipeline; a first control valve and a flow meter are sequentially arranged on the gas transmission pipeline connected to the outlet end of the gas storage tank; a pressure meter, a gas inlet pipe, and a gas inlet valve are arranged on the gas storage tank; the nozzle array includes a plurality of nozzles and corresponding branch pipelines, the branch pipelines are connected to the gas transmission pipeline; a residual slag cleaning nozzle is connected to the gas transmission pipeline via a connecting pipeline and a valve; A nozzle atomization mechanism including a second control valve, a water pump, a third control valve, a pressure gauge and a flow meter arranged in sequence along the water transport pipeline; the inlet end of the water transport pipeline is connected to a water source, and the outlet end of the water transport pipeline is connected to the atomization nozzle array.

[0062] Preferably, the nozzles in the atomizing nozzle array are gas-liquid two-fluid nozzles, the inlet ends of which are connected to the gas transport pipeline and the water transport pipeline, respectively.

[0063] Preferably, at least two slag inlets are located at the top end of the molten slag granulator body.

[0064] The device of this embodiment, which can clean and granulate the falling slag with mist, includes a molten slag granulation system and a granulated slag recovery system.

[0065] The molten slag granulation system is divided into two parts. One part is the gas nozzle array component, which ejects a high-velocity gas stream (e.g., jet velocity 90-110 m / s) for granulation. The other part is the atomization nozzle array, which ejects mist droplets for granulation within the molten slag granulation equipment. The high-velocity gas stream ejected from the gas nozzle array collides with and breaks up the liquid molten slag. The high-density mist droplets ejected from the atomization nozzle array rapidly exchange heat with the broken down slag, facilitating rapid slug formation.

[0066] A residual slag cleaning nozzle is located at the bottom of the molten slag granulator body, which cools the slag granules at the bottom and sprays them into the rear slag granule recovery section, preventing the molten slag granules from adhering to the wall and allowing them to quickly fall into the slag granule recovery section.

[0067] Compared with conventional air and water quenching processes, gas nozzle arrays are used to further improve the slag processing capacity. At the same time, atomizing nozzle arrays are used to spray mist, which improves the heat exchange effect of the slag granules, reduces water waste, and ensures that the molten slag granules do not stick to the wall and fall quickly to the recovery section.

[0068] According to another embodiment of the present invention, there is provided an apparatus for rapidly cooling molten slag using an atomizing nozzle, comprising: A molten slag granulator body having a box-shaped structure, a slag inlet being disposed at the upper end of the molten slag granulator body; A gas nozzle array is arranged on one side wall of the molten slag granulator body, and the axial direction of the gas nozzle in the gas nozzle array is perpendicular to the side wall of the molten slag granulator body; A flow field optimization nozzle array located near the slag inlet at the top inside the molten slag granulator body; slag cleaning nozzle array located at the bottom or lower part within the molten slag granulator body; An atomization nozzle array is disposed inside the molten slag granulator body and radially arranged around the slag flow on the inner wall of the molten slag granulator body, wherein the axial direction of the atomization nozzles in the atomization nozzle array is perpendicular to the axial direction of the gas nozzle.

[0069] Preferably, a granular slag recovery section is disposed at the rear of the molten slag granulator body.

[0070] Preferably, the nozzles of the flow field optimized nozzle array are gas nozzles or gas-liquid two-fluid nozzles.

[0071] Preferably, the nozzles of the slag cleaning nozzle array are gas nozzles.

[0072] Preferably, the nozzles of the atomizing nozzle array are water atomizing nozzles.

[0073] Compared with the conventional air quenching process and water quenching process, the device in this embodiment adopts a nozzle array to further improve the slag processing capacity, improve the heat exchange effect of the slag granules through mist droplet spraying, reduce the waste of water resources, and fully recover the slag waste heat.

[0074] According to another embodiment of the present invention, there is provided a water mist granulation apparatus for blast furnace molten slag granulation, comprising: Racks are frame structures; Water nozzle array components including: a main body having a box-shaped structure and disposed at the center of the rack, the main body having a flow rate adjusting plate and a flow guide plate spaced apart in sequence therein; wherein the rear end of the main body is connected to a water source; An array of water nozzles evenly distributed on the front of the body; Gas-liquid two-fluid nozzle components, including: gas-liquid two-fluid nozzles arranged parallel to each other on both sides of the water nozzle array and fixed to a rack; A gas pipeline and a water transport pipeline fixed to a rack and connected to a gas-liquid two-fluid nozzle.

[0075] Preferably, the gas-liquid two-fluid nozzles are arranged parallel to each other on either side of the water nozzle array. [Brief explanation of the drawings]

[0076] [Figure 1] FIG. 1 is a schematic structural diagram of a molten slag granulation apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 3] FIG. 3 is a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 4] FIG. 4 is a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 5] FIG. 5 is a schematic structural diagram of a gas nozzle array component in another embodiment of the present invention; [Figure 6] Figure 6 shows the flight trajectories of slug granules when the apparatus in Figure 4 employs different gas nozzle array components at different tilt angles; [Figure 7] Figure 7 shows the flight trajectory of slug granules when the tilt angle of the gas nozzle array component used in the device of Figure 4 is too large; [Figure 8] FIG. 8 is a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 9] FIG. 9 is a schematic layout diagram of a nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 10] FIG. 10 is a schematic layout diagram of a nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 11] FIG. 11 is a schematic layout diagram of a nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 12] FIG. 12 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 13] FIG. 13 is a top view of a nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 14] FIG. 14 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 15] FIG. 15 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 16] FIG. 16 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 17] FIG. 17 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 18] FIG. 18 is a schematic layout diagram of a slag cleaning nozzle in a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 19] FIG. 19 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 20] FIG. 20 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 21] FIG. 21 is a top view of a gas nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 22] FIG. 22 is a schematic structural diagram of a nozzle in a gas nozzle array of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 23] FIG. 23 is another schematic structural diagram of a gas nozzle array in a molten slag granulation apparatus according to another embodiment of the present invention; [Figure 24] FIG. 24 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 25] FIG. 25 is a schematic layout diagram of the atomizing nozzle of FIG. 24; [Figure 26] FIG. 26 is a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention; [Figure 27] FIG. 27 is a side view of the molten slag granulating apparatus of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0077] Detailed explanation The embodiments of the present invention are described by the following specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the disclosure of the specification. Although the description of the present invention is presented in conjunction with preferred embodiments, it is not intended to limit the features of the present invention to these embodiments. On the contrary, the purpose of introducing the present invention in combination with the embodiments is to cover other options or modifications that may be expanded based on the scope of the claims of the present invention. In order to provide a thorough understanding of the present invention, many specific details are included in the following description. The present invention can also be practiced without using these details. Furthermore, some specific details will be omitted to avoid confusion or unclear focus of the present invention. It should be noted that the features in the embodiments and examples of the present invention can be combined with each other without contradiction.

[0078] It should be noted herein that like reference numerals and letters represent like items in the following figures, and therefore, an item once defined in one figure need not be further defined and described in subsequent figures.

[0079] It should be noted that in the description of the embodiments, the orientation or positional relationship indicated by terms such as "top," "bottom," "inside," "bottom," etc., indicates an orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the customary orientation or positional relationship when the product of the present invention is used. These terms are intended to facilitate and simplify the description of the present invention and are not intended to indicate or suggest that the referenced device or element must have a particular orientation, be configured, or operate in a particular orientation, and therefore should not be understood as a limitation of the present invention.

[0080] Terms such as "first," "second," etc. are used solely to distinguish between descriptions and should not be understood as indicating or implying relative importance.

[0081] Also, unless explicitly specified and defined in the description of the embodiments, it should be noted that the terms "set," "coupled," and "connected" should be understood in a broad sense, and may be, for example, a fixed connection, a detachable connection, or an integral connection. They may be mechanical or electrical connections. They may be direct connections or indirect connections via an intermediate medium. They may also be internal connections between two elements. Those skilled in the art can understand the specific meanings of the above terms in the embodiments based on the specific context.

[0082] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in more detail below in conjunction with the accompanying drawings.

[0083] First, the present invention provides a method for granulating molten slag, which includes crushing molten slag to obtain molten slag granules, then cooling the molten slag granules, and recovering the resulting granulated slag.

[0084] Second, the present invention provides a molten slag granulation device including a granulation mechanism for granulating molten slag to obtain crushed molten slag granules; and a cooling mechanism for cooling the molten slag granules to obtain granulated slag.

[0085] Another embodiment of the present invention provides a method for the combined use of molten slag waste heat recovery, which involves granulating molten slag using jet granulation to obtain surface-solidified granules and steam, followed by cooling the surface-solidified granules in a swirling fluidized bed to obtain solid slag granules. This method not only achieves rapid and safe granulation of blast furnace molten slag, but also realizes multi-grade recovery and utilization of the sensible heat of the blast furnace molten slag, thereby significantly improving the waste heat recovery rate from high-temperature molten slag. By using steam as a power source, the granulated slag can be directly pulverized into ultrafine slag powder, enabling the production of high-value-added products from blast furnace molten slag.

[0086] 1, an apparatus for carrying out the molten slag granulation method according to the present embodiment is shown. Specifically, the present embodiment provides an apparatus for the above-mentioned method for coupled utilization of molten slag waste heat recovery, including: The flow guide cover 16 is a cylindrical structure; preferably, its cross section is rectangular with an aspect ratio of 2:1 to 5:1; more preferably, the online metering device 14 is disposed at the inlet end of the flow guide cover 16; a granulator 15, the outlet end of which is connected to the inlet end of a flow guide cover 16; a cyclone separator 17, a material inlet disposed on the side wall of the cyclone separator, and a material outlet disposed at the bottom of the cyclone separator; the material inlet is connected to the outlet end of the flow guide cover 16; an overflow pipeline, the lower part of which is inserted vertically into the cyclone separator 17, and a spiral heat exchange pipeline is disposed inside the overflow pipeline; a first steam-water separator 127, the first steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet; the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a spiral heat exchange pipeline in an overflow pipeline via a pipeline and a water pump 128, and the steam inlet is connected to an outlet end of the spiral heat exchange pipeline in an overflow pipeline; a waste heat recovery device 123, a gas inlet and a gas outlet arranged on the shell of the waste heat recovery device, and a heat exchange pipeline arranged inside the waste heat recovery device, and the gas inlet is connected to the outlet end of the overflow pipeline; a second steam-water separator 125, in which a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet are arranged; the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline in the waste heat recovery device 123 via a pipeline and a water pump 124, the steam inlet is connected to an outlet end of a heat exchange pipeline in the waste heat recovery device 123 via a pipeline, and the steam outlet is connected to an inlet end of the granulator 15 via a pipeline; a rotating bed 18, the rotating bed having a cylindrical structure, a heat exchange pipeline disposed inside the rotating bed, an inlet end of the rotating bed 18 connected to the material outlet of the cyclone separator 17, an outlet end of the rotating bed 18 connected to the slag bin 112, and the rotating bed provided with a pressing device for rotating it; a third steam-water separator 19, in which a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet are arranged; the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline inside the rotating bed via a pipeline and a water pump 110, and the steam inlet is connected to an outlet end of the heat exchange pipeline of the rotating bed; a gas jet mill 117, a supply pipe, a gas inlet pipe and a gas outlet pipe arranged on the shell of the gas jet mill, the supply pipe of the gas jet mill 117 being connected to the slag bin 112, and the gas outlet pipe of the gas jet mill 117 being connected to the gas inlet of the waste heat recovery device 123; The superheated steam generator 126 has a gas inlet pipe and a gas outlet pipe arranged on its shell, the gas inlet pipe of the superheated steam generator 126 is connected to the steam outlet of the first steam-water separator 127 and the steam outlet of the third steam-water separator 19, and the gas outlet pipe of the superheated steam generator 126 is connected to the gas inlet pipe of the gas jet mill 117.

[0087] Preferably, the vibrator 13 is positioned above the slag bin 112 .

[0088] Continuing to refer to Figure 1, the method for the combined utilization of slag waste heat recovery can be carried out as follows. Specifically, the method for the combined utilization of slag waste heat recovery includes the following steps: 1) Volume 1250m 3 In a steelworks with a blast furnace, molten slag at a temperature of around 1500°C enters the main slag groove 11 at an average rate of approximately 2.5 tons / min (maximum slag discharge rate: 5 tons / min) during tapping. The molten slag in the main slag groove 11 is then transferred to the slag withdrawal groove 13 by the slag extraction device 12, and then flows into the flow guide cover 16 via the online metering device 14. The cross section of the flow guide cover 16 is rectangular, measuring 300 mm in length and 100 mm in width. The molten slag entering the flow guide cover 16 collides with and is crushed by the mist fluid ejected from the granulator 15, and is then granulated into molten droplets with a diameter of 5 mm or less. The granulated molten droplets fly at high speed along the flow guide cover 16 together with the mist fluid, exchanging heat with the mist fluid during their formation and flight. They then rapidly cool and solidify, for example at a cooling rate of 20°C / s or more, generating granulated slag at 800°C or higher but not exceeding 1000°C (at this stage, only the surface of the slag particles has solidified, leaving a molten core) and a gas flow at approximately 300°C (room temperature). At this stage, the solidification rate of particles with a diameter of 2 mm or less is approximately 80%, and the granulation and cooling solidification of the molten slag are achieved; 2) Slag gas separation The granulated slag and gas flow directly enters the cyclone separator 17 after exiting the flow guide cover 16. Under the combined action of centrifugal force and gravity, the slag and gas are separated, and the temperature of the granulated slag drops to 700-800°C after separation, and it exits from the bottom of the cyclone separator 17; The separated gas stream passes through the cyclone separator 17 and the overflow pipeline, and after heat exchange with the cooling water in the spiral heat exchange pipeline in the overflow pipeline, the temperature drops to below 150°C; after leaving the cyclone separator 17 and the overflow pipeline, the gas enters the waste heat recovery device 123, where it further exchanges heat with the heat exchange pipeline carrying the cooling water to further recover waste heat and form exhaust gas with a temperature below 130°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; after being separated into steam and water in the second steam-water separator 125, saturated steam with a pressure of about 0.5 MPa is obtained, which is returned to the granulator 15 as mist fluid for granulating the molten slag; The cooling water in the spiral heat exchange pipeline absorbs heat and vaporizes; after steam-water separation in the first steam-water separator 127, saturated steam with a pressure of 1.2-1.6 MPa and a temperature of 188-201°C is generated. This saturated steam enters the superheated steam generator 126 and is further heated to obtain superheated steam with a pressure of 1.2-1.6 MPa and a temperature of 250-350°C; during the above process, the saturated steam entering the superheated steam generator 126 is further heated by the mixed coal gas or natural gas generated during the steel smelting process; 3) The granulated slag coming out of the bottom of the cyclone separator 17 enters the rotating bed 18, where it comes into contact with the heat exchange pipeline carrying cooling water and exchanges heat. The rotating bed 18 rotates at a low speed (3 rpm) along a set direction under the action of a pressing mechanism. The granulated slag is slowly pushed toward the interior of the rotating bed 18 by the pressing mechanism. After the slag is cooled to below 180°C, it is discharged from the rotating bed 18 and then sent to the slag bin 112 for storage via a chute and bucket elevator 111. The slag bin 112 is equipped with a vibrator 113 for vibrating the slag bin 12 to prevent the granulated slag from clogging at the slag bin outlet and bridging or arching within the slag bin. The cooling water in the heat exchange pipeline of the rotating bed 8 is separated into steam and water in the third steam-water separator 19, and then absorbs heat and vaporizes, generating saturated steam with a pressure of 1.2-1.6 MPa and a temperature of 188-201°C. This saturated steam enters the superheated steam generator 126 and is further heated using natural gas or a coal-mixed gas generated during steel smelting, to obtain superheated steam with a pressure of 1.2-1.6 MPa and a temperature of 250-350°C. 4) The granulated slag in the slag bin 112 is conveyed to the gas jet mill 117 through the slag discharge valve 114 and the conveying mechanism 116, and is then impinged by the superheated steam obtained in steps 2) and 3) and pulverized into ultrafine powder; the ultrafine powder is collected by the powder collection device 118 and sold as a high-quality product; The pressure of the superheated steam drops to atmospheric pressure, and the temperature of the superheated steam drops to below 150°C; the steam then enters the waste heat recovery device 123, where it further exchanges heat with a heat exchange pipeline carrying cooling water to further recover waste heat and form an exhaust gas with a temperature of about 130°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; after steam-water separation in the second steam-water separator 125, saturated steam with a pressure of about 0.4 MPa is obtained, which is returned to the granulator 15 as a mist fluid for granulating the molten slag.

[0089] Alternatively, the granulated slag in the slag bin 112 is transported by truck 115 to a fine slag production line and transported for approximately 420 m. 2 The slag is directly ground into fine powder with a specific surface area of ​​10 ...

[0090] The flue gas generated in the production process is sent to the flue gas purification device 120, where it undergoes dedusting and desulfurization treatment to meet relevant emission standards. It is then extracted by a fan 121 and discharged through a chimney 122. The desulfurization and dedusting solution is circulated through the flue gas purification device 120 by a circulation pump 119. When the concentration of the circulating solution reaches a certain value (depending on the actual treatment scenario), part of it is discharged and fresh alkaline solution is replenished from outside, so that the desulfurization and dedusting effects can be maintained normally and efficiently.

[0091] According to another embodiment of the present invention, the method for the coupled utilization of slag waste heat recovery by using the apparatus shown in Figure 1 can be carried out as follows: The method for the coupled utilization of slag waste heat recovery includes the following steps: 1) Volume 2500m 3In a steelworks with a blast furnace, molten slag at a temperature of around 1500°C enters the main slag groove 11 at an average rate of approximately 3 tons / min (maximum slag discharge rate of 6 tons / min) during tapping. The molten slag in the main slag groove 11 is then transferred to the slag withdrawal groove 13 by the slag withdrawal device 12 and then flows into the flow guide cover 16 via an online metering device. The cross section of the flow guide cover 16 is rectangular, measuring 400 mm in length and 100 mm in width. The molten slag entering the flow guide cover 16 collides with and is crushed by the mist fluid ejected from the granulator 15, and is then granulated into molten droplets with a diameter of 5 mm or less. The granulated molten droplets fly at high speed along the flow guide cover 16 together with the mist fluid, exchanging heat with the mist fluid during formation and flight, and then rapidly cooling and solidifying at a cooling rate of, for example, 20°C / s or more, generating granulated slag at 1000°C or less and 750°C or more (at this stage, only the surface of the slag particles has solidified, leaving a molten core) and a gas flow of about 300°C (room temperature). At this stage, the solidification rate of particles with a diameter of 2 mm or less is about 90%, and the granulation and cooling solidification of the molten slag is achieved; 2) Slag gas separation The granulated slag and gas flow exits the flow guide cover 16 and directly enters the cyclone separator 17. Under the combined action of centrifugal force and gravity, the slag and gas are separated, and the temperature of the separated granulated slag drops below 750°C and exits the bottom of the cyclone separator 17; The separated gas stream passes through the cyclone separator 17 and the overflow pipeline, and after heat exchange with the cooling water in the spiral heat exchange pipeline in the overflow pipeline, the temperature drops to below 200°C; after leaving the cyclone separator 17 and the overflow pipeline, the gas enters the waste heat recovery device 123, where it further exchanges heat with the heat exchange pipeline carrying the cooling water to further recover waste heat and form exhaust gas with a temperature below 140°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; after being separated into steam and water in the second steam-water separator 125, saturated steam with a pressure of about 0.45 MPa is obtained, which is returned to the granulator 15 as mist fluid for granulating the molten slag; The cooling water in the spiral heat exchange pipeline absorbs heat and vaporizes; after steam-water separation in the first steam-water separator 127, saturated steam with a pressure of about 1.4 MPa and a temperature of about 190°C is generated. This saturated steam enters the superheated steam generator 126 and is further heated to obtain superheated steam with a pressure of about 1.4 MPa and a temperature of about 300°C; during the above process, the saturated steam entering the superheated steam generator 126 is further heated by the mixed coal gas or natural gas generated during steelmaking; 3) The granulated slag coming out of the bottom of the cyclone separator 17 enters the rotating bed 18, where it comes into contact with the heat exchange pipeline carrying cooling water and exchanges heat. The rotating bed 18 rotates at a low speed (3 rpm) along a set direction under the action of a pressing mechanism. The granulated slag is slowly pushed toward the interior of the rotating bed 18 by the pressing mechanism; after being cooled to below 180°C, the slag is discharged from the rotating bed 18 and then sent to the slag bin 112 for storage via a chute and bucket elevator 111; the slag bin 112 is equipped with a vibrator 113 for vibrating the slag bin 112 to prevent the granulated slag from clogging at the slag bin outlet and bridging or arching within the slag bin 112; The cooling water in the heat exchange pipeline of the rotating bed 18 absorbs heat and vaporizes, and after steam-water separation in the third steam-water separator 19, saturated steam with a pressure of about 1.4 MPa and a temperature of about 190°C is generated. This saturated steam enters the superheated steam generator 126 and is further heated using natural gas or mixed coal gas generated during steel smelting, to obtain superheated steam with a pressure of about 1.4 MPa and a temperature of about 300°C; 4) The granulated slag in the slag bin 112 is conveyed to the gas jet mill 117 through the slag discharge valve 114 and the conveying mechanism 116, and is then impinged by the superheated steam obtained in steps 2) and 3) and pulverized into ultrafine powder. The ultrafine powder is collected by the powder collection device 118 and sold as a high-quality product. The pressure of the superheated steam drops to atmospheric pressure, and the temperature of the superheated steam drops to below 200°C; the steam enters the waste heat recovery device 123, where it further exchanges heat with a heat exchange pipeline carrying cooling water to further recover waste heat and form an exhaust gas with a temperature of about 140°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; after steam-water separation in the second steam-water separator 125, saturated steam with a pressure of about 0.45 MPa is obtained, which is returned to the granulator 15 as a mist fluid for granulating the molten slag.

[0092] Alternatively, the granulated slag in the slag bin 112 is transported by truck 115 to a fine slag production line and transported for approximately 420 m. 2 The slag is directly ground into fine powder with a specific surface area of ​​10 ...

[0093] The flue gas generated in the production process is sent to the flue gas purification device 120, where it undergoes dedusting and desulfurization treatment to meet the relevant emission standards, and is then extracted by a fan 121 and discharged through a chimney 122. The desulfurization and dedusting solution is circulated into the flue gas purification device 120 by a circulation pump 119. When the concentration of the circulating solution reaches a certain value (depending on the actual treatment scenario), part of it is discharged and fresh alkaline solution is replenished from outside, so that the desulfurization and dedusting effects can be maintained normally and efficiently.

[0094] According to another embodiment of the present invention, the method for the coupled utilization of slag waste heat recovery by using the apparatus shown in Figure 1 can be carried out as follows: The method for the coupled utilization of slag waste heat recovery includes the following steps: 1) Volume 1250m 3In a steelworks with a blast furnace, molten slag at a temperature of around 1500°C enters the main slag groove 11 at an average rate of about 3 tons / min (maximum slag discharge rate of 6 tons / min) during tapping. The molten slag in the main slag groove 11 is then transferred to the slag withdrawal groove 13 by the slag extraction device 12, and then flows into the flow guide cover 16 via the online metering device 14. The cross section of the flow guide cover 16 is rectangular, measuring 400 mm in length and 100 mm in width. The molten slag entering the flow guide cover 16 collides with and is crushed by the mist fluid ejected from the granulator 15, and is then granulated into molten droplets with a diameter of 5 mm or less. The granulated molten droplets fly at high speed (for example, 10 m / s or more, depending on the actual situation) along the flow guide cover 16 together with the mist fluid, exchanging heat with the mist fluid during formation and flight, and then rapidly cooling and solidifying, producing granulated slag at 800°C or more but not exceeding 1000°C (at this stage, the slag particles are only surface-solidified, with a molten core), and a gas flow at about 300°C (room temperature). At this stage, the solidification rate of particles with a diameter of 2 mm or less is about 85%, and the granulation and cooling solidification of the molten slag is achieved; 2) Slag gas separation The granulated slag and gas flow exits the flow guide cover 16 and directly enters the cyclone separator 17. Under the combined action of centrifugal force and gravity, the slag and gas are separated, and the temperature of the separated granulated slag drops below 800°C and exits the bottom of the cyclone separator 17; The separated gas stream passes through the cyclone separator 17 and the overflow pipeline, and after heat exchange with cooling water in the spiral heat exchange pipeline in the overflow pipeline, the temperature drops to below 300°C; after leaving the cyclone separator 17 and the overflow pipeline, the gas enters the waste heat recovery device 123, where it further exchanges heat with the heat exchange pipeline carrying cooling water to further recover waste heat and form exhaust gas with a temperature below 150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; the second steam-water separator 125 separates the water into steam and water to obtain saturated steam with a pressure of about 0.5 MPa, which is then returned to the granulator 15 as mist fluid for granulating the molten slag; The cooling water in the spiral heat exchange pipeline absorbs heat and vaporizes; after steam-water separation in the first steam-water separator 127, saturated steam with a pressure of about 1.6 MPa and a temperature of about 201°C is generated. This saturated steam enters the superheated steam generator 126 and is further heated to obtain superheated steam with a pressure of about 1.6 MPa and a temperature of about 350°C; during the above process, the saturated steam entering the superheated steam generator 126 is further heated by the mixed coal gas or natural gas generated during steelmaking; 3) The granulated slag coming out of the bottom of the cyclone separator 17 enters the rotating bed 18, where it comes into contact with the heat exchange pipeline carrying cooling water and exchanges heat. The rotating bed 18 rotates at a low speed (3 rpm) along a set direction under the action of a pressing mechanism. The granulated slag is slowly pushed toward the interior of the rotating bed 18 by the pressing mechanism. After the slag is cooled to below 180°C, it is discharged from the rotating bed 18 and then sent to the slag bin 112 via a chute and bucket elevator 111 for storage. The slag bin 112 is equipped with a vibrator 113 for vibrating the slag bin 112 to prevent the granulated slag from clogging at the slag bin outlet and bridging or arching within the slag bin 112. The cooling water in the heat exchange pipeline of the rotating bed 18 absorbs heat and vaporizes, and after steam-water separation in the third steam-water separator 19, saturated steam with a pressure of about 1.6 MPa and a temperature of about 201°C is obtained. This saturated steam enters the superheated steam generator 126 and is further heated using natural gas or mixed coal gas generated during steel smelting, to obtain superheated steam with a pressure of about 1.6 MPa and a temperature of about 350°C; 4) The granulated slag in the slag bin 112 is conveyed to the gas jet mill 117 through the slag discharge valve 114 and the conveying mechanism 116, and is then impinged by the superheated steam obtained in steps 2) and 3) and pulverized into ultrafine powder. The ultrafine powder is collected by the powder collection device 118 and sold as a high-quality product. The pressure of the superheated steam drops to atmospheric pressure, and the temperature of the superheated steam drops to below 250°C; the steam enters the waste heat recovery device 123, where it further exchanges heat with a heat exchange pipeline carrying cooling water to further recover waste heat and form an exhaust gas with a temperature of about 150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device 123 absorbs heat and vaporizes; after steam-water separation in the second steam-water separator 125, saturated steam with a pressure of about 0.5 MPa is obtained, which is returned to the granulator 15 as a mist fluid for granulating the molten slag.

[0095] Alternatively, the granulated slag in the slag bin 112 is transported by truck 115 to a fine slag production line and transported for approximately 420 m. 2 The slag is directly ground into fine powder with a specific surface area of ​​10 ...

[0096] The flue gas generated during the production process is sent to the flue gas purification device 120, where it undergoes dedusting and desulfurization treatment to meet the relevant emission standards, is extracted by a fan 121, and is discharged through a chimney 122. The desulfurization and dedusting solution is circulated into the flue gas purification device 120 by a circulation pump 119. When the concentration of the circulating solution reaches a certain value (depending on the actual treatment scenario), part of it is discharged and fresh alkaline solution is replenished from outside, so that the desulfurization and dedusting effects can be maintained normally and efficiently.

[0097] In this embodiment, a high-speed mist fluid is sprayed from the granulator to impinge on the molten blast furnace slag, crushing it, and granulating it. The flow rate of the high-speed mist fluid is controllable and varies depending on the amount of molten blast furnace slag measured by an online metering device. When the flow rate of the molten blast furnace slag is low, the flow rate of the mist fluid is appropriately reduced; when the flow rate of the slag increases, the flow rate of the mist fluid is increased accordingly. The maximum flow rate of the mist fluid ensures safe granulation of the molten blast furnace slag when it reaches its maximum amount.

[0098] The cooling water in the cyclone separator and rotating bed coil absorbs heat to form saturated steam at 1.2–1.6 MPa, which is then sent to the superheated steam generator. This saturated steam is then appropriately heated using natural gas or a coal-fired gas mixture generated during steel smelting to form superheated steam at 1.2–1.6 MPa and 250–350°C. The superheated steam is then sent directly to the gas jet mill as a power source for slag pulverization. After expansion and processing in the gas jet mill, the quality of the superheated steam decreases, its pressure drops to atmospheric pressure, and its temperature drops to 150–250°C. This portion of the gas enters the waste heat recovery device, where it undergoes shell-and-pipeline type wall-to-wall heat exchange to produce saturated steam at 0.4–0.5 MPa. The saturated steam can then be directly returned to the granulator as mist fluid for granulating blast furnace molten slag. After interacting with the blast furnace slag, the mist fluid undergoes slag-gas separation and enters the waste heat recovery device for reuse. This implementation achieves gradient recovery of sensible heat from the blast furnace slag and utilizes the recovered heat locally at the same level.

[0099] The device for the combined recovery and utilization of slag waste heat utilizes a mist granulation method combined with water cooling and air granulation to gradually recover the sensible heat of blast furnace molten slag and directly utilize the recovered heat for the treatment of the blast furnace molten slag, which not only achieves safe and rapid granulation of blast furnace molten slag, but also improves the utilization rate of the recovered waste heat, avoiding the low utilization rate of the sensible heat from the recovered blast furnace molten slag in conventional methods.

[0100] This embodiment reuses steam, avoids the waste of water resources, and reduces the cost of granulating blast furnace molten slag. This process is environmentally friendly, achieves safe and rapid granulation of blast furnace molten slag, and produces high-quality granulated slag. This allows for the utilization of blast furnace molten slag as a high-value-added resource and the efficient recovery and utilization of its sensible heat.

[0101] According to another embodiment of the present invention, a blast furnace molten slag granulation apparatus and process equipped with a high-velocity steam nozzle is provided. This combines the advantages of water quenching granulation technology and air quenching granulation technology, using high-velocity steam together with water mist to cool and granulate the molten slag. This method appropriately reduces fresh water consumption and costs, while ensuring the cooling rate of the molten slag and promoting the formation of a glass-phase solid slag. Furthermore, this apparatus can fully utilize the waste heat of the molten slag to reduce energy loss. It has the advantages of a fast cooling rate, a high molten slag crushing effect, and low energy consumption.

[0102] Specifically, referring to Figure 2, Figure 2 shows an apparatus for carrying out the molten slag granulation method according to this embodiment. Specifically, this embodiment provides a blast furnace molten slag granulation apparatus equipped with a high-speed steam nozzle, including: The molten slag granulator body 21 has a box-shaped structure, and a slag chute 211 used for charging molten slag 2100 is located on one side of the upper part of the molten slag granulator body 21, and a steam outlet passage 212 is located at the upper end of the molten slag granulator body 21.

[0103] A steam spray mechanism 22 including a first control valve F21, a water pump 221, a second control valve F22, a pressure gauge 222, a heat exchanger 223, a thermometer 224, and a nozzle 225 is arranged in sequence along the pipeline 220; the inlet end of the pipeline 220 is connected to a water source 2200; the nozzle 225 is arranged on the side wall of the molten slag granulator body 21 where the slag chute 211 is arranged, and the axial direction of the nozzle 225 is angled with the axial direction of the slag chute 211, and the outlet of the nozzle 225 is directed toward the molten slag flowing out of the slag chute 211; The heat exchanger 223 is provided with a waste heat recovery pipeline 23 and a heat exchange fluid outlet pipeline 24; the waste heat recovery pipeline 23 is provided with a valve F23.

[0104] Preferably, the first control valve F21 is an electrohydraulic gate valve.

[0105] Preferably, the axial direction of the nozzle 225 forms an angle of 30 to 60 degrees with the axial direction of the slag chute 211 .

[0106] The molten slag granulation method using the above-mentioned molten slag granulation device with a high-speed steam nozzle is carried out as follows: Water entering the pipeline is pressurized by a water pump and then directed to a heat exchanger, where it is heated by heat from the waste heat recovery pipeline. The water reaches a state where it exceeds atmospheric pressure and its boiling point at normal pressure. After being ejected from the nozzle, the water instantly vaporizes at normal pressure, forming a high-speed jet containing steam (e.g., jet velocity 90-110 m / s), which collides with the molten slag flowing out of the slag chute. This high-speed jet cools the molten slag and breaks it into small granules, which fall to the bottom of the molten slag granulator body. After impinging on the molten slag, the mixed jet ejected from the nozzle completely turns into steam and flows out the top of the device as a waste heat resource for further utilization.

[0107] Preferably, the water entering the pipeline is pressurized by a water pump to increase the pressure in the pipeline to 0.1-1 MPa; the temperature of the water in the heat exchanger is increased to 100-182°C by the heat from the waste heat recovery pipeline.

[0108] Compared with existing technologies, the advantages of using the molten slag granulation method and apparatus according to the present embodiment are as follows: The high-speed jet ejected from the nozzle crushes the molten blast furnace slag and exchanges heat with it, completely transforming it into steam. This significantly reduces water consumption, water pollution, and the emission of harmful gases compared to conventional wet processes. In addition, there is no need to dry the cooled molten blast furnace slag.

[0109] The sensible heat of the molten slag is exchanged with the jet of water ejected from the nozzle, and the enthalpy of the generated high-temperature steam is higher than that of the hot air generated by conventional air quenching processes, which improves the efficiency of sensible heat recovery and increases the possibility of waste heat recovery.

[0110] Compared with the air quenching process, the device according to this embodiment allows for higher pressure in the pipeline, lower energy consumption, reduced costs, and reduced noise pollution. Because the heat exchange medium is water, the cooling rate of the high-temperature molten slag is also faster than that of air quenching, which is more conducive to the formation of glassy slag. The higher the content and quality of the glassy slag, the higher the recovery rate of the blast furnace molten slag.

[0111] By using waste heat to heat the pipelines, all of the energy to form steam is obtained from the steel mill's waste and residual heat, improving energy utilization.

[0112] Since the fluid medium in the pipeline is water, it is easier to achieve high pressures with liquid than with gas, resulting in greater impact kinetic energy.

[0113] Another embodiment of the present invention provides a horizontal molten slag granulation process and apparatus using gas-water mixing. A high-velocity gas stream ejected from a gas nozzle array component impinges on the liquid molten slag and breaks it up. High-density mist droplets ejected from the gas-liquid two-fluid nozzle rapidly cool the granulated slag granules, aiding granulation and promoting rapid slag formation. The use of mist instead of direct water quenching reduces fresh water consumption, lowers costs, and ensures a cooling rate of the molten slag that contributes to the formation of a glass-phase solid slag. Furthermore, this process fully utilizes the waste heat of the molten slag, reducing energy loss. It has the advantages of a fast cooling rate, a high slag breakage effect, and low energy consumption.

[0114] Referring to Figure 3, this shows an apparatus for implementing the molten slag granulation method according to this embodiment. Specifically, this embodiment provides a horizontal molten slag granulation process using gas-water mixing, in which a high-speed gas stream is ejected from an air nozzle array consisting of gas nozzles to break down the falling molten slag into molten slag granules. At the same time, a row of gas-liquid two-fluid nozzles is used to spray water mist onto the molten slag granules to rapidly cool them and apply an auxiliary pressing force to ensure that they accurately enter the slag granule recovery section at the rear.

[0115] Preferably, the high velocity gas nozzle is a supersonic nozzle.

[0116] Referring to Figures 3-5, the apparatus for the above-mentioned horizontal molten slag granulation process with gas-water mixing includes: The molten slag granulator body 61 has a box-shaped structure, a slag inlet 611 is disposed at the top end of the molten slag granulator body, and a slag chute 612 is disposed above the molten slag granulator body; High velocity air jet mechanism 62 including: a compressor 621, a gas storage tank 622, a gas transport pipeline 620 connected to the gas storage tank 622, and an air nozzle array part 623 connected to one end of the gas transport pipeline 620; a first control valve F61 and a flow meter 624 are sequentially arranged in the gas transport pipeline 620 connected to the outlet end of the gas storage tank 622; the air nozzle array part 623 includes a plurality of gas flow nozzles and corresponding branch pipelines, and the branch pipelines are connected to the gas transport pipeline 620; the gas flow nozzles are arranged at the top of one side wall of the molten slag granulator body 61; the gas flow nozzles are supersonic nozzles; The gas storage tank 622 is provided with a pressure gauge 625, a gas inlet pipe 626, and a gas inlet valve 6261; The air nozzle array component 623 is connected to the gas transmission pipeline 620; A spraying mechanism 63 including a second control valve F62, a water pump 631, a third control valve F63, a pressure meter 632, a flow meter 633, and a plurality of gas-liquid two-fluid nozzles 634, 634' arranged in sequence along the water transport pipeline 630; the inlet end of the water transport pipeline 630 is connected to a water source 6100; the gas-liquid two-fluid nozzles 634, 634' are arranged at the top and bottom inside the molten slag granulator body 61, and the gas-liquid two-fluid nozzles 634, 634' are connected to the gas transport pipeline 620 and the water transport pipeline 630 via a connecting pipeline 635.

[0117] Referring to FIG. 4, the above-described gas-liquid two-fluid nozzles 634, 634' are arranged in an array.

[0118] Preferably, the axial direction of the air nozzle array component 623 forms an angle of 0 to 20° with respect to the horizontal; preferably, the width of the air nozzle array component 623 is greater than the width of the slug inlet 611 .

[0119] Preferably, the second control valve F62 is an electrohydraulic gate valve.

[0120] Preferably, the molten slag granulator body 61 is semi-closed, and a granule slag recovery section is provided at the rear of the molten slag granulator body 61.

[0121] Referring to FIG. 5, FIG. 5 shows the configuration of the outlet of the air nozzle array component 623, and the outlet of the air nozzle array component 623 includes a plurality of uniformly distributed spray holes 6231.

[0122] Taking the slag flow rate of 5 tons / min as an example, the flight trajectory of the molten slag granules is simulated and calculated.

[0123] As shown in Figure 6, we simulated the flight behavior of slag granules using different nozzle array components at different angles (0°, 10°, and 20°). The flight angle of the slag granules is affected by the inclination angle of the gas stream, but the inclination angle of the gas stream cannot be made excessively large. As shown in Figure 7, it was found that when the inclination angle of the gas stream exceeds 20°, some of the slag granules collided with the upper wall of the molten slag granulator body.

[0124] Simulations of the molten slag granulation process also indicate that the velocity of the high-speed gas jet ejected from the air nozzle array components should be between 90 and 110 m / s. If the gas flow velocity is too low, the molten slag will not be sufficiently crushed, and the molten slag will fall and adhere to the inner wall of the molten slag granulator. If the gas flow velocity is too high, the granulation effect and slag particle size will not be significantly improved.

[0125] Compared with existing technologies, the advantages of this embodiment are as follows: The high-speed jets emitted from the gas nozzles of the air nozzle array break up the molten blast furnace slag, significantly reducing water consumption, water pollution, and harmful gas emissions compared to conventional wet processes. Furthermore, the gas pipeline is less susceptible to wear and tear, requires less maintenance, and does not require additional energy to dry the cooled molten blast furnace slag.

[0126] The sensible heat of the molten slag is exchanged with a large number of mist droplets ejected from the atomizing nozzle, and the enthalpy of the generated high-temperature steam is higher than that of the hot air generated by the conventional air quenching process, which improves the efficiency of sensible heat recovery and increases the possibility of waste heat recovery.

[0127] Compared with the air quenching process, the device according to this embodiment mainly uses mist droplets formed by water fragmentation as the heat exchange medium, and the cooling rate of the high-temperature molten slag is faster than that of air quenching, which is more conducive to the formation of glassy slag. The higher the content and quality of the glassy slag, the higher the recovery rate of blast furnace slag.

[0128] Multiple rows of gas-liquid two-fluid atomizing nozzles located at the bottom and top of the molten slag granulator body create uniformly distributed mist droplets that exchange heat with the molten slag. Compared to conventional water jet impingement, the uniform mist droplets provide more complete heat exchange with the molten slag, and the uniform gas flow field ensures more uniform granulation and better slag formation.

[0129] The mist droplets ejected from the atomizing nozzle have a certain auxiliary effect on the granulation of the molten slag and the flight of the granules, and achieve better results than pure gas quenching.

[0130] The molten slag granulator body is a horizontal semi-closed device with a granule recovery section at its rear, which makes it easier to recover the granulated slag particles and prevents the slag from adhering to the wall, which can be difficult to recover.

[0131] The nozzle arrays are located near the slug inlet, in the center of the granulator, and at the bottom of the granulator to impinge, thin, and granulate the slug stream in stages, preventing the problem of insufficient granulation caused by excessive slug flow.

[0132] Another embodiment of the present invention provides an apparatus for granulating blast furnace molten slag using a gas nozzle array. High-velocity gas jets from the high-velocity gas nozzles impinge on the liquid molten slag, fragmenting it, and rapidly cool the granulated slag granules, facilitating rapid slag formation. This approach ensures a cooling rate that promotes the formation of glassy solid slag while appropriately reducing water consumption and lowering costs. Furthermore, this apparatus fully utilizes the waste heat of the molten slag to reduce energy loss, combining the advantages of both water-quenching and air-quenching granulation techniques. The cooling rate is fast, the molten slag fragmentation effect is good, and energy consumption is low.

[0133] Referring to FIG. 8, the apparatus for granulating molten blast furnace slag using a gas nozzle array according to this embodiment includes: The molten slag granulator body 31 has a box-shaped structure, and a slag inlet 311 and a steam outlet passage 312 are arranged at the top of the molten slag granulator body. The blast furnace molten slag 3100 enters the molten slag granulator body 311 through the slag chute 313 and the slag inlet 311; High-velocity air jet mechanism 32 including: a compressor 321, a gas storage tank 322, a gas transmission pipeline 323 connected to the gas storage tank 322, and a nozzle array 324 connected to one end of the gas transmission pipeline 323; a first control valve F31 and a flow meter 325 are sequentially arranged on the gas transmission pipeline 323 connected to the outlet end of the gas storage tank 322; The gas storage tank 322 is provided with a pressure gauge 326, a gas inlet pipe 327, and a gas inlet valve F32; The nozzle array 324 includes a plurality of nozzles 3241 and corresponding branch pipelines 3242, each of which is connected to a gas transport pipeline 323; the nozzles 3241 are arranged on one side wall of the molten slag granulator body 31.

[0134] Preferably, the nozzles 3241 in the nozzle array 324 are one or more selected from a supersonic nozzle, an atomizing nozzle, or a gas-liquid two-fluid nozzle; preferably, the axial direction of the nozzles 3241 in the nozzle array 324 is perpendicular to the side wall of the molten slag granulator body 31.

[0135] Referring to Figures 9 to 11, the nozzles 3241 in the nozzle array 324 are arranged in a number of rows and columns.

[0136] Preferably, as shown in Figures 10-11, the nozzles 3241 in the nozzle array 324 are arranged in a plurality of rows and columns, with the nozzles in adjacent rows being staggered vertically.

[0137] Preferably, as shown in FIG. 11, the nozzles 3241 in the nozzle array 324 are arranged in multiple rows and columns, with the number of nozzles gradually decreasing or increasing along the vertical direction.

[0138] The high-speed jet (e.g., 90-110 m / s) emitted from the high-speed gas nozzle breaks up the blast furnace molten slag, reducing water consumption, water pollution, and harmful gas emissions. Furthermore, the gas pipeline is less susceptible to wear and maintenance costs, and no additional energy is required to dry the cooled blast furnace molten slag. Compared to the air quenching process, the installation of high-speed gas nozzles allows for a higher gas velocity in the pipeline at the same pressure with less energy consumption, resulting in lower costs and reduced noise pollution. Furthermore, the cooling rate of high-temperature molten slag is faster than that of conventional air quenching, which is more conducive to the formation of glassy slag. Higher glassy slag content and quality improve the recovery rate of blast furnace molten slag. The installation of multiple high-speed gas nozzles at the bottom creates a uniformly distributed high-speed gas flow that exchanges heat with the molten slag. The nozzle array arrangement ensures more complete heat exchange with the molten slag. The gas flow field formed by the array can cover the flow area uniformly and completely, resulting in more uniform granulation and better slug formation.

[0139] 12 and 13, the molten slag granulation device of this embodiment includes: a nozzle atomization mechanism 33 including a second control valve F32, a water pump 331, a third control valve F33, a pressure gauge 332, a flow meter 333, and a plurality of atomization nozzles 334, arranged in sequence along the water transport pipeline 330; the inlet end of the water transport pipeline 330 is connected to a water source 3200; the atomization nozzles are arranged at the inner bottom of the molten slag granulation machine body 31 and are arranged in at least two rows, and the water mist is sprayed toward the molten slag flowing in from the slag inlet 311.

[0140] Referring to Figure 14, Figure 14 shows a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention, in which the nozzles in the nozzle array 324 are gas-liquid two-fluid nozzles; correspondingly, the molten slag granulation apparatus is also equipped with a nozzle water supply mechanism 36, which includes a fourth control valve F34, a water pump 361, a fifth control valve F35, a pressure gauge 362, and a flow meter 363 arranged in sequence along the water transport pipeline 360; the inlet end of the water transport pipeline 360 ​​is connected to the water source 3200, and the outlet end is connected to the inlet end of the gas-liquid two-fluid nozzle.

[0141] Referring to FIG. 15, FIG. 15 shows a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention, where the molten slag granulation apparatus further includes a waste heat recovery system 34, which includes: A heat exchange box 341 has a supply inlet 3411 arranged at the top of one side wall of the heat exchange box, the supply inlet 3411 being connected to the outlet of the molten slag granulator body 31; a heat exchange gas outlet 3412 arranged at the top end of the heat exchange box 341; a plurality of perforated floor plates 342 arranged along the height direction inside the heat exchange box 341; a molten slag granule outlet 3413 arranged at the bottom of the heat exchange box 341; The gas nozzle array 343 is arranged below the perforated floor plate 342 at the inner bottom of the heat exchange box 341, and the gas nozzles in the gas nozzle array are arranged opposite the perforated floor plate 342; the ejected gas can further cool the slag granules falling along the perforated floor plate 342.

[0142] Preferably, the perforated floor plate 342 is arranged in a zigzag pattern along the vertical direction inside the heat exchange box 341. As shown in Figure 15, the falling path of the slag granules is extended, which is beneficial to the effective cooling of the slag granules.

[0143] The molten slag granulation process takes place within the molten slag granulator itself. The high-speed air jet and atomizing nozzles provide the primary power for crushing and granulating the molten slag, and the primary heat exchange takes place. The waste heat recovery system separates the slag granules from the gas, and the secondary heat exchange takes place.

[0144] The working process is as follows: The nozzle array in the high-velocity air jet mechanism supplies a uniform, high-velocity gas stream to uniformly break down the falling molten blast furnace slag, resulting in high-temperature molten slag granules moving along a parabolic trajectory. The atomization nozzles in the nozzle atomization mechanism spray water mist onto the molten slag granules moving along a parabolic trajectory at the bottom of the molten slag granulator body, which improves heat transfer efficiency, rapidly cools the molten slag granules, and applies a compressive force to the molten slag. A slag granule recovery section is located at the rear of the molten slag granulator body, which directs the slag granules and the high-temperature gas stream formed during slag cooling to the heat exchange box of the waste heat recovery system for gas-solid separation. The slag granules pass through multiple perforated floor plates and exchange heat with the cool air ejected from the gas nozzles in the gas nozzle array below. The heat exchange air flows out the upper outlet, and the cooled slag falls from the lower outlet of the heat exchange box.

[0145] During use, the compressor is turned on to pressurize the gas and send it to the gas storage tank. The gas at stable pressure is supplied to the nozzle array (supersonic gas) through the gas storage tank. The nozzle injects a high-velocity gas stream into the molten slag granulator body, crushing the molten slag entering through the molten slag inlet. Simultaneously, the water pump is turned on to pressurize the water in the water pipeline, which is then sprayed through the atomization nozzle. The sprayed mist droplets collide with the granulated molten slag granules, which are rapidly cooled and converted into stable, small particles. The mixed jets ejected from the nozzles in the nozzle array and the atomization nozzles in the nozzle atomization mechanism collide with the hot molten slag, turning it into a mixture of hot air and steam, which flows out of the top of the molten slag granulator body as a waste heat resource for subsequent recycling and utilization.

[0146] Referring to FIG. 16, FIG. 16 shows a schematic structural diagram of a molten slag granulation apparatus according to another embodiment of the present invention, in which the waste heat recovery system 34 adopts a cyclone separator 35.

[0147] The cyclone separator 35 includes a separator body 351, and a gas-solid medium inlet 3511 connected to the discharge port 314 of the molten slag granulator body 31 is disposed at the top of one side of the separator body; an air outlet 3512 is disposed at the top end of the separator body 351, and a dust hopper 352 is disposed at the bottom of the separator body 351.

[0148] The slag granules and hot gas stream enter the cyclone separator 35 for gas-solid separation. The cyclone separator 35 is capable of separating the clean hot gas stream and fully recovering the waste heat generated during the molten slag granulation process for subsequent utilization.

[0149] Compared with existing technologies, the advantages of this embodiment are as follows: The high-speed jet emitted from the high-speed gas nozzle breaks up the molten blast furnace slag, reducing water consumption, water pollution, and harmful gas emissions. The gas pipeline is less susceptible to wear, requiring less maintenance, and no additional energy is required to dry the cooled molten blast furnace slag. Compared to the air quenching process, this equipment uses high-speed gas nozzles to allow the gas to flow faster through the pipeline at the same pressure with less energy consumption, resulting in lower costs and less noise pollution. The cooling rate of the high-temperature molten slag is also faster than that of conventional air quenching, which promotes the formation of glassy slag. The higher the content and quality of the glassy slag, the higher the recovery rate of the blast furnace molten slag.

[0150] By installing multiple high-speed gas nozzles at the bottom, a uniformly distributed high-speed gas stream (e.g., a jet velocity of 90-110 m / s) is created, which exchanges heat with the molten slag. The nozzle array arrangement ensures more complete heat exchange with the molten slag. The gas flow field created by the array can uniformly and completely cover the gas flow range, resulting in more uniform granulation and better slag formation.

[0151] By installing multiple atomizing nozzles at the bottom of the molten slag granulator, uniformly dispersed mist droplets are formed, which exchange heat with the molten slag. Compared to conventional water jet impingement, the heat exchange between the mist droplets and the molten slag is more efficient. Furthermore, the mist droplets exert a compressive force on the molten slag granules after gas quenching, preventing them from falling to the bottom of the device and sticking.

[0152] Preferably, the high-velocity gas nozzles are arranged in a (supersonic) nozzle array, and the gas flow field formed by the array can uniformly and completely cover the slug flow area, resulting in more uniform granulation and better slug formation.

[0153] This embodiment adopts a multi-layer waste heat recovery design, in which the slag granules and high-temperature gas flow enter the heat exchange box for secondary waste heat gas recovery, heat exchange, and gas-solid separation, greatly improving the efficiency of waste heat recovery. In addition, the array of gas nozzles at the bottom can quickly cool the molten slag granules and separate the high-temperature gas flow, allowing the waste heat of the molten slag to be fully recovered.

[0154] According to another embodiment of the present invention, this device can clean falling slag and granulate it using mist. A high-speed gas stream ejected from a high-speed nozzle array component collides with the liquid molten slag and breaks it up. The high-density mist droplets ejected from the atomizing nozzles rapidly cool the granulated slag granules, facilitating rapid granulation of the slag. The use of mist instead of water quenching (direct water spraying) reduces costs and ensures a cooling rate that promotes the formation of glass-phase solid slag. Furthermore, this device can fully utilize the waste heat of the molten slag to reduce energy loss. It has the advantages of a fast cooling rate, good slag breaking effect, and low energy consumption.

[0155] Referring to FIG. 17 and FIG. 18, in this embodiment, the device capable of cleaning the falling slag and granulating the slag by mist includes: The molten slag granulator body 41 has a box-shaped structure, a slag inlet 411 is disposed at the top end of the molten slag granulator body, and a slag granule recovery unit 412 is disposed at the rear of the molten slag granulator body; the molten slag 4100 enters the molten slag granulator body 411 through the slag inlet 411 and the slag chute 413; a gas nozzle array 42 arranged on one side wall of the molten slag granulator body 41; The atomizing nozzle array 43 is arranged at the inner bottom of the molten slag granulator body 41, and the direction of the gas mist ejection is directed toward the molten slag flowing in from the slag inlet 411; A falling slag cleaning nozzle 44 is arranged at the inner bottom of the molten slag granulator main body 41, and the outlet of the falling slag cleaning nozzle faces the inner bottom of the molten slag granulator main body 41 and the slag granule recovery section 412.

[0156] Preferably, the axial direction of the gas nozzle array 42 is perpendicular to one side wall of the molten slag granulator body 41 .

[0157] Preferably, the falling slag cleaning nozzle 44 is one or more selected from a water atomizing nozzle, a steam atomizing nozzle, a high velocity gas flow nozzle, or a gas-liquid two-fluid nozzle.

[0158] The gas nozzle array supplies a uniform, high-velocity gas stream (e.g., jet velocity of 90-110 m / s), which uniformly crushes the falling blast furnace molten slag, resulting in crushed molten slag granules moving along a parabolic trajectory. The atomizing nozzle sprays water mist onto the molten slag granules moving along a parabolic trajectory at the bottom of the molten slag granulator body, improving heat transfer efficiency, rapidly cooling the crushed molten slag granules, and applying a pressing force to the molten slag. A slag granule recovery section is located at the rear of the molten slag granulator body, and uses falling slag cleaning nozzles (atomizing nozzles) to exchange heat and blow away the slag granules falling to the bottom of the molten slag granulator body, preventing them from adhering to the walls.

[0159] 19 and 20, which show schematic structural diagrams of a molten slag granulation apparatus according to another embodiment of the present invention, wherein the apparatus further includes: A high velocity air jet mechanism 420 including: a compressor 421, a gas storage tank 422, a gas transmission pipeline 423 connected to the gas storage tank 422, and a gas nozzle array 42 connected to one end of the gas transmission pipeline 423; a first control valve F41 and a flow meter 424 are sequentially arranged in the gas transmission pipeline 423 at the outlet end of the gas storage tank 422; The gas storage tank 422 is provided with a pressure gauge 426, a gas inlet pipe 427, and a gas inlet valve F42; The gas nozzle array 42 includes nozzles and corresponding branch pipelines 4231, 4232, and the branch pipelines are connected to the gas transport pipeline 423; the falling slag cleaning nozzle 44 is connected to the gas transport pipeline 423 through a connecting pipeline 441 and a valve; A nozzle atomization mechanism 430 including a second control valve F42, a water pump 432, a third control valve F43, a pressure gauge 433, and a flow meter 434 arranged in sequence along a water transport pipeline 431, where the inlet end of the water transport pipeline 431 is connected to a water source 4200, and the outlet end of the water transport pipeline is connected to the atomization nozzle array 43.

[0160] Referring to FIG. 19, the nozzles of the atomizing nozzle array 43 are gas-liquid two-fluid nozzles, the inlet ends of which are connected to the gas transport pipeline 423 and the water transport pipeline 431, respectively.

[0161] Referring to FIG. 20, FIG. 20 shows a schematic structural diagram of a molten slag granulating apparatus according to another embodiment of the present invention, in which a plurality of slag inlets 411, 411′ are arranged at the upper end of the molten slag granulating apparatus body 41.

[0162] Referring to Figure 21, Figure 21 shows a top view of the slag inlet of the molten slag granulator body 41 of Figure 20, and illustrates one arrangement of the slag inlet. In this embodiment, multiple slag inlets 411, 411', 411'' are arranged at the upper end of the molten slag granulator body 41.

[0163] 22, which shows a schematic structural diagram of the nozzles in the gas nozzle array 42 in this embodiment. A large number of uniform gas flow jet holes 4201 are arranged in the center. The number and arrangement of the holes and rows can be adjusted according to the actual situation.

[0164] 23, which shows another structural design of the gas nozzle array 42 in this embodiment. Baffles 428 are arranged on both sides of the outlet position of the gas nozzle array 42, and liquid / atomization nozzles 429 are arranged outside the baffles 428. The high-velocity air ejected from the gas nozzle array 42 is used to break up and atomize the water ejected from the liquid / atomization nozzles 429.

[0165] Compared with existing technologies, the advantages of this embodiment are as follows: The high-velocity jets sprayed from the gas nozzle array break up the molten slag, significantly reducing water consumption, water pollution, and harmful gas emissions compared to conventional wet processes. Furthermore, the gas pipeline is less susceptible to wear, maintenance costs are low, and no additional energy is required to dry the cooled blast furnace molten slag.

[0166] The sensible heat of the molten slag is exchanged with the numerous mist droplets ejected from the atomizing nozzle array, and the enthalpy of the generated high-temperature steam is higher than that of the hot air generated by the conventional air quenching process, which improves the efficiency of sensible heat recovery and increases the possibility of waste heat recovery.

[0167] In this embodiment, compared with the air quenching process, the heat exchange medium uses mist droplets formed by water fragmentation, and the cooling rate of the slag is faster than that of air quenching, which is more conducive to the formation of glassy slag, and the higher the content and quality of the glassy phase, the better the recovery rate of blast furnace slag.

[0168] By installing multiple atomizing nozzles at the bottom, uniformly dispersed mist droplets are formed and heat is exchanged with the molten slag. Compared to direct water impingement, the heat exchange between the mist droplets and the molten slag is more efficient. Furthermore, the mist droplet spray provides a pressing force to the molten slag granules after gas quenching, preventing them from falling to the bottom of the device too quickly and causing adhesion.

[0169] By arranging the gas nozzles in a gas nozzle array, the gas flow field formed by the array can uniformly and completely cover the slug flow area, resulting in more uniform granulation and better slug formation.

[0170] At the bottom of the molten slag granulating device body, there is an atomizing nozzle for cleaning the falling slag, which can clean the molten slag that falls to the bottom of the granulating device and prevent the molten slag from adhering to the wall surface.

[0171] A number of molten slag inlets are installed at the top of the molten slag granulator body, which divide the molten slag into small slag flows, greatly improving the molten slag processing capacity of the nozzle and the molten slag granulation efficiency.

[0172] According to another embodiment of the present invention, an apparatus for rapidly cooling molten slag using an atomizing nozzle is provided. A high-velocity gas stream ejected from a high-velocity gas nozzle impinges on the liquid molten slag, fragmenting it. The high-density mist droplets ejected from the atomizing nozzle rapidly cool the granulated slag granules, facilitating the rapid formation of slag. The use of mist instead of direct water quenching (direct water spray) reduces costs and ensures a cooling rate that promotes the formation of glass-phase solid slag. Furthermore, this apparatus fully utilizes the waste heat of the slag, reducing energy loss. It has the advantages of a fast cooling rate, good slag fragmentation effect, and low energy consumption.

[0173] Referring to Figures 24 and 25, an apparatus for quenching molten slag using an atomizing nozzle according to this embodiment includes: The molten slag granulator body 71 has a box-shaped structure, and a slag inlet 711 is disposed at the top end of the molten slag granulator body; a gas nozzle array 72 arranged on one side wall of the molten slag granulator body 71, the axial direction of the gas nozzles in the gas nozzle array being perpendicular to the one side wall of the molten slag granulator body; a flow field optimization nozzle array 73 arranged near the slag inlet 711 at the upper inside of the molten slag granulator body 71; a slag cleaning nozzle array 74 located at the inner lower portion or bottom of the molten slag granulator body 71; An atomizing nozzle array 75 is arranged inside the molten slag granulator body 71 and is arranged radially around the slag flow 7100 on the inner wall of the molten slag granulator body 71, the axial direction of the atomizing nozzles in the atomizing nozzle array being perpendicular to the axial direction of the gas nozzle.

[0174] Preferably, a granulated slag recovery section 76 is disposed at the rear of the molten slag granulator body 71 .

[0175] Preferably, the nozzles in the flow field optimized nozzle array 73 are gas nozzles or gas-liquid two-fluid nozzles.

[0176] Preferably, the nozzles in the slag cleanup nozzle array 74 are gas nozzles.

[0177] Preferably, the nozzles in the atomizing nozzle array 75 are water atomizing nozzles.

[0178] The gas nozzle array 72 supplies a uniform, high-velocity gas stream (e.g., a jet velocity of 90–110 m / s) to uniformly crush the molten slag dropping from the slag container 77 into the molten slag granulator main body 71, producing molten slag granules moving along a parabolic trajectory. The flow field-optimized nozzle array 73 further atomizes the molten slag granules moving along a parabolic trajectory at the top of the molten slag granulator main body 71, increasing the molten slag's flight speed, promoting heat transfer, and preventing the molten slag from adhering to the wall and damaging the equipment. Multiple layers of atomizing nozzles are installed around the inner wall of the molten slag granulator main body 71, and the atomizing nozzles are evenly spaced around the inner wall to rapidly cool the molten slag granules. The slag granules and high-temperature gases generated by heat transfer are collected by a slag granule collection unit located at the rear of the molten slag granulator main body 71.

[0179] Compared with existing technologies, the advantages of this embodiment are as follows: The high-speed gas jet emitted from the high-speed gas nozzle breaks up the molten blast furnace slag, significantly reducing water consumption, water pollution, and harmful gas emissions compared to conventional wet processes. Furthermore, the gas pipeline is less susceptible to wear, maintenance costs are low, and there is no need to consume additional energy to dry the cooled molten blast furnace slag.

[0180] The sensible heat of the molten slag is exchanged with a large number of mist droplets ejected from the atomizing nozzle, and the enthalpy of the generated high-temperature steam is higher than that of the hot air generated by the conventional air quenching process, which improves the efficiency of sensible heat recovery and increases the possibility of waste heat recovery.

[0181] Compared with the air quenching process, the heat exchange medium is the mist droplets formed by water fracturing, and the cooling rate of the high-temperature molten slag is faster, which is more conducive to the formation of glassy phase slag. The higher the content and quality of the glassy phase, the better the recovery rate of blast furnace slag.

[0182] By uniformly arranging multiple atomizing nozzles around the inner wall of the molten slag granulator body, uniformly dispersed mist droplets are formed, which exchange heat with the molten slag. Compared to direct water jet impingement, the heat exchange between the mist droplets and the molten slag is more efficient.

[0183] The flow field optimized nozzle array provides additional pressing force to the initially crushed molten slag granules, preventing them from falling to the bottom of the device too quickly and causing sticking phenomenon.

[0184] The high-velocity gas nozzles are arranged in a nozzle array, and the gas flow field formed by the array can cover the slug flow area uniformly and completely, resulting in more uniform granulation and better slug formation.

[0185] According to another embodiment of the present invention, a water mist granulation apparatus for granulating blast furnace molten slag is provided. This apparatus utilizes high-speed water jets (e.g., jet velocity of 90-110 m / s) ejected from a water nozzle array component and water mist (e.g., jet velocity of 90-110 m / s) ejected from a gas-liquid two-fluid nozzle to impinge on and break up the liquid molten slag. The high-density mist droplets ejected from the atomizing nozzle rapidly exchange heat with and cool the broken molten slag granules, aiding granulation and promoting rapid slag formation. The use of mist instead of water quenching (direct water spray) reduces fresh water consumption, lowers costs, and ensures a high cooling rate of the molten slag, which contributes to the formation of a glass-phase solid slag. Furthermore, this apparatus can fully utilize the waste heat of the molten slag to reduce energy loss. It has the advantages of a fast cooling rate, good slag breaking effect, and low energy consumption.

[0186] Referring to Figures 26 and 27, this embodiment provides a water mist granulation apparatus for blast furnace molten slag granulation, including: Rack 51, which is a frame structure; a water nozzle array component 52 including: The main body 521 has a box-shaped structure and is disposed in the center of the rack 51, and is provided with a flow rate adjusting plate 522 and a flow guide plate 523 spaced apart from each other in sequence therein; the rear end of the main body 521 is connected to a water source; an array of water nozzles 524 uniformly arranged on the front surface of the body 521; Gas-liquid two-fluid nozzle components 53, including: gas-liquid two-fluid nozzles 531 arranged in parallel on both sides of the water nozzle array 524 and fixed to the rack 51; A gas pipeline 532 and a water transport pipeline 533 are both fixed to the rack 51 and connected to the gas-liquid two-fluid nozzle 531 .

[0187] Preferably, the gas-liquid two-fluid nozzles 53 , 53 ′ are arranged parallel to each other on either side of the water nozzle array 524 .

[0188] The rear end of the main body 521 of the water nozzle array part 52 is connected to a water source via a flange. After entering the main body 521, the water passes through a flow adjustment plate 522 and a flow guide plate 523 to ensure uniform water pressure distribution, and then is ejected from the water nozzle array 524. At the same time, gas and liquid enter the gas-liquid two-fluid nozzle 531 from the gas pipeline 532 and the water transport pipeline 533, respectively, for atomization.

[0189] Compared with existing technologies, the advantages of this embodiment are as follows: The high-speed jets emitted from the water nozzle array components break up the molten blast furnace slag, significantly reducing water resource consumption, water pollution, and harmful gas emissions compared to traditional wet processes.

[0190] The sensible heat of the molten slag is exchanged with a large number of mist droplets ejected from the atomizing nozzle, and the enthalpy of the generated high-temperature steam is higher than that of the hot air generated by the conventional air quenching process, which improves the efficiency of sensible heat recovery and increases the possibility of waste heat recovery.

[0191] Compared with the air quenching process, this device mainly uses the mist water droplets formed by water crushing as the heat exchange medium. Also, the cooling rate of the high-temperature molten slag is faster than that of air quenching, which is more conducive to the formation of glassy slag. The higher the content and quality of the glassy slag, the higher the recovery rate of blast furnace slag.

[0192] By installing multiple rows of atomizing nozzles at the top and bottom, uniformly dispersed mist droplets are formed and exchange heat with the molten slag, which is more efficient than the conventional water jet impingement method.

[0193] The jet flow field formed by the array can uniformly and completely cover the flow area of ​​the slug, resulting in more uniform granulation and better slug formation.

[0194] While the present invention has been shown and described with reference to certain preferred embodiments, those skilled in the art should understand that the above content further describes the present invention in connection with certain embodiments and should not be construed as limiting specific implementations of the present invention to these descriptions. Those skilled in the art may make various changes in form and details, consisting of making some simple inferences or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A method for granulating molten slag, comprising crushing molten slag to obtain molten slag granules, then cooling the molten slag granules, and recovering the resulting granulated slag.

2. 2. The method according to claim 1, wherein the molten slag is subjected to jet granulation to obtain surface-solidified granules and steam, and then the surface-solidified granules are cooled in a swirling fluidized field to obtain solid slag granules.

3. 3. The method according to claim 1 or 2, comprising the steps of: 1) The molten slag is fed into the flow guide cover, and is collided with and pulverized by the mist fluid sprayed from the granulator, forming molten droplets with a particle size of 5 mm or less. The molten droplets fly directionally along the flow guide cover together with the mist fluid, and are cooled and solidified by heat exchange with the mist fluid during the formation and flying process, producing granulated slag of 1000°C or less and a gas flow of 300-600°C, thereby achieving the granulation and cooling solidification of the molten slag; 2) After the granulated slag and gas flow exit the flow guide cover, they directly enter the cyclone separator. The separation of the slag and gas is achieved under the combined action of centrifugal force and gravity. The separated granulated slag is cooled to 700-800°C and exits from the bottom of the cyclone separator. The separated gas stream passes through the cyclone separator and the overflow pipeline, and its temperature is reduced to 150-300°C after heat exchange with the pipeline cooling water in the spiral heat exchange pipeline in the overflow pipeline; after the gas stream leaves the cyclone separator and the overflow pipeline, it enters the waste heat recovery device and undergoes contact heat exchange with the heat exchange pipeline carrying the cooling water in the waste heat recovery device to further recover waste heat, forming exhaust gas with a temperature of 130-150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam with a pressure of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag; The cooling water in the spiral heat exchange pipeline absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam with a pressure of 1.2-1.6 MPa and a temperature of 188-201°C, which enters the superheated steam generator and is further heated to obtain superheated steam with a pressure of 1.2-1.6 MPa and a temperature of 250-350°C; 3) The granulated slag leaving the bottom of the cyclone separator enters the rotating bed, where it exchanges heat with the heat exchange pipeline carrying cooling water, cools down to 150-300°C, and then discharges into the slag bin for storage; The cooling water in the heat exchange pipeline of the rotating bed absorbs heat and vaporizes, then undergoes steam-water separation to generate saturated steam with a pressure of 1.2-1.6 MPa and a temperature of 188-201°C, which enters the superheated steam generator and is further heated to obtain superheated steam with a pressure of 1.2-1.6 MPa and a temperature of 250-350°C; 4) The granulated slag in the slag bin is transported to a gas jet mill, where it is impinged and pulverized into ultra-fine powder using superheated steam obtained in steps 2) and 3); The pressure of the superheated steam is reduced to atmospheric pressure, and the temperature is reduced to 150-250°C, and then the steam is transported to a waste heat recovery device, where it is further heat exchanged with a heat exchange pipeline carrying cooling water in the waste heat recovery device to further recover waste heat, and form an exhaust gas with a temperature of 130-150°C; The cooling water in the heat exchange pipeline of the waste heat recovery device absorbs heat and vaporizes, then undergoes steam-water separation to obtain saturated steam with a pressure of 0.4-0.5 MPa, which is then returned to the granulator as a fluid for granulating the molten slag.

4. 4. The method according to claim 2 or 3, wherein the exhaust gas is discharged after being dedusted and desulfurized by a purification device.

5. 4. The method according to claim 2 or 3, wherein in step (1), the mist fluid is one or more selected from compressed air at a pressure of 0.5 to 0.8 MPa, water mist at a pressure of 0.4 to 0.5 MPa, steam at a pressure of 0.4 to 0.8 MPa, and mixtures thereof.

6. 4. The method according to claim 2 or 3, wherein in step (1), the granulated molten droplets have a solidification rate of 80% or more for granules having a particle size of 2 mm or less after cooling and solidification.

7. 4. The method according to claim 2 or 3, wherein in step (3), the saturated steam is further heated in a superheated steam generator using natural gas or mixed coal gas generated during the steelmaking process.

8. In step (3), the granulated slag entering the slag bin is transported to a slag powder production line and granulated to a specific surface area of ​​420-440 m 2 4. The method according to claim 2 or 3, wherein the slag is directly ground into slag powder of 0.1 / kg.

9. In step (4), the ultrafine powder is 450 to 750 m 2 4. The method according to claim 2 or 3, wherein the specific surface area is 0.15 to 0.15 mm / kg.

10. 11. The method of claim 1, wherein the granulation is carried out using a molten slag granulation device equipped with a high-speed steam nozzle, wherein the water entering the pipeline is pressurized by a water pump and then enters a heat exchanger, and the heat from the waste heat recovery pipeline increases the temperature of the water in the heat exchanger, so that the water is at a higher pressure than atmospheric pressure and a higher temperature than its boiling point at normal pressure. After the water is ejected from the nozzle, it instantly vaporizes at normal pressure, forming a high-speed jet containing steam that collides with the molten slag flowing out of the slag chute; the high-speed jet cools the molten slag and breaks it into small granules, which fall to the bottom of the molten slag granulator body; and the mixed jet ejected from the nozzle completely becomes steam after colliding with the molten slag, and the steam flows out from the top of the device as a waste heat resource for further use.

11. 11. The method according to claim 10, wherein the water entering the pipeline is pressurized by a water pump, and the pressure in the pipeline is increased to 0.1-1 MPa, and the heat from the waste heat recovery pipeline increases the temperature of the water in the heat exchanger to 100-182°C.

12. 2. The method according to claim 1, wherein the granulation is carried out by a horizontal molten slag granulation process using gas-water mixing, and a high-speed gas flow supplied by an air nozzle array component consisting of gas nozzles is used to break down the falling molten slag into molten slag granules; and at the same time, the molten slag granules are rapidly cooled by being sprayed with water mist by a gas-liquid two-fluid nozzle arranged in a row, and an auxiliary pressing force is applied to the molten slag granules to ensure that they accurately enter the rear slag granule recovery section.

13. 13. The method of claim 12, wherein the high velocity gas stream has a velocity of 90 to 110 m / sec.

14. A granulation mechanism for granulating the molten slag to obtain slag granules; and Cooling mechanism for cooling molten slag granules to obtain granulated slag A molten slag granulation device comprising:

15. The flow guide cover has a cylindrical structure; preferably, the cross section of the flow guide cover is rectangular with an aspect ratio of 2:1 to 5:1; more preferably, an online metering device is installed at the inlet end of the flow guide cover; a granulator having an outlet end connected to the inlet end of the flow guide cover; a cyclone separator, comprising a material inlet at its side wall and a material outlet at its bottom, wherein the material inlet is connected to the outlet end of the flow guide cover; an overflow pipeline with a lower part inserted vertically into the cyclone separator and a spiral heat exchange pipeline therein; a first steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet; wherein the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a spiral heat exchange pipeline in an overflow pipeline via the pipeline and a water pump, and the steam inlet is connected to an outlet end of the spiral heat exchange pipeline in the overflow pipeline; a waste heat recovery device having a gas inlet and a gas outlet on its shell and a heat exchange pipeline therein, the gas inlet being connected to the outlet end of the overflow pipeline; a second steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet and a steam outlet; wherein the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline in the waste heat recovery device via a pipeline and a water pump, the steam inlet is connected to an outlet end of the heat exchange pipeline in the waste heat recovery device via a pipeline, and the steam outlet is connected to the inlet end of the granulator via a pipeline; a rotating bed having a cylindrical structure and a heat exchange pipeline therein, wherein the inlet end of the rotating bed is connected to the material outlet of the cyclone separator, the outlet end of the rotating bed is connected to the slag bin, and a driving device for rotating the rotating bed is disposed on the rotating bed; a third steam-water separator having a cooling water inlet, a cooling water outlet, a steam inlet, and a steam outlet; wherein the cooling water inlet is connected to a cooling water pipeline, the cooling water outlet is connected to an inlet end of a heat exchange pipeline of the rotating bed via the pipeline and a water pump, and the steam inlet is connected to an outlet end of the heat exchange pipeline of the rotating bed; a gas jet mill having a supply pipe, a gas inlet pipe, and a gas outlet pipe on its shell, wherein the supply pipe is connected to a slag bin, and the gas outlet pipe is connected to a gas inlet of a waste heat recovery device; a superheated steam generator having a gas inlet pipe and a gas outlet pipe on its shell, wherein the gas inlet pipe is connected to the steam outlet of the first steam-water separator and the steam outlet of the third steam-water separator, and the gas outlet pipe is connected to the gas inlet pipe of the gas jet mill; 15. The apparatus of claim 14, comprising:

16. 16. The apparatus of claim 15, further comprising a vibrator disposed on the slag bin.

17. 15. The apparatus of claim 14, which is a molten slag granulation apparatus using a high-speed steam nozzle, comprising: a molten slag granulator body having a box-shaped structure and provided with a slag chute for introducing molten slag into one side of the upper part thereof and a steam outlet passage at the upper end thereof; a steam spray mechanism including a first control valve, a water pump, a second control valve, a pressure gauge, a heat exchanger, a thermometer, and a nozzle arranged in sequence along the pipeline; wherein the inlet end of the pipeline is connected to a water source; the nozzle is arranged on a side wall of the molten slag granulator body on which the slag chute is arranged, and the axial direction of the nozzle is angled with the axial direction of the slag chute, and the outlet of the nozzle is directed toward the molten slag flowing out of the slag chute; and a waste heat recovery pipeline and a heat exchange fluid outlet pipeline disposed in the heat exchanger; wherein a valve is installed in the waste heat recovery pipeline;

18. 18. The apparatus of claim 17, wherein the axial direction of the nozzle forms an angle of 30 to 60 degrees with respect to the axial direction of the slag chute.

19. 18. The apparatus of claim 17, wherein the first control valve is an electrohydraulic gate valve.

20. 15. The apparatus of claim 14, which is an apparatus for a horizontal molten slag granulation process with gas-water mixing, comprising: a box-shaped molten slag granulator body having a slag inlet at its upper end; High-velocity air jet mechanism including: a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and an air nozzle array component connected to one end of the gas transmission pipeline; wherein a first control valve and a flow meter are sequentially disposed on the gas transmission pipeline at the outlet end of the gas storage tank; wherein the pressure gauge, the gas inlet pipeline, and the gas inlet valve are disposed in the gas storage tank; and Wherein the air nozzle array part includes a plurality of gas flow nozzles and corresponding branch pipelines, and the branch pipelines are connected to the gas inlet pipeline; the gas flow nozzles are arranged at the upper part of one side wall of the molten slag granulator body; A spraying mechanism including: a second control valve, a water pump, a third control valve, a pressure gauge, a flow meter, and a plurality of gas-liquid two-fluid nozzles arranged in sequence along the water transport pipeline; wherein the inlet end of the water transport pipeline is connected to a water source; the gas-liquid two-fluid nozzles are arranged at the top and bottom inside the molten slag granulator body, and the gas-liquid two-fluid nozzles are connected to the gas transport pipeline and the water transport pipeline via connecting pipelines.

21. 21. The apparatus of claim 20, wherein an angle of 0 to 20 degrees is formed between the axial direction of the air nozzle array component and the horizontal direction.

22. 22. The apparatus of claim 20 or 21, wherein the air nozzle array component has a width greater than the width of the slug inlet.

23. 21. The apparatus of claim 20, wherein the second control valve is an electrohydraulic gate valve.

24. 21. The apparatus according to claim 20, wherein the molten slag granulator body is semi-closed, and the slag granule recovery section is located at the rear of the molten slag granulator body.

25. 21. The apparatus of claim 20, wherein the gas flow nozzle is a supersonic nozzle.

26. 15. The apparatus of claim 14, which is a molten slag granulation apparatus using a gas nozzle array, comprising: a molten slag granulator body having a box-shaped structure and provided at its upper end with a slag inlet and a steam outlet passage; High-velocity air jet mechanism including: a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and a nozzle array connected to one end of the gas transmission pipeline; wherein a first control valve and a flow meter are sequentially disposed in the gas transmission pipeline at the outlet end of the gas storage tank; and a pressure meter, a gas inlet pipe, and a gas inlet valve are disposed in the gas storage tank; Here, the nozzle array includes a plurality of nozzles and corresponding branch pipelines, each branch pipeline is respectively connected to a gas transport pipeline; and the nozzles are arranged on one side wall of the molten slag granulator body.

27. 27. The apparatus of claim 26, further comprising: A nozzle atomization mechanism including a second control valve, a water pump, a third control valve, a pressure gauge, a flow meter, and a plurality of atomization nozzles arranged in sequence along the water transport pipeline; the inlet end of the water transport pipeline is connected to a water source; the atomization nozzles are arranged at the inner bottom of the molten slag granulator body and are arranged in at least two rows, with the water mist sprayed in the direction toward the molten slag flowing in from the slag inlet.

28. a heat exchange box having a supply port connected to the discharge port of the molten slag granulator body, located at the top of one of its side walls, and a heat exchange gas outlet at its upper end, and having a plurality of perforated floor plates along its height inside and a molten slag granule outlet at its bottom; a gas nozzle array disposed at the inner bottom of the heat exchange box and below the perforated floor plate, the gas nozzles facing the perforated floor plate; Contains, or Adopting cyclone separator, 28. The apparatus of claim 26 or 27, further comprising a waste heat recovery system.

29. 29. The apparatus of claim 28, wherein the perforated floor plate is arranged in a vertical zigzag pattern within the heat exchange box.

30. 30. The apparatus according to claim 29, wherein the cyclone separator comprises a separator body, and has a gas-solid medium inlet connected to the outlet of the molten slag granulator body on one side of the upper part thereof, an air outlet at the top end thereof, and a dust hopper at the bottom thereof.

31. 27. The apparatus according to claim 26, wherein the nozzle in the nozzle array is one or more selected from a supersonic nozzle, an atomizing nozzle, or a gas-liquid two-fluid nozzle; preferably, the axial direction of the nozzle in the nozzle array is perpendicular to the side wall of the molten slag granulator body.

32. 32. The apparatus of claim 26 or 31, wherein the nozzles in the nozzle array are arranged in a plurality of rows and columns or in an arc; preferably, the nozzles in adjacent rows are staggered in the vertical direction; and more preferably, the number of nozzles gradually decreases or increases along the vertical direction.

33. 27. The apparatus according to claim 26, wherein the nozzles in the nozzle array are gas-liquid two-fluid nozzles; correspondingly, the apparatus further comprises a nozzle water supply mechanism, which includes a fourth control valve, a water pump, a fifth control valve, a pressure gauge and a flow meter arranged in sequence along the water transport pipeline; the inlet end of the water transport pipeline is connected to a water source, and the outlet end is connected to the inlet end of the gas-liquid two-fluid nozzle.

34. 15. The apparatus according to claim 14, which is an apparatus capable of cleaning falling slags and granulating slags by mist, comprising: A molten slag granulator body having a box-shaped structure and provided with a slag inlet at its upper end and a slag granule recovery section at its rear; a gas nozzle array disposed on one side wall of the molten slag granulator body; The atomizing nozzle array at the bottom of the molten slag granulator body, the direction of gas mist ejection is directed toward the molten slag flowing in from the slag inlet; A falling slag cleaning nozzle is arranged at the inner bottom of the molten slag granulator body, and the outlet of the falling slag cleaning nozzle faces the inner bottom of the molten slag granulator body and the slag granule recovery section.

35. 35. The apparatus of claim 34, wherein the axial direction of the gas nozzle array is perpendicular to one side wall of the molten slag granulator body.

36. 36. The apparatus of claim 34 or 35, wherein baffles are arranged on both sides of the outlet of the gas nozzle array, and liquid / atomizing nozzles are installed on the outside of each baffle.

37. 35. The apparatus of claim 34, wherein the falling slag cleaning nozzle is one or more selected from a water atomizing nozzle, a steam atomizing nozzle, a high velocity gas flow nozzle, or a gas-liquid two-fluid nozzle.

38. 35. The apparatus of claim 34, further comprising: a high-velocity air jet mechanism including a compressor, a gas storage tank, a gas transmission pipeline connected to the gas storage tank, and a gas nozzle array connected to one end of the gas transmission pipeline; wherein a first control valve and a flow meter are sequentially arranged in the gas transmission pipeline at the outlet end of the gas storage tank, and a pressure meter, a gas inlet pipeline, and a gas inlet valve are arranged in the gas storage tank; the nozzle array includes a plurality of nozzles and corresponding branch pipelines, the branch pipelines are connected to the gas transmission pipeline, and the falling slag cleaning nozzle is connected to the gas transmission pipeline via a connecting pipeline and a valve; a nozzle atomization mechanism including a second control valve, a water pump, a third control valve, a pressure gauge and a flow meter arranged in sequence along the water transport pipeline, wherein an inlet end of the water transport pipeline is connected to a water source, and an outlet end of the water transport pipeline is connected to the atomization nozzle array;

39. 39. The apparatus according to claim 34 or 38, wherein the nozzles in the atomizing nozzle array are gas-liquid two-fluid nozzles, and the inlet ends of the gas-liquid two-fluid nozzles are connected to the gas transport pipeline and the water transport pipeline, respectively.

40. 39. The apparatus of claim 34, 35 or 38, wherein the at least two slag inlets are located at the upper end of the molten slag granulator body.

41. 15. The apparatus of claim 14, which is an apparatus for rapidly cooling molten slag using an atomizing nozzle, comprising: a box-shaped molten slag granulator body having a slag inlet at its upper end; a gas nozzle array arranged on one side wall of the molten slag granulator body, wherein the axial direction of the gas nozzles in the gas nozzle array is perpendicular to the one side wall of the molten slag granulator body; a flow field optimization nozzle array arranged near the slag inlet at the top of the inside of the molten slag granulator body; slag cleaning nozzle array arranged at the inner lower part or bottom of the molten slag granulator body; An atomizing nozzle array arranged radially within the molten slag granulator body and around the slug flow on the inner wall of the molten slag granulator body, wherein the axial direction of the atomizing nozzles in the atomizing nozzle array is perpendicular to the axial direction of the gas nozzle.

42. The apparatus according to claim 41, wherein the slag granule recovery section is located at the rear of the molten slag granulator body.

43. 42. The apparatus of claim 41, wherein the nozzles of the flow field optimized nozzle array are gas nozzles or gas-liquid two-fluid nozzles.

44. 42. The apparatus of claim 41, wherein the nozzles of the slag cleaning nozzle array are gas nozzles.

45. 42. The apparatus of claim 41, wherein the nozzles of the atomizing nozzle array are water atomizing nozzles.

46. 15. The apparatus according to claim 14, which is a water mist granulation apparatus for molten slag granulation, comprising: Racks are frame structures; Water nozzle array components including: a main body having a box-like structure and disposed at the center of the rack; a flow rate adjusting plate and a flow guide plate disposed at intervals therein; a rear end of the main body connected to a water source; An array of water nozzles evenly distributed on the front of the body; Gas-liquid two-fluid nozzle components, including: gas-liquid two-fluid nozzles arranged in parallel on both sides of the water nozzle array and fixed to a rack; The gas pipeline and the water transport pipeline are both fixed to the rack and connected to the gas-liquid two-fluid nozzle.

47. 47. The apparatus of claim 46, wherein the gas-liquid two-fluid nozzles are arranged parallel to each other on either side of the water nozzle array.

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