A device and method for coordinating granulation of sintered dust and molten steel slag

Abstract

The present invention discloses a device for the coordinated granulation of sintering dust ash and molten steel slag, comprising a tundish, the side wall of which is connected to a combined long flow nozzle; the combined long flow nozzle is connected to a closed granulation bin, and a supersonic wind quenching nozzle is arranged below the combined long flow nozzle; a powder storage box is arranged at the upper left of the closed granulation bin, and a telescopic rotating powder spray gun is arranged at the outlet of the powder storage box; the right side of the closed granulation bin is connected to an exhaust dust removal fan, and a slag particle collection device is arranged at the lower part of the inner cavity of the closed granulation bin; an air inlet is arranged on the left side wall of the closed granulation bin, and a slag outlet is arranged at the lower part of the right side wall of the closed granulation bin. The method for using the device comprises the steps of opening the air inlet and the exhaust dust removal fan, opening the combined long flow nozzle and the supersonic wind quenching nozzle, opening the telescopic rotating powder spray gun, and discharging slag. The present invention realizes the coordinated treatment of two solid wastes, dust ash and steel slag, and improves the comprehensive economic efficiency of the waste heat recovery system. The method is simple and convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical solid waste treatment and waste heat resource utilization, and more specifically to a device and method for coordinated granulation treatment of sintering dust removal ash and molten steel slag. Background Art

[0002] Steel slag is a large solid waste in the metallurgical industry. The molten steel slag has a very high temperature (1450-1650℃), and the thermal enthalpy of steel slag is about 1670 MJ / t. It is a high-quality waste heat resource with a high recovery value. At present, the steel slag waste heat recovery technologies reported in the literature include wind quenching waste heat recovery, double inner cooling drum granulation heat energy recovery, mechanical stirring waste heat recovery, "continuous casting-continuous rolling" dry granulation and waste heat boiler slag heat energy recovery, centrifugal waste heat recovery and other processes. However, most of the above processes are only in the laboratory stage. A few semi-industrialized system devices stagnate after running for a period of time due to the low overall efficiency of the system. From the various waste heat recovery processes, it can be seen that in order to achieve waste heat recovery, the steel slag needs to be granulated first, and then a suitable heat exchange medium is used to fully exchange heat with the steel slag to achieve the purpose of steel slag waste heat recovery.

[0003] In order to realize the waste heat recovery of steel slag, the wind quenching granulation process must exchange heat in a closed granulation bin. The newly crushed slag particles need to solidify quickly during the short flight process, and the solidification ratio must be greater than 60%. Otherwise, the heat recovery of the slag particles after landing is very likely to cause surface adhesion, causing blockage in the conveying system. Although the slag has high sensible heat, its thermal conductivity is low and the convection heat exchange with air is slow. If the cooling time of the slag particles is shortened by increasing the volume of the closed granulation bin and the flow rate of the cooling medium, the comprehensive economic indicators of the waste heat recovery system will inevitably be reduced, the quality of the recovered heat will not be high (manifested by the low air temperature after heat exchange), the investment and floor space of the granulation bin will increase, and the configuration capacity of the environmental protection dust removal equipment for the exhaust outside the system will also be forced to increase.

[0004] Sintering machine head ash refers to the dust captured by the sintering flue gas through the large flue and then to the electrostatic precipitator during the sintering process. The sintering machine head electrostatic precipitator of the steel plant generally has four electric fields. From the first to the fourth electric field, the Fe content in the sintering machine head ash shows a downward trend, while the content of K, Na and Cl shows an upward trend. Its output is about 0.5~1.5kg / t of sintered ore dust removal ash. The dust removal ash at the terminal electric field has a clustered flocculent appearance, more than 95% of the particle size is less than 40 microns, the average particle size is about 20 microns, the specific surface area is greater than 600 square meters / kilogram, and it is rich in potassium and sodium compounds with a melting point of less than 800℃. Since this part of the dust removal ash is not suitable for recycling in the factory, and the pyrometallurgical and wet dechlorination and salt extraction processes developed in the market have various technical problems and cost-effectiveness limitations, the dust removal ash at the electric field at the end of the sintering machine head has always been the most difficult industrial solid waste to handle for steel companies. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a device and method for the coordinated granulation treatment of sintering dust removal ash and molten steel slag to solve the problems in the background technology.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0007] A device and method for co-granulating sintering dust and molten steel slag, comprising a tundish, the side wall of which is connected to a combined long flow nozzle arranged obliquely downward; the outlet of the combined long flow nozzle is connected to a closed granulation bin, and a supersonic wind quenching nozzle extending into the left side wall of the closed granulation bin and used for spraying air to impact the slag flow is arranged below the combined long flow nozzle; a powder storage box is arranged on the upper left of the closed granulation bin, and the inlet of the powder storage box is connected to the discharge port of a powder suction and discharge tank transport vehicle The outlet of the powder storage box is connected to a telescopic rotating powder spray gun that sprays powder toward the dispersed flying broken slag droplets; the right side of the closed granulation bin is connected to an exhaust dust removal fan, and a slag particle collecting device is provided at the lower part of the inner cavity of the closed granulation bin; the slag particle collecting device is a continuous belt conveyor that is arranged obliquely toward the slag outlet and connected with the slag outlet, and the continuous belt conveyor is connected to a motor; an air inlet is provided on the left side wall of the closed granulation bin, and a slag outlet is provided at the lower part of the right side wall of the closed granulation bin.

[0008] To further optimize the technical solution, four telescopic rotating powder spray guns are provided, three of which are located above the combined long flow nozzle, and one is located below the supersonic wind quenching nozzle, and the four telescopic rotating powder spray guns are distributed in an arc shape along the edge of the broken slag droplet ejection trajectory area.

[0009] To further optimize the technical solution, a spray gun protection sleeve is provided outside the telescopic rotating powder spray gun.

[0010] To further optimize the technical solution, the powder storage box stores the electric field dust removal ash at the end of the sintering machine head with low melting point and high specific area.

[0011] To further optimize the technical solution, two air inlets are provided.

[0012] A method for co-granulating sintering dust and molten steel slag comprises the following steps:

[0013] S1. Open the air inlet on the front wall of the closed granulation bin, and control the air volume of the closed granulation bin by frequency conversion speed regulation of the exhaust dust removal fan;

[0014] S2, opening the combined long flow nozzle and the supersonic air quenching nozzle, and the supersonic gas ejected from the supersonic air quenching nozzle impacts the slag flow of the combined long flow nozzle;

[0015] S3. Then, the telescopic rotating powder spray gun is immediately opened, and the powder is sprayed to the scattered flying broken slag droplets by adjusting the direction and position, so as to achieve the maximum combination of powder and slag particles;

[0016] S4. The slag particles whose surfaces are rapidly cooled fall into the slag particle collecting device and enter the next process through the slag particle collecting device.

[0017] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0018] The present invention provides a sintering dust ash and molten steel slag coordinated granulation treatment device and method. The device utilizes the physical characteristics of low melting point and high specific area of ​​dust ash, and uses the dust ash in the electric field at the end of the sintering machine head as the cooling medium of the molten steel slag wind quenching granulation process. When the dust contacts the high-temperature flying slag particles, it can quickly melt and bond with the slag particles, thereby greatly shortening the solidification time of the slag particles, making the bonded dust ash a heat enthalpy carrier of the steel slag, and realizing the coordinated treatment of two solid wastes, dust ash and steel slag, with stable operation and improved comprehensive economic efficiency of the waste heat recovery system. The use method of the treatment device provided by the present invention is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the device for coordinating granulation of sintered dust and molten steel slag in the present invention;

[0020] Among them: 1. Tundish, 2. Combined long flow nozzle, 3. Supersonic wind quenching nozzle, 4. Closed granulation bin, 5. Telescopic rotating powder spray gun, 6. Spray gun protection sleeve, 7. Powder storage box, 8. Exhaust dust removal fan, 9. Slag particle collection device, 10. Air inlet, 11. Slag outlet. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] A device and method for co-granulating sintered dust and molten steel slag, combined with Figure 1 As shown, it includes a tundish 1, a combined long flow nozzle 2, a supersonic wind quenching nozzle 3, a closed granulation bin 4, a telescopic rotating powder spray gun 5, a spray gun protection sleeve 6, a powder storage box 7, an exhaust dust removal fan 8, a slag particle collection device 9, and an air inlet 10.

[0023] The side wall of the tundish 1 is connected to a combined long flow nozzle 2, and the combined long flow nozzle 2 is arranged obliquely downward.

[0024] The outlet of the combined long flow nozzle 2 is connected to the closed granulation bin 4, and the outlet of the combined long flow nozzle 2 is located in the middle of the left side wall of the closed granulation bin 4 to facilitate the slag to flow out.

[0025] A supersonic air quenching nozzle 3 is arranged below the combined long flow nozzle 2. The supersonic air quenching nozzle 3 extends into the left wall of the closed granulation bin 4 and is used to spray air to impact the slag flowing from the combined long flow nozzle 2. The slag flow is instantly broken and dispersed from front to back in the closed granulation bin 4 along a parabolic direction.

[0026] A powder storage box 7 is arranged on the upper left of the closed granulation bin 4, and the powder storage box 7 stores the sintering machine end electric field dust removal ash with low melting point and high specific area. The powder is rich in potassium and sodium low melting point compounds, the particle size of less than 30 microns accounts for more than 90%, and the specific surface area is greater than 600㎡ / kg.

[0027] The inlet of the powder storage box 7 is connected to the discharge port of the powder suction tank transport vehicle, and the outlet of the powder storage box 7 is connected to the telescopic rotating powder spray gun 5 to spray powder to the dispersed flying broken slag droplets. There are four telescopic rotating powder spray guns 5, three of which are located above the combined long flow nozzle 2, and one is located below the supersonic wind quenching nozzle 3, and the four telescopic rotating powder spray guns 5 are distributed in an arc shape along the edge of the broken slag droplet ejection trajectory area. The nozzle of the spray gun rotates, and under the airflow entrainment effect formed by the front supersonic wind quenching nozzle and the rear closed granulation bin exhaust dust removal fan 8, the maximum combination of powder and slag particles is achieved.

[0028] A spray gun protection sleeve 6 is arranged outside the telescopic rotating powder spray gun 5 .

[0029] The right side of the closed granulation bin 4 is connected to an exhaust and dust removal fan 8, and a slag particle collection device 9 is provided at the lower part of the inner cavity of the closed granulation bin 4. The slag particle collection device 9 adopts an inclined continuous belt conveyor belt, the width of which is adapted to the bottom width of the closed granulation bin 4. The conveyor belt receives the slag particles that are quenched and fall from the air, and the conveyor belt is connected to the slag outlet to facilitate the discharge of the slag particles. The conveyor belt is connected to a motor for providing power, and the motor is connected to a power supply. The belt speed of the conveyor belt is adjustable to maintain the thickness of the slag particle layer on the belt surface within a certain range.

[0030] An air inlet 10 is arranged on the left wall of the closed granulation bin 4. There are two air inlets 10, one is located below the supersonic wind quenching nozzle 3, and the other is located below the second telescopic rotating powder spray gun 5 from the top.

[0031] A slag outlet 11 is provided at the lower portion of the right side wall of the closed granulation bin 4 .

[0032] The total flow rate of the powder is set in advance according to the amount of slag processed per unit time. The combined amount of powder and slag particles depends on the suction strength of the wind quenching jet formed by the supersonic wind quenching nozzle 3 in the closed granulation bin. The suction strength of the wind quenching jet is controlled by adjusting the working parameters of the three equipments: the supersonic wind quenching nozzle 3, the exhaust dust removal fan 8, and the air inlet 10 damper on the front wall of the closed granulation bin.

[0033] The present invention also provides a method for co-granulating sintering dust and molten steel slag, which is characterized by comprising the following steps:

[0034] S1. Open the air inlet 10 on the front wall of the closed granulation bin 4, and control the air intake volume of the closed granulation bin 4 by frequency conversion and speed regulation of the exhaust and dust removal fan 8.

[0035] S2, opening the combined long flow nozzle 2 and the supersonic wind quenching nozzle 3, and the supersonic gas ejected from the supersonic wind quenching nozzle 3 impacts the slag flow of the combined long flow nozzle 2.

[0036] S3. Immediately after that, the telescopic rotating powder spray gun 5 is opened, and the powder is sprayed to the dispersed and flying broken slag droplets by adjusting the direction and position, so as to achieve the maximum combination of powder and slag particles.

[0037] S4. The slag particles whose surfaces are rapidly cooled fall into the slag particle collecting device 9 and enter the next process through the slag particle collecting device 9.

[0038] In the device for coordinating granulation of sintered dust ash and molten steel slag of the present invention, the slag flow is ejected from the tundish 1 and the combined long flow nozzle 2, and the supersonic air quenching nozzle 3 ejects supersonic gas to impact the ejected slag flow, so that the slag flow is instantly broken and dispersedly flies from front to back in a closed granulation bin 4 along a parabolic direction; a telescopic rotating powder spray gun 5 installed on the wall of the closed granulation bin 4 sprays powder on the surface of the dispersed and flying broken slag droplets or slag particles, and the nozzle of the spray gun rotates, and under the airflow suction effect formed by the front supersonic air quenching nozzle and the rear closed granulation bin exhaust dust removal fan 8, the maximum combination of powder and slag particles is achieved; the slag particles whose surfaces are rapidly cooled enter the next process through the slag particle collecting device.

[0039] The method for using the above-mentioned sintering dust removal ash and molten steel slag coordinated granulation processing device specifically includes the following steps:

[0040] S1. Open the air inlet 10 on the front wall of the closed granulation bin 4, and control the air intake volume of the closed granulation bin 4 by frequency conversion and speed regulation of the exhaust and dust removal fan 8.

[0041] S2, opening the combined long flow nozzle 2 and the supersonic wind quenching nozzle 3, and the supersonic gas ejected from the supersonic wind quenching nozzle 3 impacts the slag flow of the combined long flow nozzle 2.

[0042] S3. Then, the telescopic rotating powder spray gun 5 is immediately opened, and the direction and position are adjusted according to the working parameters of the supersonic wind quenching nozzle 3, the exhaust dust removal fan 8, and the air inlet 10, so as to spray powder to the dispersed flying broken slag droplets, and realize the maximum combination of powder and slag particles under the air flow suction effect formed by the front supersonic wind quenching nozzle and the rear exhaust dust removal fan 8.

[0043] S4. The slag particles whose surfaces are rapidly cooled fall into the slag particle collecting device 9 and enter the next process through the slag particle collecting device 9.

Claims

1. A device for co-granulating sintering dust and molten steel slag, characterized in that: The invention comprises a tundish (1), wherein the side wall of the tundish (1) is connected to a combined long flow nozzle (2) arranged obliquely downward; the outlet of the combined long flow nozzle (2) is connected to a closed granulation bin (4); a supersonic wind quenching nozzle (3) is arranged below the combined long flow nozzle (2) and extends into the left side wall of the closed granulation bin (4) and is used to spray air to impact the slag flow; a powder storage box (7) is arranged at the upper left of the closed granulation bin (4); the inlet of the powder storage box (7) is connected to the discharge port of a powder suction and discharge tank transport vehicle, and the outlet of the powder storage box (7) is connected to the discharge port of a powder suction and discharge tank transport vehicle. A telescopic rotating powder spray gun (5) is connected to the dispersed flying broken slag droplets to spray powder; the right side of the closed granulation bin (4) is connected to an exhaust dust removal fan (8), and a slag particle collection device (9) is provided at the lower part of the inner cavity of the closed granulation bin (4); the slag particle collection device is a continuous belt conveyor belt inclined toward the slag outlet and connected to the slag outlet, and the continuous belt conveyor belt is connected to a motor; an air inlet (10) is provided on the left side wall of the closed granulation bin (4), and a slag outlet (11) is provided at the lower part of the right side wall of the closed granulation bin (4); The telescopic rotating powder spray guns (5) are provided with four of them, three of which are located above the combined long flow nozzle (2) and one is located below the supersonic wind quenching nozzle (3), and the four telescopic rotating powder spray guns (5) are distributed in an arc shape along the edge of the broken slag droplet spraying trajectory area; The powder storage box (7) stores low melting point and high specific area electric field dust removal ash at the end of the sintering machine head.

2. The device for co-granulating sintering dust and molten steel slag according to claim 1, characterized in that: The telescopic rotating powder spray gun (5) is provided with a spray gun protection sleeve (6) outside.

3. The device for co-granulating sintering dust and molten steel slag according to claim 1 is characterized in that: Two air inlets (10) are provided.

4. The method for using the device for co-granulating sintering dust and molten steel slag according to any one of claims 1 to 3, characterized in that: The specific steps include: S1, opening the air inlet (10) on the front wall of the closed granulation bin (4), and controlling the air inlet volume of the closed granulation bin (4) by frequency conversion and speed regulation of the exhaust and dust removal fan (8); S2, opening the combined long flow nozzle (2) and the supersonic air quenching nozzle (3), so that the supersonic gas ejected from the supersonic air quenching nozzle (3) impacts the slag flow of the combined long flow nozzle (2); S3, then immediately open the telescopic rotating powder spray gun (5), and spray powder to the dispersed and flying broken slag droplets by adjusting the direction and position, so as to achieve maximum combination of powder and slag particles; S4. The slag particles whose surfaces are rapidly cooled fall into the slag particle collecting device (9), and enter the next process through the slag particle collecting device (9).

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