Continuous spiral mixing, curing and crushing system and method for molten smelting slag

Abstract

The invention discloses a continuous spiral mixing, curing and crushing system and method for molten smelting slag. The system comprises a mixing crusher and a secondary crushing device, the mixing crusher comprises a stirring crushing cavity, a feeding groove and a chute are arranged at the front end of the stirring crushing cavity, the feeding groove is connected with a slag cooling bin through a feeder, the chute is connected with a buffer pool, a crushing roller is arranged in the stirring crushing cavity and comprises a main shaft, a plurality of spiral teeth are distributed around the main shaft along a spiral track, and a cushion layer is arranged on the inner wall of the stirring crushing cavity. The secondary crushing device comprises fine crushing rollers and a lining plate, the upper portion of the lining plate is connected with the discharging groove, the lower portion of the lining plate is connected with a discharging port, the fine crushing rollers and the lining plate are arranged at intervals, and fine crushing teeth are evenly distributed around the fine crushing rollers. According to the method, low-temperature cold slag is used as a cooling agent, a traditional water cooling medium is replaced, molten smelting slag is converted into high-temperature fine slag with uniform particles, and good physical conditions are created for waste heat recovery of the smelting slag.

Description

Technical Field

[0001] The present invention relates to the field of smelting slag processing, and in particular to a system and method for continuous spiral mixing, solidification and crushing of molten smelting slag. Background Art

[0002] my country is a major industrial nation with numerous high-temperature smelting enterprises in steel, nonferrous metals, and other industries. The country accounts for over 50% of global production of major metals. This massive metal production generates significant quantities of molten smelting slag, including blast furnace slag, steel slag, copper slag, and nickel slag. These smelting slags often contain significant amounts of inorganic materials and have potential for the production of building materials. Currently, smelting slags are often treated with simple water quenching, hot pouring, or slow cooling. These treated smelting slags are often sold at low prices or shipped directly, leaving room for further resource utilization.

[0003] The tapping temperature of molten smelting slag is often above 1300°C, and the calorific value of each ton of slag is often no less than 40 kilograms of standard coal, making it a very high value for thermal resource recovery. However, in existing treatment processes, the waste heat of molten smelting slag is wasted and cannot be effectively recovered, resulting in a significant waste of resources. my country produces nearly 1 billion tons of smelting slag annually, and the calorific value of the molten smelting slag produced each year is equivalent to more than 40 million tons of standard coal, equivalent to an economic output value of tens of billions of yuan. Therefore, if the full utilization of slag heat resources is achieved, it will have huge economic and environmental benefits and is of great significance.

[0004] At present, domestic metallurgical slag treatment still mainly uses water as the cooling medium. For example, processes such as steel slag hot stuffing and blast furnace slag water quenching can only produce hot water for very simple waste heat utilization, and cannot achieve real industrial application. The recovery of waste heat from molten smelting slag has not really achieved an industrial breakthrough. The main reason is that the liquid slag treatment process has difficulties in solid-liquid conversion, stable material transportation, and high equipment requirements. The existing industrial technology mainly recovers waste heat from solid granulated materials. How to achieve efficient and low-cost cooling, solidification and crushing of high-temperature molten smelting slag is the key to realizing the rest heat recovery technology. Therefore, there is an urgent need to develop new technologies and equipment to meet the needs of molten smelting slag. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a continuous spiral mixing, solidification and crushing system and method for molten smelting slag, so as to achieve efficient and low-cost cooling, solidification and crushing of high-temperature molten smelting slag.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A continuous spiral mixing, solidification and crushing system for molten smelting slag, including a mixing crusher and a secondary crushing device; the mixing crusher includes a buffer tank, a stirring and crushing chamber, a feeder, a feed trough, a cushion layer, and a crushing roller. A feed trough and a chute are arranged at the front end of the stirring and crushing chamber. The feed trough is connected to a cold slag bin through the feeder. The cold slag bin is used to store solid cold slag. The chute is connected to the buffer tank. The buffer tank is used to store molten smelting slag. A crushing roller is arranged inside the stirring and crushing chamber. The crushing roller includes a main shaft. A plurality of spiral teeth are distributed around the main shaft along a spiral trajectory. A cushion layer is arranged on the inner wall of the stirring and crushing chamber. A discharge trough is arranged at the rear end of the particle crushing chamber. The secondary crushing device includes a fine crushing roller and a liner. The upper part of the liner is connected to the discharge trough, and the lower part of the liner is connected to the discharge port. The fine crushing roller and the liner are arranged at intervals, and fine crushing teeth are evenly distributed around the fine crushing roller.

[0007] Furthermore, a water cooling channel is provided inside the main shaft.

[0008] Furthermore, a detachable tooth head is provided on the top of the spiral tooth.

[0009] Furthermore, the distance between the fine crushing roller and the liner is adjustable.

[0010] A method for continuous spiral mixing, solidification and crushing of molten smelting slag using the above system comprises the following steps: Feeding: The molten smelting slag in the buffer pool enters the crushing cavity through the chute, and at the same time, the solid cold slag in the cold slag bin enters the crushing cavity through the feeding trough under the action of the feeder. The molten smelting slag and the solid cold slag meet and mix, and form a molten slag layer on the cushion layer; Stirring and crushing: The driving system drives the crushing roller to rotate, and the crushing roller mixes the molten smelting slag and the solid cold slag in the slag layer. The molten smelting slag gradually cools and turns into a solid state, and then is crushed into high-temperature coarse slag together with the solid cold slag by the crushing roller; Rotating slag pushing: The hot coarse slag continues to move gradually toward the lower trough under the push of the spiral teeth of the crushing roller; Secondary crushing: The high-temperature coarse slag falling from the discharge chute falls into the secondary crushing chamber, and the fine crushing roller squeezes and crushes the high-temperature coarse slag to form high-temperature fine slag, which is discharged from the discharge port.

[0011] Furthermore, the temperature of the molten smelting slag in the buffer pool is 1200-1800°C; the temperature of the solid cold slag in the cold slag bin does not exceed 200°C, and the mass ratio of the solid cold slag to the molten smelting slag in the slag layer is (1-3):10.

[0012] Furthermore, the average particle size of the high-temperature coarse slag is 15 to 40 mm; the particle size of 90% by mass of the high-temperature coarse slag does not exceed 50 mm; and the temperature of the high-temperature coarse slag is 800 to 1200°C.

[0013] Furthermore, the average particle size of the high-temperature fine slag is 3 to 30 mm, and the particle size of 90% by mass of the high-temperature fine slag does not exceed 30 mm.

[0014] Beneficial effects: 1) The present invention innovatively proposes a continuous spiral mixing, solidification and crushing system and method for molten smelting slag, which uses low-temperature cold slag as a coolant to replace the traditional water-cooling medium, thereby achieving efficient and low-cost cooling, solidification and crushing of high-temperature molten smelting slag.

[0015] 2) The mixing crusher and secondary crushing device are used in sequence to transform the molten smelting slag into high-temperature fine slag with uniform particles, creating good physical conditions for recovering the waste heat from the smelting slag.

[0016] 3) This crushing method avoids the heat loss associated with the traditional water-cooling solidification process, creating conditions for efficient recovery of waste heat. The crushing system occupies a small footprint, is well sealed, requires low system investment, operates reliably, and achieves high waste heat recovery efficiency. This invention offers significant technical and market advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the main view of the continuous spiral mixing, solidification and crushing system for molten smelting slag; Figure 2 This is a side view of the continuous spiral mixing, solidification and crushing system for molten smelting slag; Figure 3 Schematic diagram of the crushing roller.

[0018] In the figure: 1-molten smelting slag, 2-buffer tank, 3-mixer crusher, 4-sealed cover, 5-chute, 6-solid cold slag, 7-cold slag bin, 8-feeder, 9-feeding trough, 10-cushion, 11-bottom plate, 12-slag layer, 13-drive system, 14-spindle, 15-spiral teeth, 16-tooth head, 17-high-temperature coarse slag, 18-discharging chute, 19-fine crushing roller, 20-fine crushing teeth, 21-liner, 22-high-temperature fine slag, 23-discharge port, 24-base. DETAILED DESCRIPTION

[0019] The present invention will be further explained below with reference to the accompanying drawings.

[0020] like Figures 1 to 3As shown, the present invention discloses a continuous spiral mixing, solidification, and crushing system for molten smelting slag, comprising a mixing and crushing machine 3 and a secondary crushing device. The mixing and crushing machine 3 includes a buffer tank 2, a mixing and crushing chamber, a feeder 8, a feed chute 9, a cushion layer 10, crushing rollers, and a secondary crushing chamber. The mixing and crushing chamber is composed of a sealed cover 4 and a bottom plate 10. The bottom plate 10 has a U-shaped cross-section and is fixed to a base 24. The sealed cover 4 is fixed to the upper end of the bottom plate 10. A feed trough 9 and a chute 5 are installed on the sealed cover 4 at the front end of the mixing and crushing chamber. The feed trough 9 is connected to the cold slag bin 7 through a feeder 8. The cold slag bin 7 is used to store solid cold slag 6. The chute 5 is connected to the buffer tank 2, which is used to store molten smelting slag 1. A crushing roller is installed inside the mixing and crushing chamber. The crushing roller includes a main shaft 14, around which a plurality of helical teeth 15 are distributed along a spiral trajectory. The end of the main shaft 14 is connected to the drive system 13. A cushion layer 10 is provided on the inner wall of the mixing and crushing chamber. A discharge chute 18 is provided on the bottom plate 10 at the rear end of the particle crushing chamber. The secondary crushing device includes a fine crushing roller 19 and a liner 21. The upper portion of the liner 21 is connected to the discharge chute 18, and the lower portion of the liner 21 is connected to the discharge port 23. The fine crushing roller 19 is spaced apart from the liner 21, and the fine crushing teeth 20 are evenly distributed around the fine crushing roller 19.

[0021] In this embodiment, the enclosed cover 4 is a steel structure cover body with a thickness of not less than 3 mm. The enclosed cover 4 is installed with refractory insulation material inside, and the thickness of the insulation material is not less than 50 mm. The bottom plate 11 is a steel structure lining plate with a thickness of not less than 80 cm. It is covered as a whole above the bottom plate 10 to form a closed mixing and crushing chamber. The main body of the buffer tank 2 is a steel structure trough with refractory insulation material installed inside. The thickness of the refractory insulation material is 100-300 mm. The chute 5 is a cylindrical steel structure trough with refractory insulation material installed inside. The thickness of the refractory insulation material is not less than 80 mm. The number of chutes 5 set under the buffer tank 2 is not less than 2. The cold slag bin 7 is a steel structure silo, and the feeder 8 is a vibrating feeder or a screw feeder, preferably a screw feeder. The feeding trough 9 is a steel structure chute. The drive system 13 utilizes a variable frequency drive, allowing for easy adjustment of the spindle 14's speed. The spindle 14 is constructed of high-temperature-resistant steel, with a diameter ranging from 300 to 1000 cm and a length ranging from 3 to 20 m. It also features an internal water-cooling channel. A removable tooth head 16 is attached to the top of the helical teeth 15 via bolts. The tooth head 16 can be replaced if it wears out during use. The helical teeth 15 and tooth head 16 are made of high-temperature, wear-resistant steel. The length of the helical teeth 15 ranges from 0.3 to 1 m, while the width of the tooth head 16 ranges from 30 to 300 cm. The cushion layer 10 is composed of solid smelting slag particles, 90% of which have a diameter no greater than 50 mm. The cushion layer 10 is at least 150 cm thick. The cushion layer 10 protects the base plate 11 by preventing direct contact between the high-temperature molten slag 1 and the base plate 11, which could cause deformation, corrosion, and other damage. This improves equipment life and reduces system operating costs. The main structures of the chute 18 and the discharge port 23 are both steel structures. Both are insulated with refractory insulation material, with a thickness of at least 50 mm. The base 24 is a steel or cement concrete structure. The liner 21 is a curved plate made of heat-resistant and wear-resistant steel, with a thickness of at least 50 mm. The fine crushing roller 19 is a single-tooth crushing roller constructed of high-temperature and wear-resistant steel. The fine crushing teeth 20 are 5 to 50 mm wide. The spacing between the fine crushing roller 19 and the liner 21 is adjustable, allowing for easy adjustment of the crushing fineness of the fine crushing roller 19.

[0022] The method for continuous spiral mixing, solidification and crushing of molten smelting slag using the above system comprises the following steps: Feeding: The molten smelting slag 1 with a temperature of 1200-800°C in the buffer tank 2 enters the crushing chamber through the chute 5. At the same time, the solid cold slag 6 with a temperature not exceeding 200°C in the cold slag bin 7 enters the crushing chamber through the feeder 9 under the action of the feeder 8. The molten smelting slag 1 and the solid cold slag 6 meet and mix, and form a slag layer 12 on the cushion layer 10. The mass ratio of the solid cold slag 6 to the molten smelting slag 1 in the slag layer 12 is (1-3):10; Stirring and crushing: The crushing roller is driven to rotate by the driving system 13, and the spiral teeth 15 and tooth heads 16 of the crushing roller mix and stir the molten smelting slag 1 and the solid cold slag 6 in the slag layer 12. When the high-temperature molten smelting slag 1 meets the low-temperature solid cold slag 6, the temperature drops, and the molten smelting slag 1 gradually cools and turns into a solid state. Then, it is crushed by the crushing roller together with the solid cold slag 6 into a high-temperature coarse slag 17 with a temperature of 800-1200°C. The average particle size of the high-temperature coarse slag 17 is 15-40mm, and 90% of the mass proportion of the high-temperature coarse slag 17 does not exceed 50mm. In this step, the speed of the main shaft 14 can be adjusted by the driving system 13, thereby adjusting the speed of the spiral teeth 15 and tooth heads 16, and then regulating the processing capacity of cooling, solidifying and crushing the molten smelting slag 1. The faster the speed of the main shaft 14, the greater the processing capacity of the molten smelting slag 1, and vice versa. Rotating slag pushing: The hot coarse slag 17 continues to move gradually towards the lower trough 18 under the push of the spiral teeth 15 of the crushing roller; Secondary crushing: The high-temperature coarse slag 17 that falls from the discharge chute 18 falls onto the liner of the secondary crushing chamber 21. The fine crushing roller 19 rotates, driving the fine crushing teeth 20 to squeeze and crush the high-temperature coarse slag 17 on the liner 21, thereby forming high-temperature fine slag 22. The average particle size of the high-temperature fine slag 22 is 3-30 mm, and 90% of the high-temperature fine slag 22 by mass has a particle size of no more than 30 mm. The high-temperature fine slag 22 is discharged from the discharge port 23 and reused. In this step, the processing capacity of the high-temperature fine slag 22 can be adjusted by adjusting the speed of the fine crushing roller 19. The faster the speed of the fine crushing roller 19, the greater the processing capacity, while the lower the processing capacity. At the same time, the crushing fineness of the fine crushing roller 19 can be adjusted by adjusting the distance between the fine crushing roller 19 and the liner 21. The smaller the distance, the smaller the particle size of the high-temperature fine slag 22, and the larger the particle size of the high-temperature fine slag 22.

[0023] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A continuous spiral mixing, solidification and crushing system for molten smelting slag, characterized by: The invention comprises a mixing crusher (3) and a secondary crushing device; the mixing crusher (3) comprises a buffer tank (2), a stirring and crushing chamber, a feeder (8), a feed trough (9), a cushion layer (10), and a crushing roller; a feed trough (9) and a chute (5) are arranged at the front end of the stirring and crushing chamber; the feed trough (9) is connected to a cold slag bin (7) through the feeder (8); the cold slag bin (7) is used to store solid cold slag (6); the chute (5) is connected to the buffer tank (2); the buffer tank (2) is used to store molten smelting slag (1); a crushing roller is arranged inside the stirring and crushing chamber; The crushing roller comprises a main shaft (14), a plurality of spiral teeth (15) are distributed along a spiral track around the main shaft (14), a cushion layer (10) is provided on the inner wall of the stirring and crushing chamber, a discharge chute (18) is provided at the rear end of the particle crushing chamber, and a secondary crushing device comprises a fine crushing roller (19) and a liner (21), the upper part of the liner (21) is connected to the discharge chute (18), and the lower part of the liner (21) is connected to the discharge port (23), the fine crushing roller (19) and the liner (21) are spaced apart, and fine crushing teeth (20) are evenly distributed around the fine crushing roller (19).

2. The continuous spiral mixing, solidification and crushing system for molten smelting slag according to claim 1, characterized in that: A water cooling channel is provided inside the main shaft (14).

3. The continuous spiral mixing, solidification and crushing system for molten smelting slag according to claim 1, characterized in that: A detachable tooth head (16) is provided on the top of the spiral tooth (15).

4. The continuous spiral mixing, solidification and crushing system for molten smelting slag according to claim 1, characterized in that: The spacing between the fine crushing roller (19) and the lining plate (21) is adjustable.

5. A method for continuous spiral mixing, solidification and crushing of molten smelting slag using the system of claim 1, characterized in that: The following steps are involved: Feeding: The molten smelting slag (1) in the buffer tank (2) enters the crushing chamber through the chute (5), and at the same time, the solid cold slag (6) in the cold slag bin (7) enters the crushing chamber through the feed trough (9) under the action of the feeder (8). The molten smelting slag (1) and the solid cold slag (6) meet and mix, and form a slag layer (12) above the cushion layer (10); Stirring and crushing: The driving system (13) drives the crushing roller to rotate, and the crushing roller mixes and stirs the molten smelting slag (1) and the solid cold slag (6) in the slag layer (12). The molten smelting slag (1) gradually cools and turns into a solid state, and then is crushed by the crushing roller together with the solid cold slag (6) into high-temperature coarse slag (17); Rotating slag pushing: The hot coarse slag (17) continues to move towards the lower trough (18) under the push of the spiral teeth (15) of the crushing roller; Secondary crushing: The high-temperature coarse slag (17) falling from the discharge chute (18) falls into the secondary crushing chamber (21), and the fine crushing roller (19) squeezes and crushes the high-temperature coarse slag (17) to form high-temperature fine slag (22), which is discharged from the discharge port (23).

6. The method for continuous spiral mixing, solidification and crushing of molten smelting slag according to claim 5, characterized in that: The temperature of the molten smelting slag (1) in the buffer pool (2) is 1200-1800°C; the temperature of the solid cold slag (6) in the cold slag bin (7) does not exceed 200°C, and the mass ratio of the solid cold slag (6) to the molten smelting slag (1) in the slag layer (12) is (1-3):

10.

7. The method for continuous spiral mixing, solidification and crushing of molten smelting slag according to claim 5, characterized in that: The average particle size of the high-temperature coarse slag (17) is 15 to 40 mm; the particle size of 90% by mass of the high-temperature coarse slag (17) does not exceed 50 mm; and the temperature of the high-temperature coarse slag (17) is 800 to 1200°C.

8. The method for continuous spiral mixing, solidification and crushing of molten smelting slag according to claim 5, characterized in that: The average particle size of the high-temperature fine slag (22) is 3 to 30 mm, and the particle size of 90% by mass of the high-temperature fine slag (22) does not exceed 30 mm.

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