A high-quality and multi-effect utilization system and method for molten steel slag

Abstract

The present invention discloses a high-quality multi-effect utilization system for molten steel slag, which includes a steel slag conditioning and modification device, a steel slag granulation device, a waste heat recovery device, and a gradient pore type supercritical mineralization chamber. The steel slag conditioning and modification device is used to mix molten steel slag and liquid blast furnace slag in proportion to form a molten mixed slag. The steel slag granulation device granulates and cools the mixed slag to form solidified or semi-molten slag particles. The waste heat recovery device cools the solidified or semi-molten slag particles, and then separates and recovers the cooled solid particles and high-temperature gas flow. In the gradient pore type supercritical mineralization chamber, supercritical CO2 gas and solid particles undergo a mineralization reaction to achieve CO2 fixation while further eliminating the possible residual free calcium oxide in the modified steel slag particles. Finally, the large particle modified carbonated steel slag discharged from the gradient pore type supercritical mineralization chamber is used as a solid heat storage material, thereby realizing the high-quality multi-effect utilization of molten steel slag.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature liquid slag treatment, and in particular to a high-quality and multi-effect utilization system and method for molten slag. Background Art

[0002] Steel slag is a high-temperature molten byproduct (>1500℃) formed during the steelmaking process. Its main chemical components are metal oxides such as CaO, SiO2, Fe2O3, A12O3, and MgO. At present, my country's steel slag treatment processes include hot pouring, hot stuffing, wind quenching, and drum methods. Existing processes such as wind quenching, hot pouring, and water quenching have problems such as waste of water resources, long treatment cycle, difficulty in eliminating free calcium oxide in steel slag, and low heat recovery efficiency, resulting in serious waste of a large amount of recoverable heat resources in steel slag.

[0003] In addition to its huge "heat" recovery value, steel slag also has excellent "carbon" utilization prospects. Energy storage technology based on renewable energy has been significantly developed. Thermal energy storage has great application prospects and the market demand for thermal energy storage materials is increasing. Steel slag has good thermal stability and thermal properties. After the modified steel slag particles are screened according to particle size, the large particles are used as solid heat storage materials, and the small particles are ground and mixed with molten salt as phase change heat storage materials. This idea can provide the market with cheap, high-performance heat storage materials.

[0004] In summary, the existing steel slag treatment process has low heat recovery efficiency, residual free calcium oxide, and limited resource utilization methods. There is no large-scale steel slag treatment process that can temper steel slag and blast furnace slag, combine mineralization carbon fixation and waste heat recovery, and then screen them as phase change heat storage materials. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a high-quality multi-effect utilization system and method for molten steel slag to solve the problems of low heat recovery efficiency, residual free calcium oxide and limited resource utilization methods in the existing steel slag treatment process.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A high-quality and multi-effect utilization system of molten steel slag, comprising:

[0008] A slag tempering and modification device, which is used to mix molten steel slag and liquid blast furnace slag in proportion to form a molten mixed slag;

[0009] A slag granulating device, which is used to granulate and cool the mixed slag to form solidified or semi-molten slag particles;

[0010] A waste heat recovery device is used to cool the solidified or semi-molten slag particles, and then separate and recover the cooled solid particles and the high-temperature airflow; the waste heat recovery device includes a rotary cooler, one end of the rotary cooler is provided with an inlet, and the other end is provided with an exhaust port for discharging the high-temperature airflow and a slag discharge port for discharging the solid particles, the exhaust port and the slag discharge port are respectively located at the top and bottom of the same end of the rotary cooler; and

[0011] A gradient hole type supercritical mineralization bin is provided with a feed port at the top, a discharge port at the bottom, an air inlet port at the bottom of one side of the gradient hole type supercritical mineralization bin for injecting supercritical CO2 into the gradient hole type supercritical mineralization bin, and an exhaust port at the top of the other side for discharging CO2 gas.

[0012] Furthermore, the steel slag tempering and modification device includes a slag feeder, an auxiliary heating unit and a uniform mixing unit. There are multiple slag feeders. Among the multiple slag feeders, a part of the slag feeders are used to hold molten steel slag, and another part of the slag feeders are used to hold liquid blast furnace slag. The uniform mixing unit is located below the liquid outlets of the multiple slag feeders. The auxiliary heating unit is arranged on the uniform mixing unit for auxiliary heating of the mixed slag formed by molten steel slag and liquid blast furnace slag held in the uniform mixing unit.

[0013] Furthermore, an insulation layer is provided on the slag feeder, a heating module is provided at the liquid outlet of the slag feeder, a weight sensor and an actuator are provided at the bottom of the slag feeder, the weight sensor transmits the weight signal in the slag feeder to the controller in real time, the controller analyzes the signal and sends an instruction to the actuator, and the actuator adjusts the inclination angle of the slag feeder according to the instruction.

[0014] Furthermore, the homogenizing unit is a homogenizer, and the auxiliary heating unit includes a plurality of microwave heating arrays, and the plurality of microwave heating arrays are evenly arranged along the length direction of the homogenizer.

[0015] Furthermore, a heat-insulating layer is provided inside the homogenizer, and a mechanical stirring mechanism is provided inside the homogenizer for stirring the mixed slag.

[0016] Furthermore, the steel slag granulating device includes a granulator, a blade-type airflow distributor and an inclined gravity slag discharge bin. A feed port is provided at the top of the inclined gravity slag discharge bin. The granulator is arranged at the inner top of the inclined gravity slag discharge bin, and the granulator is located below the feed port. The blade-type airflow distributor is distributed at the feed port and is used to blow a high-speed swirling airflow into the interior of the inclined gravity slag discharge bin from the feed port.

[0017] Furthermore, the two opposite side walls inside the inclined gravity slag discharge bin are both inwardly inclined structures and are symmetrically arranged, and an inclined gravity plate is provided at the bottom of the inclined gravity slag discharge bin, and a discharge port is provided at the lower end of the inclined gravity plate.

[0018] Furthermore, a rotatable shaft is provided inside the rotary cooler along the length direction, and each shaft is provided with a rotating paddle.

[0019] Furthermore, a first screen and a second screen are arranged in sequence from top to bottom inside the gradient hole supercritical mineralization chamber, and the aperture of the first screen is larger than the aperture of the second screen.

[0020] A method for high-quality and multi-effect utilization of molten steel slag, based on the high-quality and multi-effect utilization system of molten steel slag, the high-quality and multi-effect utilization system method of molten steel slag comprises the following steps:

[0021] (1) The slag tempering and modification device mixes molten steel slag and liquid blast furnace slag in a certain proportion to form mixed slag;

[0022] (2) transporting the mixed slag to a slag granulating device, pouring the mixed slag into the slag granulating device for granulation and cooling, and then the slag granulating device discharges solidified or semi-molten slag particles and high-temperature airflow;

[0023] (3) Pour the solidified or semi-molten slag particles and the high-temperature airflow into the inlet of the rotary cooler for cooling. The rotary cooler discharges the cooled solid particles from the slag discharge port and discharges the high-temperature airflow from the exhaust port for recycling;

[0024] (4) pouring solid particles into the feed port of the gradient hole type supercritical mineralization bin, and injecting supercritical CO2 gas into the gradient hole type supercritical mineralization bin through the gas inlet port, so that the supercritical CO2 gas and the solid particles undergo a mineralization reaction, thereby achieving CO2 fixation and further eliminating the residual free calcium oxide that may exist in the modified slag particles;

[0025] (5) The small-particle modified carbonated steel slag discharged from the gradient hole supercritical mineralization chamber is mixed with molten salt, then ground into fine powder and pressed into composite phase change heat storage particles after adding a binder. The large-particle modified carbonated steel slag discharged from the gradient hole supercritical mineralization chamber is directly used as solid heat storage particles.

[0026] Beneficial effects of the present invention: The high-quality multi-effect utilization system of molten steel slag is formed by tempering and modifying liquid steel slag and liquid blast furnace slag, crushing the liquid modified steel slag into uniform particles, cooling the molten modified steel slag particles, and then mixing the cooled solid steel slag particles with supercritical CO 2发The mineralization reaction can realize CO2 fixation and further eliminate the residual free calcium oxide that may exist in the modified steel slag particles. The discharged large-particle modified carbonated steel slag is directly used as solid heat storage particles, and the small-particle modified carbonated steel slag is ground and mixed with molten salt to form a composite phase change material, thereby realizing high-quality and multi-effect utilization of molten steel slag. Moreover, the high-temperature airflow discharged from the rotary cooler is recycled as a heat resource, which improves the heat recovery efficiency of the steel slag treatment process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0028] Figure 1 This is a flow chart of multi-effect and high-quality utilization of high-temperature liquid steel slag in the present invention;

[0029] Figure 2 It is a structural schematic diagram of the steel slag tempering and modification device in the present invention;

[0030] Figure 3 It is a structural schematic diagram of the steel slag granulating device in the present invention;

[0031] Figure 4 It is a schematic diagram of a rotary cooler in the present invention;

[0032] Figure 5 This is a schematic diagram of a gradient hole supercritical mineralization chamber in the present invention;

[0033] Reference numerals:

[0034] 10- steel slag tempering and modification device, 11- slag feeder, 12- microwave heating array, 13- homogenizer, 14- mechanical stirring mechanism;

[0035] 20- steel slag granulating device, 21- granulator, 22- blade type air flow distributor, 23- inclined gravity slag discharge bin, 24- feed inlet, 25- inclined gravity plate;

[0036] 30-waste heat recovery device, 31-rotating cooler, 32-inlet, 33-exhaust port, 34-slag discharge port, 35-rotating shaft, 36-rotating paddle;

[0037] 40- gradient hole type supercritical mineralization bin, 41- feed bin port, 42- discharge bin port, 43- air inlet bin port, 44- exhaust bin port, 45- first screen, 46- second screen. DETAILED DESCRIPTION

[0038] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0039] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions and positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred position or element must have a specific direction, be constructed and operated in a specific way, and therefore should not be understood as a limitation on the present invention.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] See also Figure 1 to Figure 2 The present invention provides a high-quality multi-effect utilization system for molten steel slag, comprising a steel slag tempering and modifying device 10, a steel slag granulating device 20, a waste heat recovery device 30 and a gradient hole type supercritical mineralization bin 40, wherein the steel slag tempering and modifying device 10 is used to mix molten steel slag and liquid blast furnace slag in proportion to form a molten mixed slag, the steel slag tempering and modifying device 10 pours the mixed slag into the steel slag granulating device 20, the steel slag granulating device 20 granulates and cools the mixed slag to form solidified or semi-molten slag particles, pours the solidified or semi-molten slag particles into the waste heat recovery device 30, and cools the solidified or semi-molten slag particles through the waste heat recovery device 30. The cooled solid particles and high-temperature airflow are separated and recovered, and the high-temperature airflow is discharged for recycling high-temperature resources, thereby improving the heat recovery efficiency of the slag treatment process; the solid particles are poured into the gradient hole supercritical mineralization bin 40, and supercritical CO2 is injected into the gradient hole supercritical mineralization bin 40 at the same time, so that the supercritical CO2 gas and the solid particles undergo a mineralization reaction, thereby achieving CO2 fixation and further eliminating the residual free calcium oxide that may exist in the modified slag particles, and finally the large-particle modified carbonated slag discharged from the gradient hole supercritical mineralization bin 40 is used as a solid heat storage material, thereby achieving high-quality and multi-effect utilization of the molten slag.

[0042] Specifically, the slag tempering and modification device 10 includes a slag feeder 11, an auxiliary heating unit and a uniform mixing unit. The slag feeder 11 is provided with a plurality of slag feeders 11. The uniform mixing unit is located below the liquid outlets of the plurality of slag feeders 11. The auxiliary heating unit is arranged on the uniform mixing unit to perform auxiliary heating on the mixed slag formed by the molten slag and the liquid blast furnace slag contained in the uniform mixing unit. Among the plurality of slag feeders 11, according to the mixing ratio of the molten slag and the liquid blast furnace slag, a part of the slag feeders 11 are used to hold the molten slag, and another part of the slag feeders 11 are used to hold the liquid blast furnace slag.

[0043] Among them, the slag feeder 11 is provided with a heat preservation layer, and the liquid outlet of the slag feeder 11 is provided with a heating module to prevent the viscosity from increasing due to the heat dissipation of the slag, which leads to poor slag discharge. A weight sensor and an actuator are provided at the bottom of the slag feeder 11. The weight sensor transmits the weight signal in the slag feeder to the controller in real time. The controller analyzes the signal and sends an instruction to the actuator. The actuator adjusts the inclination angle of the slag feeder 11 according to the instruction, so as to obtain a stable mixed slag flow rate. The heating module, the weight sensor, the actuator and the controller are connected by electrical signals.

[0044] The homogenizing unit is a homogenizer 13, and the auxiliary heating unit includes a plurality of microwave heating arrays 12, which are evenly arranged along the length direction of the homogenizer 13. A heat preservation layer is provided inside the homogenizer 13 to reduce the heat loss inside the homogenizer 13, so that the inside of the homogenizer 13 is in a high temperature state, and a mechanical stirring mechanism 14 is provided inside the homogenizer 13 to stir the molten mixed slag; when the plurality of microwave heating arrays 12 heat the mixed slag inside the homogenizer 13, the mixed slag is stirred by the mechanical stirrer, so as to accelerate the temperature transfer between the mixed slags to achieve homogenization and uniform temperature, and avoid the mixed slag from solidifying into a solid state due to the uniform temperature being too low inside the mixed slag.

[0045] In addition, a plurality of temperature sensors are provided inside the homogenizer 13, and the temperature sensors are connected to the auxiliary heating unit through electrical signals. The temperature of the mixed slag inside the homogenizer 13 is sensed by the temperature sensor to provide real-time feedback, so that the temperature sensor further transmits the temperature information to the auxiliary heating unit, and determines whether to start heating according to the set temperature on the auxiliary heating unit.

[0046] Please also read Figure 3 In this embodiment, the slag granulating device 20 includes a granulator 21, a blade-type airflow distributor 22 and an inclined gravity slag discharge bin 23. The top of the inclined gravity slag discharge bin 23 is provided with a feed port 24. The granulator 21 is arranged at the top of the inclined gravity slag discharge bin 23, and the granulator 21 is located below the feed port 24. The blade-type airflow distributor 22 is distributed at the feed port 24, and is used to blow a high-speed swirling airflow from the feed port 24 into the inclined gravity slag discharge bin 23. Among them, the granulator 21 is a centrifugal granulation device.

[0047] When in use, the high-temperature mixed slag is poured into the inclined gravity slag bin 23 from the feed port 24 through the homogenizer 13, so that the high-temperature mixed slag falls onto the granulator 21. The high-temperature mixed slag is granulated and broken into particles by the centrifugal force generated by the rotation of the granulator 21, and flies out along the edge of the granulator 21; at the same time, the blade-type airflow distributor 22 blows a high-speed swirling airflow (air or flue gas) from the feed port 24 of the inclined gravity slag bin 23. The airflow acts on the slag particles near the granulator 21, cools the slag particles and limits their radial movement distance to reduce the bin diameter; when the slag particles hit the side wall inside the inclined gravity slag bin 23, they fall onto the bottom wall inside the inclined gravity slag bin 23.

[0048] Preferably, the two opposite side walls inside the inclined gravity slag discharge bin 23 are both inward-inclined structures and are symmetrically arranged, and an inclined gravity plate 25 is provided at the bottom inside the inclined gravity slag discharge bin 23, and a discharge port is provided at the lower end of the inclined gravity plate 25. Since the side walls inside the inclined gravity slag discharge bin 23 are inward-inclined structures, it is convenient to prevent the slag particles from sticking to the wall after hitting the wall, and the inclined structure of the bottom wall inside the inclined gravity slag discharge bin 23 facilitates the solidified or semi-molten particles to flow into the discharge port by gravity, thereby achieving smooth slag discharge; at the same time, the high-temperature airflow will also be discharged at the same time.

[0049] Please also read Figure 4 In this embodiment, the waste heat recovery device 30 includes a rotary cooler 31, one end of which is provided with an inlet 32, and the other end of which is provided with an exhaust port 33 for discharging high-temperature airflow and a slag discharge port 34 for discharging solid particles. The exhaust port 33 and the slag discharge port 34 are respectively located at the top and bottom of the same end of the rotary cooler 31. Among them, a rotatable shaft 35 is provided inside the rotary cooler 31 along the length direction, and each shaft 35 is provided with a rotating paddle 36. The setting of the rotating paddle 36 facilitates the movement of solidified or semi-molten particles inside the rotary cooler 31, and at the same time, the solidified or semi-molten particles are temporarily separated for cooling.

[0050] When the solidified or semi-molten particles discharged from the inclined gravity slag bin 23 enter from the inlet 32 ​​of the rotary cooler 31, the high-temperature airflow also enters the interior of the rotary cooler 31 at the same time, and the rotary paddle 36 is started to rotate, pushing the solidified or semi-molten particles to move slowly from the inlet 32 ​​of the rotary cooler 31 to the outlet direction to achieve further cooling; finally, the high-temperature airflow is discharged from the exhaust port 33 of the rotary cooler 31 to be recycled as a heat resource, and the cooled solid slag particles are discharged from the slag discharge port 34 of the bottom rotary cooler 31.

[0051] Please also read Figure 5In this embodiment, a feed port 41 is provided at the top of the gradient hole supercritical mineralization bin 40, a discharge port 42 is provided at the bottom of the gradient hole supercritical mineralization bin 40, an air inlet port 43 is provided at the bottom of one side of the gradient hole supercritical mineralization bin 40 for injecting supercritical CO2 into the interior of the gradient hole supercritical mineralization bin 40, and an exhaust port 44 is provided at the top of the other side for discharging CO2 gas. Among them, the interior of the gradient hole supercritical mineralization bin 40 is provided with a first screen 45 and a second screen 46 spaced from top to bottom, and the aperture of the first screen 45 is larger than the aperture of the second screen 46. The arrangement of the first screen 45 and the second screen 46 facilitates the screening of steel slag particles of different particle sizes. The air inlet port 43, the exhaust port 44 and the discharge port 42 are all provided with valves.

[0052] When the cooled solid slag particles enter the gradient hole type supercritical mineralization chamber 40 from the discharge port 42 and are filled, supercritical CO2 gas is injected into the interior of the gradient hole type supercritical mineralization chamber 40 through the air inlet port 43, so that the supercritical CO2 reacts with the solid particles to fix CO2 and further eliminate the residual free calcium oxide that may exist in the modified slag particles; after a period of time, the valve on the exhaust port 44 is opened to discharge CO2, and then the valve on the discharge port 42 is opened to discharge slag particles of different particle sizes in turn; small particles of modified carbonated steel slag are discharged first, and then large particles of modified carbonated steel slag are discharged.

[0053] A high-quality and multi-effect utilization system method of molten steel slag comprises the following steps:

[0054] (1) The slag tempering and modification device 10 mixes molten steel slag and liquid blast furnace slag in a certain proportion to form mixed slag;

[0055] (2) transporting the mixed slag to the slag granulating device 20, pouring the mixed slag into the slag granulating device 20 for granulation and cooling, and then the slag granulating device 20 discharges solidified or semi-molten slag particles and high-temperature airflow;

[0056] (3) pouring the solidified or semi-molten slag particles and the high-temperature airflow into the inlet 32 ​​of the rotary cooler 31 for cooling; the rotary cooler 31 discharges the cooled solid particles from the slag discharge port 34 and discharges the high-temperature airflow from the exhaust port 33 for recycling;

[0057] (4) pouring solid particles into the feed port 41 of the gradient hole type supercritical mineralization bin 40, and injecting supercritical CO2 gas into the gradient hole type supercritical mineralization bin 40 through the gas inlet port 43, so that the supercritical CO2 gas and the solid particles undergo a mineralization reaction, thereby achieving CO2 fixation and further eliminating the residual free calcium oxide that may exist in the modified slag particles;

[0058] (5) The small-particle modified carbonated steel slag discharged from the gradient hole type supercritical mineralization chamber 40 is mixed with molten salt, then ground into fine powder and then pressed into composite phase change heat storage particles after adding a binder. The large-particle modified carbonated steel slag discharged from the gradient hole type supercritical mineralization chamber 40 is directly used as solid heat storage particles.

[0059] Working principle of the present invention:

[0060] (1) Molten steel slag and liquid blast furnace slag are poured into the homogenizer 13 from the slag feeder 11 in a certain proportion. After filling the homogenizer 13, they are transported to the steel slag granulation device 20. The temperature information is detected by the temperature sensor arranged in the homogenizer 13 and transmitted to the microwave auxiliary heating array for analysis. When the temperature requirement is met, the slag is discharged and flows into the inclined gravity slag discharge bin 23;

[0061] (2) After the high-temperature modified liquid mixed slag falls into the granulator 21, it is broken into fine slag droplets under the action of centrifugal force and then flies out radially. The blade-type airflow distributor 22 forms a high-speed airflow outside the granulator 21 to cool the slag particles and reduce their radial flight distance. The particles hit the wall of the inclined gravity slag discharge bin 23 and then fall onto the inclined gravity plate 25. They are then gathered and discharged under the action of the high-temperature airflow.

[0062] (3) The solidified or semi-molten particles after initial cooling enter the rotary cooler 31 under the action of gravity and high-temperature airflow, and slowly move under the action of the rotating paddle 36 to achieve further cooling. The cooled solid slag particles gradually move to the slag discharge port 34 for discharge, and the high-temperature airflow is discharged from the exhaust port 33 for other uses;

[0063] (4) The solid slag particles are further discharged into the gradient hole supercritical mineralization chamber 40, where they undergo a mineralization reaction with the supercritical CO2 gas in the chamber, thereby achieving CO2 fixation and further eliminating the residual free calcium oxide that may exist in the modified slag particles. After a period of reaction, CO2 is discharged, and the slag is discharged in sequence;

[0064] (5) The small particles of modified carbonated steel slag discharged in the early stage are mixed with molten salt and enter the ball mill system. After being ground into fine powder, a binder is added and pressed into composite phase change heat storage particles. The large particles of modified carbonated steel slag discharged in the later stage are directly used as solid heat storage particles.

[0065] Beneficial effects of the present invention: The high-quality multi-effect utilization system of molten steel slag is formed by tempering and modifying liquid steel slag and liquid blast furnace slag, crushing the liquid modified steel slag into uniform particles, cooling the molten modified steel slag particles, and then mixing the cooled solid steel slag particles with supercritical CO 2发The mineralization reaction realizes CO2 fixation and further eliminates the residual free calcium oxide that may exist in the modified steel slag particles. The discharged large-particle modified carbonated steel slag is directly used as solid heat storage particles, and the small-particle modified carbonated steel slag is ground and mixed with molten salt to form a composite phase change material, thereby realizing high-quality and multi-effect utilization of molten steel slag. Moreover, the high-temperature airflow discharged from the rotary cooler 31 is recycled as a heat resource, which improves the heat recovery efficiency of the steel slag treatment process.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A high-quality and multi-effect utilization system for molten steel slag, characterized in that: include: A slag tempering and modification device, which is used to mix molten steel slag and liquid blast furnace slag in proportion to form a molten mixed slag; A slag granulating device, which is used to granulate and cool the mixed slag to form solidified or semi-molten slag particles; A waste heat recovery device is used to cool the solidified or semi-molten slag particles, and then separate and recover the cooled solid particles and the high-temperature airflow; the waste heat recovery device includes a rotary cooler, one end of which is provided with an inlet, and the other end is provided with an exhaust port for discharging the high-temperature airflow and a slag discharge port for discharging the solid particles, and the exhaust port and the slag discharge port are respectively located at the top and bottom of the same end of the rotary cooler; and A gradient hole type supercritical mineralization bin is provided with a feed port on the top and a discharge port on the bottom of the gradient hole type supercritical mineralization bin. An air inlet port is provided on the bottom of one side of the gradient hole type supercritical mineralization bin for injecting supercritical CO2 into the gradient hole type supercritical mineralization bin, and an exhaust port is provided on the top of the other side for discharging CO2 gas.

2. The high-quality and multi-effect utilization system of molten steel slag according to claim 1 is characterized by: The steel slag tempering and modification device includes a slag feeder, an auxiliary heating unit and a uniform mixing unit. There are multiple slag feeders. Among the multiple slag feeders, a part of the slag feeders are used to hold molten steel slag, and another part of the slag feeders are used to hold liquid blast furnace slag. The uniform mixing unit is located below the liquid outlets of the multiple slag feeders. The auxiliary heating unit is arranged on the uniform mixing unit, and is used to auxiliary heat the mixed slag formed by the molten steel slag and the liquid blast furnace slag held in the uniform mixing unit.

3. The high-quality and multi-effect utilization system of molten steel slag according to claim 2 is characterized in that: The slag feeder is provided with an insulation layer, the liquid outlet of the slag feeder is provided with a heating module, and a weight sensor and an actuator are provided at the bottom of the slag feeder. The weight sensor transmits the weight signal in the slag feeder to the controller in real time. The controller analyzes the signal and sends an instruction to the actuator, and the actuator adjusts the inclination angle of the slag feeder according to the instruction.

4. A high-quality and multi-effect utilization system for molten steel slag according to claim 2 or 3, characterized in that: The homogenizing unit is a homogenizer, and the auxiliary heating unit includes a plurality of microwave heating arrays, which are evenly arranged along the length direction of the homogenizer.

5. The high-quality and multi-effect utilization system of molten steel slag according to claim 4 is characterized in that: A heat preservation layer is arranged inside the homogenizer, and a mechanical stirring mechanism is arranged inside the homogenizer for stirring the mixed slag.

6. The high-quality and multi-effect utilization system of molten steel slag according to claim 1 is characterized by: The steel slag granulating device comprises a granulator, a blade-type airflow distributor and an inclined gravity slag discharge bin. A feed port is provided at the top of the inclined gravity slag discharge bin. The granulator is arranged at the inner top of the inclined gravity slag discharge bin, and the granulator is located below the feed port. The blade-type airflow distributor is distributed at the feed port and is used to blow a high-speed swirling airflow into the interior of the inclined gravity slag discharge bin from the feed port.

7. The high-quality and multi-effect utilization system of molten steel slag according to claim 6 is characterized by: The opposite side walls inside the inclined gravity slag discharge bin are both inwardly inclined structures and are symmetrically arranged. The bottom of the inclined gravity slag discharge bin is provided with an inclined gravity plate, and a discharge port is provided at the lower end of the inclined gravity plate.

8. The high-quality and multi-effect utilization system of molten steel slag according to claim 1 is characterized by: A rotatable shaft is arranged inside the rotary cooler along the length direction, and each of the shafts is provided with a rotating paddle.

9. The high-quality and multi-effect utilization system of molten steel slag according to claim 1, characterized in that: The interior of the gradient hole type supercritical mineralization chamber is provided with a first screen and a second screen spaced apart from each other in sequence from top to bottom, and the aperture of the first screen is larger than the aperture of the second screen.

10. A high-quality and multi-effect utilization method of molten steel slag, characterized in that: Based on the high-quality and multi-effect utilization system of molten steel slag according to any one of claims 1 to 7, the high-quality and multi-effect utilization system method of molten steel slag comprises the following steps: (1) The slag tempering and modification device mixes molten steel slag and liquid blast furnace slag in a certain proportion to form mixed slag; (2) transporting the mixed slag to a slag granulating device, pouring the mixed slag into the slag granulating device for granulation and cooling, and then the slag granulating device discharges solidified or semi-molten slag particles and high-temperature airflow; (3) Pour the solidified or semi-molten slag particles and the high-temperature airflow into the inlet of the rotary cooler for cooling. The rotary cooler discharges the cooled solid particles from the slag discharge port and discharges the high-temperature airflow from the exhaust port for recycling; (4) pouring solid particles into the feed port of the gradient hole type supercritical mineralization bin, and injecting supercritical CO2 gas into the gradient hole type supercritical mineralization bin through the gas inlet port, so that the supercritical CO2 gas and the solid particles undergo a mineralization reaction, thereby achieving CO2 fixation and further eliminating the residual free calcium oxide that may exist in the modified slag particles; (5) The small-particle modified carbonated steel slag discharged from the gradient hole supercritical mineralization chamber is mixed with molten salt, then ground into fine powder and pressed into composite phase change heat storage particles after adding a binder. The large-particle modified carbonated steel slag discharged from the gradient hole supercritical mineralization chamber is directly used as solid heat storage particles.

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