Method for producing glass beads by utilizing metallurgical waste slag through multi-stage temperature control

Abstract

The invention relates to the field of resource utilization of glass materials and wastes, and discloses a method for producing glass beads by utilizing metallurgical waste slag through multi-stage temperature control, which comprises the following steps: S1, pretreatment of metallurgical waste slag; s2, a melting stage; s3, injection molding; s4, multi-section temperature control cooling: sequentially cooling the liquid drops subjected to injection molding; cooling the liquid drops in a primary cooling area; the liquid drops are further cooled in the secondary cooling area; the liquid drops are finally cooled in the final cooling area; s5, surface treatment of the microbeads; s6, performing grading treatment; and S7, collecting and storing. By adopting accurate melting temperature control and arranging a multi-section temperature control device, the melting process can be carried out in a relatively stable and moderate temperature range, and the phenomenon of non-uniform melting temperature in a traditional method is avoided. Therefore, not only is the energy consumption effectively reduced, but also the sufficient melting of each component in the metallurgical waste slag is ensured, so that the quality and the uniformity of the glass beads are improved.

Description

Technical Field

[0001] The invention relates to the field of glass materials and waste resource utilization, and in particular to a method for producing glass microbeads by utilizing metallurgical waste slag in a multi-stage temperature control manner. Background Art

[0002] As an important functional material, glass beads are widely used in road markings, reflective materials, industrial sandblasting and other fields. Traditional glass bead production mostly relies on natural ores as the main raw material, and glass beads are produced after high-temperature melting and molding. However, this method not only relies heavily on natural resources, resulting in large resource consumption, but also has high energy consumption during high-temperature melting. At the same time, due to the lack of precision in the melting process, the quality and performance of glass beads (such as uniformity, strength and reflectivity) are often not ideal. In addition, in the traditional production process, the particle size of glass beads is not easy to control, resulting in high product non-uniformity and difficulty in meeting the needs of different application scenarios. In recent years, with the rapid development of the metallurgical industry, a large amount of metallurgical waste slag has been produced as an industrial by-product. Metallurgical waste slag contains a large amount of glass-forming oxides (such as silicon dioxide, calcium oxide, aluminum oxide, etc.), which can theoretically be used as high-quality raw materials for the production of glass beads.

[0003] In the prior art, it is difficult to precisely control the melting temperature, which results in local over-high or over-low temperatures during the melting process. Too high a temperature not only increases energy consumption, but may also cause excessive volatilization of the glass liquid, affecting the quality of the product; while too low a temperature may cause some of the waste residue to fail to fully melt, resulting in unmelted particles in the product, affecting the uniformity and physical properties of the microspheres. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for producing glass microbeads using multi-stage temperature control of metallurgical waste slag, which solves the problem that the melting temperature is difficult to accurately control, resulting in local overly high or low temperatures during the melting process.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for producing glass microspheres using multi-stage temperature control of metallurgical waste slag, comprising the following steps:

[0006] S1. Pretreatment of metallurgical waste slag: The collected metallurgical waste slag is preliminarily treated, firstly by screening to remove large particle impurities and non-vitrified components; then the residual ferromagnetic metal in the waste slag is removed by magnetic separation, and then the metallurgical waste slag is crushed into a predetermined particle size range by crushing operation; finally, the crushed metallurgical waste slag is dried to reduce its water content to a level suitable for melting;

[0007] S2, melting stage: the treated metallurgical waste slag is sent into a melting furnace for heating until the waste slag is completely melted, and flux is added during the melting process according to the composition of the metallurgical waste slag;

[0008] S3, spray molding: the molten glass liquid is sprayed through the spraying device to form droplets, and the droplets enter a cooling stage after spraying, and the size and shape of the droplets are controlled by adjusting the spraying pressure, spraying speed, and nozzle diameter;

[0009] S4, multi-stage temperature control cooling: the droplets after injection molding are cooled in sequence:

[0010] Cooling the droplets in the preliminary cooling zone;

[0011] The droplets are further cooled in the secondary cooling zone;

[0012] The droplets are finally cooled in the final cooling zone;

[0013] S5. Microbead surface treatment: After the glass microbeads are cooled, surface treatment is performed;

[0014] S6, classification treatment: the cooled glass microbeads are subjected to particle size classification by a multi-stage screening device;

[0015] S7. Collection and storage: The classified glass beads are collected according to different particle sizes.

[0016] Preferably, in step S1, particle impurities larger than 5 mm are removed by screening;

[0017] The magnetic field strength of metallurgical waste slag after magnetic separation is 3000 to 6000 Gauss;

[0018] The particle size of the metallurgical waste slag after crushing is 0.1 mm to 0.5 mm;

[0019] The metallurgical waste slag is dried to reduce its moisture content to 0.1% to 0.3%.

[0020] Preferably, in the step S2, the temperature of the melting furnace is controlled at 1400° C. to 1600° C., and the heating is continued for 30 minutes to 60 minutes;

[0021] The flux is sodium oxide or potassium oxide, and the added amount is 2.5% to 4% of the total weight of the waste slag.

[0022] Preferably, in the step S3, the nozzle diameter of the injection device is 1 mm to 3 mm, the injection pressure is controlled at 0.8 MPa to 1.5 MPa, the injection speed is 800 m / s to 1500 m / s, and the diameter of the injection-molded droplets ranges from 100 μm to 300 μm.

[0023] Preferably, in the step S4, the temperature range of the preliminary cooling zone is 850° C. to 950° C., and the cooling time is 3 seconds to 8 seconds;

[0024] The temperature of the secondary cooling zone is controlled at 600°C to 700°C, and the cooling time is 10 seconds to 20 seconds;

[0025] The temperature of the final cooling zone is controlled at 25°C to 30°C, and the cooling time is 60 seconds to 120 seconds.

[0026] Preferably, in the step S5, the surface treatment includes acid washing or alkali washing, the acid washing solution is hydrochloric acid with a concentration of 15%, the alkali washing solution is sodium hydroxide with a concentration of 8%, and the treatment time is 10 minutes to 15 minutes.

[0027] Preferably, in the step S6, a multi-stage screening device is used, and the sieve aperture is 50 microns to 300 microns.

[0028] Preferably, in the step S7, the glass microbeads are stored in a vacuum sealed manner or in a nitrogen sealed manner, the storage temperature is 25° C. to 40° C., and the relative humidity is controlled below 50%.

[0029] The present invention provides a method for producing glass microspheres by using metallurgical waste slag in a multi-stage temperature control method. It has the following beneficial effects:

[0030] 1. The present invention adopts precise melting temperature control and sets a multi-stage temperature control device to enable the melting process to be carried out within a relatively stable and moderate temperature range, thus avoiding the phenomenon of uneven melting temperature in the traditional method. This not only effectively reduces energy consumption, but also ensures the full melting of various components in the metallurgical waste slag, thereby improving the quality and uniformity of the glass beads.

[0031] 2. The multi-stage cooling process of the present invention gradually reduces the temperature of the microbeads by regulating the temperature of different cooling sections. Compared with the traditional one-time cooling method, multi-stage cooling can effectively prevent the accumulation of temperature stress inside the microbeads, ensure that the surface and the interior are cooled at the same time, thereby improving the strength and structural stability of the microbeads, reducing the generation of cracks, and extending their service life.

[0032] 3. The present invention can effectively control the particle size of glass microbeads by optimizing the parameter control of the injection device (such as nozzle diameter, injection pressure, injection speed, etc.), and the particle size of the produced microbeads is uniform, which can be adjusted and classified according to the needs of different applications. This makes the glass microbeads produced by the present invention widely used in multiple fields such as road markings, reflective coatings, sandblasting, etc., and has higher market adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1The present invention is a flow chart of a method for producing glass microspheres by using metallurgical waste slag with multi-stage temperature control. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Please see attached Figure 1 The embodiment of the present invention provides a method for producing glass microspheres by using metallurgical waste slag with multi-stage temperature control, comprising the following steps:

[0036] S1. Pretreatment of metallurgical waste slag: The collected metallurgical waste slag is preliminarily treated, firstly by screening to remove large particle impurities and non-vitrified components; then the residual ferromagnetic metal in the waste slag is removed by magnetic separation, and then the metallurgical waste slag is crushed into a predetermined particle size range by crushing operation; finally, the crushed metallurgical waste slag is dried to reduce its water content to a level suitable for melting;

[0037] S2, melting stage: the treated metallurgical waste slag is sent into a melting furnace for heating until the waste slag is completely melted, and flux is added during the melting process according to the composition of the metallurgical waste slag;

[0038] S3, spray molding: the molten glass liquid is sprayed through the spraying device to form droplets. The droplets enter the cooling stage after spraying. The size and shape of the droplets are controlled by adjusting the spraying pressure, spraying speed and nozzle diameter;

[0039] S4, multi-stage temperature control cooling: the droplets after injection molding are cooled in sequence:

[0040] Cooling the droplets in the preliminary cooling zone;

[0041] The droplets are further cooled in the secondary cooling zone;

[0042] The droplets are finally cooled in the final cooling zone;

[0043] S5. Microbead surface treatment: After the glass microbeads are cooled, surface treatment is performed;

[0044] S6, classification treatment: the cooled glass microbeads are subjected to particle size classification by a multi-stage screening device;

[0045] S7. Collection and storage: The classified glass beads are collected according to different particle sizes.

[0046] Specifically, a method for producing glass microspheres by multi-stage temperature control technology. The entire method process includes five main steps: pretreatment of metallurgical waste slag, melting, spray molding, multi-stage temperature control cooling, surface treatment, graded collection and storage. This method ensures the uniformity, structural integrity and high performance of glass microspheres through scientific temperature control, spraying and treatment methods, while effectively utilizing industrial waste and having good environmental benefits.

[0047] In step S1, particle impurities larger than 5 mm are removed by screening;

[0048] The magnetic field strength of metallurgical waste slag after magnetic separation is 3000 to 6000 Gauss;

[0049] The particle size of the metallurgical waste slag after crushing is 0.1 mm to 0.5 mm;

[0050] The metallurgical waste slag is dried to reduce its moisture content to 0.1% to 0.3%.

[0051] Specifically, in the pretreatment stage of metallurgical waste slag, a screening device is first used to remove particle impurities larger than 5 mm. This is because large particles will affect the uniformity of the melting stage, which may lead to insufficient melting or too long melting time, and thus affect the stability of subsequent injection molding. By setting a 5 mm screen, it is ensured that the waste slag particles entering the melting furnace are within a reasonable range, which helps to improve the melting efficiency;

[0052] During the pretreatment process, the residual ferromagnetic metals in the waste slag are removed by using a magnetic separation device with a magnetic field strength of 3000 to 6000 Gauss. This step is crucial to prevent ferromagnetic impurities from affecting the physical properties of the glass beads during the melting process. These metal impurities will cause uneven crystallization in the melt, ultimately affecting the transparency and structural strength of the glass beads. Therefore, through proper magnetic separation operations, the purity of metallurgical waste slag can be guaranteed and the efficiency of subsequent steps can be improved;

[0053] In the crushing step, a ball mill or jaw crusher is used to control the particle size of the metallurgical waste slag to a range of 0.1 mm to 0.5 mm. Such a small particle size helps the waste slag to melt quickly and evenly during the melting stage, avoiding the presence of unmelted particles. At the same time, the glass melt in this particle size range has good fluidity, which is suitable for the formation of droplets in the subsequent injection molding stage, ensuring the uniform size and shape of the micro beads;

[0054] The crushed metallurgical waste slag is dried to reduce its water content to 0.1% to 0.3%. This step is very important because too high a water content may cause bursting during the melting stage, affecting the stability and uniformity of the melting process. By reducing the water content to this range, the melting process can be ensured to proceed smoothly, and the risk of bubbles during cooling can be reduced, ensuring the quality of the glass beads.

[0055] In step S2, the temperature of the melting furnace is controlled at 1400° C. to 1600° C., and the heating is continued for 30 minutes to 60 minutes;

[0056] The flux is sodium oxide or potassium oxide, and the added amount is 2.5% to 4% of the total weight of the waste slag.

[0057] Specifically, in the melting stage, the temperature used is 1400°C to 1600°C, and the heating time is 30 minutes to 60 minutes. This temperature range can ensure that all glass-forming oxides in the metallurgical waste slag are fully melted to form a uniform glass liquid. The setting of the heating time ensures the fluidity and uniformity of the molten material, avoiding the influence of the consistency of the droplets in the subsequent injection molding due to the partial incomplete melting;

[0058] The amount of flux Na2O or K2O added is 2.5% to 4% of the weight of the metallurgical waste slag. The addition of flux can effectively reduce the melting temperature and shorten the melting time, thereby reducing energy consumption. In addition, it can also improve the fluidity of the glass liquid, reduce the generation of bubbles during the melting process, make the molten material more uniform, and contribute to the stability of the subsequent injection molding process.

[0059] In step S3, the nozzle diameter of the injection device is 1 mm to 3 mm, the injection pressure is controlled at 0.8 MPa to 1.5 MPa, the injection speed is 800 m / s to 1500 m / s, and the diameter of the injection-molded droplets ranges from 100 μm to 300 μm.

[0060] Specifically, the nozzle diameter of the spraying device is 1 mm to 3 mm, the spraying pressure is 0.8 MPa to 1.5 MPa, and the spraying speed is 800 m / s to 1500 m / s. The nozzle diameter and the spraying pressure directly affect the size and spraying speed of the glass droplets. The diameter of the droplets is controlled within the range of 100 microns to 300 microns, which is conducive to the formation of uniform micro beads during the cooling stage. Appropriate spraying pressure and speed can ensure that the droplets form a regular shape during spraying, laying the foundation for subsequent cooling.

[0061] In step S4, the temperature range of the preliminary cooling zone is 850° C. to 950° C., and the cooling time is 3 seconds to 8 seconds;

[0062] The temperature of the secondary cooling zone is controlled at 600°C to 700°C, and the cooling time is 10 seconds to 20 seconds;

[0063] The temperature of the final cooling zone is controlled at 25°C to 30°C, and the cooling time is 60 seconds to 120 seconds.

[0064] Specifically, the temperature range of the initial cooling zone is 850°C to 950°C, and the cooling time is 3 seconds to 8 seconds. In this cooling zone, the surface of the droplets solidifies rapidly to form the initial form of microbeads. This temperature range can effectively prevent the droplets from sticking to each other while maintaining the initial shape of the microbeads. By rapidly cooling the surface, sufficient heat is still retained inside for stable cooling in the subsequent cooling stage;

[0065] The temperature range of the secondary cooling zone is controlled at 600°C to 700°C, and the cooling time is 10 to 20 seconds. The cooling speed of the droplets in this stage is relatively slow, which can effectively alleviate the temperature difference between the surface and the interior, and prevent the microbeads from cracking due to uneven stress. In addition, this temperature range helps to stabilize the internal structure of the droplets, ensuring that the final formed glass microbeads have good mechanical properties;

[0066] The temperature of the final cooling zone gradually drops to room temperature (25°C to 30°C) and the cooling time is 60 seconds to 120 seconds. This stage is mainly to ensure that the microbeads are fully solidified and ready for subsequent processing. By gradually lowering to room temperature, the internal stress caused by rapid temperature changes is reduced, ensuring the strength and toughness of the glass microbeads.

[0067] In step S5, the surface treatment includes pickling or alkali washing, the pickling solution is 15% hydrochloric acid, the alkali washing solution is 8% sodium hydroxide, and the treatment time is 10 minutes to 15 minutes;

[0068] Specifically, in the surface treatment step, 15% hydrochloric acid is used for acid washing or 8% sodium hydroxide is used for alkaline washing, and the treatment time is 10 to 15 minutes. This surface treatment step is mainly used to remove impurities on the surface of the microbeads, further improve their smoothness and cleanliness, and prepare for subsequent classification treatment. By controlling the concentration of the acid and alkali solution and the treatment time, the uniformity of the surface treatment can be ensured and the integrity of the microbeads can be maintained.

[0069] In step S6, the particle size screening device is used, and the sieve aperture is 50 microns to 300 microns.

[0070] Specifically, the glass beads are classified by particle size through a particle size screening device with a mesh size of 50 microns to 300 microns. Depending on the application scenario, beads with smaller particle sizes can be used for coatings or filling materials, while larger beads can be used for industrial sandblasting or road markings. The grading step ensures the consistency of the specifications of the beads under different application requirements and ensures the wide application of the product.

[0071] In step S7, the glass microbeads are stored in a vacuum-sealed or nitrogen-filled manner, the storage temperature is 25° C. to 40° C., and the relative humidity is controlled below 50%.

[0072] Specifically, the glass microspheres are stored in a vacuum seal or nitrogen-filled seal, with the storage temperature controlled at room temperature (25°C to 40°C) and relative humidity below 50%. The vacuum or gas-filled storage method can effectively prevent the microspheres from getting damp or contaminated by the outside world, ensuring that they maintain good physical properties during transportation and storage. This storage method is particularly suitable for long-term storage, ensuring the consistency of the performance of the glass microspheres in different application scenarios.

[0073] The following is an introduction in conjunction with specific embodiments:

[0074] Example 1: Production of glass microspheres using metallurgical waste slag

[0075] Step 1: Pretreatment of metallurgical waste slag

[0076] The collected metallurgical waste slag is first screened with a mesh size of 5 mm to remove impurities larger than 5 mm. The screened waste slag is then processed by a magnetic separation device with a magnetic field strength of 4000 Gauss to remove ferromagnetic metals from the metallurgical waste slag. Next, the waste slag is crushed to a particle size of 0.3 mm using a ball mill and dried with hot air at a drying temperature of 120°C and a moisture content of 0.2%.

[0077] Step 2: Melting process

[0078] The dried metallurgical slag is fed into the melting furnace, the temperature in the furnace is controlled at 1450℃, and the melting time is 45 minutes. During the melting process, 3% of the weight of the metallurgical slag Na2O flux is added to help speed up the melting process and reduce the melting temperature. During the melting period, a 10-minute degassing treatment is performed to ensure that the bubbles in the glass liquid are completely discharged.

[0079] Step 3: Injection Molding

[0080] The molten glass liquid is sprayed through a centrifugal spray device with a nozzle diameter of 2 mm, a spray pressure of 1.2 MPa, and a spray speed of 1000 m / s, forming droplets with a diameter of 200 μm.

[0081] Step 4: Multi-stage temperature controlled cooling

[0082] The droplets enter the preliminary cooling zone with a temperature of 900°C and a cooling time of 5 seconds to rapidly solidify the surface of the droplets. Then they enter the secondary cooling zone with a temperature of 650°C and a cooling time of 15 seconds to gradually reduce the internal temperature of the droplets and maintain their shape. Finally, the droplets enter the final cooling zone with a temperature reduction of 25°C and a cooling time of 90 seconds to ensure that the microbeads are completely solidified.

[0083] Step 5: Surface Preparation

[0084] The cooled glass microspheres were pickled with hydrochloric acid at a concentration of 15% for 12 minutes and then dried to remove impurities remaining on the surface and improve the smoothness of the microspheres.

[0085] Step 6: Grading and Storage

[0086] The processed glass beads pass through a particle size screening device with a mesh size of 100 to 200 microns. After screening, the glass beads of different particle sizes are stored in sealed bags and sealed with nitrogen to ensure that they will not be damp or contaminated during storage.

[0087] Example 2: Production of glass microspheres with different particle sizes

[0088] Step 1: Pretreatment of metallurgical waste slag

[0089] The metallurgical waste slag is screened to a particle size of less than 4 mm, and a magnetic separator with a magnetic field strength of 5000 Gauss is used to remove ferromagnetic metals. It is then crushed to a particle size of 0.2 mm by a jaw crusher, and the moisture content of the waste slag is reduced to 0.3% using a drying device.

[0090] Step 2: Melting process

[0091] The crushed and dried metallurgical waste slag was fed into a melting furnace, the melting furnace temperature was set at 1550°C, the melting time was 50 minutes, 3.5% by weight of K2O flux was added, and a degassing operation was performed for 8 minutes.

[0092] Step 3: Injection Molding

[0093] The glass liquid is sprayed through a centrifugal spray device with a nozzle diameter of 1.5 mm, a spray pressure of 1 MPa, and a spray speed of 1200 m / s to form droplets with a diameter of 150 μm.

[0094] Step 4: Multi-stage temperature controlled cooling

[0095] The droplets first enter the preliminary cooling zone at 900°C for 4 seconds, then enter the secondary cooling zone at 600°C for 12 seconds. Finally, the droplets enter the final cooling zone at room temperature for 75 seconds to form completely solidified glass beads.

[0096] Step 5: Surface Preparation

[0097] The glass microbeads were alkaline washed with a sodium hydroxide solution having a concentration of 10% for 15 minutes, and then cleaned and dried.

[0098] Step 6: Grading and Storage

[0099] The cooled glass beads are graded through a screening device with a mesh size of 50 to 150 microns, and the glass beads of different particle sizes are stored in vacuum sealed bags to ensure that they are not affected by contamination or moisture.

[0100] Example 3: Production of High Reflectivity Glass Beads for Road Markings

[0101] Step 1: Pretreatment of metallurgical waste slag

[0102] First, the metallurgical waste slag is screened through a 5 mm sieve and a magnetic separation device with a magnetic field strength of 6000 Gauss is used to remove metal impurities. Then the waste slag is crushed to less than 0.4 mm using a ball mill and dried. The drying temperature is controlled at 140°C and the moisture content is reduced to 0.15%.

[0103] Step 2: Melting process

[0104] The pre-treated metallurgical slag is fed into the melting furnace, the temperature is controlled at 1500℃, the melting time is 40 minutes, and 4% K2O by weight of the metallurgical slag is added as a flux to help accelerate the melting. During the melting process, degassing treatment is performed for 10 minutes to ensure that there are no bubbles in the glass liquid.

[0105] Step 3: Injection Molding

[0106] A centrifugal jet device was used with a nozzle diameter of 2.5 mm, a jet pressure of 1.3 MPa, a jet speed of 900 m / s, and a droplet diameter controlled at 250 μm.

[0107] Step 4: Multi-stage temperature controlled cooling

[0108] The droplets enter the primary cooling zone at 850 °C for 6 seconds, then enter the secondary cooling zone at 700 °C for 18 seconds, and finally enter the cooling zone at 25 °C for 100 seconds.

[0109] Step 5: Surface Preparation

[0110] The glass microbeads were pickled with hydrochloric acid at a concentration of 12% for 10 minutes and then dried with a dryer.

[0111] Step 6: Grading and Storage

[0112] The treated glass beads are graded through a sieve with a mesh size of 150 microns to 300 microns. Finally, the graded beads are stored in a nitrogen-filled sealed manner to ensure that they maintain their high reflectivity performance during storage and transportation, making them suitable for use in road markings.

[0113] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing glass microspheres using multi-stage temperature control of metallurgical waste slag, characterized in that: The following steps are involved: S1. Pretreatment of metallurgical waste slag: The collected metallurgical waste slag is preliminarily treated, firstly by screening to remove large particle impurities and non-vitrified components; then the residual ferromagnetic metal in the waste slag is removed by magnetic separation, and then the metallurgical waste slag is crushed into a predetermined particle size range by crushing operation; finally, the crushed metallurgical waste slag is dried to reduce its water content to a level suitable for melting; S2, melting stage: the treated metallurgical waste slag is sent into a melting furnace for heating until the waste slag is completely melted, and flux is added during the melting process according to the composition of the metallurgical waste slag; S3, spray molding: the molten glass liquid is sprayed through the spraying device to form droplets, and the droplets enter a cooling stage after spraying, and the size and shape of the droplets are controlled by adjusting the spraying pressure, spraying speed, and nozzle diameter; S4, multi-stage temperature control cooling: the droplets after injection molding are cooled in sequence: Cooling the droplets in the preliminary cooling zone; The droplets are further cooled in the secondary cooling zone; The droplets are finally cooled in the final cooling zone; S5. Microbead surface treatment: After the glass microbeads are cooled, surface treatment is performed; S6, classification treatment: the cooled glass microbeads are subjected to particle size classification by a multi-stage screening device; S7. Collection and storage: The classified glass beads are collected according to different particle sizes.

2. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S1, particle impurities larger than 5 mm are removed by screening; The magnetic field strength of metallurgical waste slag after magnetic separation is 3000 to 6000 Gauss; The particle size of the metallurgical waste slag after crushing is 0.1 mm to 0.5 mm; The metallurgical waste slag is dried to reduce its moisture content to 0.1% to 0.3%.

3. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S2, the temperature of the melting furnace is controlled at 1400° C. to 1600° C., and the heating is continued for 30 minutes to 60 minutes; The flux is sodium oxide or potassium oxide, and the added amount is 2.5% to 4% of the total weight of the waste slag.

4. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S3, the nozzle diameter of the injection device is 1 mm to 3 mm, the injection pressure is controlled at 0.8 MPa to 1.5 MPa, the injection speed is 800 m / s to 1500 m / s, and the diameter of the injection-molded droplets ranges from 100 μm to 300 μm.

5. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S4, the temperature range of the preliminary cooling zone is 850° C. to 950° C., and the cooling time is 3 seconds to 8 seconds; The temperature of the secondary cooling zone is controlled at 600°C to 700°C, and the cooling time is 10 seconds to 20 seconds; The temperature of the final cooling zone is controlled at 25°C to 30°C, and the cooling time is 60 seconds to 120 seconds.

6. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S5, the surface treatment includes acid washing or alkali washing, the acid washing solution is hydrochloric acid with a concentration of 15%, and the alkali washing solution is sodium hydroxide with a concentration of 8%, and the treatment time is 10 minutes to 15 minutes.

7. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S6, a multi-stage screening device is used, and the sieve aperture is 50 microns to 300 microns.

8. The method for producing glass microspheres by multi-stage temperature control of metallurgical waste slag according to claim 1, characterized in that: In the step S7, the glass microbeads are stored in a vacuum-sealed or nitrogen-filled manner, the storage temperature is 25° C. to 40° C., and the relative humidity is controlled below 50%.

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