Coal gangue bedrock cotton fiber and preparation method thereof

Abstract

The invention discloses coal gangue-based rock wool fiber and a preparation method thereof, belongs to the technical field of comprehensive utilization of coal gangue, and aims to effectively utilize coal gangue, reduce the production cost of rock wool fiber and guarantee the quality and performance of rock wool fiber. According to the solution, the coal gangue bedrock cotton fiber comprises the following components in parts by weight: 10 parts of coal gangue and 0.1-1 part of a conditioning agent; the preparation method of the coal gangue bedrock cotton fiber comprises the processes of raw material crushing, raw material powder pretreatment, primary melting centrifugal thread throwing, secondary melting centrifugal thread throwing, tertiary melting centrifugal thread throwing and forming and post-treatment. The coal gangue is used as a main raw material to prepare the rock wool fiber, effective utilization of the coal gangue can be realized, meanwhile, a high-quality product is provided for the rock wool fiber industry, and the method has important economic and social significance.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive utilization of coal gangue, and specifically relates to a coal gangue-based rock wool fiber and a preparation method thereof. Background Art

[0002] Coal gangue is a solid waste generated during coal mining and washing processes. According to relevant statistics, the annual output of coal gangue is huge, maintaining at hundreds of millions of tons all year round, and with the continuous development of the coal industry, the annual output of coal gangue is still in a stable growth period. For a long time, most of the coal gangue has been piled up in the open air or landfilled, which not only occupies a large amount of precious land resources, but also brings serious environmental problems.

[0003] As a high-quality thermal insulation, fireproof and sound insulation material, rock wool fiber has a wide range of applications in fields such as building, industrial equipment and pipeline insulation. Traditional rock wool fiber production mainly uses natural ores such as basalt as raw materials, and under high-temperature melting conditions, it is made into fibrous materials through processes such as centrifugation and blowing. This production mode not only consumes a large amount of non-renewable resources, but also consumes a large amount of energy during the high-temperature melting process, resulting in high production costs. At the same time, the over-exploitation of natural ores causes a series of ecological problems such as damage to mountain landforms and soil erosion, which does not conform to the concept of sustainable development.

[0004] Applying coal gangue to rock wool fiber production has opened up a new way for the resource utilization of coal gangue, effectively solving the raw material and cost problems faced by traditional rock wool fiber production. Coal gangue is rich in elements such as silicon and aluminum, which are similar to the chemical components required for rock wool fiber production. After appropriate treatment, it can completely replace part of the natural ore as the raw material for rock wool fiber production. It not only realizes the resource utilization of waste, reduces the negative impact on the environment, but also reduces the dependence on natural ores in rock wool fiber production, significantly reducing production costs. At present, there are also some methods for processing coal gangue into rock wool fiber, such as the patent documents "A Method for Producing Rock Wool Fiber Using Coal Gangue" (Publication No.: CN 112030350 A) and "A Method for Producing Nano-Inorganic Fibers from Coal Gangue" (Publication No.: CN 108218239 A), both of which disclose technical solutions for applying coal gangue to rock wool fiber production. However, in addition to coal gangue, the above two methods also use materials such as slag and silica, and at the same time have problems such as large composition fluctuations, high melting energy consumption, and unstable fiber quality. Therefore, the present invention proposes a method for preparing high-quality rock wool fiber with coal gangue as the raw material, aiming to achieve the low-cost preparation of high-quality rock wool fiber to obtain good economic and environmental benefits. Summary of the Invention

[0005] The present invention aims to provide a coal gangue-based rock wool fiber prepared from coal gangue and a preparation method thereof. This method can effectively utilize coal gangue, reduce the production cost of rock wool fiber, and at the same time ensure the quality and performance of the rock wool fiber.

[0006] The design concept of the present invention is as follows: First, the coal gangue and the conditioning agent need to be crushed into a particle size suitable for melting. If the coal gangue is directly used in the production of rock wool fiber, the sulfur, nitrogen and other volatile substances contained therein are not conducive to the production of rock wool fiber. Therefore, the crushed coal gangue powder also needs to be preheated by heating to remove the sulfur, nitrogen and other volatile substances therein, so as to reduce the harmful substances entering the molten liquid during the subsequent melting process; in addition, due to the difference in the chemical composition of coal gangue from the raw materials for the production of traditional rock wool fiber, an appropriate amount of conditioning agent also needs to be added to adjust the high-temperature melting performance of coal gangue; On this basis, the high-temperature melting process of coal gangue is the key step in the preparation of rock wool fiber. Since coal gangue contains various oxides, it will melt in different temperature ranges, and the molten liquids melted in different temperature ranges have different properties. If the same fiber-forming process is used, the quality of the fiber cannot be guaranteed to be consistent. Therefore, different fiber-forming processes need to be adopted to ensure the consistency of the quality of the obtained fibers. For this purpose, the temperature of the high-temperature furnace needs to be controlled at an appropriate temperature to ensure that the useful components in the coal gangue can be fully melted. In order to make the quality of the fibers consistent, the material is stepwise melted and centrifugally fiberized in different temperature zones here, which ensures the consistency of the fiberization of the melted material in different temperature zones and also saves energy. Specifically as follows: First, the molten liquid melted at 1150 - 1200 °C is centrifugally spun to form rock wool fiber, and the rotation speed of the centrifuge is controlled at 5000 - 6000 rpm; then the molten liquid melted at 1200 - 1250 °C is centrifugally spun to form rock wool fiber, and the rotation speed of the centrifuge is controlled at 6000 - 7000 rpm; finally, the molten liquid melted at 1350 - 1400 °C is centrifugally spun to form rock wool fiber, and the rotation speed of the centrifuge is controlled at 7000 - 8000 rpm. In order to further enhance the specific surface area of the fiber and the binding force between the fibers, a modifier and a binder can be sprayed onto the fibers synchronously during the centrifugal spinning process; Finally, the formed rock wool fiber is subjected to operations such as cotton collection, cotton laying, and cotton pressing, and then post-treatments such as shaping, curing, cutting, and packaging are carried out to obtain the final coal gangue-based rock wool fiber product.

[0007] The present invention is realized through the following technical solutions: A coal gangue-based rock wool fiber, its composition and weight parts are as follows: Coal gangue: 10 parts; Conditioning agent: 0.1 - 1 part.

[0008] Furthermore, the sum of the weights of SiO2 and A12O3 in the gangue is not less than 50% of the total weight of the gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the gangue.

[0009] Furthermore, the conditioning agent is at least two of iron slag, lime, soda ash, sodium hydroxide or potassium hydroxide.

[0010] Furthermore, the diameter of the rock wool fiber is < 3um, the thermal conductivity is < 0.035W / (m·K), and the upper limit of the service temperature is not less than 800°C.

[0011] A preparation method of the gangue-based rock wool fiber as described above, which is prepared from gangue as raw material, includes raw material crushing, raw material powder pretreatment, primary melting centrifugal spinning, secondary melting centrifugal spinning, tertiary melting centrifugal spinning, and forming and post-treatment processes, and includes the following steps: S1. Raw material crushing: Weigh the raw materials according to the composition and weight parts of the gangue-based rock wool fiber, crush them with a crusher and then pass through a 100-mesh standard sieve to obtain raw material powder. S2. Raw material powder pretreatment: Place the raw material powder in a heating furnace and heat it to 600°C - 900°C in an inert atmosphere, and keep it warm for 5min - 10min. S3. Primary melting centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace and heat it to 1150°C - 1200°C, keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the primary high-temperature melting furnace, and centrifugal spinning is used to obtain primary melting centrifugal rock wool fiber. S4. Secondary melting centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace and heat it to 1250°C - 1300°C, keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the secondary high-temperature melting furnace, and centrifugal spinning is used to obtain secondary melting centrifugal rock wool fiber. S5. Tertiary melting centrifugal spinning: Transfer the unmelted material in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat it to 1350°C - 1400°C in a CO2 gas atmosphere (to reduce the viscosity of the system), keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal spinning is used to obtain tertiary melting centrifugal rock wool fiber. S6. Shaping and Post-treatment: Perform cotton collection, cotton laying, and cotton pressing operations on the primary melted centrifugal rock wool fibers, secondary melted centrifugal rock wool fibers, and tertiary melted centrifugal rock wool fibers prepared in Step S3, Step S4, and Step S5 to obtain a preliminarily shaped rock wool fiber product; then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, perform cutting and packaging on the cured rock wool fiber product according to actual usage requirements. The coal gangue-based rock wool fibers prepared by the present invention have better performance than the national standard GB / T 25975 and stable performance, and can be widely used in multiple fields such as building insulation, heat insulation, and sound insulation.

[0012] Further, in the said Step S3, the rotational speed of the centrifuge is 5000 rpm to 6000 rpm; in the said Step S4, the rotational speed of the centrifuge is 6000 rpm to 7000 rpm; in the said Step S5, the rotational speed of the centrifuge is 7000 rpm to 8000 rpm.

[0013] Further, in the said Steps S3 - S5, during the primary, secondary, and tertiary melting and centrifugal fiber throwing processes, a modifier and a binder are sequentially sprayed onto the fibers to enhance the specific surface area of the fibers and the binding force between the fibers.

[0014] Further, the modifier is a sodium hydroxide solution with a concentration of 1M to 5M, and the binder is a modified phenolic resin.

[0015] The beneficial effects of the present invention are as follows: (1) Efficiently utilize the industrial waste - coal gangue, reduce the dependence on natural mineral raw materials in the production process of rock wool fibers, reduce environmental pollution, and achieve the recycling of resources; (2) Adopt a three-step melting and three-step fiber-forming process to ensure the consistency of the fiber quality of the materials melted in different temperature ranges, and thus ensure the quality of the final product, rock wool fibers; (3) Modify the surface of the rock wool fibers with a modifier and a binder, to a certain extent, increase the specific surface area of the rock wool fibers, and improve their heat insulation, sound insulation, and thermal insulation performance.

[0016] In summary, the present invention can effectively utilize coal gangue, and at the same time provide high-quality products for the rock wool fiber industry, which has important economic and social significance. Specific Embodiments

[0017] The following further describes the present invention in detail with reference to embodiments. Embodiment 1

[0018] A preparation method of coal gangue-based rock wool fibers includes the following steps: S1. Raw material crushing: Weigh the raw materials of gangue and conditioning agent according to the weight ratio of 100:1, crush them with a crusher and then pass through a 100-mesh standard sieve to obtain raw material powder. Among them, the sum of the weights of SiO2 and A12O3 in the gangue is not less than 50% of the total weight of the gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the gangue. The conditioning agent is a mixture of iron slag and soda ash according to the weight ratio of 1:1. S2. Pretreatment of raw material powder: Place the raw material powder in a heating furnace, heat it to 600 °C in an inert atmosphere, and keep it warm for 10 minutes. S3. Primary melting and centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace, heat it to 1200 °C, keep it warm for 10 minutes. During the heat preservation process, the melted material is discharged from the liquid discharge port of the primary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 5000 rpm to obtain primary melted centrifugal rock wool fibers. S4. Secondary melting and centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace, heat it to 1250 °C, keep it warm for 20 minutes. During the heat preservation process, the melted material is discharged from the liquid discharge port of the secondary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 7000 rpm to obtain secondary melted centrifugal rock wool fibers. S5. Tertiary melting and centrifugal spinning: Transfer the unmelted material in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat it to 1400 °C in a CO2 gas atmosphere, keep it warm for 15 minutes. During the heat preservation process, the melted material is discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 8000 rpm to obtain tertiary melted centrifugal rock wool fibers. S6. Forming and post-treatment: Carry out operations of cotton collection, cotton laying, and cotton pressing on the primary melted centrifugal rock wool fibers, secondary melted centrifugal rock wool fibers, and tertiary melted centrifugal rock wool fibers prepared in step S3, step S4, and step S5 to obtain a preliminarily formed rock wool fiber product. Then, send the preliminarily formed rock wool fiber product into a curing furnace for curing. Finally, according to the actual use requirements, carry out cutting and packaging treatment on the cured rock wool fiber product.

[0019] The diameter of the gangue-based rock wool fibers prepared in this Example 1 is 1 μm to 3 μm, the thermal conductivity is 0.028 W / (m·K), and the upper limit of the use temperature is higher than 800 °C. Example 2

[0020] A preparation method of gangue-based rock wool fibers, comprising the following steps: S1. Raw material crushing: Weigh the raw materials of gangue and conditioning agent according to the weight ratio of 50:1, crush them with a crusher and then pass through a 100-mesh standard sieve to obtain raw material powder. Among them, the sum of the weights of SiO2 and A12O3 in the gangue is not less than 50% of the total weight of the gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the gangue. The conditioning agent is a mixture of iron slag and lime according to the weight ratio of 2:1. S2. Pretreatment of raw material powder: Place the raw material powder in a heating furnace and heat it to 700°C in an inert atmosphere for a holding time of 10 min. S3. Primary melting and centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace, heat it to 1150°C, and hold for 20 min. During the holding process, the melted liquid material is discharged from the liquid discharge port of the primary high-temperature melting furnace and centrifugally spun with a centrifuge at a speed of 5000 rpm. During the primary melting and centrifugal spinning process, a modifier and a binder are sequentially sprayed onto the fibers. The modifier is a sodium hydroxide solution with a concentration of 3M, and the binder is a modified phenolic resin, to obtain primary melting and centrifugal rock wool fibers. S4. Secondary melting and centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace, heat it to 1250°C, and hold for 20 min. During the holding process, the melted liquid material is discharged from the liquid discharge port of the secondary high-temperature melting furnace and centrifugally spun with a centrifuge at a speed of 6000 rpm. During the secondary melting and centrifugal spinning process, a modifier and a binder are sequentially sprayed onto the fibers. The modifier is a sodium hydroxide solution with a concentration of 3M, and the binder is a modified phenolic resin, to obtain secondary melting and centrifugal rock wool fibers. S5. Tertiary melting and centrifugal spinning: Transfer the unmelted material in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat it to 1350°C in a CO2 gas atmosphere, and hold for 20 min. During the holding process, the melted liquid material is discharged from the liquid discharge port of the tertiary high-temperature melting furnace and centrifugally spun with a centrifuge at a speed of 7000 rpm. During the tertiary melting and centrifugal spinning process, a modifier and a binder are sequentially sprayed onto the fibers. The modifier is a sodium hydroxide solution with a concentration of 3M, and the binder is a modified phenolic resin, to obtain tertiary melting and centrifugal rock wool fibers. S6. Shaping and post-treatment: Perform cotton collection, cotton laying, and cotton pressing operations on the primary melting and centrifugal rock wool fibers, secondary melting and centrifugal rock wool fibers, and tertiary melting and centrifugal rock wool fibers prepared in step S3, step S4, and step S5 to obtain a preliminarily shaped rock wool fiber product. Then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing. Finally, perform cutting and packaging on the cured rock wool fiber product according to actual usage requirements.

[0021] The diameter of the coal gangue-based rock wool fibers prepared in this Example 2 is 1 μm to 3 μm, the thermal conductivity is 0.030 W / (m·K), and the upper limit of the service temperature is higher than 800 °C. Example 3

[0022] A preparation method of coal gangue-based rock wool fibers includes the following steps: S1. Raw material pulverization: Weigh the coal gangue and the conditioning agent according to a weight ratio of 50:1, pulverize them with a pulverizer and then pass through a 100-mesh standard sieve to obtain raw material powder. Among them, the sum of the weights of SiO2 and A12O3 in the coal gangue is not less than 50% of the total weight of the coal gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the coal gangue; the conditioning agent is a mixture of lime and soda ash according to a weight ratio of 1:3. S2. Pretreatment of raw material powder: Place the raw material powder in a heating furnace, heat it to 800 °C in an inert atmosphere, and the holding time is 8 min. S3. Primary melting and centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace, heat it to 1200 °C, and the holding time is 10 min. During the holding process, the melted material is discharged from the liquid discharge port of the primary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 5500 rpm. During the primary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 5 M, and the binder is a modified phenolic resin to obtain primary melting and centrifugal rock wool fibers. S4. Secondary melting and centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace, heat it to 1300 °C, and the holding time is 10 min. During the holding process, the melted material is discharged from the liquid discharge port of the secondary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 6500 rpm. During the secondary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 5 M, and the binder is a modified phenolic resin to obtain secondary melting and centrifugal rock wool fibers. S5. Tertiary melting and centrifugal spinning: Transfer the unmelted material in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat it to 1400 °C in a CO2 gas atmosphere, and the holding time is 10 min. During the holding process, the melted material is discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge at a speed of 7500 rpm. During the tertiary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 5 M, and the binder is a modified phenolic resin to obtain tertiary melting and centrifugal rock wool fibers. S6, Shaping and Post-treatment: Perform cotton collection, cotton laying, and cotton pressing operations on the primary melted centrifugal rock wool fibers, secondary melted centrifugal rock wool fibers, and tertiary melted centrifugal rock wool fibers prepared in steps S3, S4, and S5 to obtain a preliminarily shaped rock wool fiber product; then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, perform cutting and packaging on the cured rock wool fiber product according to actual usage requirements.

[0023] The diameter of the coal gangue-based rock wool fibers prepared in this Example 3 is 1um - 3um, the thermal conductivity is 0.032W / (m·K), and the upper limit of the service temperature is higher than 800°C. Example 4

[0024] A preparation method of coal gangue-based rock wool fibers, comprising the following steps: S1, Raw material pulverization: Weigh the raw materials of coal gangue and the conditioning agent according to a weight ratio of 30:1, pulverize them with a pulverizer and then pass through a 100-mesh standard sieve to obtain raw material powder; among them, the sum of the weights of SiO2 and A12O3 in the coal gangue is not less than 50% of the total weight of the coal gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the coal gangue; the conditioning agent is a mixture of iron slag, lime, and sodium hydroxide according to a weight ratio of 1:2:1; S2, Pretreatment of raw material powder: Place the raw material powder in a heating furnace and heat it to 900°C in an inert atmosphere, with a holding time of 5 minutes; S3, Primary melting and centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace and heat it to 1180°C, with a holding time of 15 minutes. During the holding process, the melted material is discharged from the liquid discharge port of the primary high-temperature melting furnace and centrifugally spun with a centrifuge at a speed of 5800 rpm. During the primary melting and centrifugal spinning process, a modifier and a binder are sprayed on the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 1M, and the binder is a modified phenolic resin, to obtain primary melted centrifugal rock wool fibers; S4, Secondary melting and centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace and heat it to 1280°C, with a holding time of 8 minutes. During the holding process, the melted material is discharged from the liquid discharge port of the secondary high-temperature melting furnace and centrifugally spun with a centrifuge at a speed of 6800 rpm. During the secondary melting and centrifugal spinning process, a modifier and a binder are sprayed on the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 3M, and the binder is a modified phenolic resin, to obtain secondary melted centrifugal rock wool fibers; S5. Tertiary melting and centrifugal fiber spinning: Transfer the unmelted materials in the secondary high-temperature melting furnace in step S4 to the tertiary high-temperature melting furnace, heat them to 1380 °C in a CO2 gas atmosphere, keep the temperature for 8 minutes. During the heat preservation process, the melted liquid materials are discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal fiber spinning is carried out using a centrifuge with a rotation speed of 7800 rpm. During the tertiary melting and centrifugal fiber spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 2M, and the binder is modified phenolic resin, to obtain tertiary melting and centrifugal rock wool fibers; S6. Shaping and post-treatment: Carry out cotton collection, cotton laying, and cotton pressing operations on the primary melting and centrifugal rock wool fibers, secondary melting and centrifugal rock wool fibers, and tertiary melting and centrifugal rock wool fibers prepared in step S3, step S4, and step S5 to obtain a preliminarily shaped rock wool fiber product; then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, according to actual use requirements, perform cutting and packaging on the cured rock wool fiber product.

[0025] The diameter of the coal gangue-based rock wool fibers prepared in Example 4 of this embodiment is 1 μm to 3 μm, the thermal conductivity is 0.026 W / (m·K), and the upper limit of the use temperature is higher than 800 °C. Example 5

[0026] A preparation method of coal gangue-based rock wool fibers, comprising the following steps: S1. Raw material pulverization: Weigh the coal gangue and the conditioning agent according to a weight ratio of 100:1, pulverize them using a pulverizer, and pass through a 100-mesh standard sieve to obtain raw material powder; among them, the sum of the weights of SiO2 and A12O3 in the coal gangue is not less than 50% of the total weight of the coal gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the coal gangue; the conditioning agent is a mixture of iron slag, lime, and potassium hydroxide according to a weight ratio of 1:1:2; S2. Pretreatment of raw material powder: Place the raw material powder in a heating furnace, heat it to 900 °C in an inert atmosphere, and keep the temperature for 5 minutes; S3. Primary melting and centrifugal fiber spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace, heat it to 1150 °C, keep the temperature for 15 minutes. During the heat preservation process, the melted liquid materials are discharged from the liquid discharge port of the primary high-temperature melting furnace, and centrifugal fiber spinning is carried out using a centrifuge with a rotation speed of 6000 rpm. During the primary melting and centrifugal fiber spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 1M, and the binder is modified phenolic resin, to obtain primary melting and centrifugal rock wool fibers; S4. Secondary melting and centrifugal fiber spinning: Transfer the unmelted materials in the primary high-temperature melting furnace in step S3 to the secondary high-temperature melting furnace, heat them to 1300 °C, and keep them at this temperature for 6 minutes. During the heat preservation process, the melted materials are discharged from the liquid discharge port of the secondary high-temperature melting furnace, and centrifugal fiber spinning is carried out using a centrifuge with a rotation speed of 7000 rpm. During the secondary melting and centrifugal fiber spinning process, a modifier and a binder are sequentially sprayed onto the fibers. The modifier is a sodium hydroxide solution with a concentration of 2M, and the binder is a modified phenolic resin, obtaining secondary melting and centrifugal rock wool fibers; S5. Tertiary melting and centrifugal fiber spinning: Transfer the unmelted materials in the secondary high-temperature melting furnace in step S4 to the tertiary high-temperature melting furnace, heat them to 1400 °C in a CO2 gas atmosphere, and keep them at this temperature for 6 minutes. During the heat preservation process, the melted materials are discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal fiber spinning is carried out using a centrifuge with a rotation speed of 8000 rpm. During the tertiary melting and centrifugal fiber spinning process, a modifier and a binder are sequentially sprayed onto the fibers. The modifier is a sodium hydroxide solution with a concentration of 3M, and the binder is a modified phenolic resin, obtaining tertiary melting and centrifugal rock wool fibers; S6. Shaping and post-treatment: Carry out cotton collection, cotton laying, and cotton pressing operations on the primary melting and centrifugal rock wool fibers, secondary melting and centrifugal rock wool fibers, and tertiary melting and centrifugal rock wool fibers prepared in step S3, step S4, and step S5 to obtain a preliminarily shaped rock wool fiber product; then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, according to actual usage requirements, perform cutting and packaging on the cured rock wool fiber product.

[0027] The diameter of the coal gangue-based rock wool fibers prepared in this Example 5 is 1 μm to 3 μm, the thermal conductivity is 0.033 W / (m·K), and the upper limit of the service temperature is higher than 800 °C. Example 6

[0028] A preparation method of coal gangue-based rock wool fibers includes the following steps: S1. Raw material pulverization: Weigh coal gangue and a conditioning agent according to a weight ratio of 60:1, pulverize them using a pulverizer, and then pass through a 100-mesh standard sieve to obtain raw material powder; among them, the sum of the weights of SiO2 and A12O3 in the coal gangue is not less than 50% of the total weight of the coal gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the coal gangue; the conditioning agent is a mixture of iron slag, lime, soda ash, and potassium hydroxide according to a weight ratio of 1:2:3:1; S2. Pretreatment of raw material powder: Place the raw material powder in a heating furnace, heat it to 650 °C in an inert atmosphere, and keep it at this temperature for 9 minutes; S3. Primary melting and centrifugal spinning: Transfer the powder materials pretreated in step S2 to a primary high-temperature melting furnace, heat them to 1150 °C, and keep the temperature for 20 min. During the heat preservation process, the melted liquid materials are discharged from the liquid discharge port of the primary high-temperature melting furnace, and then centrifugal spinning is carried out using a centrifuge with a rotational speed of 6000 rpm. During the primary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 5 M, and the binder is a modified phenolic resin, thus obtaining primary melting and centrifugal rock wool fibers; S4. Secondary melting and centrifugal spinning: Transfer the unmelted materials in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace, heat them to 1300 °C, and keep the temperature for 10 min. During the heat preservation process, the melted liquid materials are discharged from the liquid discharge port of the secondary high-temperature melting furnace, and then centrifugal spinning is carried out using a centrifuge with a rotational speed of 7000 rpm. During the secondary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 1 M, and the binder is a modified phenolic resin, thus obtaining secondary melting and centrifugal rock wool fibers; S5. Tertiary melting and centrifugal spinning: Transfer the unmelted materials in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat them to 1400 °C in a CO2 gas atmosphere, and keep the temperature for 10 min. During the heat preservation process, the melted liquid materials are discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and then centrifugal spinning is carried out using a centrifuge with a rotational speed of 7500 rpm. During the tertiary melting and centrifugal spinning process, a modifier and a binder are sprayed onto the fibers in sequence. The modifier is a sodium hydroxide solution with a concentration of 3 M, and the binder is a modified phenolic resin, thus obtaining tertiary melting and centrifugal rock wool fibers; S6. Shaping and post-treatment: Carry out operations of cotton collection, cotton laying, and cotton pressing on the primary melting and centrifugal rock wool fibers, secondary melting and centrifugal rock wool fibers, and tertiary melting and centrifugal rock wool fibers prepared in step S3, step S4, and step S5 to obtain a preliminarily shaped rock wool fiber product; then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, according to the actual use requirements, carry out cutting and packaging treatments on the cured rock wool fiber product.

[0029] The diameter of the coal gangue-based rock wool fibers prepared in this Example 6 is 1 um to 3 um, the thermal conductivity is 0.027 W / (m·K), and the upper limit of the use temperature is higher than 800 °C.

[0030] As mentioned above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A coal gangue-based rock wool fiber, characterized in that, The composition and weight parts of the coal gangue-based rock wool fiber are as follows: Coal gangue: 10 parts; Conditioning agent: 0.1 - 1 part.

2. The coal gangue-based rock wool fiber according to claim 1, characterized in that: The sum of the weights of SiO2 and A12O3 in the coal gangue is not less than 50% of the total weight of the coal gangue, and the sum of the weights of CaO and MgO is not less than 10% of the total weight of the coal gangue.

3. A coal gangue-based rock wool fiber according to claim 1, characterized in that: The conditioning agent is at least two of iron slag, lime, soda ash, sodium hydroxide or potassium hydroxide.

4. A coal gangue-based rock wool fiber according to claim 1, characterized in that: The diameter of the rock wool fiber < 3um, the thermal conductivity < 0.035W / (m·K), and the upper limit of the service temperature is not less than 800℃.

5. A preparation method of the coal gangue-based rock wool fiber according to any one of claims 1 to 4, characterized in that, It includes the following steps: S1. Raw material pulverization: Weigh the raw materials according to the composition and weight parts of the coal gangue-based rock wool fiber, pulverize them with a pulverizer and then pass through a 100-mesh standard sieve to obtain the raw material powder. S2. Pretreatment of the raw material powder: Place the raw material powder in a heating furnace and heat it to 600℃ - 900℃ in an inert atmosphere, and keep it warm for 5min - 10min. S3. Primary melting and centrifugal spinning: Transfer the powder pretreated in step S2 to a primary high-temperature melting furnace and heat it to 1150℃ - 1200℃, keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the primary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge to obtain the primary melted and centrifuged rock wool fiber. S4. Secondary melting and centrifugal spinning: Transfer the unmelted material in the primary high-temperature melting furnace in step S3 to a secondary high-temperature melting furnace and heat it to 1250℃ - 1300℃, keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the secondary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge to obtain the secondary melted and centrifuged rock wool fiber. S5. Tertiary melting and centrifugal spinning: Transfer the unmelted material in the secondary high-temperature melting furnace in step S4 to a tertiary high-temperature melting furnace, heat it to 1350℃ - 1400℃ in a CO2 gas atmosphere, keep it warm for 10min - 20min. During the heat preservation process, the melted material is discharged from the liquid discharge port of the tertiary high-temperature melting furnace, and centrifugal spinning is carried out with a centrifuge to obtain the tertiary melted and centrifuged rock wool fiber. S6. Shaping and post-treatment: Carry out cotton collection, cotton laying and cotton pressing operations on the primary melted and centrifuged rock wool fiber, secondary melted and centrifuged rock wool fiber and tertiary melted and centrifuged rock wool fiber prepared in step S3, step S4 and step S5 to obtain the preliminarily shaped rock wool fiber product. Then, send the preliminarily shaped rock wool fiber product into a curing furnace for curing; finally, carry out cutting and packaging treatment on the cured rock wool fiber product according to the actual use requirements.

6. The preparation method of a coal gangue-based rock wool fiber according to claim 5, wherein, In step S3, the rotation speed of the centrifuge is 5000rpm - 6000rpm; in step S4, the rotation speed of the centrifuge is 6000rpm - 7000rpm; in step S5, the rotation speed of the centrifuge is 7000rpm - 8000rpm.

7. The preparation method of a coal gangue-based rock wool fiber according to claim 5, characterized in that, In steps S3 - S5, a modifier and a binder are sprayed on the fiber successively during the primary, secondary and tertiary melting and centrifugal spinning processes.

8. The preparation method of a coal gangue-based rock wool fiber according to claim 7, characterized in that: The modifier is a sodium hydroxide solution with a concentration of 1M - 5M, and the binder is a modified phenolic resin.