Preparation method of sub-micron basalt fiber high-efficiency gas filter material

Abstract

The application discloses a sub-micron basalt fiber high-efficiency gas filter material and a preparation method thereof. The gas filter material is prepared through a wet papermaking process and is composed of sub-micron basalt fibers obtained through a gravity separation (centrifugal) grading method, plant fibers after beating, and polyacrylamide and sodium carboxymethyl cellulose. The filter material fully utilizes the advantages of the sub-micron basalt fibers, such as high-temperature resistance, corrosion resistance and environmental protection, and adds the plant fibers to enhance the tensile strength and bending strength of the filter material. The preparation process of the filter material is simple, the cost is low, and the filter material is good for PM 0.3 2.5 filtration, shows excellent filtering performance, and is helpful for breaking the monopoly of foreign high-efficiency filter materials in related fields.

Description

Technical Field

[0001] This invention relates to the field of filtration materials technology, specifically to a submicron-sized basalt fiber high-efficiency gas filtration material and its preparation method. Background Technology

[0002] In many large-scale industrial equipment and production operations, such as the compressor stations in the West-East Gas Pipeline and the intake systems of heavy-duty gas turbines, high purity of gas is required. The presence of a large number of particles in the gas can not only damage equipment but also pose significant safety hazards. To meet these gas quality requirements, gas filters are indispensable devices, with gas filter materials being key components for efficient filtration. Currently, most filter materials on the market are made of glass fiber, which possesses excellent properties such as extremely high filtration efficiency, low resistance, and chemical stability. For example, Chinese patent CN112982011A discloses an air filter paper made of glass fiber and polyvinyl alcohol, which can effectively filter particulate matter and purify the indoor environment. However, related glass fiber products generally suffer from problems such as low strength, susceptibility to breakage, high production costs, and poor wear resistance.

[0003] Basalt fiber possesses excellent mechanical properties, with a strength of 3000-4840 MPa and an elastic modulus of 79-93 GPa; it also exhibits good thermal stability, with an operating temperature range of -269-700℃; it is an environmentally friendly fiber, producing no harmful substances during its preparation and degradable to soil parent material after disposal; furthermore, it possesses good dielectric properties, high flame retardancy, and strong corrosion resistance, making it suitable as a filtration material for special environmental conditions. Chinese patent CN111632433A discloses a filter bag for preparing a composite polytetrafluoroethylene membrane using polyphenylene sulfide-encapsulated basalt fiber, characterized by high strength, resistance to deformation, and long service life, effectively filtering PM2.5. 2.5 The filtration efficiency reaches over 99%. However, basalt fibers have a wide diameter distribution, generally in the micrometer range. According to the gas filtration mechanism, the larger the fiber diameter, the lower the filtration efficiency, which does not meet the requirements for PM2.5 filtration. 0.3 There is a demand for high-efficiency filter materials, and the particulate matter generated during the fiber production process can affect filtration performance, making it difficult to use directly as a raw material for filter media.

[0004] In view of this, the present invention provides a method for preparing a submicron-sized basalt fiber high-efficiency gas filter material. The method involves combining submicron-sized basalt fibers obtained through gravity separation (centrifugation) with plant fibers, and using a simple wet papermaking process to prepare the high-efficiency gas filter material, which effectively filters PM2.5. 0.3 It exhibits excellent filtration performance. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing a high-efficiency gas filter material made of submicron-sized basalt fiber. This method utilizes a wet papermaking process to prepare a gas filter material composed of submicron-sized basalt fiber obtained by gravity separation (centrifugation), pulped plant fiber, and a blend of polyacrylamide and sodium carboxymethyl cellulose. This filter material fully leverages the advantages of submicron-sized basalt fiber, such as high-temperature resistance, corrosion resistance, and environmental friendliness, while the addition of plant fiber enhances its tensile and flexural strength. The preparation process of this filter material is simple and low-cost, and it effectively filters PM... 0.3 It exhibits excellent filtration performance, which helps to break the monopoly of foreign countries in the field of high-efficiency filtration materials.

[0006] The preparation method of the submicron-sized basalt fiber high-efficiency gas filter material of the present invention is carried out according to the following steps:

[0007] A method for preparing a submicron-sized basalt fiber high-efficiency gas filter material comprises the following steps:

[0008] a. Gravity-based classification of basalt fibers: Basalt fibers with an average diameter of 0.1-10μm are ablated at 400℃, refluxed with acetone at 70℃ or sonicated with ethanol at 25℃ to remove the surface binder. After cooling, 5-20g of basalt fibers are stirred and dispersed, transferred to a cylindrical tank for sedimentation for 2-20min, the supernatant is collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0009] b. Preparation of plant fibers: Cotton fiber, kapok fiber, flax fiber, sisal fiber, coconut fiber, softwood fiber, hardwood fiber or ramie fiber are slowly added to a pulper and ground for 1-120 minutes. The pulp is then filtered, dried and ready for use.

[0010] c. Preparation of fiber dispersion: Dissolve 4.5-18g of polyacrylamide and 7.5-30g of sodium carboxymethyl cellulose in water and stir to mix. Add 0.01-7.10g of submicron basalt fiber obtained in step a, and then add 0.01-7.10g of dried plant fiber obtained in step b. Stir evenly to obtain a dispersion.

[0011] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, and then dried at a temperature of 80-105℃ and a pressure of 0.01-0.12MPa for 5-30 minutes. After demolding, submicron-sized basalt fiber filter material is obtained.

[0012] The preparation method of the submicron-sized basalt fiber high-efficiency gas filtration material described in this invention has the following innovations compared with the prior art:

[0013] 1. This invention classifies basalt fibers with a wide diameter distribution through gravity separation (centrifugation), enriching the smaller diameter fibers and removing particulate matter from the fibers to obtain submicron-sized basalt fibers, making them more suitable for use in the preparation of high-efficiency gas filtration materials. Basalt fibers endow the filter media with excellent properties such as high strength, heat resistance, corrosion resistance, and insulation, meeting the requirements for use in harsh and extreme environments. Furthermore, it is an environmentally friendly material with minimal harm to the environment and human health.

[0014] 2. This invention utilizes the traditional wet papermaking process to combine basalt fiber and plant fiber to prepare filter material. The process is simple, easy to industrialize, low in cost, and has great market potential. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the basalt fiber grading effect of the present invention;

[0016] Figure 2 This is a schematic diagram of the submicron-sized basalt fiber filter material of the present invention. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods; and the reagents and materials used are commercially available unless otherwise specified.

[0019] Example 1

[0020] a. Gravity-based basalt fiber classification: Basalt fibers with an average diameter of 2μm were ablated at 400℃ for 1 hour to remove the surface binder. After cooling, 20g of basalt fibers were stirred and dispersed, transferred to a cylindrical barrel for sedimentation for 20 minutes, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0021] b. Preparation of plant fiber: Slowly add cotton fiber into a pulper and grind it for 120 minutes. Filter, dry, and set aside for use.

[0022] c. Preparation of fiber dispersion: Dissolve 4.5g of polyacrylamide and 15g of sodium carboxymethyl cellulose in water and stir to mix. Add 0.01g of submicron basalt fiber obtained in step a, and then add 7.10g of cotton fiber obtained in step b. Stir evenly to obtain a dispersion.

[0023] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, dried at 105℃ and 0.01MPa for 10 min, and then demolded to obtain submicron-sized basalt fiber filter material.

[0024] The submicron-sized basalt fiber filter material obtained in Example 1 achieved a filtration efficiency of 98.42%.

[0025] Example 2

[0026] a. Gravity-based classification of basalt fibers: Basalt fibers with an average diameter of 2.5 μm were ablated at 400℃ for 1 hour to remove the surface binder. After cooling, 18 g of basalt fibers were stirred and dispersed, transferred to a cylindrical barrel for sedimentation for 18 minutes, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0027] b. Preparation of plant fiber: Slowly add kapok fiber into a pulper and grind it for 110 minutes. Filter, dry and set aside for later use.

[0028] c. Preparation of fiber dispersion: Dissolve 5g of polyacrylamide and 14g of sodium carboxymethyl cellulose in water and stir to mix. Add 1.42g of submicron basalt fiber obtained in step a, and then add 5.68g of kapok fiber obtained in step b. Stir evenly to obtain a dispersion.

[0029] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, dried at 105℃ and 0.02MPa for 12min, and then demolded to obtain submicron-sized basalt fiber filter material.

[0030] The submicron-sized basalt fiber filter material obtained in the example has a filtration efficiency of 94.61%.

[0031] Example 3

[0032] a. Gravity-based classification of basalt fibers: Basalt fibers with an average diameter of 3μm are ablated at 400℃ for 1 hour to remove the surface binder. After cooling, 16g of basalt fibers are stirred and dispersed, transferred to a cylindrical tank for sedimentation for 2-20 minutes, and the supernatant is collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0033] b. Preparation of plant fiber: Slowly add flax fiber into a pulper and grind it for 100 minutes. Filter, dry, and set aside for use.

[0034] c. Preparation of fiber dispersion: Dissolve 4.5g of polyacrylamide and 13g of sodium carboxymethyl cellulose in water and stir to mix. Add 1.775g of submicron basalt fiber obtained in step a, and then add 5.325g of flax fiber obtained in step b. Stir evenly to obtain a dispersion.

[0035] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, dried at 95℃ and 0.03MPa for 14min, and then demolded to obtain submicron-sized basalt fiber filter material.

[0036] The submicron-sized basalt fiber filter material obtained in Example 3 has a filtration efficiency of 92.85%.

[0037] Example 4

[0038] a. Gravity-based grading of basalt fibers: Basalt fibers with an average diameter of 3.5 μm were subjected to acetone reflux at 70 °C to remove the surface binder. After cooling, 14 g of basalt fibers were stirred and dispersed, transferred to a cylindrical tank for sedimentation for 14 min, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0039] b. Preparation of plant fiber: Slowly add sisal fiber into a pulper and grind for 90 minutes. Filter, dry and set aside for later use.

[0040] c. Preparation of fiber dispersion: Dissolve 6g of polyacrylamide and 12g of sodium carboxymethyl cellulose in water and stir to mix. Add 2.13g of submicron basalt fiber obtained in step a, and then add 4.97g of sisal fiber obtained in step b. Stir evenly to obtain a dispersion.

[0041] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, and then dried at 85℃ and 0.04MPa for 16 minutes. After demolding, submicron-sized basalt fiber filter material is obtained.

[0042] The submicron-sized basalt fiber filter material obtained in Example 4 has a filtration efficiency of 89.92%.

[0043] Example 5

[0044] a. Gravity-based basalt fiber classification: Basalt fibers with an average diameter of 4μm were subjected to acetone reflux at 70℃ to remove the surface binder. After cooling, 12g of basalt fibers were stirred and dispersed, transferred to a cylindrical tank for sedimentation for 12min, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0045] b. Preparation of plant fiber: Slowly add coconut fiber into a pulper and grind for 80 minutes. Filter, dry, and set aside for use.

[0046] c. Preparation of fiber dispersion: Dissolve 6.5g of polyacrylamide and 11g of sodium carboxymethyl cellulose in water and stir to mix. Add 2.485g of submicron basalt fiber obtained in step a, and then add 4.615g of coconut fiber obtained in step b. Stir evenly to obtain a dispersion.

[0047] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a paper sheet forming machine, dehydrated and filtered, dried at 100℃ and 0.08MPa for 5 minutes, and then demolded to obtain submicron-sized basalt fiber filter material.

[0048] The submicron-sized basalt fiber filter material obtained in Example 5 has a filtration efficiency of 83.27%.

[0049] Example 6

[0050] a. Gravity-based grading of basalt fibers: Basalt fibers with an average diameter of 4.5 μm were subjected to acetone reflux at 70 °C to remove the surface binder. After cooling, 20 g of basalt fibers were stirred and dispersed, transferred to a cylindrical tank for sedimentation for 2 min, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0051] b. Plant fiber preparation: Slowly add coniferous wood fiber into a pulper and grind it for 120 minutes. Filter, dry, and set aside for use.

[0052] c. Preparation of fiber dispersion: Dissolve 7g of polyacrylamide and 10g of sodium carboxymethyl cellulose in water and stir to mix. Add 2.84g of submicron basalt fiber obtained in step a, and then add 4.26g of coniferous fiber obtained in step b. Stir evenly to obtain a dispersion.

[0053] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, and then dried at 80℃ and 0.12MPa for 30 min. After demolding, submicron-sized basalt fiber filter material is obtained.

[0054] The submicron-sized basalt fiber filter material obtained in Example 6 has a filtration efficiency of 78.56%.

[0055] Example 7

[0056] a. Gravity-based grading of basalt fibers: Basalt fibers with an average diameter of 5μm were subjected to ultrasonic treatment with ethanol at 25℃ to remove the surface binder. After cooling, 20g of basalt fibers were stirred and dispersed, transferred to a cylindrical tank for sedimentation for 20min, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0057] b. Plant fiber preparation: Slowly add the broadleaf wood fiber into a pulper and grind it for 120 minutes. Filter, dry, and set aside for use.

[0058] c. Preparation of fiber dispersion: Dissolve 18g of polyacrylamide and 30g of sodium carboxymethyl cellulose in water and stir to mix. Add 7.10g of submicron basalt fiber obtained in step a, and then add 7.10g of hardwood fiber obtained in step b. Stir evenly to obtain a dispersion.

[0059] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, dried at 90℃ and 0.10MPa for 5 minutes, and then demolded to obtain submicron-sized basalt fiber filter material.

[0060] The submicron-sized basalt fiber filter material obtained in Example 7 has a filtration efficiency of 61.66%.

[0061] Example 8

[0062] a. Gravity-based grading of basalt fibers: Basalt fibers with an average diameter of 10μm were subjected to ultrasonic treatment with ethanol at 25℃ to remove the surface binder. After cooling, 5g of basalt fibers were stirred and dispersed, transferred to a cylindrical barrel for sedimentation for 2min, and the supernatant was collected, filtered, and dried to obtain submicron-sized basalt fibers.

[0063] b. Preparation of plant fiber: Ramie fiber is slowly added to a pulping machine and ground for 1 minute. The pulp is then filtered, dried, and set aside for use.

[0064] c. Preparation of fiber dispersion: Dissolve 15g of polyacrylamide and 7.5g of sodium carboxymethyl cellulose in water and stir to mix. Add 7.10g of submicron basalt fiber obtained in step a, and then add 0.01g of ramie fiber obtained in step b. Stir evenly to obtain a dispersion.

[0065] d. Filter material sheet forming: The dispersion obtained in step c is transferred to a sheet forming machine, dehydrated and filtered, dried at 105℃ and 0.12MPa for 24min, and then demolded to obtain submicron-sized basalt fiber filter material.

[0066] The submicron-sized basalt fiber filter material obtained in Example 8 has a filtration efficiency of 45.85%.

Claims

1. A method for preparing a sub-micron basalt fiber high-efficiency gas filtration material, characterized in that, The following steps are taken: a. Grading basalt fibers by gravity: basalt fibers with an average diameter of 0.1-10 μm are ablated at a temperature of 400°C, the surface adhesive is removed by refluxing in acetone at a temperature of 70°C or ultrasonic treatment in ethanol at a temperature of 25°C, after cooling, 5-20 g of basalt fibers are stirred and dispersed, transferred to a cylindrical barrel for sedimentation, time 2-20 min, take the supernatant, suction filtration, drying, to obtain sub-micron basalt fibers; b. Plant fiber preparation: cotton fiber, kapok fiber, flax fiber, sisal fiber, coconut fiber, coniferous wood fiber, broadleaf wood fiber or ramie fiber are slowly added to a beater for pulp refining, time 1-120 min, suction filtration, drying, ready for use; c. Preparation of fiber dispersion liquid: 4.5-18 g of polyacrylamide and 7.5-30 g of sodium carboxymethyl cellulose are separately dissolved in water and stirred and mixed, 0.01-7.10 g of sub-micron basalt fibers obtained in step a are added, 0.01-7.10 g of dried plant fibers obtained in step b are added, stirred uniformly to obtain a dispersion liquid; d. Filter sheet forming: the dispersion liquid obtained in step c is transferred to a paper sheet former, after dehydration and suction filtration, drying at a temperature of 80-105°C, 0.01-0.12 MPa for 5-30 min, demolding, to obtain sub-micron basalt fiber filter material.

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