A method for producing high-alkali-resistant continuous basalt fiber by raw material multi-component compounding

Abstract

The present application belongs to the field of inorganic non-metallic materials, and particularly relates to a method for producing high-alkali corrosion resistant continuous basalt fiber by mixing raw materials. The present application adjusts the chemical composition of the raw material by mixing and homogenizing the multi-element mineral material to improve the spinnability of the raw material; meanwhile, the alkali corrosion resistance of the fiber is improved by adding a proper amount of alkali corrosion resistant oxide; and a trace amount of atmosphere (oxidizing or reducing) adjusting agent is introduced to comprehensively improve the alkali corrosion resistance of the fiber precursor. The present application successfully improves the high alkali corrosion resistance of the continuous basalt fiber precursor, so that it can meet the application requirements in more harsh environments. Meanwhile, the tensile strength and drawing modulus of the fiber precursor are also greatly increased, further widening the application range of the fiber in various fields and bringing new opportunities for the development of basalt fiber materials.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of inorganic non-metallic materials, and particularly relates to a method for producing high-alkali-erosion-resistant continuous basalt fiber by multi-element mixing of raw materials. BACKGROUND

[0002] With the rapid development of material science and technology, basalt fiber, as an inorganic fiber made of silica lava as raw material through melt-drawing process, has been widely used in many fields such as national defense and military industry, transportation, fire prevention and heat insulation, power and new energy, national infrastructure construction, marine affairs, dielectric materials, automobile manufacturing, etc. due to its green and environmentally friendly characteristics and excellent comprehensive performance, and is known as a new green inorganic fiber material in the 21st century.

[0003] Continuous basalt fiber has significant high and low temperature resistance and thermal shock stability, can maintain stable performance in extreme temperature environment; has low thermal conductivity and is an excellent heat insulation material; has good electrical insulation and dielectric properties, has great application potential in the electronic field; has excellent sound absorption and sound insulation and corrosion resistance, and can be used in scenes with high requirements for acoustic environment and corrosion resistance; has high tensile strength and elastic modulus and can withstand large external forces.

[0004] For a long time, continuous basalt fiber has been widely used in cement concrete, marine affairs and other strong alkali corrosion environments due to its strong alkali corrosion resistance. However, how to further improve its alkali corrosion resistance has been the focus of the industry.

[0005] Under normal circumstances, a specific ore raw material has a specific mineral composition and chemical composition content, which plays a leading role in the performance of the resulting fiber, including alkali corrosion resistance. In recent years, some research attempts to improve the alkali corrosion resistance of continuous basalt fiber by replacing ore raw materials, but due to the inability to overcome the natural defects of ore raw materials, an effective preparation method has not been found. At present, high-alkali-erosion-resistant continuous basalt fiber products are still in a blank state in the market, which to some extent limits the in-depth application of basalt fiber in some fields with extremely high requirements for alkali corrosion resistance. SUMMARY

[0006] In order to overcome the natural defects of single ore raw material in producing high-alkali-erosion-resistant continuous basalt fiber, the present application adjusts the chemical composition of the raw material by mixing and homogenizing multi-element ore, improves the spinnability of the raw material, appropriately adds alkali corrosion resistant oxides to improve the alkali corrosion resistance of the fiber, and introduces a trace amount of atmosphere (oxidizing or reducing) adjusting agent, thereby comprehensively improving the alkali corrosion resistance of the fiber, and filling the market gap of high-alkali-erosion-resistant continuous basalt fiber products in China.

[0007] Specifically, the technical scheme adopted by the present application is as follows: a method for producing high-alkali-erosion-resistant continuous basalt fiber by mixing raw materials, the method comprising the following steps:

[0008] (1) selecting one or more neutral magmatic rocks with a SiO2 mass percentage content greater than or equal to 54% and less than 66% as a main material, and selecting one or more basic-neutral magmatic rocks with a SiO2 mass percentage content greater than or equal to 52% and less than 54% as an ingredient;

[0009] (2) determining the chemical composition content of the main material and the ingredient selected in step (1) by means of material detection, and determining the ratio of the main material to the ingredient according to the target composition content of the mixed material;

[0010] (3) mixing the raw materials after ratioing, crushing, grinding, and passing through an 80-100 mesh sieve to obtain a mixed material, and sampling and detecting to determine that the actual composition content of the mixed material is within the target composition content range;

[0011] (4) selecting and adding alkali-erosion-resistant oxides according to the actual composition and content of the mixed material and the expected alkali-erosion resistance of the continuous basalt fiber product;

[0012] (5) selecting and adding an atmosphere adjusting agent according to the ratio of FeO / (Fe2O3+FeO) in the actual composition content of the mixed material;

[0013] (6) mixing the selected alkali-erosion-resistant oxides and the atmosphere adjusting agent with the mixed material and performing homogenization treatment to obtain a homogenized powder;

[0014] (7) fiber production: drawing the homogenized powder obtained in step (6) to produce continuous basalt fiber.

[0015] As used herein, basic-neutral magmatic rock and neutral magmatic rock refer to the conventional rock classification of magmatic rocks in the art according to the mass percentage content of silicon dioxide.

[0016] Further, the neutral magmatic rock includes andesite or diorite.

[0017] Further, the basic-neutral magmatic rock includes basalt, basaltic andesite, diabase, diabase andesite, or pyroxene andesite.

[0018] Further, the mass fraction of total iron of the main material is 6%-10%, and the mass fraction of total iron of the ingredient is 7%-12%. As used herein, total iron means the total mass fraction of Fe2O3 and FeO in the ore.

[0019] Further, the FeO / (Fe2O3+FeO) of the main batch and the FeO / (Fe2O3+FeO) of the batch are both 0.2-0.6 by mass.

[0020] Further, the mineral composition of the main batch and the batch is dense or porphyritic.

[0021] Further, the quartz mineral content of the main batch and the batch is both ≤15%, the CaO content of the main batch and the batch is both ≤9%, and the loss on ignition of the main batch and the batch is both ≤2.0%.

[0022] As used herein, mixed batch means a mixture of the selected main batch and batch.

[0023] Further, the target component content of the mixed batch in step (2) is: 56%-62% SiO2, 14%-20% Al2O3, 7%-11%(Fe2O3+FeO), 6%-10% MgO, 5%-8% CaO, 1.5%-3% Na2O, 2%-4% K2O, and 1.5%-5% TiO2 by mass percentage.

[0024] Further, the FeO / (Fe2O3+FeO) of the target component content of the mixed batch is 0.2-0.6 by mass.

[0025] Further, the mass fraction of plagioclase + pyroxene of the target component content of the mixed batch is ≥70%.

[0026] Further, the alkali-resistant corrosion-resistant oxide is selected from one or more of the following: 1) network structure reinforcement type: SiO2, MgO, Li2O, BeO, rare earth oxides (including, for example: CeO2, Y2O3, Sc2O3, La2O3, etc.); 2) OH - ion adsorption type: ZrO2, Al2O3, Hf2O, TiO2; 3) fiber surface protection film type: ZrO2+TiO2, Fe2O3+Al2O3, Fe2O3+rare earth oxides (including, for example: CeO2, Y2O3, Sc2O3, La2O3, etc.), Fe2O3+CaO+hydroxide gel; 4) network structure interweaving type: P2O5.

[0027] Further, the alkali-resistant corrosion-resistant oxide can be added to the mixed batch in the form of a pure oxide. As used herein, pure oxide means that it contains ≥99% of the oxide by mass percentage.

[0028] Further, the alkali-resistant corrosion-resistant oxide is added to the mixed batch in the form of a mineral containing the alkali-resistant corrosion-resistant oxide.

[0029] Further, one or more or all of the above-mentioned four categories of alkali- corrosion resistant oxides (or contained minerals) can be added, and any one or more alkali- corrosion resistant oxides in each category can be selected.

[0030] Further, the type and amount of alkali-corrosion resistant oxide to be added are determined according to the alkali-corrosion resistant oxides already contained in the actual ingredients of the mixed material and the expected alkali-corrosion resistance of the continuous basalt fiber product. For example, if a certain alkali-corrosion resistant oxide is already contained in the mixed material, only the insufficient part of this type of oxide required for the expected alkali-corrosion resistance of the continuous basalt fiber product needs to be added, while selecting to add the same or different alkali-corrosion resistant oxide (for example, network structure reinforcement type, OH - ion adsorption type, fiber surface protective film type, or network structure interweaving type). For another example, if a certain alkali-corrosion resistant oxide is already contained in the mixed material and the mass percentage content is sufficient, no addition of this type of oxide is needed, and other alkali-corrosion resistant oxides in the same category or different alkali-corrosion resistant oxides in other categories are added to meet the expected alkali-corrosion resistance of the continuous basalt fiber product.

[0031] Further, the atmosphere adjusting agent is selected from one or more of the following: 1) oxidizing agent: MnO2, V2O5, CeO2, NaNO3, KMnO4, KClO3, PbO2; 2) reducing agent: sodium borohydride (NaBH4), magnesium powder, citric acid, graphite, oxalic acid, oxalic acid.

[0032] Further, by adding an atmosphere adjusting agent, the oxidation-reduction atmosphere of the mixed material is adjusted to a level of FeO / (Fe2O3+FeO) ≈ 0.4. Specifically, when the ratio of FeO / (Fe2O3+FeO) in the actual ingredient content of the mixed material is greater than 0.4 and less than or equal to 0.6, an oxidizing atmosphere adjusting agent is added; when the ratio of FeO / (Fe2O3+FeO) in the actual ingredient content of the mixed material is equal to 0.4, no atmosphere adjusting agent is added; when the ratio of FeO / (Fe2O3+FeO) in the actual ingredient content of the mixed material is greater than or equal to 0.2 and less than 0.4, a reducing atmosphere adjusting agent is added. The amount of atmosphere adjusting agent added can be determined according to the deviation of the ratio of FeO / (Fe2O3+FeO) from 0.4.

[0033] Further, if the atmosphere agent and the alkali-corrosion resistant oxide are the same type of oxide, no additional addition is needed due to the dual effect.

[0034] Further, in step (6), the particle size of the alkali-corrosion resistant oxide and the atmosphere adjusting agent mixed with the mixed material is 80-100 mesh, preferably the same mesh size as the mixed material.

[0035] Further, in step (6), the component content of the homogenized powder is: 45-55% SiO2, 16-20% Al2O3, 5-11% (Fe2O3+FeO), 6-10% MgO, 3-8% CaO, 1-3% Na2O, 1-3% K2O, 1-6% TiO2, 0-10% ZrO2, 0-2% Hf2O, 0-2% Li2O, 0-2% BeO, 0-10% rare earth oxides (such as: CeO2, Y2O3, La2O3, etc.), 0-1.5% network structure interwoven oxides (such as: P2O5), in terms of mass percentage.

[0036] As used herein, the drawing of the homogenized powder is produced using conventional processes well known in the art, for example, the drawing production can be carried out using the processes of melting, drawing forming, and dip coating.

[0037] In other aspects, the present application also provides continuous basalt fibers produced by the method described herein.

[0038] Advantages of the application

[0039] The present application fundamentally changes the chemical composition and structural properties of the raw material by multi-element mixing of different raw materials and moderate optimization of the mass percentage of the main oxides, which not only improves the spinnability of the raw material and ensures the smoothness of the drawing production process, but also lays the foundation for improving the alkali corrosion resistance of the fiber.

[0040] Without changing the "natural" and "environmental" advantages of the continuous basalt fiber, the addition of four types of alkali corrosion resistant oxides with high bond strength and no environmental hazards in an appropriate amount can improve the alkali corrosion resistance of the fiber through various mechanisms such as enhancing the integrity of the network structure, adsorbing OH- ions, and promoting the formation of a protective film on the fiber surface. At the same time, the internal structure of the fiber is further optimized, and the comprehensive performance of the fiber precursor is improved.

[0041] The introduction of trace amounts of atmosphere (oxidizing or reducing) adjusting agents precisely controls the ratio of FeO / (Fe2O3+FeO) in the mixture, greatly improving the homogeneity and thermal conductivity of the glass liquid during fiber drawing production. This not only helps to more accurately control the thermal conductivity and homogeneity of the molten liquid, ensuring continuous and stable industrial production, but also has a positive impact on the alkali corrosion resistance and other physical properties of the fiber.

[0042] Through the above series of innovative measures, the continuous basalt fiber precursor with high alkali corrosion resistance is successfully improved, which can meet the application requirements in more harsh environments. At the same time, the tensile strength and drawing modulus of the fiber precursor are also greatly increased, which further widens the application range of the fiber in various fields, and brings new opportunities for the development of basalt fiber materials. DETAILED DESCRIPTION

[0043] The application will be further described in conjunction with specific examples, but the examples do not limit the application in any form. Unless otherwise specified, the reagents, methods and equipment used in the application are conventional reagents, methods and equipment in the technical field.

[0044] Example:

[0045] The application provides a method for producing continuous basalt fiber with high alkali corrosion resistance by multi-component mixing of raw materials, comprising:

[0046] (1) Selection of raw materials: In this embodiment, the ores from two mining points of Huangcaoliang diorite in Wanyuan City, Sichuan Province and Guoka diorite in Ganzi County, Sichuan Province are selected as main materials, and the ore from Wuyi Village diabase in Jin'kouhe District, Sichuan Province is selected as a material. The specific information is shown in Table 1.

[0047] Table 1: Multi-component mixed raw material reference mining point

[0048] Serial number Ore site Rock type Note 1# Huangcaoliang diorite mine in Wanyuan City, Sichuan Province Diorite Main material 1-1 2# Guoka diorite mine in Ganzi County, Sichuan Province Diorite Main material 1-2 3# Wuyicun diabase mine in Jinhuohe District, Sichuan Province Diabase Batching material 2-1

[0049] (2) Determine the content of each component in each reference ore. See Table 2.

[0050] Table 2: Chemical composition content table of each reference ore

[0051]

[0052] (3) Material blending: According to the target content (i.e. ≥70% of plagioclase + pyroxene; 56%-62% SiO2, 14%-20% Al2O3, 7%-11% (Fe2O3+FeO), 6%-10% MgO, 5%-8% CaO, 1.5%-3% Na2O, 2%-4% K2O, 1.5%-5% TiO2; FeO / (Fe2O3+FeO) = 0.2-0.6, the mixing mass percentage of each mixed material is calculated according to the content of each component in Table 2. As shown in Table 3, 35 parts of 1-1# main material, 40 parts of 1-2# main material and 25 parts of 2-1# material are mixed according to the mass percentage. The comparative example is only composed of diabase (material) from Wuyi Village in Jin'kouhe District, Sichuan Province.

[0053] Table 3: Weight percentage of reference ore

[0054] Ore point Example 1-6 Comparative example 1-1# (main) 35 0 1-2# (main) 40 0 2-1# (batch) 25 100

[0055] (4) After crushing, grinding, and sieving (80-100 mesh) of the mixed materials of Examples 1-6, sample testing was performed to ensure that the content of each component of the mixed materials was within the required range (if not, secondary mixing was performed), and mixed powder was obtained. The test results of the content of each component of the mixed powder of Examples and Comparative Examples are shown in Table 4.

[0056] Table 4: Test results of the content of each component of the mixed ore

[0057]

[0058]

[0059] (5) Addition of atmosphere adjuster: mixed material FeO / (Fe2O3+FeO) = 0.437. According to the mass percentage, 0.5% MnO2 oxidant was added to the mixed material of each example.

[0060] (6) Addition of alkali-resistant oxide: according to the main oxides and their contents of the mixed material, as shown in Table 5, the corresponding alkali-resistant oxide was added to the mixed material of each example and homogenized.

[0061] Table 5: Percentage content of alkali-resistant oxide and atmosphere adjuster added to the mixed powder of each example (based on the percentage content of the mixed material)

[0062]

[0063] (7) Fiber drawing production: the homogenized powder obtained in the previous step was gradually added to the pool kiln, and after the raw materials in the pool kiln were completely replaced, the melting, fiber drawing forming, and immersion coating process were used for fiber drawing production, and the production parameters were recorded to obtain continuous basalt fibers.

[0064] (8) The production efficiency and fiber performance of the basalt fibers were tested, and the results are shown in Table 6.

[0065] Table 6: Melting parameters of the raw materials of the basalt fibers of each example and fiber performance

[0066]

[0067]

[0068]

[0069] As can be seen from Table 6: in Example 1, by multi-component blending of raw materials, and introducing 6.0% of Al2O3, 5.0% of MgO, 4.5% of TiO2, and 1.5% of Li2O in the blended material, the chemical composition of the blended material is effectively adjusted, while continuing to introduce 0.5% of MnO2 strong oxidizing atmosphere adjuster, the atmosphere of the furnace melting is precisely controlled, the ratio of FeO / (Fe2O3+FeO) is adjusted to about 0.4, which significantly improves the spinnability and alkali corrosion resistance of the blended material. On this basis, 2.0% of ZrO2, 0.5% of P2O5, 1.0% of CeO2, and 1.0% of Y2O3 are added, which further improves the alkali corrosion resistance of the fiber precursor. As can be seen from the melting temperature, forming temperature, liquidus temperature, and fiber forming rate and full bucket rate, the effect of Example 1 is good, which meets the industrial production process of basalt, and compared with the comparative example, the alkali corrosion resistance of the fiber precursor (yarn breaking strength and strength retention rate after corrosion) is greatly improved, and the alkali corrosion resistance of the fiber precursor can reach the BAS I alkali corrosion resistance index in “Basalt Fiber Classification and Grading and Code” (GB / T38111-2019). At the same time, the tensile strength and drawing modulus of the fiber precursor are also greatly increased.

[0070] Example 2 increases the percentage of alkali corrosion resistant oxide ZrO2 to 3.0%, the percentage of Al2O3 to 6.35%, and the percentage of MgO to 5.2% based on Example 1, which can further improve the alkali corrosion resistance of the fiber precursor, and the fiber precursor can reach the BAS II alkali corrosion resistance index in “Basalt Fiber Classification and Grading and Code” (GB / T38111-2019).

[0071] Example 3 increases the percentage of alkali corrosion resistant oxide ZrO2 to 4.0%, the percentage of Al2O3 to 6.70%, and the percentage of MgO to 5.4% based on Example 2; Example 4 increases the percentage of alkali corrosion resistant oxide ZrO2 to 5.0%, the percentage of Al2O3 to 7.05%, and the percentage of MgO to 5.6% based on Example 3; Example 5 increases the percentage of alkali corrosion resistant oxide ZrO2 to 6.0%, the percentage of Al2O3 to 7.40%, and the percentage of MgO to 5.8% based on Example 4; these gradual increases of alkali corrosion resistant oxides further improve the alkali corrosion resistance of the fiber precursor.

[0072] Example 6 increases 1.0% of La2O3 based on Example 5, La2O3 as a rare earth oxide not only can enhance the network structure, but also can increase the formation of iron-rare earth protective film, thereby further improving the alkali corrosion resistance of the fiber precursor.

[0073] Compared with the single diabase ore raw material of Wuyi Village, Jin'kouhe District, Sichuan Province (comparative example), the present application adjusts the chemical composition of the raw material by multi-element mixing and homogenization of the ore to improve the spinnability of the raw material; at the same time, a proper amount of alkali-resistant oxide is added to promote the formation of a multi-layer protective film on the surface of the fiber; and a trace amount of atmosphere (oxidizing or reducing) adjusting agent is introduced to comprehensively improve the alkali corrosion resistance of the fiber precursor. The homogenized mixture after adjustment has the following advantages:

[0074] (1) High alkali corrosion resistance. The alkali corrosion resistance of the fiber precursor of Example 1 reaches the BAS I alkali salt resistance performance index in "Basalt Fiber Classification and Grading and Code" (GB / T 38111-2019); the alkali corrosion resistance of the fiber precursors of Examples 2-6 can all reach the BAS II alkali salt resistance performance and above in "Basalt Fiber Classification and Grading and Code" (GB / T 38111-2019), filling the blank of alkali-resistant basalt fiber precursor products in China.

[0075] (2) Lower melting temperature, forming temperature and liquidus temperature for industrial production. In the multi-element mixing process, the reasonable matching of the raw materials reduces the energy demand of the system, while leaving space for the interaction of the alkali-resistant oxide addition, and the trace introduction of the atmosphere adjusting agent helps to reduce the viscosity of the melt and improve its flowability, so that good melting, forming and other processes can be achieved at lower temperatures, which is beneficial to energy saving and process control in industrial production.

[0076] (3) Higher yarn forming rate and full bucket rate to ensure the economic benefits of high modulus precursor production. Multi-element mixing reduces the production instability factors caused by defects of single ore raw material, and the synergistic effect of alkali-resistant oxide and atmosphere adjusting agent further improves the stability of the production process, so that the fiber is more easily formed and the quality is more stable in the production process, thereby improving the yarn forming rate and full bucket rate.

[0077] It should be noted that the present application provides a preferred embodiment of the present application in the specification, but the present application can be implemented in many different forms and is not limited to the embodiments described in the specification, which are not additional limitations on the content of the present application. The purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Furthermore, the above technical features continue to be combined with each other to form various embodiments not listed above, which are considered to be within the scope of the present application. Furthermore, for those skilled in the art, the above description can be improved or changed, and all these improvements and changes shall fall within the scope of the appended claims of the present application.

Claims

1. A type of highly alkali-resistant continuous basalt fiber produced by multi-component blending and drawing of raw materials, characterized in that... The homogenized powder obtained by blending multiple raw materials for wire drawing production has the following composition by mass percentage: 46.19%-48.92% SiO2, 17.31%-17.57% Al2O3, 3.31%-3.50% Fe2O3, 2.57%-2.72% FeO, 8.11%-9.25% MgO, 3.95%-4.06% CaO, and 1.57%-1.66% N. The composition includes a2O, 1.49%-1.58% K2O, 4.70%-4.98% TiO2, 0.50%-0.52% P2O5, 0.39%-0.41% MnO2, 1.64%-4.68% ZrO2, 1.16%-1.23% Li2O, 0.77%-0.82% CeO2, 0.77%-0.82% Y2O3, and 0%-0.77% La2O3. Furthermore, the highly alkali-resistant continuous basalt fiber produced by multi-component raw material blending and drawing is prepared by a method comprising the following steps: (1) Raw material selection: Select one or more neutral igneous rocks with a SiO2 mass percentage content greater than or equal to 54% and less than 66% as the main material, and select one or more basic-intermediate igneous rocks with a SiO2 mass percentage content greater than or equal to 52% and less than 54% as the auxiliary material; (2) Raw material ratio: The chemical composition content of the main material and the ingredients selected in step (1) is determined by material testing methods, and the ratio of the main material and the ingredients is determined by the target component content of the mixture. (3) Mixing process: After mixing the proportioned raw materials, crush, grind and pass through an 80-100 mesh sieve to obtain the mixture. Sampling and testing are conducted to determine whether the actual component content of the mixture is within the target component content range. (4) Selection and addition of alkali-resistant oxides: Based on the actual composition and content of the mixture and the expected alkali resistance of the continuous basalt fiber product, determine the type and amount of alkali-resistant oxides to be added; (5) Selection and addition of atmosphere modifiers: Based on the ratio of FeO / (Fe2O3+FeO) in the actual composition of the mixture, determine the type and amount of atmosphere modifier to be added; (6) The selected alkali-resistant oxide and atmosphere modifier are mixed with the mixture and homogenized to obtain homogenized powder; (7) Fiber production: The homogenized powder obtained in step (6) is drawn into fibers to obtain continuous basalt fibers.

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