Method for improving strength and modulus of continuous basalt fiber through multi-element mixing of raw materials

Abstract

The invention belongs to the field of inorganic non-metallic materials, and particularly relates to a method for improving the strength and modulus of continuous basalt fibers through multi-element mixing of raw materials. Different basalt raw materials for fibers are mixed, the mass percent content of raw material minerals and main oxides, namely the mass percent content of network forming bodies, network intermediates and network changing body oxides, is properly adjusted, and on the premise that the advantages of'nature 'and'environmental protection' of the continuous basalt fibers are not changed, the continuous basalt fibers are obtained. By adding a proper amount of enhanced modulus-increasing oxide which is high in bond strength and free of environmental harm, the integrity of a network structure of the glass is enhanced, a trace amount of atmosphere (oxidation or reduction) regulator is introduced, and the ratio of FeO / (Fe2O3 + FeO) in a mixed material is accurately controlled, so that the homogeneity and the thermal conductivity of molten glass in the fiber drawing production process are greatly improved, and the production efficiency is improved. Therefore, the diathermancy and homogeneity of the molten liquid are more accurately controlled, and the strength and modulus of the continuous basalt fiber precursor are improved on the premise of ensuring continuous and stable industrial production.

Description

Technical Field

[0001] The invention belongs to the field of inorganic non-metallic materials, and specifically relates to a method for improving the strength and modulus of continuous basalt fibers by multi-component mixing of raw materials. Background Art

[0002] Continuous basalt fiber is made of basic-neutral igneous rock ores such as basalt, diabase, gabbro, basaltic andesite, diabase diorite, and pyroxene diorite. The mineral and chemical composition content of the ore is within an appropriate range. The ore fiber is made through a melt-drawing process. It has excellent properties in mechanics, dielectric, heat resistance, alkali corrosion resistance, etc., and the production process is environmentally friendly. It is known as the new green inorganic fiber material of the 21st century.

[0003] Usually, a specific ore has its specific mineral composition and chemical content, which plays a major role in determining the properties of the prepared fiber, including strength and modulus. Compared with glass fiber, basalt fiber is difficult to form in a continuous and stable manner, has a high coefficient of dispersion, and is difficult to effectively control the strength and modulus of the product. This has been a long-standing problem that has been difficult to solve in the basalt fiber industry. In recent years, some studies have attempted to improve the strength and modulus properties of continuous basalt fibers by replacing ore raw materials, but due to the inability to solve the natural defects of ore raw materials, no effective preparation method has been found, resulting in the lack of continuous basalt fiber raw materials with special properties such as high strength and high modulus. Summary of the invention

[0004] In order to overcome the natural defects of producing high modulus continuous basalt fiber with a single ore raw material, the present invention improves the tensile strength and tensile modulus performance of the fiber precursor by mixing and homogenizing multiple mineral materials, adding an appropriate amount of reinforcing and modulus-increasing oxide, and introducing a trace amount of atmosphere (oxidation or reduction) regulator.

[0005] Specifically, the technical solution adopted by the present invention is: a method for improving the strength and modulus of continuous basalt fiber by multi-mixing of raw materials, the method comprising the following steps:

[0006] (1) Raw material selection: one or more neutral igneous rocks with a SiO2 mass percentage content greater than or equal to 54% and less than 66% are selected as the main material, and one or more basic-neutral igneous rocks with a SiO2 mass percentage content greater than or equal to 52% and less than 54% are selected as the auxiliary material;

[0007] (2) Raw material ratio: Determine the chemical composition content of the main ingredient and the ingredients selected in step (1) by material testing means, and determine the ratio of the main ingredient and the ingredients based on the target component content of the mixed ingredients;

[0008] (3) Mixing: Mixing the raw materials in the right proportions, crushing, grinding, and sieving, and homogenizing the obtained powder to obtain a mixed material, and sampling and testing to determine whether the actual content of the mixed material is within the target content range;

[0009] (4) Selection and addition of reinforcing and modulus-enhancing oxides: Determine the type and amount of reinforcing and modulus-enhancing oxides to be added based on the actual content of the mixed ingredients and the expected strength and modulus of the continuous basalt fiber product;

[0010] (5) Selection and addition of atmosphere adjusters: Determine the type and amount of atmosphere adjusters to be added based on the ratio of FeO / (Fe2O3+FeO) in the actual content of the mixed materials;

[0011] (6) mixing the selected reinforcing and mold-enhancing oxide and atmosphere regulator with the mixed ingredients and performing a homogenization treatment;

[0012] (7) Fiber production: The homogenized powder obtained in step (6) is subjected to wire drawing to obtain continuous basalt fibers.

[0013] As used herein, basic-neutral igneous rocks and neutral igneous rocks refer to conventional rock classifications of igneous rocks in the art based on the mass percentage content of silicon dioxide.

[0014] Furthermore, the neutral igneous rock includes andesite or diorite.

[0015] Furthermore, the basic-neutral igneous rocks include basalt, diabase, gabbro, basaltic andesite, diabase andesite, and pyroxene andesite.

[0016] Furthermore, the mass fraction of total iron in the main material is 6%-10%, and the mass fraction of total iron in the batch material is 7%-12%. As used herein, total iron refers to the total mass fraction of Fe2O3 and FeO in the ore.

[0017] Furthermore, the mineral structure of the main material is dense or obliquely porphyritic, and the mineral structure of the supplementary material is dense or obliquely porphyritic.

[0018] Furthermore, the ignition loss of the main ingredient and the supplementary ingredients is ≤2.0%.

[0019] Furthermore, the target component contents of the mixed materials in step (2) are: by mass percentage, 54%-60% SiO2, 16%-18% Al2O3, 7%-11% Fe2O3+FeO, 6%-10% MgO, 6%-9% CaO, 2%-3% Na2O, 0.5%-1.5% K2O, and 1%-4% TiO2.

[0020] Furthermore, the target component content of the mixed material is, by mass, FeO / (Fe2O3+FeO)=0.4-0.8.

[0021] Furthermore, in the target component content of the mixed material, the mass fraction of plagioclase + pyroxene is ≥ 70%.

[0022] Furthermore, the reinforcing and mold-increasing oxide is selected from one or more of the following: 1) network formers: GeO2, Al2O3, ZrO2, V2O5; 2) network intermediates: Nb2O5, CeO2, Y2O3, Sc2O3, La2O3, TiO2; 3) network modifiers: MgO, Li2O, BeO.

[0023] Furthermore, the addition amount of the reinforcing and modulus-increasing oxide may be 0-20%, such as 0-15%, 0-10%, etc., which may be adjusted as appropriate according to the actual content of the mixed ingredients and the expected strength and modulus of the continuous basalt fiber product.

[0024] Furthermore, when the ratio of FeO / (Fe2O3+FeO) in the actual component content of the mixed material is greater than or equal to 0.4 and less than 0.6, a reducing atmosphere adjuster is added; when the ratio of FeO / (Fe2O3+FeO) in the actual component content of the mixed material is equal to 0.6, no atmosphere adjuster is added; when the ratio of FeO / (Fe2O3+FeO) in the actual component content of the mixed material is greater than 0.6 and less than or equal to 0.8, an oxidizing atmosphere adjuster is added.

[0025] Furthermore, the amount of atmosphere adjuster added is 0-3%, which can be increased or decreased as appropriate depending on the deviation of the FeO / (Fe2O3+FeO) ratio from 0.6.

[0026] Furthermore, the atmosphere adjuster is selected from one or more of the following: 1) oxidizing agent: MnO2, V2O5, CeO2; 2) reducing agent: MnO, citric acid, graphite, oxalic acid.

[0027] Furthermore, in step (3), the sieving is through a 80-100 mesh sieve.

[0028] As used herein, the mixed powder is subjected to wire drawing production using conventional processes well known in the art, for example, the wire drawing production can be carried out using melting, wire drawing forming, and infiltration coating process means.

[0029] In other aspects, the present invention also provides continuous basalt fibers produced by the methods described herein.

[0030] Advantageous Effects of the Invention

[0031] In order to solve the inherent natural spinnability defects of single basalt ore raw material for fiber and the volatility of raw material mineral and component content, the inventor previously applied for an invention patent for "A method for improving continuous basalt fiber production efficiency and fiber performance through multi-mixing of raw materials", disclosing a method for solving the difficulties in single raw material production through raw material mixing and homogenization, effectively reducing gas and electricity consumption in production, improving fiber spinning rate, especially achieving a significant increase in fiber full barrel rate, and stabilizing the tensile strength and tensile elastic modulus of the fiber precursor.

[0032] The present invention is an improvement on the above patent application. Specifically, the present invention mixes different raw materials, and appropriately adjusts the mass percentage content of raw material minerals and main oxides, i.e., the mass percentage content of network formers, network intermediates and network modifiers. Without changing the advantages of "naturalness" and "environmental protection" of continuous basalt fiber, the present invention appropriately adds reinforcing and modulus-enhancing oxides with large bond strength and no environmental hazards to enhance the integrity of its network structure, and introduces a trace amount of atmosphere (oxidation or reduction) regulator to accurately control the ratio of FeO / (Fe2O3+FeO) in the mixture, so that the homogeneity and thermal conductivity of the glass liquid in the fiber drawing production process are greatly improved, so as to more accurately control the thermal permeability and homogeneity of the molten liquid, and on the premise of ensuring continuous and stable industrial production, thereby improving the strength and modulus of the continuous basalt fiber precursor. DETAILED DESCRIPTION

[0033] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0034] Example:

[0035] The present invention provides a method for improving the strength and modulus of continuous basalt fiber by multi-component mixing of raw materials, comprising:

[0036] (1) Raw material selection: In this embodiment, the ore of Xiangzhangping basalt mine in Hanyuan County, Sichuan Province and Tiesuoqiao diorite mine in Kangding City, Sichuan Province were selected as the main materials, and the ore of Longzhoushan basalt mine in Huili County, Sichuan Province was selected as the supplementary material. The specific information is shown in Table 1.

[0037] Table 1: Mineral Points for Mixed Raw Materials

[0038] Serial number Ore Land Rock Type Remark 1# Tiesuoqiao diorite mine in Kangding City, Sichuan Province Diorite Ingredients 1-1 2# Xiangzhangping basalt mine in Hanyuan County, Sichuan Province Basaltic andesite Ingredients 1-2 3# Longzhoushan Basalt Mine, Huili County, Sichuan Province Basalt Ingredients 2-1

[0039] (2) Determine the content of each component in each ore. See Table 2

[0040] Table 2: Chemical composition of each ore

[0041]

[0042] (3) Batching: According to the target content (i.e., ≥70% of plagioclase + pyroxene; 54%-60% SiO2, 16%-18% Al2O3, 7%-11% (Fe2O3+FeO), 6%-10% MgO, 6%-9% CaO, 2%-3% Na2O, 0.5%-1.5% K2O, 1%-4% TiO2; FeO / (Fe2O3+FeO)=0.4-0.8, the mass percentage of each mixed ingredient is calculated according to the content of each component in Table 2. As shown in Table 3, 60 parts of 1-1# main material, 28 parts of 1-2# main material, and 12 parts of 2-1# batching were weighed and mixed according to mass percentage. The comparative example is composed of only a single mineral material of Longzhoushan basalt (batch) in Huili County, Sichuan Province.

[0043] Table 3: Weight percentage of the ore

[0044] Ore Point Examples 1-6 Comparative Example 1-1#(home) 60 0 1-2#(home) 28 0 2-1#(matching) 12 100

[0045] (4) The mixed materials of Examples 1-6 were crushed and ground into powders with a particle size of 80-100 mesh and homogenized, and then sampled and tested to ensure that the content of each component of the mixed materials was within the required range (if the requirements were not met, secondary mixing was required) to obtain mixed powders. The test results of the content of each component in the Examples and Comparative Examples are shown in Table 4.

[0046] Table 4: Detection content of each component after ore mixing

[0047]

[0048]

[0049] (5) Adding atmosphere adjuster: FeO / (Fe2O3+FeO)=0.52. In terms of mass percentage, 0.5% of oxalic acid with weaker reducing property was added to the mixed materials of each embodiment.

[0050] (6) Adding reinforcing and mold-increasing oxides: According to the main oxide content of the mixed material, as listed in Table 5, corresponding reinforcing and mold-increasing oxides were added to the mixed material of each embodiment and homogenized respectively.

[0051] Table 5: Percentage of the reinforced mold-enhancing oxide and atmosphere regulator added to the mixed powder in each embodiment

[0052]

[0053] (7) Wire drawing production: The mixed powder obtained in the previous step is gradually added to the pool kiln. After the raw materials in the pool kiln are completely replaced, the wire drawing production is carried out by means of melting, wire drawing forming, and impregnation coating processes. The production parameters are recorded to obtain continuous basalt fibers.

[0054] (8) The production efficiency and fiber properties of basalt fiber were tested, and the results are shown in Table 6.

[0055] Table 6: Melting parameters of basalt fiber raw materials and fiber properties of various examples

[0056]

[0057]

[0058] It can be seen from Table 6 that in Example 1, the redox atmosphere of the furnace melting is controlled by introducing 0.5% oxalic acid reducing atmosphere adjuster; at the same time, according to the content of the main chemical components of the mixed materials, 2.6% TiO2 and 2.0% MgO are further added to make the content of each main oxide in the raw material ideal, and the drawing effect and the original strength and modulus of the fiber are significantly better than those of the control example.

[0059] Example 2 is based on Example 1, adding 0.5% Li2O with stronger bond energy and smaller atomic radius, and adding 0.5% Y2O3 and 0.5% CeO2, two rare earth oxides with stronger bond strength, to increase the percentage of high-strength modulus oxides, thereby further improving the strength and modulus of the fiber precursor.

[0060] Example 3 is based on Example 2, and the percentage of the three oxides Li2O, Y2O3, and CeO2 added is increased to 1%. With the increase in the content of the reinforcing and modulus-enhancing oxides, the bonding force between atoms is enhanced, and the improvement of the internal crystal structure of the fiber is more obvious, making the strengthening effect in the fiber more significant, thereby improving the strength and modulus of the fiber.

[0061] Example 4 is based on Example 3, and the percentage of the two rare earth oxides Y2O3 and CeO2 added is increased to 1.5%. This incremental change continuously optimizes the internal structure of the fiber, and through the synergistic effect of the rare earth oxides and other components, the crystallization of the fiber is more perfect, the crystal defects are reduced, and the overall performance of the fiber is improved.

[0062] Example 5 is based on Example 4, and the percentage of the two rare earth oxides Y2O3 and CeO2 added is increased to 2.0%. At this time, the high content of rare earth oxides further strengthens the microstructure of the fiber, so that when the fiber is subjected to force, the stress can be more effectively transmitted and dispersed inside the fiber, thereby improving the tensile capacity and load-bearing capacity of the fiber, and the strength and modulus of the fiber are further improved.

[0063] Example 6 is based on Example 3, and 1.0% Sc2O3 and 1.0% La2O3 are added. The introduction of Sc2O3 and La2O3, more diverse chemical compositions and richer atomic particle sizes further adjust the crystal structure and chemical bond characteristics of the fiber, and interact with other components in the mixture, which may produce new reinforcing phases or change the distribution of the original phases, thereby continuing to affect the strength and modulus properties of the fiber.

[0064] Compared with the single basalt ore raw material of Longzhou Mountain (comparative example), all embodiments of the present invention have the following advantages in the homogenized mixture after the multi-component mixing and homogenization of the ore, the appropriate amount of reinforcing and increasing oxides, and the introduction of a trace amount of atmosphere (oxidation or reduction) regulator:

[0065] (I) It has much higher tensile strength and tensile elastic modulus. The tensile strength of all embodiments is greater than 2700MPa, and the tensile elastic modulus is greater than 92GPa, breaking the bottleneck of the tensile strength of continuous basalt fiber precursor in my country being less than 2600MPa and the tensile modulus being less than 90GPa. This is because the multi-component mixing makes the raw material composition more reasonable, the addition of the modulus-enhancing oxide optimizes the internal structure of the fiber and enhances the bonding force between atoms, and the atmosphere adjuster ensures the stability of the melting process, which together improve the modulus of the fiber.

[0066] (ii) It has a low melting temperature, molding temperature and liquidus temperature that can be implemented in industrial production. In the multi-component mixing process, the reasonable combination of raw materials reduces the energy demand of the system. At the same time, the atmosphere adjuster helps to reduce the viscosity of the melt and improve its fluidity, so that good melting and molding processes can be achieved at a lower temperature, which is beneficial to energy conservation and process control in industrial production.

[0067] (III) Higher yarn formation rate and full barrel rate can ensure the economic benefits of high modulus raw yarn production. Multi-component blending reduces the production instability caused by defects in a single ore raw material, and the synergistic effect of the enhanced modulus oxide and atmosphere regulator further improves the stability of the production process, making the fiber easier to shape and more stable in quality during the production process, thereby improving the yarn formation rate and full barrel rate.

[0068] It should be noted that the preferred embodiments of the present invention are given in the specification and drawings of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not used as additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all regarded as the scope of the present invention; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the protection scope of the claims attached to the present invention.

Claims

1. A method for improving the strength and modulus of continuous basalt fiber by multi-component mixing of raw materials, characterized in that: The method comprises the following steps: (1) Raw material selection: one or more neutral igneous rocks with a SiO2 mass percentage content greater than or equal to 54% and less than 66% are selected as the main material, and one or more basic-neutral igneous rocks with a SiO2 mass percentage content greater than or equal to 52% and less than 54% are selected as the auxiliary material; (2) Raw material ratio: Determine the chemical composition content of the main ingredient and the ingredients selected in step (1) by material testing means, and determine the ratio of the main ingredient and the ingredients based on the target component content of the mixed ingredients; (3) Mixing: Mixing the raw materials in the right proportions, crushing, grinding, and sieving, and homogenizing the obtained powder to obtain a mixed material, and sampling and testing to determine whether the actual content of the mixed material is within the target content range; (4) Selection and addition of reinforcing and modulus-enhancing oxides: Determine the type and amount of reinforcing and modulus-enhancing oxides to be added based on the actual content of the mixed ingredients and the expected strength and modulus of the continuous basalt fiber product; (5) Selection and addition of atmosphere adjusters: Determine the type and amount of atmosphere adjusters to be added based on the ratio of FeO / (Fe2O3+FeO) in the actual content of the mixed materials; (6) mixing the selected reinforcing and mold-enhancing oxide and atmosphere regulator with the mixed ingredients and performing a homogenization treatment; (7) Fiber production: The homogenized powder obtained in step (6) is subjected to wire drawing to obtain continuous basalt fibers.

2. The method according to claim 1, characterized in that The neutral igneous rock includes andesite or diorite; The basic-neutral igneous rocks include basalt, diabase, gabbro, basaltic andesite, diabase andesite, and pyroxene andesite.

3. The method according to claim 1, characterized in that The mass fraction of total iron in the main material is 6%-10%, and the mass fraction of total iron in the auxiliary material is 7%-12%.

4. The method according to claim 1, characterized in that: The mineral structures of the main material and the supplementary materials are dense or porphyritic.

5. The method according to claim 1, characterized in that The ignition loss of the main ingredient and the supplementary ingredients is ≤2.0%.

6. The method according to claim 1, characterized in that The target component contents of the mixed materials in step (2) are: by mass percentage, 54%-60% SiO2, 16%-18% Al2O3, 7%-11% Fe2O3+FeO, 6%-10% MgO, 6%-9% CaO, 2%-3% Na2O, 0.5%-1.5% K2O, and 1%-4% TiO2.

7. The method according to claim 6, characterized in that The target component content of the mixed material is, by mass, FeO / (Fe2O3+FeO)=0.4-0.8; Furthermore, in the target component content of the mixed material, the mass fraction of plagioclase + pyroxene is ≥ 70%.

8. The method according to claim 1, characterized in that: The reinforcing and mold-increasing oxide is selected from one or more of the following: 1) network formers: GeO2, Al2O3, ZrO2, V2O5; 2) network intermediates: Nb2O5, CeO2, Y2O3, Sc2O3, La2O3, TiO2; 3) network modifiers: MgO, Li2O, BeO.

9. The method according to claim 1, characterized in that: When the ratio of FeO / (Fe2O3+FeO) in the actual content of the mixed material is greater than or equal to 0.4 and less than 0.6, a reducing atmosphere adjuster is added; when the ratio of FeO / (Fe2O3+FeO) in the actual content of the mixed material is equal to 0.6, no atmosphere adjuster is added; when the ratio of FeO / (Fe2O3+FeO) in the actual content of the mixed material is greater than 0.6 and less than or equal to 0.8, an oxidizing atmosphere adjuster is added; Furthermore, the atmosphere adjuster is selected from one or more of the following: 1) oxidizing agent: MnO2, V2O5, CeO2; 2) reducing agent: MnO, citric acid, graphite, oxalic acid.

10. A continuous basalt fiber produced by the method of any one of claims 1-9.

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