A glass fiber formula containing coal gangue

Abstract

The present invention provides a glass fiber formula containing coal gangue. The raw materials, measured by weight percentage, include: 0-10wt% kaolin; 0-20wt% quicklime; 0-20wt% limestone; 60-70wt% pyrophyllite; 0-10wt% quartz sand; 0.05-1.5wt% coal gangue; 5-12wt% dolomite; and 0-1wt% soda ash. The present invention applies coal gangue to the production of glass fiber, expanding the raw material source for glass fiber, effectively solving the shortage of high-quality low-sulfur pyrophyllite, reducing the production cost of glass fiber, improving the performance of glass fiber, controlling the color of glass fiber, and making the operability and adjustability more suitable for the high-temperature melting process of glass fiber. Furthermore, the present invention solves the problem of recycling coal gangue, and has high economic and social benefits.

Description

Technical Field

[0001] The invention relates to the technical field of glass fiber production and manufacturing, and in particular to a glass fiber formula containing coal gangue. Background Art

[0002] Glass fiber is an inorganic non-metallic material with the advantages of abundant raw material resources, high specific strength, large specific surface area, good chemical stability, no secondary pollution and a certain degree of functional designability. It has a wide range of uses in transportation, industry, construction, environment and other fields.

[0003] The existing glass fiber production process mostly uses pyrophyllite, quartz sand, limestone, dolomite, colemanite, magnesite and other minerals as raw materials, and adds carbon powder and thenardite. It is manufactured through high-temperature melting, wire drawing, yarn winding, weaving and other processes. Among them, carbon powder acts as a reducing agent to prevent the formation of nitrate water when the glass batch contains sulfate, and converts part of the sulfate into sulfide. The appropriate amount of thenardite plays the role of fluxing and clarifying. The clarification of glass liquid is a very important process in glass melting. The quality of clarification plays a decisive role in the quality of glass liquid and whether it can be used for molded products.

[0004] Chinese patent application 201711032970X discloses a composite glass fiber composed of the following raw materials, by weight: 60-66 parts pyrophyllite, 20-22 parts colemanite, 32-33 parts limestone, 10-14 parts kaolin, 10-12 parts quartz sand, 3-5 parts firefly powder, 3-4 parts sodium sulfate, and 1-2 parts soda ash. To ensure the performance of the produced glass fiber, sodium sulfate is added as a clarifier.

[0005] For example, Chinese patent application No. 2017110813331 discloses a glass fiber production process, which includes the following steps: raw material preparation; raw material pulverization; raw material mixing and auxiliary raw material addition; melting; drawing; cooling; continuous heat treatment; batch heat treatment; and surface chemical treatment. During this production process, it is necessary to add auxiliary raw material clarifiers to improve the quality of the glass fiber.

[0006] The existing technology needs to strictly control the sulfur content in pyrophyllite, and needs to use high-quality low-sulfur pyrophyllite, wherein the content of sulfur oxide is ≤0.30 wt%. However, low-sulfur pyrophyllite is in short supply and has a high price, and the pyrophyllite ore source is becoming increasingly scarce, and the quality of pyrophyllite is continuously declining. In addition, the demand for high-quality pyrophyllite in the glass fiber industry is too great. How to control the local uneven composition caused by the reduction in the quality of pyrophyllite, which is not conducive to the high-temperature reaction in the furnace, and thus affects the quality of the glass liquid. How to reduce the quality requirements of pyrophyllite, expand the source of raw materials for pyrophyllite, effectively solve the problem of the shortage and high price of high-quality low-sulfur pyrophyllite in the existing technology, reduce the production cost of glass fiber, and make the manufactured glass fiber maintain stable performance, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of the present invention is to provide a glass fiber formula containing coal gangue, which solves the problems of glass fiber in the prior art, such as raw material limitation, high cost, difficult to control glass fiber color, and poor stability.

[0008] In order to achieve the above object, the present invention discloses a glass fiber formula containing coal gangue, wherein the raw materials of the glass fiber are composed of the following components: 0-10 wt% kaolin; 0-20 wt% quicklime; 0-20 wt% limestone; 60-70 wt% pyrophyllite; 0-10 wt% quartz sand; 0.05-1.5 wt% coal gangue; 5-12 wt% dolomite; 0-1 wt% soda ash; wherein the components of the coal gangue are, by mass percentage, as follows: SiO2: 40-48 wt%; Al2O3: 25-32 wt%; Fe2O3: 0.5-1.2 wt%; TiO2: 0.005-0.012 wt%; K2O: 1.0-2.50 wt%; Na2O: 0.5-2.5 wt%; CaO: 0.1 ~0.7wt%; MgO: 0.1 ~0.7wt%; SO3: 0.1 ~0.5wt%; C: 2 ~6wt%; the effective components used in the pyrophyllite are expressed as follows in weight percentage: AL2O3: 10~25wt%; Fe2O3≤0.5wt%; K2O≤0.80wt%; 0.6 <SO3≤1.35wt% 。

[0009] Furthermore, the raw materials of the glass fiber are composed of the following components:

[0010] Kaolin 3.0-4.0wt%;

[0011] Quicklime 16.5-18.0wt%;

[0012] Limestone 0-3.0wt%;

[0013] Pyrophyllite 65.0-66.5wt%;

[0014] Quartz sand 0-4.5wt%;

[0015] Gangue 0.2-0.5wt%;

[0016] Dolomite 11.0-12.0wt%;

[0017] Soda ash 0.14-0.32wt%.

[0018] Furthermore, the amount of coal gangue added is determined by the sulfate in the glass fiber raw material.

[0019] Furthermore, the mass ratio of the sulfate to elemental carbon in the raw material of the glass fiber is 2-10.

[0020] Furthermore, the color of the glass fiber is blue-green.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The glass fiber formula containing coal gangue of the present invention expands the raw material source of glass fiber and effectively solves the problem of shortage and high price of high-quality low-sulfur pyrophyllite in the prior art. High-sulfur pyrophyllite with a sulfur oxide content of 0.30 to 2.0 wt% can be used as the raw material, which is beneficial to reducing the production cost of glass fiber.

[0023] (2) The glass fiber formula containing coal gangue of the present invention solves the problem that sodium sulfate or a clarifier must be added separately to the raw materials to achieve sulfur clarification. At the same time, under high temperature conditions, the reaction effect of the elemental carbon in the coal gangue and the sulfur oxide in the raw materials is better, and the operability and adjustability are more suitable for the high-temperature melting process of glass.

[0024] (3) The glass fiber formula containing coal gangue of the present invention is conducive to controlling the color of the generated glass, and the glass fiber is stable blue-green.

[0025] (4) In the glass fiber formulation of the present invention, the coal gangue reacts with the sulfate in the raw material to form a sulfide, so that the sulfur contained in the raw material escapes from the melt in the form of SO2 in the early stage of the melting process, and the SO2 bubbles will not accumulate on the surface of the glass fiber to form foam. Because the amount of bubbles in the glass fiber is significantly reduced, the performance of the obtained glass fiber is improved, and the thickness of the foam layer in the kiln is effectively controlled.

[0026] (5) The glass fiber formulation containing coal gangue of the present invention effectively solves the problem of recycling solid waste coal gangue, reduces the emission of solid waste, and has high economic and social benefits. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other in any way.

[0028] The present invention provides a glass fiber formula containing coal gangue. The raw materials of the glass fiber include the following components: 0-10 wt% of kaolin; 0-20 wt% of quicklime; 0-20 wt% of limestone; 60-70 wt% of pyrophyllite; 0-10 wt% of quartz sand; 0.05-1.5 wt% of coal gangue; 5-12 wt% of dolomite; and 0-1 wt% of soda ash.

[0029] The components of the coal gangue, in percentage by mass, are as follows: SiO2: 40-48wt%; Al2O3: 25-32wt%; Fe2O3: 0.5-1.2wt%; TiO2: 0.005-0.012wt%; K2O: 1.0-2.50wt%; Na2O: 0.5-2.5wt%; CaO: 0.1-0.7wt%; MgO: 0.1-0.7wt%; SO3: 0.1-0.5wt%; and C: 2-6wt%. It should be noted that carbon powder and thenardite do not need to be added separately to the glass fiber raw material.

[0030] According to the present application, a process for preparing glass fiber containing coal gangue is provided:

[0031] Step S101: Raw material selection before production, including the following steps:

[0032] 1) Field research, sampling and testing;

[0033] 2) Sample composition and stability analysis;

[0034] 3) Determine the origin of the coal gangue and the ratio of pyrophyllite to coal gangue;

[0035] 4) Analysis of coal gangue mineral phase to determine whether it contains harmful substances;

[0036] 5) Measure and analyze the COD value of coal gangue to determine whether it affects the reaction atmosphere of the kiln;

[0037] 6) Applied to glass raw materials for production.

[0038] Step S102: Powder

[0039] Coal gangue with a diameter of less than 30cm is selected and ground into 200-mesh powder through ore processing.

[0040] Step S103: batch material preparation

[0041] Powders that meet the particle size requirements, including pyrophyllite, limestone, quicklime, kaolin, dolomite, and coal gangue, are weighed and mixed according to the formula components and transported to the kiln head bin.

[0042] Step S104: Kiln melting process

[0043] The so-called glass melting process refers to the process in which the batch materials undergo silicate reaction at high temperature and melt into homogeneous glass liquid.

[0044] The heated and melted mixed components are clarified and homogenized to produce high-temperature molten glass. Clarification refers to the process of removing bubbles from the molten glass.

[0045] The powder passes through high temperature (about 1600℃ in space and 1400℃ in glass liquid), and the important process parameters such as the melting atmosphere of the glass liquid (oxidizing or reducing atmosphere) and the furnace temperature, pressure, and liquid level need to be strictly controlled.

[0046] In existing glass fiber production technology, carbon powder and thenardite are separately added to the glass fiber raw materials. This is because the glass fiber raw materials contain sulfates, necessitating the addition of a reducing agent. The most common method is to add carbon to prevent the formation of nitrate water. Carbon can be introduced from materials such as coal powder, graphite, coke, and carbon black to reduce some of the sulfates to sulfides. The addition of an appropriate amount of thenardite primarily aids in the fluxing and clarification of sulfur by utilizing the oxidizing properties of thenardite in the presence of elemental carbon.

[0047] The specific chemical reaction process is as follows:

[0048] Na2SO4+C→Na2S+CO2Na2SO4+Na2S→Na2O+SO2

[0049] Sodium sulfate reacts with alkali metal or alkaline earth metal sulfides and chemically decomposes. This decomposition begins at a relatively low temperature (900°C). When sulfate is used alone, the thermal decomposition temperature of the sulfate needs to reach about 1288°C. Therefore, the "surfactant" effect of the sulfate and the interfacial turbulence effect are in effect above the primary melt temperature and continue until the sulfate and sulfide react completely.

[0050] At high temperatures (above 900°C), elemental carbon and sulfur react more readily to produce carbon dioxide and sulfur dioxide. When gangue is added, it reacts with sulfates to form sulfides, causing nearly all of the sulfur in the raw materials to escape from the melt as SO₂ early in the melting process. This minimizes the formation of foam at hot spots in the kiln (primarily due to the decomposition of residual sulfates) or the later generation of secondary bubbles in the clarifier. Even if SO₂ is present in the atmosphere above the melt, surface tension causes rising bubbles to burst upon reaching the melt surface, preventing them from accumulating and forming foam on the glass fiber surface. By replacing expensive carbon powder with inexpensive and readily available gangue, the thickness of the foam layer during the melting process is reduced by one-fifth to a stable, controllable 3-4 cm. This also significantly reduces the amount of bubbles in the resulting glass fiber, improving its performance.

[0051] In order to effectively discharge carbon dioxide and sulfur dioxide gases produced by the reaction of elemental carbon and sulfate from the glass liquid, the amount and weight of the added coal gangue are determined by the sulfate in the glass fiber raw material. The amount of coal gangue and pyrophyllite is adjusted by adjusting the content ratio of sulfate and elemental carbon. The mass ratio of sulfate and elemental carbon in the raw material of the glass fiber is preferably 2-10.

[0052] Step S105: Wire drawing

[0053] After the molten glass flows out of the melting part of the kiln, it enters the main passage for further clarification, homogenization and temperature adjustment, then enters the distribution passage and the forming passage, and then enters the platinum-rhodium alloy leak plate through the flow trough. After cooling and coating with wetting agent, it is wound onto the wire drawing machine, which stretches the glass liquid into glass fiber of a certain fineness. Example 1:

[0054] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 4.0 wt%; quicklime: 1.68 wt%; limestone: 2.20 wt%; pyrophyllite: 65.0 wt%; quartz sand: 2.0 wt%; dolomite: 11.40 wt%; soda ash: 0.13 wt%; carbon powder: 0.008 wt%; and thenardite: 0.1 wt%.

[0055] Among them, the sulfur oxide content in pyrophyllite is 0.25 wt%.

[0056] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0057] During the melting process a layer thickness of 5-10 cm of foam was observed.

[0058] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 1,169 bubbles in 1 kilogram of glass. Example 2:

[0059] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 4.0 wt%; quicklime: 16.5 wt%; limestone: 3.0 wt%; pyrophyllite: 65.0 wt%; quartz sand: 2.2 wt%; coal gangue: 0.2 wt%; dolomite: 11.0 wt%; and soda ash: 0.24 wt%.

[0060] Among them, the sulfur oxide content in pyrophyllite is 0.50 wt%,

[0061] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0062] A layer thickness of 4.2 cm was observed for the foam during the melting process.

[0063] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 427 bubbles in 1 kilogram of glass. Example 3:

[0064] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 3.0 wt %; quicklime: 16.84 wt %; limestone: 2.2 wt %; pyrophyllite: 66.16 wt %; quartz sand: 2.2 wt %; coal gangue: 0.24 wt %; dolomite: 11.40 wt %; and soda ash: 0.24 wt %.

[0065] Among them, the sulfur oxide content in pyrophyllite is 0.6wt%,

[0066] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0067] During the melting process, a layer thickness of 3.9 cm of foam was observed.

[0068] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 288 bubbles in 1 kilogram of glass. Example 4:

[0069] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 3.6 wt %; quicklime: 17.7 wt %; limestone: 0 wt %; pyrophyllite: 66.2 wt %; quartz sand: 4.35 wt %; coal gangue: 0.28 wt %; dolomite: 11.9 wt %; and soda ash: 0.32 wt %.

[0070] Among them, the sulfur oxide content in pyrophyllite is 0.67wt%,

[0071] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0072] During the melting process, a layer thickness of 3.8 cm of foam was observed.

[0073] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 256 bubbles in 1 kilogram of glass. Embodiment 5:

[0074] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 3.4 wt %; quicklime: 17.7 wt %; limestone: 0 wt %; pyrophyllite: 66.26 wt %; quartz sand: 4.4 wt %; coal gangue: 0.32 wt %; dolomite: 12.0 wt %; and soda ash: 0.32 wt %.

[0075] Among them, the sulfur oxide content in pyrophyllite is 1.35wt%,

[0076] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0077] A layer thickness of 3.5 cm of foam was observed during the melting process.

[0078] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 178 bubbles in 1 kilogram of glass. Example 6:

[0079] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 3.28 wt %; quicklime: 17.8 wt %; limestone: 0 wt %; pyrophyllite: 66.2 wt %; quartz sand: 4.5 wt %; coal gangue: 0.4 wt %; dolomite: 12.0 wt %; and soda ash: 0.32 wt %.

[0080] Among them, the sulfur oxide content in pyrophyllite is 1.59wt%,

[0081] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0082] A layer thickness of 3.4 cm of foam was observed during the melting process.

[0083] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope. This is equivalent to 108 bubbles in 1 kg of glass. Embodiment seven:

[0084] The raw materials of the glass fiber include the following components in parts by weight: kaolin: 3.15 wt%; quicklime: 18 wt%; limestone: 0 wt%; pyrophyllite: 66.5 wt%; quartz sand: 4.3 wt%; coal gangue: 0.5 wt%; dolomite: 12.0 wt%; and soda ash: 0.32 wt%.

[0085] Among them, the sulfur oxide content in pyrophyllite is 1.94wt%,

[0086] The components of the glass fiber raw materials are mixed, and heated, clarified and homogenized in sequence to obtain high-temperature molten glass.

[0087] A layer thickness of 3.1 cm of foam was observed during the melting process.

[0088] The high-temperature glass liquid flows out through a bushing and is cooled, soaked, and wound in sequence to obtain glass fiber. 3-5 grams of glass beads with a diameter of about 2 mm are weighed and the number of bubbles is observed under a microscope, which is equivalent to 0 bubbles per kilogram of glass.

[0089] In the present invention, in order to achieve the best production effect, the glass fiber formula containing coal gangue is preferably composed of the following raw materials, calculated by weight percentage: kaolin: 3.0-4.0wt%; quicklime: 16.5-18.0wt%; limestone: 0-3.0wt%; pyrophyllite: 65.0-66.5wt%; quartz sand: 0-4.5wt%; coal gangue: 0.2-0.5wt%; dolomite: 11.0-12.0wt%; and soda ash: 0.14-0.32wt%.

[0090] Among them, the sulfur oxide content in pyrophyllite is preferably 0.6-1.35 wt%. In order to ensure the normal operation of flue gas desulfurization and avoid excessive desulfurization pressure, the sulfur oxide content in pyrophyllite is more preferably 0.67 wt%.

[0091] In the present invention, coal gangue is applied to the production of glass fiber. By analyzing the chemical composition of coal gangue, after adding coal gangue, the silicon oxide and aluminum oxide in its components can also be introduced as raw materials for glass production. Iron oxide, potassium oxide, sodium oxide, and titanium oxide as impurity components will not affect the melting of the glass fiber raw materials, nor will they affect the performance of the produced glass. The introduced elemental carbon as a reducing substance can react with sulfur oxide in other raw materials with oxidizing properties to eliminate the influence of sulfur oxide. Sulfur oxide is a harmful element that is commonly present in the raw materials of glass fiber. Eliminating the influence of sulfur oxide can expand the source of raw materials. After adding coal gangue, the content of sulfur oxide in pyrophyllite is increased to 0.30-2wt%, which can effectively solve the problem of shortage of high-quality low-sulfur pyrophyllite. Low-priced high-sulfur pyrophyllite can be used in the production of glass fiber, which is conducive to reducing the production cost of glass fiber.

[0092] Coal gangue is a waste product from coal mining and occupies a large amount of land for storage. After experiments, it was found that when coal gangue is used in glass fiber production, there is no need to add carbon powder and Glauber's salt separately to the raw materials to achieve sulfur clarification. Under high temperature conditions, the elemental carbon in coal gangue reacts better than directly using high-purity carbon powder and sulfur oxide in the raw materials. Its operability and adjustability are more suitable for the high-temperature melting process of glass fiber raw materials.

[0093] By analyzing the mineral phase to determine whether there are harmful impurities, and measuring the COD value to calculate whether it affects the reaction atmosphere of the kiln, and analyzing the reaction mechanism of organic matter and sulfur oxides, it is also possible to eliminate the adverse effects of sulfur oxides in pyrophyllite on kiln melting, turning it into a favorable factor to improve the melting quality of glass fiber raw materials. Through coal gangue, the glass fiber, which was unstable yellow in the original production technology, can be adjusted to a stable and controllable state, and the color of the glass fiber is stable blue-green.

[0094] In summary, the glass fiber formula containing coal gangue provided by the present invention can effectively solve the technical problems existing in the glass fiber process, help reduce the cost of glass fiber production; it can also solve the environmental problems faced by coal gangue solid waste, and has high economic and social benefits.

[0095] The above embodiments are intended to illustrate the technical solutions of the present invention and are not intended to limit the same. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A glass fiber comprising coal gangue, characterized in that: The raw materials of the glass fiber are composed of the following components: 0-10 wt% kaolin; 0-20 wt% quicklime; 0-20 wt% limestone; 60-70 wt% pyrophyllite; 0-10 wt% quartz sand; Gangue 0.05 ~ 1.5 wt%; dolomite 5 ~ 12 wt%; soda ash 0 ~ 1 wt%; wherein, the components of the gangue are calculated by mass percentage: SiO2: 40 ~ 48wt%; AL2O3: 25 ~ 32wt%; Fe2O3: 0.5 ~ 1.2wt%; TiO2: 0.005 ~ 0.012wt%; K2O: 1.0 ~ 2.50wt%; Na2O: 0.5 ~ 2.5wt%; CaO: 0.1 ~ 0.7wt%; MgO: 0.1 ~ 0.7wt%; SO3: 0.1 ~ 0.5wt%; C: 2 ~ 6wt%; the effective components used in the pyrophyllite are calculated by weight percentage, 0.6 <SO3≤1.35wt% 。 2. The glass fiber containing coal gangue according to claim 1, characterized in that: The raw materials of the glass fiber are composed of the following components: Kaolin 3.0-4.0wt%; Quicklime 16.5-18.0wt%; Limestone 0-3.0wt%; Pyrophyllite 65.0-66.5wt%; Quartz sand 0-4.5wt%; Gangue 0.2-0.5wt%; Dolomite 11.0-12.0wt%; Soda ash 0.14-0.32wt%; The components of the pyrophyllite further include, by weight percentage: AL2O3: 10-25wt%; Fe2O3≤0.5wt%; K2O≤0.80wt%.

3. The glass fiber containing coal gangue according to claim 1, characterized in that: The amount of coal gangue added is determined by the sulfate in the glass fiber raw material.

4. The glass fiber containing coal gangue according to claim 1, characterized in that: The mass ratio of the sulfate to elemental carbon in the raw material of the glass fiber is 2-10.

5. The glass fiber containing coal gangue according to claim 4, characterized in that: The color of the glass fiber is blue-green.