KR101438366B1 - A manufacturing method for E-glass fibers using the coal Waste and manufacturing for E-glass fibers - Google Patents

Abstract

The present invention relates to an E-glass fiber manufacturing method using coal waste and the E-glass fiber manufactured by using same. The present invention includes 1) a step for stirring and mixing E-glass fiber raw materials; 2) a step for forming molten glass through high-temperature melting of the mixed raw materials; and 3) a step for turning the molten glass into a fiber with a fiberizing device. Sandstone-based coal waste of silica-alumina with a relatively low carbon content is used and a waste input amount is changed so that bulk glass and fiber glass with the E-glass composition can be manufactured. The present invention can make a glass fiber satisfy thermal characteristics, optical characteristics, a thermal expansion coefficient, optical transparency, tensile strength, and the like. Accordingly, a high-efficiency glass fiber material can be manufactured with high efficiency and low costs. Also, resources recycling can be improved.

Description

Technical Field [0001] The present invention relates to a method for manufacturing an E-glass fiber using coal waste, and an E-glass fiber produced by the method.

The present invention relates to a method for producing E-glass fiber using coal waste seals and an E-glass fiber produced thereby. More specifically, the present invention relates to a method for producing E-glass fiber by using silica-alumina sandstone coal waste having a relatively small carbon content, Which is made of the E-glass of the present invention, to produce bulk glass and fiber glass, thereby making it possible to satisfy the glass fiber with thermal properties, optical properties, thermal expansion coefficient, light transmittance and tensile strength. And to an E-glass fiber produced by the method.

Generally, a large amount of coal waste is generated as an incidental product due to the development of coal. In the meantime, recycling of coal waste has not been developed and it has been difficult to perform simple landfill, so it has been neglected around coal mines. Such abandoned coal mines, which have not been treated for a long period of time, are harmful to the surrounding landscape and pollute the natural environment.

According to the data of domestic coal mine pollution surveyed by the coal rationalization project group, abandoned coal mine from 1989 to 1993 produced about 200 million tons of waste segregation, and in the nine coal mines currently available, 36 million tons And it has been reported that there is a limit.

In addition, the study on the utilization of coal waste has been diversely researched and utilized in various fields such as cement raw materials, ceramics, ceramic aggregate, industrial raw materials and civil engineering. In Korea, there have been studies on utilization as ceramics and industrial use, but it is very poor. Research on the recycling of waste resources has been carried out mainly on the production of artificial lightweight aggregates by using coal ash and sewage sludge generated from thermal power plants.

On the other hand, in this study, the use of coal waste from mine to combine the raw materials based on the silica (SiO ₂ ) component contained in the coal waste, melts and vitrifies it, and glass that can be used as a reinforcing material The development of secondary products, such as fiber, has been studied in order to save the environment and increase the added value of waste resources. The most important thing in making glassware is to determine the target chemical composition for vitrification and to select the blending ratio of the raw materials to match the composition.

It is also important to select the melting conditions to make amorphous transparent glass. After determining the chemical composition of the coal waste and the composition of the glass to be produced, the ratio of the additional raw materials required here must be set to meet this requirement. In the present invention, the glass fiber to be produced using the coal waste scrap can be classified into A-Glass, C-Glass, E-Glass, S-glass and AR-Glass depending on the characteristics and chemical composition. Of these, E-Glass is the most commonly used glass fiber. This is because the E-glass fiber has various characteristics such as mechanical strength, electrical properties, and chemical properties, and is very useful in terms of utilization. A typical E-Glass chemical composition is _{silica (SiO 2), alumina (} Al 2 O 3), calcium oxide (CaO), magnesium oxide (MgO), boric oxide (B 2 O 3) and a small amount of alkali (Na ₂ O of / K ₂ O). By substituting about 6 to 8% of the SiO ₂ content with B ₂ O ₃ , the glass has an effect of lowering the melting temperature and viscosity of the glass. As a result, the alkali (Na ₂ O, K ₂ O ) Content is as low as less than 1% and thus has excellent electrical insulating properties. Such glass fiber is used as a composite material in a wide range of applications, and it is widely used as a reinforcing material for fiber reinforced plastic (FRP) in aircraft, automobile, and various leisure products.

Accordingly, the present invention seeks to develop a new method for improving the environment and producing a high value-added product by recycling such coal waste as a resource.

An object of the present invention is to improve the above-mentioned conventional characteristics, and it is an object of the present invention to provide a method for producing a silica-alumina- Glass fiber fabrication method using coal waste stones which makes it possible to produce bulk glass and fiber glass of glass composition so that thermal property, optical property, thermal expansion coefficient, light transmittance and tensile strength can be satisfied with glass fiber and To provide the produced E-glass fibers.

The present invention has the following structure in order to achieve the above object.

The method for producing E-glass fiber using coal waste seals according to the present invention comprises the steps of: 1) mixing and mixing raw materials of E-glass fibers; 2) melting the mixed raw material at a high temperature to form a molten glass; And 3) fiberizing the molten glass using a fibrousizing apparatus.

The raw materials include coal waste, aluminum oxide (Al ₂ O ₃ ), calcium carbonate (CaCO ₃ ), boric acid (H ₂ BO ₃ ) and wave glass.

The raw material is composed of 35 wt% of coal waste, 3 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) and 32 wt% of glass wastes.

The raw materials were 15 to 30 wt% of coal waste, 3 to 5.7 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) %, and silicon dioxide (SiO ₂₎ is made to 4.2 ~ 17.3% by weight.

It is preferable that the coal waste lime is sandstone lime waste coal.

And a pretreatment step of adjusting the carbon content and the oxidation state in the coal waste so that the redox condition for optimizing the fining property for removing bubbles in the molten glass is controlled before or during the step 1).

The purifying and oxidizing agent includes sodium sulfate (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), arsenic oxide (As ₂ O ₃ ), and antimony oxide (Sb ₂ O ₃ ).

In the pretreatment step, the carbon content in coal waste can be controlled within 1 to 2%.

Also, in the pretreatment step, the oxidation state can be controlled so that the redox value in the coal waste scrap is 0.15-0.25.

In the step 2), the stirred raw material is placed in a platinum crucible and melted in a box-shaped electric furnace at 1550 ° C for 2 hours.

Meanwhile, the present invention includes E-glass fibers prepared by the method of manufacturing E-glass fibers using coal waste.

By using the silica-alumina sandstone waste waste having a relatively small carbon content according to the present invention, it is possible to produce the bulk glass and the fiber glass of each E-glass composition produced by changing the input amount of the waste stone, By making the glass fiber satisfactory in properties, optical properties, thermal expansion coefficient, light transmittance and tensile strength, it is possible not only to produce a glass fiber material with high efficiency at a low cost, but also to increase the recyclability of resources.

1 is a block diagram showing a process for producing E-glass fiber using coal waste seals according to the present invention and a process for producing E-glass fiber produced thereby.
Figure 2 shows a fibrous device according to the invention.
Figure 3 is a photograph of an E-glass tested according to the present invention.
FIG. 4 is a graph showing the TG-DAT analysis of coal waste segregation according to the present invention. FIG.
5 is a graph showing the transmittance of an E-glass according to the present invention.
6 is a graph showing the chromaticity of an E-glass according to the present invention.
7 is a photograph showing a state in which the E-glass according to the present invention is tested for hydrochloric acid.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

It is to be understood that the following specific structure or functional description is illustrative only for the purpose of describing an embodiment in accordance with the inventive concept, and that the embodiments according to the concept of the present invention may be embodied in various forms, It should not be construed as being limited to examples.

Since the embodiments according to the concept of the present invention can make various changes and have various forms, specific embodiments are illustrated in the drawings and described in detail herein. However, it should be understood that the embodiments according to the concept of the present invention are not intended to limit the present invention to specific modes of operation, but include all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

The terms first and / or second etc. may be used to describe various components, but the components are not limited to these terms. The terms may be named for the purpose of distinguishing one element from another, for example, without departing from the scope of the right according to the concept of the present invention, the first element being referred to as the second element, The second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when it is mentioned that an element is "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions for describing the relationship between components, such as "between" and "between" or "adjacent to" and "directly adjacent to" should also be interpreted.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It will be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, parts or combinations thereof, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

As shown in FIG. 1, the method for producing E-glass fiber using coal waste stone of the present invention comprises the steps of 1) mixing and mixing raw materials of E-glass fibers; 2) melting the mixed raw material at a high temperature to form a molten glass; And 3) fiberizing the molten glass using a fibrousizing apparatus.

The raw materials include coal waste, aluminum oxide (Al ₂ O ₃ ), calcium carbonate (CaCO ₃ ), boric acid (H ₂ BO ₃ ) and wave glass.

The raw material is composed of 35 wt% of coal waste, 3 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) and 32 wt% of glass wastes.

The raw materials were 15 to 30 wt% of coal waste, 3 to 5.7 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) %, and silicon dioxide (SiO ₂₎ is made to 4.2 ~ 17.3% by weight.

It is preferable that the coal waste lime is sandstone lime waste coal.

And a pretreatment step of adjusting the carbon content and the oxidation state in the coal waste so that the redox condition for optimizing the fining property for removing bubbles in the molten glass is controlled before or during the step 1).

The purifying and oxidizing agent includes sodium sulfate (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), arsenic oxide (As ₂ O ₃ ), and antimony oxide (Sb ₂ O ₃ ).

In the pretreatment step, the carbon content in coal waste can be controlled within 1 to 2%.

Also, in the pretreatment step, the oxidation state can be controlled so that the redox value in the coal waste scrap is 0.15-0.25.

In the step 2), the stirred raw material is placed in a platinum crucible and melted in a box-shaped electric furnace at 1550 ° C for 2 hours.

Meanwhile, the present invention includes E-glass fibers prepared by the method of manufacturing E-glass fibers using coal waste.

For example, the present invention relates to a method for producing a raw material comprising 35 wt% of coal waste, 3 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) 15 to 30% by weight of coal waste stones further containing 4.2 to 17.3% by weight of silicon dioxide (SiO ₂ ), 3 to 5.7% by weight of aluminum oxide (Al ₂ O ₃ ) , 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ), and 32 wt% of wax glass were mixed and stirred to prepare an E-glass fiber, (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), arsenic oxide (As ₂ O ₃ ) and antimony oxide (Sb ₂ O ₃ ) are mixed and used to adjust the carbon content in the mixture and the oxidation state of the mixing batch . Through this process, the carbon content and the oxidation state in the molten glass formed by heating and melting on the furnace are controlled to produce pure white-colored E-glass fiber.

The process for producing an E-glass of the present invention will be described concretely with reference to the following examples.

The most important thing in making glassware is to determine the target chemical composition for vitrification and to select the blending ratio of the raw materials to match the composition.

It is possible to produce a glass having desired physical and chemical characteristics depending on how the synthesis ratio of the raw materials is made and to produce a transparent glass having good characteristics under the melting temperature condition. In the present invention, the raw material was used as coal mine waste, and sandstone coal wastes having low carbon content were used among coal mine waste mine.

Chemical compositional analysis values of the sandstone coal waste seals used in the present invention are shown in Table 1. Table 2 shows the mixing ratio of the glass composition using the coal waste lime used. The composition ratio of glass for vitrification was changed to 15 ~ 35% by changing the content of coal waste to E-glass. Representative E-glass composition was as shown in Table 2, there are used in combination to fit the raw materials silica sand, limestone, alumina and the like on the mixing ratio, as in this way in the present invention is used as a main raw material for the general coal washability pumice and silica sand here (SiO ₂₎ (Al ₂ O ₃ ), calcium carbonate (CaCO ₃ ), boric acid (H ₃ BO ₃ ) and E-glass wave glass. The wave glass has a lower melting temperature of the glass, (SiO ₂ ) was used for the purpose of enhancing the homogeneity and mechanical strength.

Here, the silica sand is a main raw material commonly used in the production of E-glass fiber, and it is to reduce the production cost of E-glass fiber and the recyclability of resources by using coal waste as a substitute material.

SiO ₂ Al ₂ O ₃ Na ₂ O CaO K ₂ O MgO TiO ₂ Fe ₂ O ₃ SO ₃ Refused  coal ore
( Normal ) 81.1 12.0 0.18 0.06 3.36 0.28 0.51 0.51 1.96

<Chemical composition analysis of sandstone waste coal waste (Wt%)>

Raw materials Batch Composition  ( wt .%) Remarks CNEF -0 CNEF -15 CNEF -20 CNEF -25 CNEF -30 CNEF -35 Refused
coal ore   (CN) 15.00 20.00 25.00 30.00 35.00 ( Target of Glass
Composition )

SiO ₂ : 54.5
Al ₂ O ₃ : 14
Na ₂ O : 0.8
CaO : 22.1
K ₂ O : 0.2
MgO : 0.6
TiO ₂ : 0.5
Fe ₂ O ₃ : 0.2
B ₂ O ₃  : 6.6
SiO ₂ 28.50 17.30 13.00 8.60 4.20 0.00 Al ₂ O ₃ 7.50 5.70 5.00 4.40 3.80 3.00 Na ₂ CO ₃ 0.70 CaCO ₃ 20.00 20.00 20.00 20.00 20.00 20.00 K ₂ CO ₃ 0.20 MgCO ₃ 0.77 E- glass   cullet 32.00 32.00 32.00 32.00 32.00 32.00 H ₃ BO ₃ 10.00 10.00 10.00 10.00 10.00 10.00 Fe ₂ O ₃ 0.08 TiO ₂ 0.25

<Composition table of E-glass composition>

Remarks shown in Table 2 are formed by each of the compositions of CNEF-0 to CNEF-35 as a condition for the composition for producing E-glass, and the CNEF-15 to CNEF-35 corresponding to the present invention A pretreatment process is required to satisfy the composition conditions.

Further, the cleaning and oxidizing agents for the pretreatment include sodium sulfate (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), arsenic oxide (As ₂ O ₃ ) and antimony oxide (Sb ₂ O ₃ ) Can be adjusted within 1 ~ 2%.

In the pretreatment step, it is preferable to adjust the redox value in the coal waste liquor to be 0.15-0.25.

The coal waste stone used in the present invention was sampled from coal pellets collected from Samcheok coal mine. The mineral raw materials were pulverized to 300 μm or less with a ball mill to control the grain size uniformly.

The ground mineral materials, the chemical raw materials and the wave glass were combined at the blending ratios shown in Table 2, mixed and plated in a platinum crucible for melting for 2 hours at 1550 ° C in a box-type electric furnace.

Then, the molten glass was taken out from the furnace and poured onto a graphite mold to prepare a specimen,

 For the stress relief, the molded specimens were held in the annealing furnace maintained at 657 ° C, the annealing temperature of the boron-free E-glass, BF composition, And the final glassy spirits were collected and confirmed to be vitrified.

In addition, to grasp the characteristics in the fiber state, a separate fiber pulling device as shown in FIG. 2 was manufactured by melting the raw glass, and a single filament was manufactured and its properties were evaluated. In order to measure the tensile strength, one glass fiber is placed in the center of 50mm grooved cardboard and fixed with a strong adhesive. The tensile strength of the specimens is measured 30 times or more per composition by using a universal testing machine with a load cell of 100N at a tensile speed of 1 mm / min. The average value was then taken.

The thermal expansion coefficients of the glass specimens were measured using TMA (Thermomechanical Analyzer: Q400, TA, USA) and the softening point was measured using a softening point meter (SP-3A, ORTON, USA) And the softening point was measured.

In order to investigate the vitrification state and optical properties, the glass specimens were mirror-polished uniformly at 3 mm, and then the light transmittance in the visible light region and the chromaticity of the color coordinates were measured using a UV / VIS / IR Spectrometer (V570, JASCO, JAPAN) The chemical properties of glass fiber were measured by glass fiber specimens. Single glass fiber specimens of each composition were subjected to microscopic observation of changes in the surface state of the fibers with a 5% hydrochloric acid solution at 90 ° C over time. Field emission scanning electron microscope (FE-SEM, JSM 6700, JEOL) was used for this purpose. In addition, INSTRON (5544, 2712-013, USA) was used for measuring the tensile strength of single glass fiber of each composition in order to evaluate mechanical properties as reinforcing fiber.

As shown in Table 1, the contents of SiO ₂ and Al ₂ O ₃ were 81.1% and 12.0%, respectively, in general coal pumice. Table 2 shows the target composition and blending ratio of E-glass adopted in the present invention.

In this experiment, only the change in the content of coal waste was aimed with the aim of the previously announced E-glass composition (CNEF-0 in Table 2). CaCO ₃ , H ₃ BO ₃ , and wave glass were fixed except for the components of SiO ₂ and Al ₂ O ₃ , which are the major components of the waste segregation, in order to change the contents of coal waste.

The CaCO ₃ , H ₃ BO ₃ and wave glass components did not change.

In the present invention, the characteristics of vitrification and glass were observed while changing the content of coal waste to 15 to 35% based on the batch composition.

In addition, the iron oxide (Fe ₂ O ₃ ) raw material present in the waste liquor may not be meaningful in experimental experiments, but it is intended to grasp the influence of the iron oxide component as an impurity in mass production in the future. In the case of a glass obtained by melting a mixed batch and taking it out of a high-temperature box, molding it in a graphite mold, and slowly cooling the mixture in a high-temperature annealing furnace at 657 ° C, as shown in the photographs of (a) to (f) And showed a clear greenish transparent glass state. Partial bubbles were observed to be contained in the glass specimen, but particles such as unmelted or silt were not found, and it was judged that complete vitrification was achieved. The reason why the glass specimens are light green is considered to be the influence of the iron oxide (Fe ₂ O ₃ ) component included in the batch composition, and the process for preparing the glass specimens close to pure white is prepared by including a pretreatment process. In the case of the glass fiber produced using the fiber lifting device, as shown in the lower drawing of Fig. 3 (a) to (f), glass fiber with white color could be produced visually.

However, in the present invention, it is possible to improve the function as glass fiber through a pretreatment process in order to improve the performance as an actual product. The coal waste stone mined from the coal mine is divided into shale and sandstone. And the carbon content is large. In the case of the shale coal waste lime stone, vitrification into a waste stone having a relatively large amount of carbon constitutes a black glass, which can be utilized for manufacturing general craft and molding glass, but is unsuitable for E-glass fiber as in the present invention. Therefore, it is possible to use sandstone coal waste. That is, due to the carbon component contained in the coal waste, they are oxidized by the temperature rise in the melting process and are gasified into the CO2 state, but they serve to reduce the glass itself. Therefore, the melting condition, defoaming condition, And so on, it can be used only if it is controlled.

Therefore, when the raw material of coal waste for glass fiber is used, the difference in the carbon content of each lot may occur. Therefore, the IG. You have to adjust the compounding ratio by measuring the exact amount of loss. The explanation for this is based on the clarification and reduction composition ratio.

For example, as described above, when vitrification is carried out by using the coal waste stone raw material, it is necessary to calculate the degree of reduction of the glass according to the carbon content in the waste lime and further add the amount of the oxidizing agent and the defoaming agent according to need, The degree of reduction is represented by the term "Redox". As the glass is converted to a reduced state by the carbon component, the iron oxide component in the glass is converted from FeO 3 to FeO and the heat transfer from the molten glass specimen to the bottom in the melting furnace is not performed well The upper temperature is increased and the lower temperature is lowered, thereby changing the melting state of the glass.

In addition, since the purifying characteristic of the glass, that is, the defoaming characteristic of the bubble, changes according to the change of "Redox", it is necessary to keep the redox condition of the glass constant in order to produce a clean glass without bubbles.

Accordingly, it is possible to produce the required uniform E-glass fiber by controlling the carbon content in the coal waste and regulating the redox state in the raw material mixing batch, and the oxidizing agent, the refining agent and the controlling ratio thereof are as described above.

In view of the characteristics of the E-glass fiber produced by the manufacturing method of the present invention,

* Light transmittance characteristic of E-glass

In the present invention, in order to grasp the vitrification state and the melting state of the specimen according to each composition of the E-glass according to the content of the coal waste, the molten glass specimen is mirror-polished to a thickness of 3.0 mm, and then, using a spectrophotometer, The light transmittance was measured. As can be seen from the graphs shown in Table 3 and FIG. 5, the visible light transmittance values of all the specimens were 81 to 84% in the light transmittance, which was almost similar to the light transmittance level in the commercial transparent plate glass. Compared with CNEF-35 containing 35% compared to CNEF-15 containing 15% of waste, it can be seen that the permeability gradually decreases. As the content of waste segregation increases, the amount of carbon contained in the wastes increases. As a result, the difference in bubble and fume existing during melting and the difference in surface condition and Fe ₂ O ₃ content increases, Of the total. On the other hand, CNEF-0 shows a similar transmittance value to the specimen containing 20% of waste lime. As a result, it can be seen that the tendency of the change of the permeability according to the amount of the waste lime is not large up to 20% of the waste lime content.

For example, it can be seen that the present invention of CNEF-15 to CNEF-35 has relatively low transparency compared to CNEF-0 manufactured in the conventional manner, but maintains the light transmittance standard or more.

Sample name Light Transmittance
(%) Chromaticity L a * b * CNEF -0 83.9 93.92 -3.18 4.43 CNEF -15 84.7 94.22 -2.99 3.52 CNEF -20 83.8 94.00 -3.17 3.73 CNEF -25 82.7 93.51 -3.30 4.18 CNEF -30 82.3 93.32 -3.67 4.85 CNEF -35 81.7 92.90 -3.78 5.30

<Comparison of light transmittance and chromaticity of sample>

* Chromaticity of E-glass

Although it is not an important characteristic in the production of glass fiber, it is a method for confirming the degree of optical difference of E-glass produced according to the change of the input amount of coal waste, and the chromaticity diagram is used to determine the color distribution I measured it. The color coordinates of each specimen were measured using a spectrophotometer, which is shown in FIG. As can be seen in the figure, all of the six composition samples were almost distributed on the coordinates of '0' representing pure white color, and it was confirmed that the coordinate values were slightly shifted to the green direction due to the coloration due to iron oxide. In order to confirm the difference of the chromaticity values for the molten glass, the L value and the b value were found to be slightly expanded from 92.9 ~ 94.22 and 3.52 ~ 5.30, respectively. 2.99 ~ -3.78, but it was not considered to be a big problem because it was not a deviation that can be classified into the naked eye, and it can be confirmed that the difference of the increase amount of the waste lime is shown.

In other words, as can be seen from this experiment, it is satisfactory to manufacture E-glass fiber by using only the coal waste stone, but it is possible to enhance the color stability of the glass through a pretreatment process to improve the quality, .

* Thermal properties of glass

The thermal properties of the glass fiber are not only a significant influence on the heat resistance as reinforcing fibers of the composite material but also have a very important factor as a factor for determining the melting of the glass and the fiberization conditions of the glass fiber. Therefore, glass fiber has softening point of 830 ~ 860 ℃ in general E-glass fiber according to the heat resistance characteristic, 916 ℃ of existing BF (Boron Free E-glass) fiber, high strength and high heat resistance S -glass fiber has a softening point of 1,050 ° C or higher.

The softening point as a thermal property of the glass is a value representing the temperature at which the viscosity value of the glass is 10 ^7.6 poise and is regarded as an important value for determining the properties of the glass and the manufacturing process together with the working point of the glass.

The results of measuring the softening point of each composition of the prepared glass samples show 851 ~ 860 ° C as shown in Table 4. Compared with CNEF-15, the softening point decreased slightly as the content of waste stones increased. This is probably due to the alkaline content of waste wastes. All of the six compositions were placed in line with the E-glass as the target composition. However, the alkaline content of the waste is inevitably increased with increasing the amount of the alkali, and the glass transition temperature and softening temperature are lowered as the alkali content is increased. However, it can be seen that the softening point of general E-glass is 830 ~ 860 ℃ and that all of the samples obtained in this experiment are similar to the values within the softening point range generally used.

Sample name Softening point
 (° C) Thermal expansion coefficient
 (x10 ^-6 / ° C) CNEF -0 851 5.612 CNEF -15 860 5.392 CNEF -20 856 5.408 CNEF -25 856 5.411 CNEF -30 855 5.469 CNEF -35 855 5.612

<Comparison of thermal characteristics>

The thermal expansion coefficient of the glass specimen was measured using a thermomechanical analyzer (TMA) as one of the thermal characteristics. The results are shown in Table 4. As can be seen in the table, the thermal expansion coefficient of 'BF' specimen was 5.392 ~ 5.612x10 ^-6 / ℃ for each composition. As can be seen in Table 4, the coefficient of thermal expansion tends to increase gradually as the content of waste clay increases. The E-glass fiber has a thermal expansion coefficient of about 4.9 to 6.0 × 10 ^-6 / ° C, and the specimen in this experiment is within the general range. Generally, the smaller the thermal expansion coefficient of glass, the greater the thermal shock resistance to thermal change. The thermal shock resistance is expressed by the temperature difference (ΔT) at which the glass breaks, and is expressed by the following equation.

? T =? (1-v) / (E *?) * S

E is Young's Modulus, α is the coefficient of linear expansion, and S is the value depending on the shape of the test specimen.

Therefore, although the thermal properties of the reinforcing fibers do not greatly affect the role of the fibers themselves, they show that they exhibit sufficiently good properties in terms of thermal properties as compared with the conventional "E-Glass" in terms of thermal properties have.

* Chemical properties of E-glass

In general, fiber glass has a larger specific surface area than a bulk glass, and thus is highly corrosive due to acid and alkali.

Therefore, in order to compensate for these characteristics, the glass fiber used for reinforcing cement and concrete is made of AR (Alkali Resistant) glass fiber and a special composition of glass fiber containing zirconia (ZrO ₂ ) is used.

On the other hand, a glass fiber having a composition of a general E-glass contains a component which is easily dissolved in an acid, so that cracks are generated on the surface of the glass fiber when contacted with an acid and cause total corrosion of the glass fiber, Corrosion of fibers is a result of strengthening reinforcement, resulting in deterioration of physical properties of the entire composite material.

In this experiment, to determine the chemical characteristics of E-glass, glass fibers were prepared for each composition through a glass fiber pulling apparatus as shown in FIG. 2, and each of the fiber specimens The samples were sampled at a fixed time from 20 minutes to 180 minutes after immersion, and the change of fiber surface state was observed with a microscope.

Figure 7 shows photographs of the six types of glass fiber specimens after 20, 40, 60, 120, and 180 minutes of solution deposition, respectively, depending on the input of coal waste. As can be seen in the photograph, the surface state of the pre-immersion fiber showed a relatively clean surface state, but in the case of CNEF-0, it is observed that fine cracks occurred on the surface after 40 minutes of immersion.

On the other hand, the CNEF-15 to 35 produced by using the coal waste abatement of the present invention shows a reaction on the surface after a lapse of 180 minutes although there is a slight difference in each sample. Compared with the conventional E-glass, E-glass fiber containing coal waste is remarkably good on acid-resistant surface.

However, in the case of CNEF-0 produced by the conventional method, the reaction starts to show from 20 minutes, and after 180 minutes, it is observed that the shape of the fiber is collapsed due to the peeling phenomenon on the surface. This is the same target composition, but it is considered to be the difference between the case of using chemical raw materials and the case of using mineral as raw material.

Therefore, the E-glass composition with coal waste was superior in terms of erosion resistance, indicating that it has sufficient qualification as a reinforcing fiber.

* Tensile strength of E-glass

In order to reduce the experimental error in the tensile strength test, the total fiber weight per composition was measured 35 times. Table 5 shows the tensile strength of glass fiber measured at room temperature.

As a result, the glass fibers showed a distribution in the range of 200 to 600 MPa although there were differences in sample and diameter.

As can be seen from Table 5, it can be seen that the strength value tends to decrease when the diameter of the fiber increases by composition. This can be understood by the theory proposed by Griffith. The surface of the glass is so invisible as to be invisible. There are flaws everywhere, and these flaws act to increase the internal stress. This flaw is called Griffith's flaw. Defects will be present in thick fibers, which show the relationship between thickness and tensile strength.

Also, it can be confirmed that the strength value is decreased although the difference is not great as the content of waste lime increases. Despite the fact that it has been emitted as an experimental result, it is possible to radiate various fibers from 30 μm band to 200 μm band. If the thickness of commercially available fiber is 10 ~ 20 μm, it is enough to control the thickness sufficiently The results of this experiment were confirmed.

Sample name Fiber
Diameter (탆) Load  ( Mpa ) Average strength
( MPa ) CNEF -0 90 to 140 267-511 380 140-190 251-289 270 CNEF -15 30 to 50 360 ~ 1765 738 50 to 90 217 to 923 461 90 to 140 209-757 439 140-190 292 to 419 356 CNEF -30 30 to 50 488 to 900 656 50 to 90 381 to 509 449 90 to 140 247 ~ 489 333 140-190 155 to 367 238

<Tensile strength comparison>

As in the present invention, the conventional E-glass fiber which is widely used as reinforcing fiber of composite material was subjected to experimental melting test and characteristics measurement using SiO ₂ and Al ₂ O ₃ , which are main components of sandstone coal waste. The amount of coal waste was varied from 15 to 35%, and the composition of each composition was melted at 1550 ° C for 2 hours, resulting in a clear glass. The visible light transmittance of the molten glass is 81 ~ 84%, and the permeability decreases as the amount of waste stones increases. The softening point, which is a thermal characteristic, tends to decrease when the content of waste stone increases from 850 to 860 ° C. And 5.392 ~ 5.612x10 ^-6 / ℃, respectively.

In the acid-fastness test of the glass fiber produced by the experimental test at 90 ° C hydrochloric acid solution, fine cracks occurred on the surface of the fiber after 180 minutes from the CNEF-15 to 35 produced using the mineral raw material as the immersion time elapsed CNEF-0, which is produced only as a chemical raw material, shows a peeling phenomenon on the surface after 20 minutes, and the fiber shape collapses after 180 minutes. As a result, it was confirmed that the erosion resistance of the glass fiber of E-glass composition using mineral raw material was excellent, and that the strength value was decreased as the fiber size was increased through the tensile strength characteristic, which is one of the important characteristics of the reinforcing fiber there was.

As a result of the experiments, it was confirmed that the E-glass composition using the sandstone coal waste, which is the mineral raw material adopted in this experiment, And it has similar thermal characteristics compared to the E-glass of the prior art.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. There is no doubt that it is within.

Claims (11)

1) mixing the raw materials of the E-glass fibers by stirring;
2) melting the mixed raw material at a high temperature to form a molten glass; And
3) fiberizing the molten glass by using a fibrous device. [3] The method for manufacturing an E-glass fiber using coal waste seals according to claim 1, The method according to claim 1,
A method for producing an E-glass fiber using coal waste seals, wherein the raw materials include coal waste, aluminum oxide (Al ₂ O ₃ ), calcium carbonate (CaCO ₃ ), boric acid (H ₂ BO ₃ ) . 3. The method of claim 2,
The raw material is composed of 35 wt% of coal waste, 3 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) To produce an E-glass fiber using coal waste. 3. The method of claim 2,
The raw material is composed of 15 to 30 wt% of coal waste, 3 to 5.7 wt% of aluminum oxide (Al ₂ O ₃ ), 20 wt% of calcium carbonate (CaCO ₃ ), 10 wt% of boric acid (H ₂ BO ₃ ) And 4.2 to 17.3% by weight of silicon dioxide (SiO ₂ ). 3. The method of claim 2,
Wherein the coal waste seals are sandstone-based coal waste seals. The method according to claim 1,
And a pretreatment step of controlling the carbon content and the oxidation state in the coal waste so that the redox condition for optimizing the fining property for removing bubbles in the molten glass is controlled before or during the step 1) Method for manufacturing E - glass fiber using coal waste. The method according to claim 6,
Wherein the purifying and oxidizing agent includes sodium sulphate (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), arsenic oxide (As ₂ O ₃ ), and antimony oxide (Sb ₂ O ₃ ) - Method of manufacturing glass fibers. 8. The method of claim 7,
Wherein the pretreatment step allows the carbon content in the coal waste liquor to be controlled within 1 to 2%. 9. The method of claim 8,
Wherein the oxidation state of the waste lime is controlled so as to be in the range of 0.15 to 0.25 in the pretreatment step. The method according to claim 1,
The method of manufacturing an E-glass fiber using the coal waste septum according to claim 2, wherein the stirred raw material is placed in a platinum crucible and melted in a box-type electric furnace at 1550 ° C for 2 hours. An E-glass fiber produced by a process for producing an E-glass fiber using the coal waste stone according to any one of claims 1 to 10.

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