JP4862279B2 - Method for preparing mixed raw material for glass and method for producing glass article - Google Patents

Description

The present invention relates to a method for preparing a mixed raw material for glass melting for producing a homogeneous inorganic glass article.

  Glass articles are used in various applications in order to utilize their optical properties and chemical durability. In addition to glass used for general window glass and container applications, various modern industries It is a product that becomes the foundation to support Particularly in the electronics industry and the advanced information industry, glass products with special functions are used in many fields. Glass products that achieve high functionality in multiple members are used in applications such as optical fibers and related optical components, flat panel displays such as liquid crystal display devices and plasma displays, and image input devices such as digital cameras. ing. The manufacturing method of such a glass article is to mix various inorganic glass raw materials that become inorganic glass by melting at a high temperature at a predetermined ratio to mix mixed raw materials for glass melting (this is a batch raw material, a melting batch, It may be expressed as a mixed batch, etc.), and it is put into a glass melting furnace or glass melting pot (or glass melting crucible or glass melting container) that employs a refractory or platinum or other high melting point metal material and heated for a predetermined time. To remove the vaporized components in the raw material to make molten glass, to improve the homogeneity of the molten glass using various homogenizing means, and to use various molding methods according to the purpose of the glass article In general, a glass article is formed by forming a glass article having a desired shape.

  There are many factors that determine the homogeneity of the glass article obtained in such a manufacturing process, but one of the important factors is what glass raw material is put into the glass melting furnace. . A raw material having the optimal composition and properties is selected from various inorganic glass raw materials, and an optimal mixing method is realized so that the vitrification reaction at a high temperature between the raw materials proceeds rapidly. The series of steps of putting the batch mixture into the furnace is one of the most important steps for determining the performance and homogeneity of glass articles, although it is the first basic process among all the processes for producing glass articles. There is no room for debate.

For this reason, various improvements and inventions have been made for this initial process. Patent Document 1 is an improvement of a method for producing soda ash for glass raw materials that is generally used in soda lime glass. After pulverizing trona ore, it is roasted at 500 to 800 ° C. in an oxygen-containing atmosphere. By doing so, soda ash can be easily adjusted. Patent Document 2 discloses an invention about a method for removing metal pieces and the like mixed in a cullet for glass raw material. Further, in Patent Document 3, in a mixed raw material for glass containing silica sand and strontium carbonate or dolomite such as glass material for cathode ray tube and glass material for liquid crystal, the average particle size of strontium carbonate or dolomite should be within 8 times that of silica sand. Thus, an invention has been carried out in which melting at low temperatures can be realized even with difficult-to-melt raw materials. On the other hand, Patent Document 4 discloses a technique relating to a method and apparatus for utilizing high-temperature exhaust gas generated from a melting furnace for preheating glass raw materials. Patent Document 5 pays attention to the point that carbon dioxide in the generated exhaust gas is recovered and reused. Further, Patent Document 6 discloses an invention relating to a method and an apparatus for increasing the capacity by using static electricity in a method for preheating a raw material using waste heat from a glass melting process.
JP-A-10-139423 Japanese Patent Laid-Open No. 11-157846 Japanese Patent Laid-Open No. 2003-40641 JP-A-10-101341 JP 09-118529 A JP-A-2001-220148

  However, the improvement of the glass raw material that has been performed up to now is not sufficient depending on the application. The degree of homogeneity required for various glass articles mounted on and used in electronic equipment for information transmission applications, etc., has always been required to have a high level of quality, and future technological development may require even higher quality. Because it is expensive. In addition, with the progress of image display technology and the demand for large image display devices, glass articles that are large and have high homogeneity are further required. For this reason, the glass manufacturing process has been urged to review all technologies related to manufacturing, and there is an increasing need to quickly establish various technological innovations for constructing the next-generation glass manufacturing process.

  And the basic problem of what kind of glass raw material is put into the glass melting furnace is no exception, and it is a hardly fusible raw material composition adopted to realize the high performance required for glass articles. However, there is a need for a solution to the problem of being able to melt into a homogeneous state at a low temperature. In addition, it is important to melt glass raw materials uniformly at a low temperature from the viewpoint of realizing the production of glass articles with high cost performance by extending the service life of the glass production apparatus.

The present inventors have found that according view of the circumstances, the method of adjusting the glass raw material mixture can be produced homogeneous glass article at a low temperature of melting environment, the glass manufacturing system by using a glass material mixture its It is an object of the present invention to provide a method for producing a glass article capable of extending the useful life.

The method for preparing a mixed raw material for glass according to the present invention includes a step of weighing a plurality of inorganic raw materials, a step of mixing inorganic raw materials after weighing, pulverizing the obtained inorganic raw material mixture, and adding the particle size of the granular material It is characterized by having a step of setting D90, which is an effective particle size in the curve, to 50 μm or less, and a step of adding glass cullet to the ground inorganic raw material mixture .

  Here, the mixed raw material for glass melting to be charged into the glass melting furnace is a raw material for melting inorganic glass to be charged into a glass melting furnace having a function of heating the raw material to form molten glass. For two or more types of raw materials, the raw materials are in a mixed state by using a mixing device or the like.

  Further, the particles of inorganic raw materials having a plurality of different compositions pulverized after mixing are in a dispersed state, and D90, which is an effective particle size in the particle size accumulation curve of the granular material, is 50 μm or less. Is pulverized after mixing two or more kinds of raw materials, and particles resulting from raw materials having different compositions are pulverized and dispersed, and the effective particles in the particle size accumulation curve for the powder in that state This means that the particle size corresponding to the diameter D90 is 50 μm or less.

  When the particle size corresponding to D90, which is the effective particle size in the particle size accumulation curve, is 50 μm or less, the reaction between the glass raw materials at a high temperature is promoted, the vitrification reaction proceeds at a high speed, and the molten glass is homogenized. This is preferable because the time required is shortened. From this point of view, the particle size corresponding to D90, which is the effective particle size in the particle size accumulation curve, is preferably 30 μm or less, more preferably 25 μm or less, and even more preferably 20 μm or less. It is.

In the present invention , the mixed raw material for glass melting does not mean a single raw material having a plurality of cations alone. That is, particles having a plurality of physically different compositions are randomly present by the mixing operation. Specific examples of this include mineral raw materials containing multiple cations such as mullite, kaolinite, montmorillonite, halloysite, pyrophyllite, brapasite, colemanite, etc., and silicon nitride, sialon, crystallized glass. Since only one kind of artificial mineral produced artificially by a sintering operation, a granulating operation, etc. is selected and a plurality of cations are present, it is not a mixed raw material . The mixed raw material for glass melting in the matter, regarded as a raw material of the raw materials for variety containing these more cationic, means a further Tsu names in a state of being mixed with other ingredients species and powder state.

  However, as described above, it is not reasonable to manufacture by the process of mixing only two kinds of raw materials and then pulverizing because the manufacturing process becomes long. Therefore, it is preferable to mix 3 types from 3 types, 4 types from 3 types, and 5 types from 4 types before pulverization, and most preferably all the raw material types to be charged into the glass melting furnace. Is previously mixed before pulverization.

  However, even if only specific multiple constituent species are mixed and then pulverized in advance, and other constituent raw materials are not pulverized, if this specific multiple constituent species is effective, It is not always necessary to grind all the raw material species. Therefore, it is desirable to determine whether or not to pulverize all the raw material species in advance after considering various conditions relating to pulverization, such as its cost.

  And from the viewpoint of promoting the reaction, at least a glass network former (Network-former, NWF) such as Si, B or P, and its oxide becomes an oxide glass by itself when heated and melted. It is preferable to mix one kind of raw material containing the element that will form) and another kind of raw material before pulverization.

Furthermore, in the present invention, the raw material contains at least one kind of network former as an oxide equivalent, that is, SiO ₂ , B ₂ O ₃ or P ₂ O ₅ , and the total is based on the total mass of the raw material. It is preferable that it is 40 mass% or more. More preferably, the oxide of the network former is 50% by mass or more.

  In the present invention, the network modifier (also referred to as network-modifier, NWM) in the raw material, that is, at least one alkali metal element such as sodium or potassium, in terms of oxide, includes the total mass of the raw material. The reference is preferably 20% by mass or less.

  In addition, the fact that particles of inorganic raw materials having a plurality of different compositions pulverized after mixing are in a dispersed state means that particles having different compositions are adjacent and in contact with each other. is there. Furthermore, each particle that has been mechanically powdered by grinding is solidified into a floc, agglomerated, lump, or cake by the action of other media such as water, a binder, a grinding aid or a grinding accelerator. What is in a bonded state is in a preferable state corresponding to a state in which particles of inorganic raw materials having a plurality of different compositions pulverized after mixing in the present invention are dispersed. Furthermore, by adopting an appropriate heating means after becoming a flock-like, agglomerated, lump-like or cake-like solidified by the action of other media such as water, binder, grinding aid, grinding accelerator, etc. Drying, heating, etc. may be performed in a solidified state, and particles having different compositions may be sintered and solidified in an adjacent state.

  In this way, the inorganic raw materials are consolidated or further sintered, so that each powder has a sufficiently fine particle size, and the raw materials are easy to handle. In order to help prevent dust generation and scattering in a series of processes in a batch plant, such as weighing, storage, and transportation until the present invention is put into the glass melting furnace, and charging operation into the glass melting furnace. In addition, it is possible to prevent the segregation phenomenon (also referred to as segregation) of the raw material that occurs between the raw materials having different particle sizes and different weights depending on the operation added to the raw material in a series of steps. Further, it is preferable since the risk of causing a problem such as scattering of raw materials (also referred to as carry-over) due to the atmosphere in the furnace before the melting reaction is started by heating after being put into the glass melting furnace is preferable. For the improvement of the performance of such raw materials, it is possible to reflect the results measured by the evaluation means such as the angle of repose and bulk density by means of a dust meter, particle hardness meter, powder meter, etc. as a means for evaluating the raw material. is there.

From the above viewpoints, the mixed raw material for glass prepared by the method of the present invention can be used in a finely pulverized state according to the use, and consolidated as described above if necessary. It can be handled even in the state.

  As a method for realizing such a consolidated state and sintered state of the raw material, any method may be used, and various conditions regarding the consolidated state and the sintered state can be appropriately controlled. Is preferable. As such a method, in order to obtain a consolidated state, for example, a press molding method using a stamp made of an appropriate material, a roll molding method, a casting molding method using an organic solvent, or the like can be adopted. Further, as the drying and solidification, a granulation method by spray drying or the like, a drying and solidification method performed by a drying apparatus every predetermined volume, or the like can be employed. In order to obtain a sintered state, for example, by using appropriate equipment such as a firing furnace or a belt furnace in combination with the above-described method for forming a consolidated state, a sintering time, a sintering temperature, a sintering atmosphere during heating are used. It is possible to obtain an optimum sintered state by appropriately adjusting.

  The mixing device, the mixing method, the pulverizing device, and the pulverizing method may be any as long as they can realize a desired function. Further, the pulverizer is preferably selected in consideration of this point, although impurities derived from the apparatus from the apparatus being pulverized to the raw material are mixed to some extent.

  Further, the mixing operation and the pulverizing operation may employ either a dry method or a wet method. In other words, the atmosphere for dry operation is air, helium, neon, argon, krypton xenon, fluorine, chlorine, bromine, knox (NOx), sox (SOx), nitrogen, carbon monoxide, carbon dioxide, hydrogen Chlorine, water vapor, or a mixed atmosphere of these gases may be employed. Furthermore, the pressure of these gases can be changed arbitrarily, and may be performed under atmospheric pressure, or may be performed under reduced pressure or under high pressure. In addition, when the operation is performed in a wet manner, the reactive component in a state in which a part or all of the raw material is dissociated into ions, such as water, hydrogen peroxide solution, an aqueous solution to which a surfactant is added, and salt. It is possible to use an appropriate amount of a liquid such as an aqueous solution, acid solution, alkaline solution, ion-activated water, plasma irradiation water, carbon dioxide saturated water and other gas saturated water, nonpolar organic solvent, and polar organic solvent.

  The measurement of particle size distribution may be based on any principle, but it is a method that can measure each particle in a dispersed state, and the reproducibility of the measurement result is within 5%. It is suitable if it is difficult for individual differences due to handling to occur. For example, it is preferable to employ measurement by a laser diffraction measurement apparatus using a sample subjected to reduction operation. In the case of measurement of sintered raw materials, it is possible to substitute by measuring the particle size distribution by using an electron microscope, an observation device for various fine structures and an analysis device for the obtained image, etc. .

In addition to the above, the mixed raw material for glass obtained by the present invention is a gas under the same conditions of a plurality of inorganic raw material mixtures before pulverization, in which the amount of carbon dioxide gas generated by heating is from 300 ° C. to 500 ° C. It is preferable to be 3 times or more with respect to the released amount.

  Here, the gas release amount between 300 ° C. and 500 ° C. of the carbon dioxide gas generated by heating is at least three times the gas release amount under the same conditions of the plurality of inorganic raw material mixtures before pulverization. And heating the mixed pulverized raw material for glass melting described above at normal pressure, thereby causing thermal decomposition of carbon-containing components such as carbonates present in the mixed and pulverized raw material, As a result, the release amount of carbon dioxide gas generated from 300 ° C. to 500 ° C. at a temperature rising rate of 6 ° C./min is the same as that of the raw material mixture in a state where only the mixing before pulverization is performed. This means that the value is three times or more larger than the amount of carbon dioxide gas released when the temperature is raised by heating.

  Compared to before the pulverization, the total generation amount of carbon dioxide corresponding to the initial stage of the vitrification reaction from 300 ° C to 500 ° C is more than three times larger, resulting in a larger amount of carbon. Since the gas that must be generated with vitrification is released without lingering indefinitely, after the molten glass is formed, many bubbles due to carbon dioxide do not remain in the molten glass. Accordingly, molten glass is preferred because it facilitates rapid homogenization. When the total amount of carbon dioxide generated from 300 ° C. to 500 ° C. is less than three times, a large effect is expected particularly in a glass melting apparatus that needs to heat a large volume of mixed pulverized raw material at one time. become unable. Therefore, this total generation amount is more preferably 3.5 times or more, further preferably 4 times or more, and further preferably 4.5 times or more. Preferably it is 5 times or more.

  Here, as a method for measuring the amount of carbon dioxide gas released by heating, the amount of gas generated by heating is continuously measured over time by using, for example, a quadrupole mass spectrometer. Can be calculated.

  In addition, “a plurality of inorganic raw material mixture before pulverization” is a state before pulverization using a pulverizer or the like, and each raw material species is weighed and mixed, and is held in a container. It means a raw material that is in a state, and is a raw material that has been subjected to a mixing operation but not pulverized.

In addition to the above, the mixed raw material for glass obtained by the present invention has a gas release rate of carbon dioxide gas generated by heating of 0.005 to 0.5 μl / g · sec (0 at 400 ° C. and 1 atm). ° C., it is preferable that the range of 1 atm).

  Here, the gas release rate of carbon dioxide gas generated by heating is in the range of 0.005 to 0.5 μl / g · sec (0 ° C., 1 atm) under the conditions of 400 ° C. and 1 atm, as described above. Carbon-containing components such as carbonates present in the mixed crushed raw material by heating the mixed pulverized raw material for glass melting at a temperature increase rate of 6 ° C./min at normal pressure The resulting carbon dioxide gas is released at a rate of 0.005 μl / g · sec (0 ° C., 1 atm) to 0.5 μl / g · sec (400 ° C.) when the temperature is raised. 0 ° C., 1 atm).

  Further, when the release rate of the carbon dioxide gas becomes 4005 ° C. and 1 atm at 0.005 μl / g · sec (0 ° C., 1 atm) or more at the time of temperature rise, fusion of particles of each raw material occurs and proceeds. Since a large amount of gas is released from between the particles before the generated gas is confined between the particles, the reaction proceeds efficiently, so that the molten glass is heated at a temperature higher than 400 ° C. The volume of gas that must be released as bubbles from the molten glass in order to homogenize is reduced. Therefore, the release rate of carbon dioxide gas is preferably 0.005 μl / g · sec (0 ° C., 1 atm) or more under the conditions of 400 ° C. and 1 atm, more preferably 0.01 μl / g · sec (0 ° C, 1 atm) or more, more preferably 0.02 μl / g · sec (0 ° C, 1 atm) or more, more preferably 0.04 μl / g · sec (0 ° C, 1 atm) or more, and most preferably 0.8. It should be at least 08 μl / g · sec (0 ° C., 1 atm).

  On the other hand, if the release rate of carbon dioxide gas is higher than 400 ° C. and 1 atm at a temperature of 0.5 μl / g · sec (0 ° C., 1 atm), the fine powder material is scattered from the glass material during the initial heating. Is likely to occur. Such scattering of the raw material increases the risk of causing the composition of the molten glass to deviate from the target composition, and further, as the unmelted raw material is mixed in the molten glass, the melting becomes insufficient, and as a non-uniform glass article There is also a possibility that a large number of defective products may be produced by molding. For this reason, the release rate of carbon dioxide gas is preferably 0.5 μl / g · sec (0 ° C., 1 atm) or less under the condition of 400 ° C. and 1 atm, more preferably 0.4 μl / g · sec (0 C, 1 atm) or less, more preferably 0.35 μl / g · sec (0 ° C., 1 atm) or less, more preferably 0.30 μl / g · sec (0 ° C., 1 atm) or less.

Further, glass raw material mixture obtained by the present invention, 400 ° C. of carbon dioxide gas generated by the heating in addition to the above, the gas generation rate of 1atm conditions, 300 ° C., 8 times or more relative to the value of 1atm conditions and It is preferable to become .

  Here, the gas generation rate of carbon dioxide gas generated during heating and heating at 400 ° C. under 1 atm condition is 8 times or more than the value at 300 ° C. under 1 atm condition for glass melting as described above. By heating the pulverized raw material at normal pressure after the mixing is completed, pyrolysis of carbon-containing components such as carbonates present in the mixed pulverized raw material occurs, and as a result, generated carbon dioxide. It means that the generation rate of carbon gas is 8 times or more at 400 ° C. with respect to 300 ° C. at 1 atm.

  When the rate of carbon dioxide gas generation is 8 times greater at 400 ° C than at 300 ° C, a large amount of gas emission continues even after a high temperature such as 900 ° C to 1000 ° C. This is preferable because a sufficiently large amount of gas can be released at a low temperature. Therefore, the release rate of carbon dioxide gas is preferably 9 times or more at 400 ° C. with respect to 300 ° C. at 1 atm, more preferably 10 times or more, and more preferably 12 times. The value is more than double.

In addition to the above, the mixed raw material for glass obtained by the present invention has a glass yield of 98% by mass to 60% by mass, and contains an oxide of at least one of Si, Al and B. Is preferred.

  Here, the glass yield is from 98% by mass to 60% by mass and includes at least one oxide of at least one of Si, Al, and B. The mixed pulverization for glass melting as described above. When the mass of the mixed raw material for melting the glass is 100, the glass yield value representing the mass value of the glass article obtained by melting is 98 mass% to 60 mass%. It is within the range and has any one element of silicon, aluminum, and boron, and one or more raw materials mainly containing these oxides are included in a plurality of raw materials.

  Regarding the glass yield, by making the range from 98% by mass to 60% by mass, the application of heat energy required for vitrification can be reduced, and the total volume of gas generated by heating should be reduced. It is something that can be done. Here, in the case of melting at a glass yield exceeding 98% by mass, since the amount of gas generated is small, it becomes possible to realize a fairly fast melting without applying the present invention. It is not necessary to apply the present invention to. Further, for glass yields lower than 60% by mass, the amount of gas generated is too large, so that the present invention can contribute accordingly, but the present invention alone may not be sufficient.

  Further, it means that at least one oxide of at least one of Si, Al, and B contains an oxide of a glass network in an oxide glass article after the mixing for glass melting of the present invention is completed. It contains either Si or B among the main constituent elements that form the structure, and does not directly participate in the formation of the network structure, but provides thermodynamic and chemical stability in the glass structure. By selecting Al that can bring about glass physical properties, it is possible to make a raw material species that can constitute a glass article that realizes an excellent function.

  Furthermore, by comprising any of the above oxides, it is possible to add to the mixed raw material a raw material species that vitrifies without generating gas when heated, and the volume of the generated gas is reduced. It can be made smaller.

In addition to the above elements, the mixed raw material for glass obtained by the present invention includes P, Zn, Ca, Mg, K, Na, Li, Sb, Cl, S, Ga, Cs, Tl, Ti, Fe, and Pb. , Pt, Ba, As, V, Bi, F, Mn, La, Rh, Zr, Sn, N, Sr, Cu, Y, Ag, Ce, Mo, or Co can be contained.

In addition to the above, the mixed raw material for glass obtained by the present invention preferably has a bulk density in the range of 1.4 g / ml to 0.3 g / ml. This is because the bulk pulverized raw material for glass melting as described above falls within the range of 1.4 g / ml to 0.3 g / ml in terms of the bulk density value expressed as mass number per unit volume. That is.

  Here, by setting the bulk density in the range of 1.4 g / ml to 0.3 g / ml, it is possible to realize such a suitable raw material configuration that is not bulky and that quickly releases the gas generated during heating to the outside of the system. It will be a thing. An excessively bulky mixed raw material is not preferable because the gas phase existing between the raw material particles may cause a delay in homogenization of the glass during melting, in addition to the disadvantage that the raw material is likely to be scattered due to the airflow in the furnace.

Moreover, it is suitable for the mixed raw material for glass obtained by this invention that D50 which is an effective particle diameter in a particle size accumulation curve in addition to the above is 10 micrometers or less.

  Here, D50, which is an effective particle size in the particle size accumulation curve, is 10 μm or less, not by one kind of inorganic raw material, but by measuring in a state in which plural kinds of raw materials are homogeneously mixed. Means D50.

  Moreover, D50 which is an effective particle diameter in a particle diameter accumulation curve is 10 micrometers or less is based on the measurement of the particle diameter by the laser particle diameter measuring apparatus defined by JISR1629 (1997).

Further, the mixed raw material for glass melting obtained by the present invention can contain at least 50% by mass of SiO ₂ in addition to the above.

Here, containing at least 50% by mass or more of SiO ₂ means that the glass melt raw material of the present invention can contain 50% by mass or more of silica as a constituent component in terms of mass percentage.

In addition to the above, the mixed raw material for glass obtained by the present invention is preferably a raw material for borosilicate glass, alkali-free glass, or aluminosilicate glass.

  Here, the borosilicate glass is a glass mainly composed of boron and silicic acid, and the alkali-free glass is a glass containing substantially no alkali component. The aluminosilicate glass means a glass mainly composed of alumina and silica. And the raw material which can comprise these glasses by melting has a common point that in order to obtain a glass article, it must be heated to 1500 degreeC or more. In such a molten glass that is not homogenized unless heated to a high temperature, it is particularly preferable to apply the raw material configuration of the present invention.

Glass mixed material obtained by the present invention, you containing glass cullet added to the above.

  Here, containing glass cullet means that the mixed raw material for glass melting contains glass cullet obtained by pulverizing the glass after melting the raw material once and cooling it to glass. That means.

Here, as a method for containing glass cullet, to employ a method of adding a glass cullet to a raw material mixture already pulverizng. The glass cullet can be appropriately changed in particle size, and the amount added can be changed as necessary.

  Here, having a step of weighing a plurality of inorganic raw materials, a step of mixing the inorganic raw materials after weighing, and a step of pulverizing the obtained inorganic raw material mixture in a mixed state are raw materials obtained by precalculating two or more raw material species Based on the weighing calculation, the weighing operation is performed with an accuracy of at least one digit gram (0.1 g) after the decimal point, and then each raw material after weighing is put into one container and mixed using a mixing device. It is meant that a mixed raw material having the above-described performance is obtained by pulverizing the mixed raw material after further mixing.

  For the step of weighing a plurality of inorganic raw materials according to the method for preparing an inorganic raw material for glass of the present invention, a weighing meter having a function of measuring two or more raw material species with the accuracy as described above is used, and the glass melting furnace is used. Any weighing process may be used as long as the method can quickly measure the volume corresponding to the amount to be charged.

  Moreover, about the process of mixing the raw material after the weighing which concerns on the adjustment method of this invention, it mixes by using the mixing apparatus which can mix a 2 or more inorganic raw material seed | species in a homogeneous state by one mixing operation. Any mixing step can be used as long as it can be performed.

  As the step of pulverizing the inorganic raw material mixture in the mixed state according to the method for preparing the mixed raw material for glass of the present invention, any pulverization apparatus can be used as long as the desired mixing effect can be realized. It is.

  In particular, any material that can perform wet pulverization may be used. For example, it is possible to pulverize using any of a ball mill, a medium stirring mill, and an airflow pulverizer.

  Here, pulverization using any one of a ball mill, a medium agitation mill, and an airflow pulverizer means that at least one of a ball mill, a medium agitation mill, and an airflow pulverizer is used as the pulverizer in the above-mentioned various environments. Is to be used.

  Here, the ball mill means the above-described ball mill in a broad sense. That is, this is a processing device that uses ceramics or natural ore as a medium called a ball, and repeatedly crushes and crushes the material to be crushed by repeatedly colliding the medium with the surface of the material to be crushed. As this ball mill, a rolling ball mill (a ball mill in a narrow sense) that performs grinding in the most general cylindrical or conical containers, a vibration mill that performs fine grinding by applying fine vibration to the ball, It includes a medium planetary mill that has been accelerated to improve the grinding efficiency. When the present invention is applied to this apparatus, pulverization can be performed while adding an aqueous solution such as water or hydrogen peroxide solution into the container. The production method of the present invention can also be realized by adjusting the oxygen concentration, nitrogen concentration, carbon dioxide concentration and the like in the environment in which this apparatus operates.

  The media agitation mill, like the ball mill, causes the media to collide with the object to be crushed, but it provides a complex motion for the media by providing a disk or wing-like rotating body in the container that contains the media. It is a pulverizing apparatus that enables efficient pulverization. As the medium agitating mill, generally, an aniler mill type, a tower mill type, a sand grinder mill type, an attritor mill type or the like can be used. Even when these devices are used, it is possible to apply the present invention by taking the same measures as in the case of the above-described ball mill.

  Furthermore, the airflow type pulverizer is a pulverization apparatus that employs a method of pulverizing by forcibly colliding the object to be pulverized by a high-speed jet airflow or the like, and is suitable for adjusting powder having a uniform particle size. In particular, when the apparatus is used, a desired pulverization environment can be realized by setting the atmosphere of the jet stream itself to be adjusted so as to be maintained in a high humidity environment.

  In addition, the above-described pulverizing apparatus may be used alone, or connected to other pulverizing apparatuses or the like to be used as a continuous plant facility. It is possible to select appropriately according to the kind, amount, usage, etc. of the dressing material.

  In addition to the above, the method for preparing a mixed raw material for glass according to the present invention is preferably a method for preparing a mixed raw material for glass mounted on an image input / output device.

  Here, adjusting the mixed raw material for glass mounted on the image input / output device means that the glass article manufactured by using the mixed raw material that has been mixed according to the present case is used. Is incorporated into an electronic device that controls the input / output of various images such as still images and moving images, and is used as a member used for a part that plays a role as an interface for directly transmitting image data. This means that high homogeneity and dimensional accuracy are often required.

  Specific examples of the image input device or the image output device include still image / moving image display devices such as televisions (TVs) and flat panel displays (FPDs), projection tubes such as projectors, various types equipped with line sensors and area sensors. Various cameras typified by scanners, digital cameras, etc., camera-equipped mobile phones, image display portable terminals such as PHS, large-area illuminated image display devices provided with LDs, neon tubes, etc., various optical fiber transmission devices Such electronic devices and electronic devices are applicable.

  In the method for preparing a mixed raw material for glass of the present invention, in addition to the above, the image input / output device is preferably a flat panel display.

  Here, the image input / output device is a flat panel display. The image input / output device according to the present embodiment is a PDP (Plasma Display Panel), VFD (Vacuum Fluorescent Display), FED ( Field Emission Display (ELD), ELD (Electro Luminescent Display), LED Display (Light Emitting Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display), LCD (Liquid Crystal Display). Black Click display), EPD (Electrophoretic Display: in the sense that those containing an electrophoretic display), and the like.

  Moreover, it is suitable for the preparation method of the mixed raw material for glass of this invention that the grinding | pulverization with a mechanochemical effect is performed in the process of grind | pulverizing a mixture inorganic raw material in addition to the above-mentioned.

  Here, in the step of pulverizing the mixture inorganic raw material, pulverization with a mechanochemical effect is performed. By applying mechanical energy for pulverizing two or more raw materials in a mixed state, By cutting the atomic bonds between the particles that make up the raw material by energy, changing the structure of each particle, and making it an active state rich in reactivity, the effect of forcibly promoting the solid-phase reaction is achieved. That is, the pulverization is performed under the pulverization conditions that can be realized.

  The method for producing a glass article of the present invention includes an inorganic material having a plurality of different compositions adjusted in a step of weighing a plurality of inorganic raw materials, a step of mixing the inorganic raw materials after weighing, and a step of pulverizing the obtained inorganic raw material mixture. A step of heating a mixed raw material for glass in which D90, which is an effective particle size in a particle size accumulation curve of a granular material, is 50 μm or less to a molten glass in a state where raw material particles are dispersed; And a step of forming molten glass.

  Here, particles of inorganic raw materials having a plurality of different compositions adjusted in a step of weighing a plurality of inorganic raw materials, a step of mixing the inorganic raw materials after weighing, and a step of pulverizing the obtained inorganic raw material mixture were dispersed. A step of heating a mixed raw material for glass in which D90, which is an effective particle size in the particle size accumulation curve of the granular material, is 50 μm or less to form molten glass, and a step of forming the molten glass It means that the mixed finely pulverized raw material as described above is heated by various heat sources to cause a eutectic reaction, and the vaporized components are discharged out of the system to form a molten glass. This means that after the glass is homogenized, molding is performed by employing a molding method according to the application of the glass article.

  With respect to the process of heating the mixed and pulverized raw material according to the present invention into a molten glass, the structural strength required for producing the glass can be maintained at a high temperature, and the chemical strength with the molten glass can be maintained. It is possible to heat mixed finely pulverized raw materials continuously or intermittently using equipment and equipment composed of materials with low reactivity, and is equipped with ancillary equipment for homogenizing molten glass Any melting equipment can be used.

  The heat source for the heating may be gaseous fuel, liquid fuel, or finely divided solid fuel. Further, as ancillary equipment for homogenization, a stirrer such as a stirrer that works to homogenize the heterogeneous glass portion in the molten glass may be used, or various gases may be generated to generate bubbles in the molten glass. It may be a bubbling device having a function of defoaming.

  Moreover, if it illustrates concretely about a fusion facility, it may be what heats a mixed finely pulverized raw material by using a glass melting furnace constructed with a refractory ceramic material. The mixed finely pulverized raw material may be heated using a configured pot, crucible, or container.

  About the process which shape | molds the molten glass which concerns on this invention, what kind of thing is what can be continuously formed or intermittently formed with the shaping | molding apparatus which can be shape | molded in the shape applied to the use of a glass article, There is no problem.

  Further, the glass article manufacturing method of the present invention includes various glass products for electronic parts, such as liquid crystal backlight glass tubes, diode glass tubes, reed switch glass tubes, xenon lamp glass tubes, and vacuum exhaust glass stem tubes. It can also be applied to glass tubes for illumination such as fluorescent lamps and ferrule tube glasses for optical fiber connection. Furthermore, it is used for glass production methods such as glass for glass such as crystallized glass and powdered glass, glass block for radiation shielding, glass block for building material, and various uses such as FRP and FRC. It can also be applied to the production of glass fibers.

(1) As described above, glass raw material mixture obtained by the process of the present invention reduces the occurrence of unmelted material, yet faster homogenization of molten glass by high reaction, 100 compared to the previous It realizes an excellent function that enables low-temperature melting at or above ℃.
(2) Further, the method of the present invention can be incorporated into the glass manufacturing system that has been conventionally performed without significant changes, and the best process can be performed while making good use of the good part of the conventional process. It is possible to build.

( 3 ) Moreover, the mixed raw material for glass obtained by the method of the present invention has a gas release amount of 300 ° C. to 500 ° C. of carbon dioxide gas generated by heating. If it is more than 3 times the amount of gas released under the conditions, it may be possible to produce molten glass even if the heating temperature is set to a low temperature. It can be extended and the cost required for melting the glass can be reduced.

( 4 ) Further, the mixed raw material for glass obtained by the method of the present invention has a gas release rate of carbon dioxide gas generated by heating of 0.005 to 0.5 μl / g · sec under the conditions of 400 ° C. and 1 atm. If it is in the range of (0 ° C., 1 atm), it is possible to promote the vitrification reaction in the glass melting environment, and it may be possible to realize production at a higher rate than before. .

( 5 ) Furthermore, the mixed raw material for glass obtained by the method of the present invention has a gas generation rate of carbon dioxide gas generated by heating at 400 ° C. under the condition of 1 atm, which is 8 times the value at 300 ° C. under the condition of 1 atm. If it is above, it is possible to suppress the scattering of the raw material in the initial stage of heating, and the raw material flows out to the molding zone in an unreacted state as the reaction proceeds at a high speed after the initial stage. It is a mixed raw material that does not easily cause problems, and it is possible to make various facilities related to the melting process compact.

( 6 ) Further, the mixed raw material for glass obtained by the method of the present invention has a glass yield of 98% by mass to 60% by mass, and contains an oxide of at least one of Si, Al and B. If it is, the manufacturing cost can be reduced by selecting the optimum combination from a plurality of inexpensive raw material configurations.

( 7 ) Moreover, if the D50 which is an effective particle size in a particle size accumulation curve is 10 micrometers or less, the mixed raw material for glass obtained by the method of this invention employ | adopts various raw material injection | pouring apparatuses as needed. It is of a quality that enables the stable operation of the auxiliary equipment of the glass melting apparatus such as the raw material charging apparatus, etc., in the long-term use without causing the raw material charging apparatus to be worn out at an early stage.

( 8 ) Moreover, if the mixed raw material for glass obtained by the method of the present invention contains at least 50% by mass or more of SiO ₂ , the glass material that has been used for a long time has stable quality. For the composition to constitute, it is easier to achieve homogenization than before, and helps to establish production conditions that can supply a large amount of glass articles having high functions to the market.

( 9 ) Further, if the mixed raw material for glass obtained by the method of the present invention is a raw material for borosilicate glass, non-alkali glass or aluminosilicate glass, it is hardly soluble in terms of initial melting by heating. Even in the case where a hindrance to homogenization due to volatilization or the like is recognized due to the need for high-temperature melting, an improvement effect is achieved by realizing easy melting.

(10) In addition, glass raw material mixture obtained by the process of the present invention contains a glass cullet, and not interfere with the re-use of the glass article or the like that has been damaged or corrupted, the effective use of rather available resources To promote.

  (11) Moreover, if the method for preparing a mixed raw material for glass of the present invention is to prepare a mixed raw material for glass mounted on an image input / output device, the homogeneity of quality required for the image input / output device. It is possible to reduce the manufacturing effort required to achieve the above.

  (12) Further, in the method for preparing a mixed raw material for glass according to the present invention, if the image input / output device is a flat panel display, high optical homogeneity is required on the other hand, though a large volume is required. The glass article is suitable when it is necessary to exhibit the performance of the glass article as much as possible.

  (13) Further, the method for preparing a mixed raw material for glass is used in any method for producing molten glass, as long as the mixed inorganic raw material is pulverized and pulverized with a mechanochemical effect. It will be a basic technology and will bring great progress and progress to recent glass melting technology.

  (14) The method for producing a glass article of the present invention comprises a plurality of different compositions adjusted in a step of weighing a plurality of inorganic raw materials, a step of mixing the inorganic raw materials after weighing, and a step of pulverizing the obtained inorganic raw material mixture A process of heating a glass mixed material in which D90, which is an effective particle size in a particle size accumulation curve of the granular material, is 50 μm or less to form a molten glass in a state where particles of an inorganic material having a particle are dispersed And the step of forming the molten glass, it is easy to use in combination with other glass homogenizing means, and it is possible to develop further advanced technology by using other means in combination. It can be done.

Adjustment method for glass melting for mixing Aihara material of the present invention below, and a method for manufacturing the glass using a mixed raw material, will be described with reference to Examples.

First, the example which applied this invention about the raw material for glass melting for manufacturing the glass fiber utilized as a glass chopped strand, roving, yarn, etc. is shown. This glass is an aluminosilicate glass usually called E glass, and its glass composition is generally expressed in terms of mass percentage of SiO ₂ 54%, B ₂ O ₃ 7%, Al ₂ O ₃ 15%, CaO 21%, MgO 2%, R ₂ O + MO (R = Na + K, M = Sr + Ba + Zn) 1%, and it is necessary to use a raw material containing Si, Al, and B. Further, since the Si raw material adopts an oxide raw material in terms of the raw material structure, it is necessary to use carbonate as a raw material for alkaline earth elements and the like. The improvement of homogeneity in melting of oxide glass not only lowers the rate of yarn breakage during spinning, but also raises the quality of the produced glass fiber, and is therefore an important issue in the process of producing glass fiber. One.

  Conventionally, the raw materials for glass fibers are weighed with a large-scale weighing machine and then mixed with a rotary mixer for 6 hours to form a batch for melting the glass, and in a supply container connected to the raw material charging device. It was stored and sequentially put into the furnace by a screw charger and heated in the melting chamber of the glass melting furnace to form molten glass, then clarified and homogenized, and then formed as a glass monofilament. When the batch particle size after the mixing operation was measured for all the raw materials after the reduction operation, the average particle size (D50) was 15.2 μm and D90 was 70.4 μm.

  However, in order to reduce the defect rate associated with defects such as foreign matter defects in the melted glass, the following improvements were implemented. First, the raw material mixture mixed with the rotary mixer was pulverized for 4 hours with a ball mill using alumina balls having a diameter of 30 mm. The thus obtained finely pulverized mixed raw material for melting the glass was measured for its particle size using a laser diffraction particle size distribution measuring device (SALD-2000J, manufactured by Shimadzu Corporation). The average particle size (D50) Was 7.2 μm and D90 was 40.4 μm. This finely pulverized mixed raw material for glass melting was added to a glass melting furnace in the same manner by adding 85% by mass and 25% E glass cullet. In a melting furnace maintained at a high temperature, the finely pulverized and mixed raw material glass and glass cullet are heated to form molten glass, and the molten glass dough having been homogenized is introduced into the forming region to form glass fibers. Went. By adopting such a series of manufacturing methods, it has been found that 2.2% improvement can be achieved with respect to defects caused by foreign object defects in the manufactured glass fabric, which can greatly contribute to the reduction of manufacturing costs. It has become possible.

Then, the following method for adjusting and properties of raw materials. One mixed-pre raw material, to produce a glass article also used as a large molded material of the liquid crystal cover glass is mounted on a thin glass or a solid-state imaging device or for building material applications, to be mounted on a flat panel display The survey results on the mixed raw materials for glass melting are summarized. This thin glass sheet for liquid crystal is a non-alkali glass composed of Si, Al, B, R ′ (R ′ = Mg, Ca, Sr, Ba, Zn) as constituent elements. The oxide raw material, R ′, is carbonate. The glass yield of this raw material is 83.3% according to the raw material blending calculation.

  About this raw material, the raw material equivalent to 1000 g of glass was previously weighed with an accuracy of 3 digits of decimal point, and a batch was prepared by mixing for 1 hour using a tumbler mixer. And about this batch, after adding 3 liters of water and repeating the manual operation which rolls a container in order to deaerate the gas which the batch took in several times, the ball mill made from a zirconia (rotation speed 100rpm, ball diameter 1.5). ˜2.5 cm, ball weight 5.3 kg) was used for pulverization in a wet environment. As for the pulverization time, sampling was carried out at non-pulverized, 1 hour, 4 hours, 32 hours and 64 hours. After sampling, in order to perform a series of evaluations, drying by heating at 80 ° C. for 24 hours and 100 ° C. for 72 hours is performed in an atmospheric atmosphere at normal pressure, and the cake-like material obtained after drying is crushed to 10 to 5 mm. A series of evaluations were performed using the pellets. The particle size was evaluated in the same manner as described above for comparison with an unground sampled product. In addition, 50 g of pellets prepared from each batch mixed pulverized raw material sampled were put in a platinum crucible and held in a box-type electric resistance furnace at 1500 ° C. for 2 hours in an air atmosphere to evaluate the initial meltability of the raw material. Went. For meltability evaluation, the sample subjected to the above heat treatment is taken out from the electric furnace and visually observed for bubbles and unmelted materials. If the bubbles and unmelted materials are 10% or less of the total volume, Otherwise, it is determined as x. The above results are shown in Sample No. 1 of Table 1. 1 to No. Summarize in five.

Further, instead of performing the pulverization treatment after the raw material mixing such as this, merely by addition of 3 liters of water were mixed raw material, except for the grinding process by performing an operation that subsequently a drying process Sample No. 6 were prepared and a series of evaluations were performed. Further, each raw material was finely pulverized individually in advance, and a sample obtained by mixing it by the same operation as described above was No. 7 was prepared and the same evaluation as described above was performed. These results are also summarized in Table 1.

As can be seen from Table 1, 4 hours milling time after mixing the raw materials, 32 hours, 64 hours and the specimen No. 3-No. For No. 5, an average particle size (D50) of 10 μm or less was obtained, D90 was also 10 μm, and good results were obtained for the meltability test. When the weight of the glass was measured and the glass yield was calculated , the yield was as high as 88.2%. On the other hand, specimen No. As for No. 2, even when pulverization is performed, the average particle size is not 10 μm or less, and D90 is also in a state exceeding 50 μm, and it can be confirmed that many fine bubbles remain in the meltability evaluation. was Tsu der.

And sample no. No. 6 was obtained by omitting only the pulverization process, but the sample No. 1 and resulted in almost show the same trend. Furthermore, sample no. For No. 7, the mixture is not pulverized after mixing but is mixed in advance. For this reason, although the raw material particle size after mixing is D50 of 10 μm or less and D90 is also 10 μm or less, satisfactory results cannot be obtained for the meltability evaluation, and the presence of many fine bubbles and undissolved raw materials is confirmed. It became a thing.

From the above investigation, it was found that the mixed raw material for melting an inorganic glass used in the method of the present invention can realize a performance excellent in meltability.

Then summarizes the findings about the behavior during heating of the glass melt for raw materials in the following. A series of test results for this test are summarized in Table 2.

Using an alumina ball mill (capacity 7.3 liters; ball diameter 1.5 to 2.5 cm) as a glass raw material for realizing the same glass composition as described above, a batch of 850 g was subjected to conditions of 1 hour and 20 hours. The raw materials obtained by pulverization under atmospheric conditions under dry conditions at atmospheric pressure (corresponding to sample No. 10 in Table 2 and sample No. 11 in Table 3) with the same raw material configuration prepared unpulverized ( Comparison with Sample No. 8) was performed. First, 1 g of each sample is weighed, held in a platinum crucible, heated in a helium atmosphere at a heating rate of 6 ° C./min, and the generated gas is a quadrupole mass spectrometer (10 ⁻⁴ Pa). It measured by Anelva Co., Ltd. product M-100QA-M. The results obtained are summarized in Table 2.

As is apparent from Table 2, the generation rate of carbon dioxide gas is 0.0008 μl / g · sec (0 ° C., 1 atm) at an atmospheric pressure of 300 ° C. when unpulverized, and 0.0038 μl at an atmospheric pressure of 400 ° C. / G · sec (0 ° C., 1 atm). Therefore, the value at 400 ° C. is 4.7 times that at 300 ° C. Sample No. Even if pulverization is performed as in No. 9, one hour is insufficient, and is 0.0004 μl / g · sec (0 ° C., 1 atm) at a normal pressure of 300 ° C., and 0.0009 μl / g at a normal pressure of 400 ° C. -It becomes sec (0 degreeC, 1 atm). Therefore, the value at 400 ° C. is 2.0 times that at 300 ° C. On the other hand , the sample No. 1 was crushed for 20 hours. 10 is 0.0023 μl / g · sec (0 ° C., 1 atm) at a normal pressure of 300 ° C., and 0.1760 μl / g · sec (0 ° C., 1 atm) at a normal pressure of 400 ° C. Therefore, the value at 400 ° C. is 75.0 times that at 300 ° C.

Further, for this sample, the same meltability evaluation as described above was performed. Samples Nos. 8 and 9 had many bubbles and were judged as x. No. 10 was confirmed to be good in homogeneity, and judged as good. Further examining the nature of these powders, specimen No. No. 8 has a bulk density of 1.18 g / ml and an average particle size of 96 μm. No. 9 has a bulk density of 0.70 g / ml, an average particle size of 33.6 μm, and sample No. 10, a bulk density of 0.71 g / ml, average particle size was 3.2 .mu.m.

  Next, regarding the behavior during heating following Example 3, in the case of wet pulverization and the case of dry pulverization, as compared with the raw material in a state of being simply mixed without being pulverized, 300 ° C. to 500 ° C. The results of a comparison of the amount of carbon dioxide gas generated during the temperature rising process up to that point, the meltability by heating, and the particle size of the raw materials are shown below.

  A raw material composition having the same glass composition as in Example 2 and dry conditions using a zirconia ball mill (capacity 7.3 liters; ball diameter 1.5 to 2.5 cm; ball total amount 5.3 kg) under normal pressure conditions Crushing was performed for 16 hours under the wet conditions and 6 hours under the wet conditions. Here, the wet pulverization condition is a state in which 2 liters of pure water is added to 1118.8 g of the mixed batch, and the rotational speed during pulverization is 100 rpm.

  For wet pulverized products, drying by heating at 80 ° C. for 24 hours and 100 ° C. for 72 hours was performed in an atmospheric atmosphere at normal pressure, and the solidified cake-like material obtained after drying was crushed. The pellets in a solidified state of about 10 to 5 mm were used, and the above-described series of evaluations were performed. The evaluation results are summarized in Table 3.

The amount of gas generated during the temperature increase from 300 ° C. to 500 ° C. during the temperature increase from 300 ° C. to 400 ° C. of the carbon dioxide gas is the same as the method for measuring the generation rate. That is, a sample of 1 g of raw material is weighed, held in a platinum crucible and heated in a helium atmosphere at a heating rate of 6 ° C./min, and the generated gas is a quadrupole mass spectrometer (10 ⁻⁴ Pa). It measured by Anelva Co., Ltd. product M-100QA-M. As a result, for both wet pulverization and dry pulverization, the amount of carbon dioxide gas generated during the temperature rise from 300 ° C. to 500 ° C. No. 13 dry grinding was 90.5 μl / g, sample no. Wet grinding of 12 is a 1025.8μl / g, specimen No. In the case of 11 unpulverized, it is 12.4 μl / g, whereas in dry pulverization, it is 7.3 times, and in wet pulverization, it is 82.7 times. And had high performance. Regarding the raw material particle size, 12, no. Both 13 of D90 is not more 50μm or less, it had the following values 10μm also D50.

As described above, the mixed raw material prepared by the method of the present invention is a raw material rich in reactivity during heating, and it has become clear that it can exhibit effective performance in the production of molten glass. From the above results, it has also been clarified that wet pulverization has a characteristic that a desired performance can be obtained in a short time, although there are more steps than pulverization operation than dry pulverization.

Claims (12)

The step of weighing a plurality of inorganic raw materials, the step of mixing the inorganic raw materials after weighing, the obtained inorganic raw material mixture is pulverized, and the effective particle size D90 in the particle size accumulation curve of the granular material is 50 μm or less. And a step of adding glass cullet to the pulverized inorganic raw material mixture . A method for preparing a mixed raw material for glass, comprising:   The obtained mixed raw material for glass has a gas release amount of 300 ° C. to 500 ° C. of carbon dioxide gas generated by heating with respect to the gas release amount under the same conditions of a plurality of inorganic raw material mixtures before pulverization. The method for preparing a mixed raw material for glass according to claim 1, wherein the method is three times or more.   The obtained mixed raw material for glass has a gas generation rate of carbon dioxide gas generated by heating in the range of 0.005 to 0.5 μl / g · sec (0 ° C., 1 atm) under the conditions of 400 ° C. and 1 atm. The method for preparing a mixed raw material for glass according to claim 1.   The obtained mixed raw material for glass is characterized in that the gas generation rate of carbon dioxide gas generated by heating at 400 ° C. under 1 atm condition is 8 times or more than the value at 300 ° C. under 1 atm condition. Item 2. A method for preparing a mixed raw material for glass according to Item 1.   The obtained mixed raw material for glass has a glass yield of 98% by mass to 60% by mass and contains an oxide of at least one of Si, Al and B. The preparation method of the mixed raw material for glass of description.   The method for preparing a mixed raw material for glass according to any one of claims 1 to 5, wherein the obtained mixed raw material for glass has an effective particle diameter D50 of 10 µm or less in a particle size accumulation curve. The resulting glass mixing raw materials, process for the preparation of glass material mixture according to claim 1, characterized in that it contains SiO ₂ more than at least 50 wt%.   The obtained mixed raw material for glass is a raw material for borosilicate glass, non-alkali glass, or aluminosilicate glass, The method for preparing a mixed raw material for glass according to any one of claims 1 to 7 . Process for the preparation of glass material mixture according to claim 1-8, characterized in that it is intended to prepare a mixed raw material for glass to be mounted in the image input-output device. The method for preparing a mixed raw material for glass according to claim 9 , wherein the image input / output device is a flat panel display. The method for preparing a mixed raw material for glass according to any one of claims 1 to 10 , wherein pulverization with a mechanochemical effect is performed in the step of pulverizing the inorganic raw material mixture. A method for producing a glass article, comprising: a step of heating a mixed raw material for glass prepared by the method of claims 1 to 11 to form a molten glass; and a step of forming the molten glass.