Method for manufacturing recycled glass and method for manufacturing glass articles

Abstract

The technical objective of this invention is to promote the recycling of waste glass by devising a method that can remove impurities and other components from waste glass simply, efficiently, and selectively. [Solution] The present invention provides a method for producing recycled glass, comprising: a separation step of immersing waste glass containing at least Fe and Si in an acidic aqueous solution to separate it into a solution containing at least Fe and an undissolved substance containing at least Si; an extraction step of extracting at least Fe from the solution by wet-treating the solution obtained in the separation step; a drying step of volatilizing the solution after the extraction of Fe in the extraction step to obtain a dried product; and a regeneration step of melting the undissolved substance obtained in the separation step and the dried product obtained in the drying step to obtain recycled glass.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing recycled glass and a method for manufacturing glass articles. Specifically, it relates to a method for removing coloring impurities such as Fe from waste glass to obtain recycled glass, and a method for manufacturing glass articles using the recycled glass as a glass raw material.

Background Art

[0002] In recent years, recycling of waste glass has been strongly demanded from the perspective of resource circulation. In addition, natural raw materials such as sand and ore are used as glass raw materials, but these glass raw materials rely almost entirely on imports from overseas, increasing the environmental load due to transportation. Recycling of waste glass is also important in this regard.

[0003] However, at present, only bottle glass is being recycled, and waste glass of special glasses such as glass fiber, tempered glass, and glass for solar panels is being discarded by landfill disposal or the like. In addition, a part of the waste glass discharged during the manufacturing process is not recycled either.

[0004] Reasons for the lack of progress in recycling include impurities in the glass, special components that hinder recycling, and contamination by impurities other than glass (metals, ceramics, organic substances). When glass containing these components is remelted and recycled, it causes coloring and reduction of the glass, leading to glass defects.

[0005] Especially in the case of special glasses, special components may be intentionally introduced to meet the required characteristics. Recycling waste glass containing special components may cause a decrease in properties. Therefore, it is difficult to directly return waste glass of special glasses to the melting furnace.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Patent Document 1 discloses a method for removing impurities such as coloring components by depositing them onto the metal phase through a reduction treatment. However, it is anticipated that this method makes it difficult to completely separate the glass phase and the metal phase. Furthermore, the reduction treatment is performed at high temperatures of 1300°C or higher, requiring a great deal of energy. In addition, there is the problem that the reducing agent used in the reduction treatment cannot be reused.

[0008] Patent Document 2 discloses a method that utilizes the phase separation phenomenon to incorporate impurities into a boron(B)-rich phase and remove them by acid treatment. However, this method requires a large amount of boron. Furthermore, the boron used in the phase separation cannot be reused, which is undesirable from the standpoint of environmental recycling. There is also the problem that useful components such as alkali metal components are removed at the same time.

[0009] Therefore, the technical objective of the present invention is to promote the recycling of waste glass by devising a method that can remove impurities and other components from waste glass simply, efficiently, and selectively. [Means for solving the problem]

[0010] As a result of diligent research, the inventors have found that the above technical problems can be solved by immersing waste glass in an acidic aqueous solution to separate it into a dissolved solution containing impurities and undissolved material, and then extracting and removing the impurities from the dissolved solution by a solvent extraction method or an ion exchange resin method, and propose this as the present invention. That is, the present invention provides a method for producing recycled glass, comprising: a separation step of immersing waste glass containing at least Fe and Si in an acidic aqueous solution to separate it into a dissolved solution containing at least Fe and undissolved material containing at least Si; an extraction step of extracting at least Fe from the dissolved solution by wet treatment of the dissolved solution obtained in the separation step; a drying step of volatilizing the dissolved solution after the extraction of Fe in the extraction step to obtain a dried product; and a regeneration step of melting the undissolved material obtained in the separation step and the dried product obtained in the drying step to obtain recycled glass.

[0011] According to the method of the present invention, impurities, particularly colored impurities such as Fe, can be removed from waste glass simply, efficiently, and selectively. As a result, waste glass can be upcycled into high-quality recycled glass, rather than being disposed of in landfills or downcycled into materials for road construction.

[0012] In the present invention's method for manufacturing recycled glass, it is preferable to wet-treat the dissolved solution obtained in the separation step using either a solvent extraction method or an ion exchange resin method during the extraction step. This makes it easier to remove impurities and other components from waste glass simply, efficiently, and selectively. It also makes it easier to ensure safety during the removal of impurities. The solvent extraction method is an extraction method that utilizes the distribution of substances between a water tank and an organic phase. The ion exchange resin method is an extraction method that utilizes the exchange and adsorption of metal ions in a solution with ions of the same sign on an ion exchange resin.

[0013] In the method for producing recycled glass according to the present invention, it is preferable that the temperature of the acidic aqueous solution in the separation step be 50 to 200°C. This makes it easier to dissolve the components of waste glass in the acidic aqueous solution.

[0014] In the method for producing recycled glass according to the present invention, it is preferable to immerse the waste glass in an acidic aqueous solution for 1 to 48 hours during the separation step. This makes it easier to dissolve the components of the waste glass in the acidic aqueous solution.

[0015] In the method for producing recycled glass according to the present invention, it is preferable that the concentration of the acidic aqueous solution in the separation step is 3 to 12 M. This makes it easier to dissolve the components of waste glass in the acidic aqueous solution.

[0016] In the method for producing recycled glass of the present invention, it is preferable to adjust the pH of the dissolution during the extraction step. This allows for the selective extraction and removal of specific impurities.

[0017] In the method for producing recycled glass of the present invention, it is preferable to recover the volatile matter that has been vaporized during the drying process. In this way, the volatile matter can be reused as an acidic aqueous solution in the separation process.

[0018] In the method for manufacturing recycled glass of the present invention, it is preferable that the melting temperature in the recycling process is 1200 to 1700°C. This allows for proper revitrification of the undissolved material obtained in the separation process and the dried material obtained in the drying process.

[0019] In the present invention, the method for manufacturing recycled glass preferably involves extracting at least Fe from the dissolution using an extractant or ion exchange resin during the extraction step, and then regenerating the extractant or ion exchange resin after the extraction step with a regenerating agent. This makes it possible to reuse expensive extractants and ion exchange resins. Furthermore, it reduces the environmental burden from the standpoint of resource recycling. Moreover, if the extracted impurities such as Fe are concentrated to a high purity, they can also be recycled for other uses.

[0020] The method for manufacturing recycled glass according to the present invention includes a separation step of separating, by immersing waste glass containing at least a dissolved component in an acidic aqueous solution, into a solution in which the dissolved component is dissolved and undissolved matter; an extraction step of extracting at least the dissolved component from the solution by subjecting the solution obtained in the separation step to wet treatment; a drying step of volatilizing the solution after the dissolved component has been extracted in the extraction step to obtain a dried product; and a recycling step of obtaining recycled glass by melting the undissolved matter obtained in the separation step and the dried product obtained in the drying step. According to the method of the present invention, components to be removed, such as coloring impurities of Fe, can be removed simply, with high efficiency, and selectively. As a result, the waste glass can be upcycled into high-quality recycled glass instead of being disposed of by landfill or downcycled as road materials.

[0021] The method for manufacturing a glass article according to the present invention is a method for manufacturing a glass article by melting and shaping a glass raw material to obtain a glass article, and it is preferable to manufacture the glass article using recycled glass produced by the method for manufacturing recycled glass described above for part or all of the glass raw material. By doing so, a new glass article can be manufactured from the recycled glass.

[0022] In the method for manufacturing a glass article according to the present invention, it is preferable that the glass article is any one of glass fiber, toughened glass, and display glass.

Brief Description of the Drawings

[0023] [Figure 1] It is a photograph taken from above a crucible of recycled glass produced from waste glass of glass fiber. [Figure 2] It is a photograph taken from above a crucible of remelted material produced from waste glass of glass fiber. [Figure 3] It is a photograph taken from above a crucible of recycled glass produced from waste glass of toughened glass. [Figure 4] It is data showing the extraction rate of Fe of the extractant after the recycling treatment in the examples. [Modes for carrying out the invention]

[0024] The manufacturing method of the recycled glass of the present invention will be described in detail below, step by step.

[0025] The present invention provides a method for manufacturing recycled glass, which includes a separation step in which waste glass containing at least Fe and Si is immersed in an acidic aqueous solution to separate it into a dissolved solution containing at least Fe and undissolved material containing at least Si. Various types of waste glass can be used as the waste glass. Among these, tempered glass, fiberglass, glass for solar panels, display glass, bottle glass, heat-resistant glass, fire-resistant glass, double-glazed glass, and laminated glass are preferred, and it is particularly preferable to use waste glass from fiberglass, tempered glass, and glass for solar panels. Because waste glass from these applications contains many impurities and special components, recycling of this waste glass has not progressed much. Therefore, using waste glass from these applications in the method for manufacturing recycled glass of the present invention is effective from the viewpoint of resource circulation.

[0026] Waste tempered glass, for example, contains, by mass%, SiO2 50-80%, Al2O3 5-25%, B2O3 0-15%, Na2O 1-20%, K2O 0-10%, and Fe2O3 0.005-1%. Waste glass fiber contains, for example, by mass%, SiO2 52-62%, Al2O3 10-16%, B2O3 0-8%, MgO 0-5%, CaO 16-25%, R2O (where R is one or more of Li, Na, and K) 0-2%, Fe2O3 0.005-1%, and SO3 0.01-1%. Waste glass from solar panels, for example, contains the following glass compositions by mass%, including SiO2 45-65%, Al2O3 1-18%, Li2O 0-5%, Na2O 1-10%, K2O 0-15%, MgO 0-12%, CaO 0-12%, SrO 0-18%, BaO 0-18%, ZrO2 0-10%, and Fe2O3 0.005-1%.

[0027] From the viewpoint of Fe extraction rate, the waste glass is preferably in powder or particulate form, and its central particle size D 50 The particle size is preferably 3 to 100 μm.

[0028] Various acidic aqueous solutions can be used as the acidic aqueous solution, but from the viewpoint of solubility of impurities such as Fe, it is preferable to use an acidic aqueous solution of a strong acid. Examples of strong acids include hydrochloric acid, nitric acid, and sulfuric acid, but hydrochloric acid is preferred.

[0029] The temperature of the acidic aqueous solution is preferably 50 to 200°C, more preferably 70 to 150°C, and particularly preferably 80 to 100°C. If the temperature of the acidic aqueous solution is too low, it becomes difficult to dissolve impurities such as Fe from the waste glass. On the other hand, if the temperature of the acidic aqueous solution is too high, safety is likely to decrease due to the generation of toxic gases.

[0030] The immersion time of waste glass in the acidic aqueous solution is preferably 1 to 48 hours, more preferably 2 to 36 hours, and particularly preferably 3 to 24 hours. If the immersion time of waste glass is too short, it becomes difficult to dissolve impurities such as Fe from the waste glass. On the other hand, if the immersion time of waste glass is too long, the efficiency of the separation process tends to decrease.

[0031] The concentration of the acidic aqueous solution is preferably 3 to 12 M (molar concentration), more preferably 4 to 10 M, and particularly preferably 5 to 7 M. If the concentration of the acidic aqueous solution is too low, it becomes difficult to dissolve impurities such as Fe from the waste glass. On the other hand, if the concentration of the acidic aqueous solution is too high, it becomes difficult to handle from a safety standpoint.

[0032] In the separation process, the dissolution contains at least Fe, but may also contain other components. For example, it may contain one or more of Al, B, Mg, Ca, Li, Na, K, P, Sr, and Ba.

[0033] In the separation process, the undissolved material contains at least Si, but may also contain other components, such as Ti.

[0034] Various methods can be used to separate the dissolved solution from the undissolved material, but from the viewpoint of simplicity, filtration, particularly suction filtration, is preferred.

[0035] The present invention provides a method for manufacturing recycled glass, which includes an extraction step in which at least Fe is extracted from the dissolved solution obtained in the separation step by wet treatment.

[0036] Various methods can be used for wet processing, but wet processing by solvent extraction or ion exchange resin is preferred, and wet processing by solvent extraction is particularly preferred. This makes it easier to remove impurities such as Fe from waste glass simply, efficiently, and selectively. It also makes it easier to ensure safety during the removal of impurities.

[0037] In the extraction process, at least Fe is extracted from the solution, but other components may also be extracted. For example, impurities such as Cr, Co, Ni, Ti, Pt, Sn, Sb, Pb, Cu, Zn, Mn, Bi, Ag, and Nb may be extracted. The extraction process may be performed multiple times for each impurity.

[0038] The extraction rate of Fe is preferably 80% or higher, 85% or higher, 90% or higher, 98% or higher, 99% or higher, and especially over 99%. If the extraction rate of Fe is too low, the recycled glass will become discolored, making it difficult to promote the recycling of waste glass.

[0039] In solvent extraction, various materials can be used as extractants depending on the impurities to be removed. However, from the viewpoint of Fe extraction rate, it is preferable to use one or more of 2-undecanone, 1-octanol, and 1-decanol, and it is particularly preferable to use a mixture of the three. In ion exchange resin methods, various ion exchange resins can be used depending on the impurities to be removed.

[0040] It is preferable to regenerate the extractant or ion exchange resin with a regenerating agent after the extraction process. From the viewpoint of the regeneration efficiency (back extraction efficiency) of the extractant, it is preferable to use an acidic aqueous solution of a strong acid as the regenerating agent. Examples of strong acids include hydrochloric acid, nitric acid, and sulfuric acid, but hydrochloric acid is particularly preferred. Furthermore, it is preferable to use an acidic aqueous solution of the same type as the acidic aqueous solution used in the separation process as the regenerating agent, and it is preferable to use an acidic aqueous solution with a lower or equivalent acid concentration than the acidic aqueous solution used in the separation process. This makes it easier to reuse the extractant and ion exchange resin.

[0041] Furthermore, the present invention provides a method for producing recycled glass, comprising: a separation step of immersing waste glass containing at least the components to be dissolved in an acidic aqueous solution to separate it into a dissolved solution containing the components to be dissolved and undissolved material; an extraction step of extracting at least the components to be dissolved from the dissolved solution by wet treatment of the dissolved solution obtained in the separation step; a drying step of volatilizing the dissolved solution after the extraction of the components to be dissolved in the extraction step to obtain a dried product; and a regeneration step of melting the undissolved material obtained in the separation step and the dried product obtained in the drying step to obtain recycled glass. Here, the components to be dissolved may be components other than Fe as described above, and may include one or more of Al, B, Mg, Ca, Li, Na, K, P, Sr, and Ba.

[0042] The present invention provides a method for manufacturing recycled glass, which includes a drying step in which the dissolved solution obtained after extracting Fe in the extraction step is volatilized to obtain a dried product. The method for volatilizing the dissolved solution is not particularly limited, but for example, vacuum drying, freeze-drying, hot air drying, etc. are preferred, and vacuum drying is preferred from the viewpoint of efficiency. When the dissolved solution obtained after extracting Fe in the extraction step is volatilized, a dried product is obtained, which is generally composed of components remaining after removing the components removed in the extraction step from the components dissolved in the dissolved solution in the separation step.

[0043] The present invention provides a method for producing recycled glass, comprising a recycling step in which recycled glass is obtained by melting the undissolved material obtained in the separation step and the dried material obtained in the drying step. From the viewpoint of melting efficiency, it is preferable to use the undissolved material obtained in the separation step and the dried material obtained in the drying step that have been pulverized in the pulverization step, and from the viewpoint of homogeneity of recycled glass, it is preferable to use a mixture of the two that have been pulverized. The central particle size D of the pulverized material 50 For example, this ranges from 1 to 200 μm.

[0044] The melting temperature in the recycling process is preferably 1200 to 1700°C, and particularly preferably 1400 to 1600°C. If the melting temperature is too low, the homogeneity of the recycled glass tends to decrease. On the other hand, if the melting temperature is too high, erosion of refractories and other materials inside the furnace becomes severe during melting.

[0045] The present invention relates to a method for manufacturing glass articles, which involves melting and shaping glass raw materials to obtain glass articles. It is preferable to use recycled glass as part or all of the glass raw materials in the manufacturing process. In this way, new glass articles can be manufactured from recycled glass.

[0046] The melting of glass raw materials is generally carried out in a melting furnace. The glass raw materials are usually fed continuously using a raw material feeder such as a screw charger, but this can also be done intermittently. The glass raw materials fed into the melting furnace are heated by a combustion atmosphere such as a burner or electrodes installed inside the melting furnace to become molten glass. After undergoing clarification, stirring, and feeding processes, the molten glass is fed into a molding device and formed into glass articles.

[0047] In the method for manufacturing glass articles of the present invention, it is preferable that the glass article is made of glass fiber, tempered glass, or display glass. Because glass fiber, tempered glass, and display glass have strict control standards for impurities in the glass, the recycling of waste glass has not progressed much. However, according to the present invention, impurities and special components can be extracted and removed from waste glass, thereby increasing the recycling rate of glass articles for these applications.

[0048] It is preferable that the use of the glass articles be the same as the original use of the waste glass. This makes it easier to blend the glass raw materials because the glass composition of the glass articles and the waste glass will be similar. Furthermore, from the perspective of resource recycling, it is even preferable that the use of the glass articles be for an application with stricter impurity control standards than the original use of the waste glass. [Examples]

[0049] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0050] <Separation process> Powdered waste glass was prepared from glass fiber (EF glass manufactured by Nippon Electric Glass Co., Ltd.), tempered glass (T2X-7 manufactured by Nippon Electric Glass Co., Ltd.), and solar panel glass (SS-1 manufactured by Nippon Electric Glass Co., Ltd.). Each type of waste glass was weighed to 200g per liter of hydrochloric acid solution and immersed in a Teflon® container containing 6M hydrochloric acid solution. Next, the hydrochloric acid solution was stirred at 90°C for 3 hours to dissolve some of the glass components into the hydrochloric acid solution. After that, undissolved material containing at least Si was separated by suction filtration.

[0051] The hydrochloric acid aqueous solution Waq after separating undissolved substances was measured using an ICP-OES instrument, and the concentration of each component was quantified. The solubility L of each component was then calculated using Equation 1 below. The results are shown in Table 1. Table 1 shows that, in the separation process, most components other than Si dissolved in the hydrochloric acid aqueous solution.

[0052]

number

[0053] [Table 1]

[0054] <Selection of extractants using simulated Fe solution> First, extractants were selected using a simulated Fe solution. A simulated Fe solution was prepared by adding ferric oxide to a Teflon® container containing a 6M hydrochloric acid solution so that the Fe content was 10.17g (approximately 9250ppm) per liter of hydrochloric acid solution, and stirring at 90°C for 5 hours. In addition, extractants A to E were prepared by mixing 2-undecanone, 1-octanol, and 1-decanol in the ratios shown in the table below.

[0055] Next, 50 mL of simulated Fe solution was placed in a 200 mL PFA separatory funnel, 20 mL each of extractants A-E were added, and the funnel was shaken 100 times. Then, the simulated Fe solution was drained from the bottom of the separatory funnel, and the funnel was tilted to remove the extractants from the top.

[0056] Next, the simulated Fe solution Waq before extraction and the simulated Fe solution (Waq)n after extraction were measured using a dispersive X-ray fluorescence analyzer (EDX), and the Fe concentration of each solution was analyzed to calculate the extraction rate E (%) of extractants A to E using the following formula 2.

[0057]

number

[0058] Table 2 shows the Fe extraction rates for extractants A through E. As can be seen from Table 2, extractant E showed the best Fe extraction rate.

[0059] [Table 2]

[0060] <Extraction of Fe using solvent extraction method> 50 mL of the dissolved solution after the separation process and 20 mL of the extractant E were added to a 200 mL PFA separatory funnel and shaken 100 times. Then, the dissolved solution was drained from the bottom of the separatory funnel, and the separatory funnel was tilted to remove the extractant E from the top. Next, the dissolved solution was returned to the separatory funnel, and 20 mL of fresh extractant E was added and shaken 100 times. This process was repeated three times for waste glass fiber, and twice for waste tempered glass and waste glass from solar panels.

[0061] The concentrations of each component were quantified by measuring the dissolved solution before and after the extraction process using an ICP-OES instrument. The extraction rate of each component was calculated using Equation 2. The results are shown in Table 3. From Table 3, it can be seen that Fe was selectively removed.

[0062] [Table 3]

[0063] <Extraction of Fe using ion exchange resin method> A column packed with 10 mL of strongly basic anion exchange resin was passed through 50 mL of the dissolved solution after the separation process at a flow rate of 20 mL / h. The first 20 mL was discarded, and the concentration of each component in the remaining 30 mL of dissolved solution was quantified.

[0064] The concentrations of each component were quantified by measuring the dissolved solution before and after the extraction process using an ICP-OES instrument. The extraction rate of each component was calculated using Equation 2. The results are shown in Table 4. From Table 4, it can be seen that Fe was selectively removed.

[0065] [Table 4]

[0066] <Drying process> Next, using an evaporator, the dissolved solution after extracting Fe and other elements was evaporated at 80°C, and a dried product was obtained.

[0067] <Regeneration process> The undissolved material obtained in the separation process and the dried material obtained in the drying process were crushed and mixed using a grinder. The resulting pulverized material was then melted in a Pt / Au triangular crucible at a temperature of 1400-1600°C for 1 hour, cooled and revitrified, and then annealed at 650°C to obtain recycled glass. The absorbance of the obtained recycled glass was measured and the results were compared with those of remelted waste glass. The comparison results are shown in Table 5 and Figures 1-3. Figure 1 is a photograph of recycled glass made from waste glass fiber, taken from above the triangular crucible. Figure 2 is a photograph of remelted material made from waste glass fiber, taken from above the triangular crucible. Figure 3 is a photograph of recycled glass made from waste tempered glass, taken from above the triangular crucible. The remelted waste glass is prepared by coarsely crushing the waste glass, melting the resulting pulverized material in a Pt / Au triangular crucible at a temperature of 1400-1600°C for 1 hour, then removing it from the crucible and annealing it at 650°C.

[0068] [Table 5]

[0069] Table 5 and Figures 1-3 show that recycled glass made from waste glass fiber and tempered glass has less coloration because Fe is significantly extracted and removed during the process.

[0070] <Regeneration of extractants> 20 mL of the extractant after the extraction process was placed in a 200 mL PFA separatory funnel, and 4 mL of 0.2 M hydrochloric acid solution was added as a regeneration agent. The mixture was shaken 100 times. The 0.2 M hydrochloric acid solution was then drained from the bottom of the separatory funnel, and the funnel was tilted to remove the extractant from the top. The extractant was returned to the separatory funnel, and 4 mL of new 0.2 M hydrochloric acid solution was added. The mixture was shaken 100 times. This process was repeated a total of three times.

[0071] The regenerated extractant was reused for Fe extraction using a solvent extraction method. The reused extractant was prepared by repeating the above extraction process and regeneration treatment 1 to 10 times. The results are shown in Figure 4.

[0072] As can be seen from Figure 4, even after 10 cycles of the extraction process and regeneration treatment, the extraction rate of Fe from the extractant exceeded 90%.

Claims

1. A separation step involves immersing waste glass containing at least Fe and Si in an acidic aqueous solution to separate it into a solution containing at least Fe and undissolved material containing at least Si. An extraction step is performed by wet processing the dissolved solution obtained in the separation step to extract at least Fe from the dissolved solution. A drying process is performed to obtain a dried product by volatilizing the dissolved solution after extracting Fe in the extraction process. A method for producing recycled glass, comprising a recycling step of melting an undissolved material obtained in a separation step and a dried material obtained in a drying step to obtain recycled glass.

2. A method for producing recycled glass according to claim 1, wherein in the extraction step, the dissolved solution obtained in the separation step is wet-treated by a solvent extraction method or an ion exchange resin method.

3. A method for producing recycled glass according to claim 1 or 2, wherein the temperature of the acidic aqueous solution in the separation step is 50 to 200°C.

4. A method for producing recycled glass according to claim 1 or 2, wherein in the separation step, waste glass is immersed in an acidic aqueous solution for 1 to 48 hours.

5. A method for producing recycled glass according to claim 1 or 2, wherein the concentration of the acidic aqueous solution in the separation step is 3 to 12 M.

6. A method for producing recycled glass according to claim 1 or 2, wherein the pH of the dissolution is adjusted in the extraction step.

7. A method for manufacturing recycled glass according to claim 1 or 2, wherein volatile substances are recovered during the drying process.

8. A method for manufacturing recycled glass according to claim 1 or 2, wherein the melting temperature in the recycling process is 1200 to 1700°C.

9. A method for producing recycled glass according to claim 1 or 2, comprising extracting at least Fe from a dissolution using an extractant or ion exchange resin in the extraction step, and regenerating the extractant or ion exchange resin after the extraction step with a regenerating agent.

10. A separation step involves immersing waste glass containing at least the component to be dissolved in an acidic aqueous solution to separate it into a dissolved solution containing the component to be dissolved from the undissolved material. An extraction step is performed by wet processing the dissolved solution obtained in the separation step to extract at least the component to be dissolved from the dissolved solution. A drying process involves volatilizing the dissolved solution after the extraction of the components to be dissolved in the extraction process to obtain a dry product, A method for producing recycled glass, comprising a recycling step of melting an undissolved material obtained in a separation step and a dried material obtained in a drying step to obtain recycled glass.

11. A method for manufacturing glass articles, which involves melting and shaping glass raw materials to obtain glass articles, A method for manufacturing a glass article, wherein a part or all of the glass raw material is recycled glass produced by the method for manufacturing recycled glass described in any of claims 1, 2, or 10.

12. A method for manufacturing a glass article according to claim 11, wherein the glass article is made of glass fiber, tempered glass, or display glass.

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