JP7555367B2 - Method for utilizing shell waste, system for utilizing shell waste, and method for manufacturing products derived from shell waste - Google Patents

Description

The present invention relates to a method for utilizing shell waste, a system for utilizing shell waste, and a method for manufacturing products made from shell waste.

Conventionally, products made from shells have been provided, such as shell buttons as disclosed in the following Patent Document 1. The prior art in Patent Document 1 and other documents disclose a method for reusing pearl oyster shells, the majority of which are discarded, by using shells to make buttons for clothing, and by subjecting the shells to surface treatment with plating or vapor deposition while retaining their natural shape and texture.

Japanese Patent Application Publication No. 08-252106

As described above, the prior art provides a method for utilizing shell waste as a resource by mechanically processing the shell waste to produce products such as buttons. However, the use of shell waste only by mechanically processing it as in the prior art is limited. Therefore, the prior art has a problem in that the large amount of shell waste generated is not fully utilized as a resource. Even if shells can be mechanically processed to be utilized as shell buttons, there is a problem in that the measures for further utilizing the shell buttons are limited. Specifically, when a garment using shell buttons is to be discarded, there is no effective way to utilize the shell buttons other than removing the shell buttons from the garment and reusing them in another garment. Thus, the prior art has a problem in that the use of shell waste as a resource is limited, and the utilization of shell waste is not sufficiently promoted.

The present invention aims to provide a method for effectively utilizing shell waste as a resource, a system for utilizing shell waste, and a method for manufacturing products made from shell waste.

Based on the above findings, the inventors conducted extensive research and came to the conclusion that shells themselves and buttons and other articles made from shells can be suitably used as part or all of the calcium component that constitutes the glass raw material.

(1) The present invention, which is based on this knowledge, is a method for utilizing shell waste material consisting of shells or shell-derived molded products, and is characterized by forming a glass product through a process including a recovery process for recovering the shell waste material, a recycled material preparation process for creating a shell-derived recycled material containing calcium as a main component using the shell waste material recovered in the recovery process, a glass raw material preparation process for preparing a glass raw material using the shell-derived recycled material as part or all of the calcium component constituting the glass raw material, a heating and melting process for heating and melting the glass raw material prepared in the raw material preparation process to form a molten material, and a glass molding process for molding the molten material to form a glass product.

In the method for utilizing shell waste according to the present invention, the shell waste collected in the collection step can be prepared as shell-derived recycled material containing calcium as a calcium component in the recycled material preparation step. In addition, in the method for utilizing shell waste according to the present invention, a glass raw material is prepared in the glass raw material preparation step using shell-derived recycled material as part or all of the calcium component, and then this glass raw material is heated and melted in the heating and melting step, and the melt thus obtained is molded in the glass molding step. In the method for utilizing shell waste according to the present invention, through these steps, the shell waste can be effectively utilized as a raw material for glass products. Therefore, the present invention can provide a method for utilizing shell waste that can effectively utilize the shells themselves and shell-derived molded products such as shell buttons as resources for manufacturing glass.

(2) The above-mentioned method for utilizing shell waste of the present invention may be characterized in that in the glass raw material preparation step, at least one of silica sand, soda ash, and lime is added as the glass raw material depending on the amount of the calcium component derived from the shell waste and contained in the shell-derived recycled material.

According to this method, the amounts of silica sand, soda ash, and lime can be adjusted according to the amount of shell-derived calcium contained in the shell-derived recycled material, and a glass raw material with an optimal composition ratio for manufacturing glass products can be prepared. Therefore, the method of utilizing shell waste of the present invention provides a method of utilizing shell waste that can be effectively used as a resource for manufacturing glass.

Glass made from uranium, known as uranium glass, is known to emit fluorescence. However, because uranium is a radioactive substance, concerns about radiation exposure cannot be eliminated at any stage, either during or after production, and the greatest care must be taken to ensure safety during production and use, making it extremely difficult to handle.

The inventors therefore investigated a method for producing glass that can achieve a design effect through fluorescence without using radioactive materials, such as the uranium glass described above. As a result, they discovered that by using shell-derived recycled material prepared by storing shells or molded products using shells in an atmosphere below a certain temperature, it is possible to produce glass that emits fluorescence and has a high design effect.

(3) Based on this knowledge, the above-mentioned method of utilizing shell waste materials of the present invention may be characterized in that, in the recycled material preparation step, the shell-derived recycled material is prepared in an atmosphere at a temperature lower than a predetermined temperature by preparing shells or molded products derived from shells.

The method for utilizing shell waste according to the present invention is provided based on the findings of the inventors described above. The method for utilizing shell waste according to the present invention can be effectively used to manufacture fluorescent glass with a high design effect that is safe and easy to handle. Therefore, glass products manufactured by the method for utilizing shell waste according to the present invention can be used with the same safety as commonly used glass products, and can be suitably used as part or all of a product that requires design, such as decorative items such as accessories.

The inventors further investigated further and discovered that in order to manufacture fluorescent glass products with a highly decorative effect, it is preferable to use black lipped pearl oyster or pearl oyster shells, or molded products derived from these shells, and prepare them in an atmosphere at a temperature below a predetermined temperature.

(4) Based on this knowledge, the above-mentioned method of utilizing shell waste materials of the present invention may be characterized in that in the recycled material preparation step, the shell-derived recycled material is prepared in an atmosphere at a temperature lower than a predetermined temperature from the shells of black lipped pearl oysters or pearl oysters, or from molded products derived from the shells.

The method of utilizing shell waste according to the present invention allows fluorescent glass products with highly decorative effects to be manufactured under even more suitable conditions.

Here, the inventors have further investigated intensively to find an optimal method for producing non-fluorescent glass products using shell-derived recycled materials derived from shells or shell-based molded products, utilizing shell waste. As a result, the inventors have discovered that when shell-derived recycled materials are used, it is possible to produce glass that does not emit fluorescence by optimizing the heat treatment conditions.

(5) The method for utilizing shell waste provided based on this knowledge of the present invention is preferably characterized in that the recycled material preparation process includes a crushing process for crushing shells or shell-derived molded products, and a heat treatment process for heat-treating the shells or shell-derived molded products, or the crushed material obtained in the crushing process, in an atmosphere having a temperature equal to or higher than a predetermined temperature.

According to the method for utilizing shell waste materials of the present invention, shell waste materials can be utilized to manufacture glass products that do not emit fluorescence, similar to commonly used glass products, while using recycled materials derived from shells. As a result, the method for utilizing shell waste materials of the present invention can be suitably used in the manufacture of glass products that can be used as substitutes for commonly used glass products.

(6) The method for utilizing shell waste of the present invention described above may be characterized in that in the recovery process, shell buttons attached to clothing are recovered as the shell waste.

The method for utilizing shell waste of the present invention makes it possible to use shell-derived recycled materials that utilize shell buttons used for clothing, etc., in the manufacture of glass products. Therefore, according to the present invention, a method for utilizing shell waste that can contribute to the recycling of articles that use shell buttons, such as clothing, can be provided.

(7) The shell waste utilization system of the present invention is for utilizing shell waste consisting of shells or shell-derived molded products, and is characterized by comprising a recycled material preparation section that uses the shell waste to create shell-derived recycled material, a glass raw material preparation section that prepares glass raw material containing the shell-derived recycled material, a heating and melting section that heats and melts the glass raw material prepared in the raw material preparation process to produce a molten material, and a molding section that molds the molten material.

The shell waste utilization system according to the present invention can prepare glass raw materials using shell-derived recycled materials in the glass raw material preparation section by using shell-derived recycled materials created in the recycled material preparation section. The shell waste utilization system according to the present invention can also manufacture glass products by heating and melting the glass raw materials prepared in the raw material preparation process in the heating and melting section to produce a molten material, and then molding the molten material in the molding section. In this way, the shell waste utilization system according to the present invention can utilize shell waste materials to manufacture glass products. Therefore, according to the present invention, a shell waste utilization system can be provided that can effectively utilize shells themselves and shell-derived molded products such as shell buttons as resources for manufacturing glass.

(8) The method for producing a product derived from shell waste of the present invention uses shell waste consisting of shells or shell-derived molded products, and is characterized by forming a product derived from shell waste that contains the glass product as a part or whole through the steps including a recovery step for recovering the shell waste, a recycled material preparation step for creating a shell-derived recycled material using the shell waste recovered in the recovery step, a glass raw material preparation step for preparing a glass raw material containing the shell-derived recycled material, a heating and melting step for heating and melting the glass raw material prepared in the raw material preparation step to form a molten material, a glass forming step for forming the molten material into a glass product, and a processing step for forming a product derived from shell waste by at least one of mechanically processing the glass product and incorporating the glass product into another article.

In the method for producing a product derived from shell waste material according to the present invention, the shell waste material collected in the collection step can be prepared as a shell-derived recycled material containing calcium components in the recycled material preparation step. In addition, in the method for producing a product derived from shell waste material according to the present invention, a glass raw material using shell-derived recycled material as part or all of the calcium components is prepared in the glass raw material preparation step, and then the glass raw material is heated and melted in the heating and melting step, and the melt obtained thereby is molded in the glass molding step, thereby producing a glass product. In the method for producing a product derived from shell waste material according to the present invention, a product derived from shell waste material containing a part or all of the glass product can be formed by performing a processing step by mechanically processing the glass product obtained through such steps or by incorporating the glass product into another object. In this way, the method for producing a product derived from shell waste material according to the present invention can effectively utilize shell waste material as a raw material for a product derived from shell waste material. Therefore, the method for producing a product derived from shell waste material according to the present invention can be used to effectively utilize shells themselves and shell-derived molded products such as shell buttons as resources for producing a product derived from shell waste material.

The present invention provides a method for effectively utilizing shell waste as a resource, a system for utilizing shell waste, and a method for manufacturing products made from shell waste.

1 is a system configuration diagram showing the configuration of a shell waste utilization system according to one embodiment of the present invention. 1 is a flowchart showing a method for utilizing shell waste and a method for producing products made from shell waste according to one embodiment of the present invention. 10 is a flowchart showing the flow of a recycled material preparation process. 1 is a flowchart showing an example of a method for utilizing shell waste and a method for producing products made from shell waste according to one embodiment of the present invention, which is linked to a clothing recycling flow. 1 is a diagram for explaining the characteristics of glass samples A to H made using shell-derived recycled materials according to samples 1 to 4 in Example 1. FIG. FIG. 1 is a diagram showing the results of TMA (thermomechanical analysis) performed on sample G according to Example 1 using a thermal expansion measuring device. FIG. 1 is a diagram showing the results of TMA (thermomechanical analysis) performed on Sample H according to Example 1 using a thermal expansion measuring device. 11 is a diagram showing the results of examining the lightness Y [%], dominant wavelength λd [nm], and purity Pe [%] for sample G and sample H according to Example 1. FIG. FIG. 13 is a diagram showing the measurement results of the excitation-emission matrix measurement according to Example 2.

The following describes a method for utilizing shell waste and a method for manufacturing products derived from shell waste according to one embodiment of the present invention, as well as a shell waste utilization system 10 (hereinafter simply referred to as "utilization system 10") that is used to realize these methods. In the following explanation, the utilization system 10 will be described first, and then the method for utilizing shell waste and the method for manufacturing products derived from shell waste will be described.

<About Utilization System 10>
Next, the configuration of the utilization system 10 will be described with reference to Fig. 1. As shown in Fig. 1, the utilization system 10 includes a recycled material preparation section 20, a glass frit preparation section 30, a heating and melting section 40, a forming section 50, and a processing section 60.

The recycled material preparation unit 20 performs processing to prepare recycled materials using collected shell waste. As shown in FIG. 3, the preparation of recycled materials is carried out through one or more steps selected from the group consisting of a cleaning step, a sorting step, a crushing step, and a heat treatment step. Therefore, the recycled material preparation unit 20 is equipped with a cleaning unit 22, a sorting unit 24, a crushing unit 26, and a heat treatment unit 28, etc.

The washing section 22 is a section where a process (washing process) for washing shell waste consisting of shells or molded products using shells is carried out. The washing section 22 is equipped with washing equipment for removing foreign matter adhering to the shells or molded products by rinsing the shells or molded products with water or using chemicals such as surfactants. The washing section 22 is not an essential process in the recycled material preparation section 20, and can be omitted in cases where the shell waste to be treated does not require washing or where washing the shell waste does not affect the quality of glass products or products derived from shell waste.

The sorting section 24 is a section that carries out a process (sorting process) of separating shell waste into shells and non-shell materials such as fibers, resin, wood, etc. As with the cleaning section 22 described above, the sorting section 24 can be omitted as appropriate depending on the type and condition of the shell waste, other processes being carried out, etc.

The crushing section 26 is for carrying out the process of crushing the shell waste (crushing process). The crushing section 26 is equipped with crushing equipment such as a conventionally known crusher, and is for physically crushing the shell waste using the crushing equipment to a size suitable for use in forming glass. As with the cleaning section 22 and sorting section 24 described above, the crushing section 26 can be omitted as appropriate depending on the type and condition of the shell waste, other processes being carried out, etc.

The heat treatment section 28 is for carrying out a process of heat treating the shell waste (heat treatment process). The heat treatment section 28 is used for the purpose of directly or indirectly heating the shell waste to thermally decompose and remove substances that are unnecessary in glass production or that have a negative effect on glass production. When the shell waste is directly heated, for example, the heat treatment section 28 can be one that directly burns shells in a combustion furnace. When the shell waste is indirectly heated, for example, a heat treatment device or heat treatment equipment such as a rotary kiln can be used as the heat treatment section 28, and the conditions can be set so that the temperature inside the furnace is a predetermined temperature so that the heat treatment can be carried out. The heat treatment section 28 can be omitted as appropriate depending on the type and state of the shell waste, other processes to be carried out, etc., just like the cleaning section 22, sorting section 24, and crushing section 26 described above.

The frit preparation section 30 is for carrying out a process for preparing frits for forming glass products (friction preparation process). The frit preparation section 30 uses the shell-derived recycled material (shell-derived recycled material) prepared in the recycled material preparation section 20 to mix the raw materials necessary for manufacturing glass products. The frit preparation section 30 mixes and prepares the raw materials necessary for forming glass products, such as silica sand, soda ash, and lime, in an appropriate mixture ratio according to the amount of calcium contained in the shell-derived recycled material.

The heating and melting section 40 performs a process (heating and melting process) in which the glass raw material prepared in the glass raw material preparation section 30 is heated and melted to produce a molten material. The heating and melting section 40 may be configured, for example, by a large-scale glass melting furnace such as a Siemens-type continuous furnace, or a small-scale melting furnace such as an optical furnace or a hand-blowing furnace.

The molding section 50 is for carrying out a process of removing the molten material obtained by melting the glass raw material in the heating and melting section 40 from the melting furnace, molding it, and slowly cooling it (glass molding process). The molding section 50 can be in the form of glass products G, such as glass bottles, or cullets that can be used as raw materials for glass products G.

The processing section 60 is used to carry out the process of turning the glass products obtained in the molding section 50 into products made from shell waste (processing process) by mechanically processing the glass products and incorporating them into other items, such as ornaments such as rings, necklaces, and earrings, ornaments, and everyday items.

<How to utilize shell waste and how to manufacture products made from shell waste>
The method for utilizing shell waste and the method for manufacturing products derived from shell waste of this embodiment will be described. The method for manufacturing products derived from shell waste of this embodiment uses glass products manufactured by the method for utilizing shell waste to manufacture products derived from shell waste. Therefore, as shown in the flow chart of FIG. 2, the method for utilizing shell waste of this embodiment constitutes a part of the method for manufacturing products derived from shell waste. Therefore, in the following description, the method for manufacturing products derived from shell waste of this embodiment will be described, and the method for utilizing shell waste will also be described.

As shown in FIG. 2, the method for producing shell waste-derived products of this embodiment produces shell waste-derived products through multiple steps including a collection step (step 1), a recycled material preparation step (step 2), a glass raw material preparation step (step 3), a heating and melting step (step 4), a glass formation step (step 5), and a processing step (step 6). Of these steps, the steps from the collection step of step 1 to the glass formation step of step 5 correspond to the shell waste utilization method of this embodiment. In addition, in the recycled material preparation step of step 2, as shown in FIG. 3, the product is produced through one or more steps selected from the raw material preparation step (step 2-1), the cleaning step (step 2-2), the sorting step (step 2-3), the crushing step (step 2-4), and the heat treatment step (step 2-5). Below, each step will be explained in order, first with reference to the flowchart of FIG. 2. In addition, the recycled material preparation step (step 2) performed in the flow shown in FIG. 2 will be explained in detail with reference to the flowchart of FIG. 3 after explaining the flow related to FIG. 2.

(Step 1: Recovery process)
The method for producing a product derived from shell waste (method for utilizing shell waste) of this embodiment begins with collecting shell waste in step 1, a collection process. In the collection process, shells from which the meat has been removed and molded products using shells (such as shell buttons) are collected. The collection process can be carried out by collecting waste generated from manufacturing processes in various manufacturing industries such as food manufacturing, ornament manufacturing, pharmaceutical manufacturing, and fragrance manufacturing, waste generated in fishing, retail, and restaurants, waste discarded as waste by other corporations or individuals that do not fall into these industries, and waste separated from articles such as clothing and accessories collected for recycling.

Here, the shell waste material that is the raw material for the shell-derived recycled material can be shells of various shellfish or molded products using these. Specifically, the shell waste material can be shells of shellfish such as black lipped pearl oysters, pearl oysters, silver lipped pearl oysters, abalone, scallops, oysters, clams, sea urchins, turban shells, clams, cockles, and ark shells, as well as molded products using these shells.

Once the shell waste has been collected as described above, the manufacturing method for products made from shell waste (method of utilizing shell waste) proceeds to step 2, the recycled material preparation process.

(Step 2: Recycled material preparation process)
The recycled material preparation step is a step for preparing a recycled material (shell-derived recycled material) using the shell waste material collected in step 1. The recycled material preparation step is carried out in the recycled material preparation section 20 of the utilization system 10 described above. The shell-derived recycled material in the recycled material preparation step is prepared in accordance with the flow of Fig. 3, which will be described in detail later.

The shell-derived recycled material can constitute the entire calcium component of the glass raw material used to form glass products. The shell-derived recycled material can also constitute a part of the calcium component of the glass raw material together with other calcium components. Specifically, the shell-derived recycled material can constitute the calcium component of the glass raw material together with limestone, calcium carbonate reagent, calcium oxide reagent, etc., or can constitute the calcium component of the glass raw material together with a recycled material containing a calcium component created using a material other than shells.

In addition, the glass raw material using the above-mentioned shell-derived recycled material can contain not only the calcium component used in forming the glass, but also other components such as silicon. For example, the glass raw material can be made of a mixture containing shell-derived recycled material as part or all of the calcium component, as well as recycled materials that constitute other components such as silicon required for glass production. More specifically, after extensive research, the inventors have come to the finding that by using grains such as rice husks as materials, grain-derived recycled materials containing grain-derived silicon components can be used as the silicon component required for glass production. Therefore, the glass raw material can be a mixed material (mixed recycled material) in which the above-mentioned shell-derived recycled material is mixed with grain-derived recycled material.

Here, when the glass raw material is the mixed recycled material described above, it is advisable to adjust the mixing ratio of the calcium component and silicon component in the mixed recycled material, taking into consideration the mixing ratio of the silicon component and calcium component contained in the raw material for glass production, the color of the glass to be produced, and other conditions. More specifically, when using silica sand and limestone as raw materials for producing soda-lime glass to form molded products such as glass bottles, if a mixed recycled material is used as part or all of the silica sand or limestone, it is advisable that the silicon component contains silicon dioxide in a range of 73% by weight or less, and the calcium component contains calcium carbonate in a range of 13% by weight or less. In addition, when producing transparent (flint) glass, it is advisable that the mixing ratio of iron oxide is 0.09% by weight or less.

Once the preparation of the shell-derived recycled material in the recycled material preparation process is completed as described above, the process proceeds to step 3, the glass raw material preparation process.

(Step 3: Glass raw material preparation process)
The frit preparation process is a process for preparing frits for forming glass products. The frit preparation process is carried out in the frit preparation unit 30 of the utilization system 10 described above. The frit preparation process is a process for mixing raw materials necessary for manufacturing glass products using the shell-derived recycled material prepared in the recycled material preparation process of step 2. In the frit preparation process, the raw materials necessary for forming glass products, such as silica sand, soda ash, and lime, are mixed in an appropriate mixing ratio according to the amount of calcium contained in the shell-derived recycled material, to prepare the frits.

Specifically, when manufacturing glass products using recycled glass molding materials, the standard mixing ratio is set to 27 by weight of calcium carbonate, 28 by weight of sodium carbonate, 1.5 by weight of sodium sulfate, and 0.1 by weight of carbon when the weight of silicon oxide is taken as 100, and the raw materials are mixed by varying the mixing ratio of each component depending on the characteristics of the glass to be manufactured (e.g., viscosity, etc.). When mixing the raw materials in this way, the above-mentioned shell-derived recycled material (recycled glass molding material) is mixed as part or all of the calcium carbonate. When the glass raw material preparation process is completed in this way, the process proceeds to step 4, the heating and melting process.

(Step 4: Heating and dissolving process)
The heating and melting process is a process in which the glass frit prepared in the glass frit preparation process in step 3 is heated and melted to produce a melt. The heating and melting process is performed in the heating and melting section 40 of the utilization system 10 described above. The heating and melting process is performed by feeding glass frits into a melting furnace provided in the heating and melting section 40 and melting them. After the glass frits are melted in the heating and melting process, the process proceeds to the glass formation process in step 5.

(Step 5: Glass Formation Process)
The glass forming process is a process in which the melt obtained by melting the raw materials including the shell-derived recycled materials in the heating and melting process in step 4 is removed from the melting furnace, and the melt is formed into a shape such as a glass bottle, and then slowly cooled to produce a glass product. The glass forming process is carried out in the forming section 50 of the utilization system 10 described above. Once the glass product is formed in the glass forming process, the process proceeds to the processing process in step 6.

(Step 6: Processing)
The processing step is a step in which the glass product obtained in the glass forming step is mechanically processed or the glass product is incorporated into other articles to produce shell waste-derived products. The processing step is carried out in the processing unit 60 of the utilization system 10 described above. By processing the glass product in the processing step, shell waste-derived products such as ornaments, such as rings, necklaces, and earrings, ornaments, and daily necessities using glass products are formed.

As described above, the method for utilizing shell waste and the method for manufacturing products derived from shell waste include a step in the recycled material preparation process of step 2 to produce shell-derived recycled material that will become part or all of the recycled material for glass molding from a material other than glass, and in this respect, the method has a major characteristic. Below, we will explain in more detail the method for manufacturing shell-derived recycled material carried out in the recycled material preparation process for producing shell-derived recycled material (recycled material for glass molding) from a material other than glass.

<Manufacturing method for shell-derived recycled materials>
As shown in FIG. 3, the shell-derived recycled material is produced through one or more steps selected from the steps including a raw material preparation step (step 2-1), a washing step (step 2-2), a sorting step (step 2-3), a crushing step (step 2-4), and a heat treatment step (step 2-5). In producing the shell-derived recycled material, the selection of steps and the order of the selected steps can be appropriately changed depending on the type and condition of the raw shell or molded product using the shell. Below, the production process of the shell-derived recycled material will be explained step by step. In addition, the steps selected in producing the shell-derived recycled material and the order of the selected steps will be explained using examples of a case where a shell button attached to clothing, etc. is used as a raw material, and a case where shells generated as waste in, for example, the food manufacturing industry or the ornament manufacturing industry are used.

(Step 2-1: Raw material preparation process)
The raw material preparation step is a step of preparing shells or molded products using shells, which are the raw material for the shell-derived recycled material. For example, the raw material preparation step can be carried out by collecting shells generated as waste in the food manufacturing industry, the accessory manufacturing industry, etc. Also, the raw material preparation step can be carried out by removing shell buttons from clothing to be recycled, collecting accessories using shells, etc., and collecting them in the form of molded products using shells.

(Step 2-2: Cleaning process)
The washing step is a step of washing the shells or the molded products using shells collected in the raw material preparation step. In the washing step, the shells or the molded products are washed with water or with a chemical such as a surfactant to remove foreign matter adhering to the shells or the molded products. The washing step can be omitted as appropriate depending on the type and condition of the shells or the molded products using shells that are the raw material for the shell-derived recycled material, other steps to be performed, etc. Specifically, in cases where the raw material for the shell-derived recycled material is a shell button, which has a low effect on the molding quality of the glass even without washing, or in cases where the quality of the final shell-derived recycled material can be sufficiently ensured by performing another process instead of the washing step, it is preferable to omit the washing step and simplify the manufacturing method (manufacturing process) of the shell-derived recycled material.

(Step 2-3: Separation process)
The sorting process is a process for separating shells or shell-based molded products into shells and non-shell materials such as fibers, resins, and wood. The sorting process, like the washing process, can be omitted as appropriate depending on the type and condition of shells or shell-based molded products that are the raw material for the shell-derived recycled material, and other processes that are performed. Specifically, in cases where the raw material for the shell-derived recycled material is a defective product generated in the manufacturing process of a shell button or a scrap material generated in the manufacture of a shell button that does not have any foreign matter such as fibers attached thereto, for example, or where the quality of the final shell-derived recycled material can be sufficiently ensured by performing another process for other treatment instead of the sorting process, it is preferable to omit the sorting process and simplify the manufacturing method (manufacturing process) for the shell-derived recycled material.

(Step 2-4: Crushing process)
The crushing process is a process of crushing shells or molded products using shells. The crushing process is a process of physically crushing shells to a size suitable for use in molding glass using a conventionally known crusher or the like. The crushing process can be omitted as appropriate depending on the type and condition of the shells or molded products using shells that are the raw material for the shell-derived recycled material, other processes to be performed, etc., just like the above-mentioned washing process and sorting process. Specifically, for example, when shell buttons are used as the raw material for the shell-derived recycled material, it is assumed that the diameter is in the range of about 5 mm to about 3 cm, and the shape and size are within a predetermined range. Therefore, in such a case, the crushing process can be omitted. In addition, the crushing process can be omitted in cases where the quality of the final shell-derived recycled material can be sufficiently ensured by performing another process for other treatment. In this way, the crushing process can be omitted as appropriate depending on the state of the raw material for the shell-derived recycled material, thereby simplifying the manufacturing method (manufacturing process) of the shell-derived recycled material.

(Step 2-5: Heat treatment process)
The heat treatment step is a step of heat treating shells or molded products using shells. In the heat treatment step, shells or molded products using shells, which are the raw material for the shell-derived recycled material, are directly or indirectly heated, so that substances that are unnecessary in glass production or that have a negative effect on glass production can be thermally decomposed and removed. When directly heating shells, which are the raw material for the shell-derived recycled material, it is preferable to directly burn shells, etc. in a combustion furnace. When indirectly heating shells, etc., it is preferable to use a heat treatment device such as a rotary kiln and set conditions so that the temperature inside the furnace is a predetermined temperature.

When the calcium component contained in the shells or molded products using shells is calcium carbonate, it is advisable to heat the shells at a temperature range lower than the thermal decomposition temperature of calcium carbonate. This makes it possible to prevent calcium carbonate from being thermally decomposed into calcium oxide. As a result, the shell-derived recycled material can be handled as a raw material for glass in the same way as limestone used in the glass manufacturing process.

Here, the inventors have conducted extensive research and have found that a shell-derived recycled material suitable for producing fluorescent glass can be produced by preparing a shell-derived recycled material in an atmosphere at a temperature below a predetermined temperature (below 700°C) using, for example, the shells of a black lipped pearl oyster or a pearl oyster, or a molded product derived from such shells, as the raw material. On the other hand, they have found that if the shell-derived recycled material is prepared in an atmosphere at a temperature above a predetermined temperature (700°C or above) using the shells of the above-mentioned shellfish or a molded product using such shells as the raw material, the glass produced using this shell-derived recycled material will not emit fluorescence. Therefore, when producing a shell-derived recycled material for producing fluorescent glass using, for example, the shells of a black lipped pearl oyster or a pearl oyster, as the raw material, it is advisable to omit the heat treatment process or to carry out the heat treatment process under a temperature condition below the predetermined temperature (below 700°C). On the other hand, when preparing shell-derived recycled materials for manufacturing non-fluorescent glass using these shells as raw materials, it is recommended to carry out the heat treatment process in an atmosphere at a temperature above a specified temperature (700°C or higher).

As with the above-mentioned cleaning process, the heat treatment process can be omitted as appropriate depending on the type and condition of the shells or molded products using shells that are the raw material for the shell-derived recycled material, and other processes that are performed. Specifically, for example, when it is desired to produce a shell-derived recycled material for use in fluorescent glass using black lipped or pearl oyster shells as described above, when it is possible to remove impurities without carrying out heat treatment, or when it is desired to use the shell-derived recycled material as calcium oxide for glass production, it is advisable to omit the heat treatment process and simplify the production method (production process) for the shell-derived recycled material.

(Other processes)
In producing the shell-derived recycled material, other steps may be added as appropriate, or other steps may be used instead of the steps described above. For example, instead of or in addition to the washing step or the sorting step, a foreign matter removal step may be provided to remove foreign matter. The foreign matter removal step may be, for example, a step in which foreign matter is removed chemically using a chemical solution or the like, or a step in which foreign matter is removed physically by applying an external force.

The above-mentioned method for utilizing shell waste and the method for manufacturing products derived from shell waste can also be linked to other recycling flows, such as the recycling flow of clothing. For example, as shown in FIG. 4, the above-mentioned method for utilizing shell waste and the method for manufacturing products derived from shell waste can be linked to the recycling system X of clothing, etc., and the recycling system Y of clothing, etc. can be linked. More specifically, by sharing the process of collecting shell buttons attached to clothing in the recycling system Y of clothing, etc. with the collection process (step 1) of the recycling system X, the shell buttons collected in the recycling system Y of clothing, etc. can be used as raw materials for making glass products. In addition, in the method for utilizing shell waste and the manufacturing method of products derived from shell waste of this embodiment, the shell waste products created in the processing process of step 6 can be used as items for clothing such as glass ornaments and buttons, and a process (step Y-1: shell waste product use process) can be provided in the recycling system Y to make clothing using the shell waste products. By adopting such a configuration, the use of shell waste can be further promoted.

Next, examples of shell-derived recycled materials made by the method described in the above embodiment and glass products made using the same will be described. In this example, samples 1 to 4 were prepared as shell-derived recycled materials made from pearl oysters, fringe shells, white-lipped oysters, and black-lipped oysters as shown in Table 1, after going through the raw material preparation process and crushing process in the above-mentioned method for manufacturing shell-derived recycled materials. Also, as shown in Figure 5, the shell-derived recycled materials of samples 1 to 4 were used to create glasses of samples A to H in accordance with the above-mentioned glass manufacturing method. Note that the shell-derived recycled materials used in samples A and H were shell-derived recycled materials of samples 1 and 4 that had been subjected to a heat treatment process in an atmosphere at a temperature above a predetermined temperature (700°C or higher).

As shown in Table 1, the shell-derived recycled materials for Samples 1 to 4, which were made from pearl oysters, pearl oysters, white lipped oysters, and black lipped oysters, all had a composition that was 95% or more calcium. In light of the test results in Table 1, it is believed that all of these shell-derived recycled materials can be suitably used in the manufacture of glass. Note that in this example, measurements were performed using a scanning X-ray fluorescence analyzer (XRF: ZSX Primus II manufactured by Rigaku Corporation), so in Table 1, the composition is shown by the form of oxides.

In addition, glass manufacturing tests were conducted using the above-mentioned shell-derived recycled materials of Samples 1 to 4, according to the above-mentioned glass manufacturing method. As a result, the glass compositions of Samples A to H were as shown in Figure 5, and were found to be within the appropriate range for glass. Furthermore, visual inspection revealed that when any of the shell-derived recycled materials of Samples 1 to 4 were used, glass could be properly manufactured, as shown in the attached photograph in Figure 5.

The results of TMA (thermomechanical analysis) performed using a thermal expansion measuring device for sample G, which was not fired (heat-treated) using black lip shell as the raw material, and sample H, which was fired (heat-treated) using black lip shell as the raw material, are shown in Figures 6 and 7. For sample G, the heat distortion temperature (softening temperature) was 616 [°C], the glass transition temperature was 582 [°C], and the linear thermal expansion coefficient was 93.2 [1/K]. For sample H, the heat distortion temperature (softening temperature) was 643 [°C], the glass transition temperature was 579 [°C], and the linear thermal expansion coefficient was 96.2 [1/K]. These results show that whether or not the raw shell waste is fired (heat-treated) has little effect on the properties of glass formed using shell-derived recycled material made from the shell waste, and that glass with approximately the same properties can be obtained.

In addition, among the glass samples made using shell-derived recycled materials in Sample 1 and Sample 4, which use pearl oysters and black lipped oysters, Samples B, F, and F, which used shell-derived recycled materials without firing, each produced amber-colored glass. Because the shells of pearl oysters and black lipped oysters have parts that are black or dark in color, it is believed that the effects of trace components contained in the shells were evident when the glass was manufactured.

Figure 8 shows the results of examining the brightness Y [%], dominant wavelength λd [nm], and purity Pe [%] for sample G, which was made from black lip oysters but was not fired (heat-treated), and sample H, which was made from black lip oysters but was fired (heat-treated). (In the graph in Figure 8, sample G is labeled "NHT black lip oysters" and sample H is labeled "HT black lip oysters.") As a result of the color test, sample G, which was made from black lip oysters but was not fired (heat-treated), had a dominant wavelength λd of 573.91 [nm], which is close to the dominant wavelength λd = 580 to 590 nm that brown (amber) glass bottles usually exhibit. Therefore, it was confirmed that sample G exhibits a brown-like color tone, as confirmed by visual inspection. In addition, for sample H, which was calcined (heat-treated) from black lip shell, the dominant wavelength λd was 513.84 [nm], which was shorter than the brown color and showed a wavelength close to the dominant wavelength λd = 550 to 585 nm range normally shown by colorless (flint) glass bottles. Therefore, it was confirmed that sample H exhibits a colorless color tone, as confirmed by visual inspection. In addition, when comparing the results of the color tone measurement for sample G and sample H, a clear difference was observed in the transmittance (%) from wavelengths of 380 [nm] to 525 [nm]. Note that while the transmittance of colorless glass bottles usually shows a value in the 80 [%] range, the transmittance of sample H was in the 75 [%] range, which was slightly lower than that of colorless glass bottles. This is thought to be due to the fact that the glass related to sample H prepared for this test contained many air bubbles. However, as can be seen by looking at the graph in Figure 8, Sample H, unlike Sample G, exhibited a characteristic that changed gradually overall regardless of the increase or decrease in wavelength, and had characteristics similar to colorless glass. Therefore, it was confirmed that Sample H, which was made from heat-treated black lip oysters, exhibited a color tone that was clearly different from that of Sample G, which was made from black lip oysters that had not been heat-treated.

Of the glass samples made using shell-derived recycled materials, Sample 1 and Sample 4, which used pearl oysters and black lipped oysters, Sample A and Sample H, which used fired shell-derived recycled materials, each had a flint color. Therefore, even if amber-colored glass is obtained using shell-derived recycled materials prepared without firing, such as pearl oysters and black lipped oysters, it was found that the shell-derived recycled materials can be effectively used as a raw material for obtaining flint-colored glass by firing them before using them in glass production.

In addition, the glass samples C, D, and E, which were made using shell-derived recycled materials according to Samples 2 and 3, which were made from the Takase shell and the White-lipped shell, which are whitish in color overall, and were produced by the above-mentioned manufacturing method, all had a flint color.

Furthermore, when the characteristics of the glass related to the above-mentioned samples A to H were examined, it was found that among the samples using black lipped pearl oysters, samples F and G, which used shell-derived recycled material without firing it, exhibited the characteristic of exhibiting fluorescence when irradiated with ultraviolet light.

Next, we will explain the results of excitation emission matrix measurements (EEM) performed on a glass product made using a powder of the black lip oyster, the raw material of sample 4 shown in Example 1 above, and the recycled shell material derived from the black lip oyster in sample 4.

The excitation-emission matrix measurement in Example 2 was carried out for the purpose of obtaining the excitation-emission characteristics of each of the above-mentioned samples and comparing the changes in the emission characteristics before and after they were made into glass products. This measurement was carried out by fluorescence spectroscopy using a modular fluorescence spectrometer (Fluorolog3 manufactured by Horiba, Ltd.). The specific measurement conditions were as follows: (Condition 1) to (Condition 3).

(Condition 1) Measurements are performed with a powdered black lipped oyster and a glass product made from recycled shell material derived from black lipped oyster set in a solid sample holder.
(Condition 2) The mounting angle of the solid sample holder is adjusted so that the emitted light is taken into the emission side spectroscope (surface photometry).
(Condition 3) Other measurement conditions are as shown in Table 2 below.

The results of the above-mentioned excitation-emission matrix measurement are shown in FIG. 9. FIG. 9(a) shows the measurement results for powdered black lip oyster, and FIG. 9(b) shows the measurement results for a glass product made using the shell-derived recycled material derived from black lip oyster of sample 4. As a result, a clear difference was confirmed in the excitation and emission characteristics between the powdered black lip oyster and the glass product made using the shell-derived recycled material derived from black lip oyster of sample 4. In addition, when comparing the two, multiple emissions with different excitation and emission characteristics were observed. In this way, it was found that the glass product made using the shell-derived recycled material derived from black lip oyster emits fluorescence in the same way as the powdered black lip oyster, but the fluorescent characteristics are not the same as those of the powdered black lip oyster, but have their own unique characteristics.

Considering the above-mentioned embodiment and each example, the present invention provides the following advantages (1) to (8).

(1) In the above-mentioned method for utilizing shell waste, the shell waste collected in the collection step (step 1) can be prepared as a shell-derived recycled material containing calcium components in the recycled material preparation step (step 2). In addition, in the above-mentioned method for utilizing shell waste, a glass raw material is prepared in the glass raw material preparation step (step 3) using shell-derived recycled materials as part or all of the calcium components, and then this glass raw material is heated and melted in the heating and melting step (step 4), and the melt obtained thereby can be molded in the glass molding step (step 5). According to the method for utilizing shell waste of this embodiment, by going through such steps, the shell waste can be effectively used as a raw material for glass products. Therefore, the method for utilizing shell waste of this embodiment can be said to be a method that can effectively use shells themselves and shell-derived molded products such as shell buttons as resources for manufacturing glass.

(2) As described above, in the method for utilizing shell waste in this embodiment, at least one of silica sand, soda ash, and lime is added as a glass raw material in the glass raw material preparation step according to the amount of calcium components derived from the shell waste and contained in the shell-derived recycled material. Therefore, according to the method exemplified in this embodiment, the amount of silica sand, soda ash, and lime can be adjusted according to the amount of shell-derived calcium components contained in the shell-derived recycled material, and a glass raw material having an optimal composition ratio for manufacturing glass products can be prepared. Therefore, the method for utilizing shell waste in this embodiment can be said to be a method that can be effectively used as a resource for manufacturing glass.

(3) As described above, as exemplified in this embodiment and the examples, if in the recycled material preparation process, the shell-derived recycled material is prepared in an atmosphere of a temperature below a predetermined temperature using shells or shell-derived molded products, it can be effectively used to manufacture fluorescent glass with a high design effect that is safe and easy to handle. As a result, the glass product manufactured by the method for utilizing shell waste according to the above embodiment can be used with the same safety as glass products that are widely and commonly used, and can be suitably used as a part or all of a product that requires design, such as decorative items such as accessories.

(4) As illustrated in the present embodiment and examples, the above-mentioned method of utilizing shell waste uses black lipped pearl oyster or pearl oyster shells, or molded products derived from such shells, as shell-derived recycled materials, and prepares the shell-derived recycled materials by heating them in an atmosphere at a temperature below a predetermined temperature, making it possible to manufacture fluorescent glass products with highly decorative design effects under even more favorable conditions.

(5) As illustrated in the present embodiment and examples, the above-mentioned method for utilizing shell waste may include a crushing step for crushing shells or shell-derived molded products, and a heat treatment step for heat treating the shells or shell-derived molded products, or the crushed material obtained in the crushing step, in an atmosphere having a temperature equal to or higher than a predetermined temperature. This makes it possible to utilize shell waste to manufacture glass products that do not emit fluorescence, similar to commonly used glass products, while using shell-derived recycled materials.

(6) The method for utilizing shell waste in this embodiment can contribute to the recycling of articles that use shell buttons, such as clothing, by collecting shell buttons attached to clothing as shell waste during the collection process.

(7) In the shell waste utilization system 10 of this embodiment, by using shell-derived recycled materials created in the recycled material preparation section 20 using shell waste, glass raw materials can be prepared in the glass raw material preparation section 30 using shell-derived recycled materials. In addition, in the shell waste utilization system 10 of this embodiment, the glass raw materials prepared in the glass raw material preparation section 30 are heated and melted in the heating and melting section 40 to form a melt, and then the melt is molded in the molding section 50 to manufacture glass products. In this way, the shell waste utilization system 10 of this embodiment can utilize shell waste to manufacture glass products. Therefore, the shell waste utilization system 10 of this embodiment can contribute to the effective use of shells themselves and shell-derived molded products such as shell buttons as resources for manufacturing glass.

(8) In the manufacturing method of the shell waste product of this embodiment, the shell waste collected in the recovery step (step 1) can be prepared as a shell-derived recycled material containing calcium components in the recycled material preparation step (step 2). In addition, in the manufacturing method of the shell waste product of this embodiment, in the glass raw material preparation step (step 3), a glass raw material using shell-derived recycled material as part or all of the calcium component is prepared, and then this glass raw material is heated and melted in the heating and melting step (step 4), and the melt obtained thereby is molded in the glass molding step (step 5), thereby manufacturing a glass product. In the manufacturing method of the shell waste product exemplified in this embodiment, a shell waste product containing a glass product as part or all of the glass product can be formed by performing a processing step by mechanically processing the glass product obtained through such steps or incorporating the glass product into another article. In this way, the manufacturing method of the shell waste product described above can effectively utilize the shell waste as a raw material for the shell waste product. Therefore, the above-mentioned manufacturing method for products made from shell waste allows the effective use of shells themselves and shell-derived molded products such as shell buttons as resources for manufacturing products made from shell waste.

The present invention is suitable for use in glass made from recycled glass molding materials recycled from materials other than glass, and for the manufacture of such glass.

10: Shell waste utilization system 20: Recycled material preparation section 22: Cleaning section 24: Separation section 26: Crushing section 28: Heat treatment section 30: Glass raw material preparation section 40: Heating and melting section 50: Forming section 60: Processing section

Claims (6)

A method for utilizing shell waste materials consisting of shells or shell-derived molded products, comprising:
A recovery step of recovering the shell waste material;
a regenerated material preparation process for preparing a shell-derived regenerated material mainly composed of calcium components using the shell waste material recovered in the recovery process;
A glass frit preparation step of preparing a glass frit using the shell-derived recycled material as a part or all of the calcium component constituting the glass frit;
A heating and melting process in which the glass frit prepared in the glass frit preparation process is heated and melted to obtain a melt;
a glass forming step of forming the melt into a glass product;
A glass product is formed through a process including the steps of:
The recycled material preparation step includes:
A crushing step of crushing shells or shell-derived molded products;
A heat treatment step of heating and heat-treating the shells or shell-derived molded products, or the crushed material obtained in the crushing step, in an atmosphere having a temperature lower than a predetermined temperature;
and
A method for utilizing shell waste, characterized in that the shells or the molded products derived from shells are shells of a black lipped pearl oyster or a pearl oyster, or the molded products derived from said shells. 2. The method for utilizing shell waste material according to claim 1, wherein the predetermined temperature is 700°C. The method for utilizing shell waste according to claim 1 or 2, characterized in that in the glass raw material preparation step, at least one of silica sand, soda ash, and lime is added as the glass raw material depending on the amount of the calcium component derived from the shell waste and contained in the shell-derived recycled material. In the recovery step, the shell buttons attached to the clothes are recovered as the shell waste material.
A method for utilizing shell waste material according to any one of claims 1 to 3 . A system for utilizing shell waste materials consisting of shells or shell-derived molded products by the method for utilizing shell waste materials according to any one of claims 1 to 4,
A recycled material preparation unit for carrying out the recycled material preparation process of preparing a shell-derived recycled material using the shell waste material;
A frit preparation unit for performing the frit preparation step of preparing a frit containing the shell-derived recycled material;
A heating and melting unit for performing the heating and melting step of heating and melting the glass frit prepared in the glass frit preparation step;
a forming section for performing the glass forming step of forming the melt;
The system for utilizing shell waste is characterized by comprising: A method for producing a shell waste product using shell waste consisting of shells or shell-derived molded products, comprising:
A recovery step of recovering the shell waste material;
A regenerated material preparation process for preparing a regenerated material derived from shells using the shell waste material recovered in the recovery process;
A glass frit preparation step of preparing a glass frit containing the shell-derived recycled material;
A heating and melting process in which the glass frit prepared in the glass frit preparation process is heated and melted to obtain a melt;
a glass forming step of forming the melt into a glass product;
A processing step of converting the glass product into a shell waste product by performing at least one of mechanical processing on the glass product and incorporating the glass product into another product;
A shell waste product is formed which contains the glass product as a part or whole through a process including the steps of:
A method for producing a product derived from shell waste, comprising the steps of: the recovery step; the recycled material preparation step; the glass raw material preparation step; the heating and melting step; and the glass molding step, by the method for utilizing shell waste according to any one of claims 1 to 4.

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