A method for manufacturing Japanese paper using concrete drainage.
By incorporating concrete drainage into the Japanese paper boiling process, the method addresses high treatment costs and environmental impact, achieving cost savings and reduced chemical usage.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2026-03-18
AI Technical Summary
The high treatment costs and environmental impact of concrete drainage, coupled with the low recycling rate, and the rising costs and chemical requirements of handmade Japanese paper production, particularly due to the use of caustic soda and soda ash, pose significant challenges.
Integrating concrete drainage, specifically supernatant water, into the boiling process of Japanese paper manufacturing to neutralize its alkalinity and reduce chemical usage.
Reduces wastewater treatment costs for concrete companies and lowers chemical expenses for paper manufacturers while minimizing environmental harm.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention links concrete drainage to the boiling process of making Japanese paper, aiming to solve environmental problems and reduce the costs of concrete drainage and Japanese paper making.
Background Art
[0002] Although the demand for fresh concrete is on a decreasing trend, the industrial waste discharged from fresh concrete manufacturers remains flat. Also, according to the "Investigation Report on the Discharge and Treatment Status of Industrial Waste in Fiscal Year 2022", waste alkali has the second-lowest recycling rate among all industrial wastes. Usually, concrete drainage is treated through the following steps: (1) separating the wastewater from the mixer truck into gravel / sand and sludge water; (2) separating the sludge water into dewatered cake and supernatant water; (3) neutralizing the supernatant water to a neutral range (pH 5.8 - 8.6); and (4) discharging the treated water.
[0003] The process of making hand-drawn Japanese paper generally includes the following steps: (1) soaking the raw materials in water to soften the fibers (soaking process); (2) boiling the raw materials in a strongly alkaline liquid such as caustic soda or soda ash to soften them (boiling process); (3) removing the dirt attached to the raw materials and the ash generated during boiling (dust removal process); (4) putting the raw materials into a machine called a beater to further loosen the fibers into "paper pulp" (beating process); (5) using tools called sieves and frames to draw the paper (paper drawing process); (6) dewatering process using a dehydrator; and (7) drying process using sunlight or a heated iron plate.
Summary of the Invention
Problems to be Solved by the Invention
[0004] Treating concrete drainage costs millions of yen annually, depending on the scale of the factory. In addition to the treatment cost, there are concerns about the negative impact on the environment. The recycling rate of concrete drainage is the second lowest among all industrial wastes.
[0005] The production of handmade Japanese paper incurs costs such as raw material costs, utility costs, and labor costs. In addition, the boiling process requires chemicals such as caustic soda and soda ash to purify the highly alkaline water. The price of caustic soda has been on the rise in recent years due to the rising prices of crude oil and coal. [Means for solving the problem]
[0006] As a means of treating concrete wastewater (supernatant water from the above procedure), which is industrial waste, in a way that has minimal adverse effects on the environment, it is utilized in the boiling process of washi paper manufacturing. [Effects of the Invention]
[0007] As shown in Figure 3, when wastewater was taken from a pot boiling kozo (mulberry), the raw material for washi paper, at regular intervals and its pH was measured after the water temperature had cooled, the pH changed from 12.6 before boiling to 8.4 after 800 minutes. Since kozo is acidic, boiling it in concrete wastewater changed it from strongly alkaline to neutral. Normally, the pH at which wastewater can be discharged without neutralization is 8.6 or lower, so it can be discharged without the treatment that is conventionally performed by concrete contractors.
[0008] Since the supernatant water generated by ready-mix concrete companies is industrial waste, utilizing it would not only reduce wastewater treatment costs for ready-mix concrete companies but also mitigate negative environmental impacts.
[0009] For washi (Japanese paper) manufacturers, this can reduce the costs associated with chemicals used to purify highly alkaline water, such as caustic soda and soda ash. [Brief explanation of the drawing]
[0010] [Figure 1] Block diagram showing the manufacturing process of handmade Japanese paper. [Figure 2] Block diagram showing the concrete wastewater treatment process. [Figure 3] Graph showing the change in pH of ready-mix concrete wastewater due to the boiling of paper mulberry fibers. [Modes for carrying out the invention]
[0011] The supernatant water generated by the concrete company is transported to the washi paper manufacturer and used as water during the boiling process. The present invention will be described in detail below with reference to Figure 1. 1-1 In the soaking process, the raw materials, paper mulberry, mitsumata, and ganpi, are soaked in water to soften them. 1-2 In the boiling process, the raw materials are boiled for 1.5 to 2 hours using chemicals such as caustic soda and soda ash to soften the fibers. 1-3 In the dust removal process, dirt attached to the raw materials and impurities that come out during boiling are removed. Dirt that is too hard to remove before boiling becomes softer after boiling, making it possible to remove it. 1-4 In the beating process, the softened raw material is further broken down into finer fibers. A machine called a beater is used to loosen the fibers and create a mushy state called "paper material". 1-5 In the papermaking process, using tools called a screen and a frame, water, paper pulp, and a viscous liquid called "neri" are mixed in a papermaking vat, and the mixture is gradually scooped up to create paper. Shaking the mixture as it is scooped up causes the fibers to intertwine, resulting in strong paper. 1-6 In the dewatering process, the paper that has been made contains a large amount of water, so the water is squeezed out by applying pressure from above in a dewatering machine. 1-7 In the drying process, the pieces that have had some moisture removed are dried one by one. There are two methods: one is to attach each piece to a board and dry it in the sun, and the other is to attach it to a hot iron plate heated with steam and dry it.
[0012] 2-1 Separate the wastewater from the mixer truck into gravel and sand. 2-2 The dewatered cake (sludge) is allowed to settle from the sludge water (separated clean water). 2-3 Neutralize the supernatant water (highly alkaline water, pH 13 or higher) obtained by settling the dehydrated cake using a neutralizing agent to bring the pH down to 5.8-8.6. 2-4 Discharge the neutralized concrete wastewater.
Claims
1. A method for manufacturing Japanese paper, characterized by using the supernatant water from the treatment process of ready-mix concrete wastewater in the boiling process of Japanese paper manufacturing.
2. The method for producing Japanese paper according to claim 1, characterized in that the pH of the supernatant water is 11 to 14.
3. The method for manufacturing washi paper according to claim 1, characterized in that, by going through the washi paper manufacturing process, acidic plants, which are the raw materials for washi paper, are boiled in strongly alkaline concrete wastewater, thereby changing the wastewater from strongly alkaline to neutral and treating it.