Porous body, method and equipment for manufacturing porous body, and method and equipment for processing siliceous shale

Abstract

To provide a porous body, a method and a facility for producing a porous body, a method and a facility for processing siliceous shale, which expand the use of siliceous shale.SOLUTION: A porous body 11 is formed by reduced siliceous shale having Fe2+. The porous body 11 is produced by a production facility 31, and a production method includes a wet treatment process and a contact treatment process. The wet treatment process is carried out by a wet treatment unit 34, which impregnates siliceous shale 13 or granular siliceous shale 13A with liquid water. The contact treatment process is carried out by a contact treatment device 37, in which superheated steam is brought into contact with siliceous shale 13 or granular siliceous shale 13A in a moisture-containing state.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a porous body, a method and equipment for manufacturing the porous body, and a method and equipment for processing siliceous shale.

Background Art

[0002] Diatomaceous earth has fine pores and is a fossilized product of aqueous plants (diatomaceous plants) due to crustal movement. It is composed of silicon dioxide and trace amounts of minerals. Diatomaceous earth is used in the form of fired diatomaceous earth or unfired diatomaceous earth. Its applications include water absorbents, humidity control materials, filtration aids, desiccants, wall coating materials, heat insulation materials, abrasives, etc. Diatomaceous earth is also approved and used as a food additive (applied from May 6, 2011, food additive number 119, manufacturing agent) and a feed additive (excipient and diluent number 27 defined in the criteria for the method of manufacturing general feed additives in Appendix 2 of Article 35 of the Ministry of Agriculture, Forestry and Fisheries Order). Fired diatomaceous earth of a certain standard is regarded as a soil improvement material under the Soil Fertility Enhancement Law.

[0003] Also, diatomaceous earth is used for oral ingestion by livestock. For example, Patent Document 1 discloses a feed obtained by adding and mixing diatomaceous earth, defecation-free powder, and seaweed powder to feed raw materials.

[0004] Since siliceous shale is a natural substance existing in nature, there are reports that microorganisms exist, for example, inside pores, and there are also reports suggesting the existence of unidentified microorganisms. In this regard, Patent Document 2 describes that in order to sterilize coexisting microorganisms, heat treatment is performed at a temperature of 100°C or higher and 400°C or lower, and effectively, live bacteria of coexisting microorganisms are removed by directly heating at 120°C for 20 minutes. Also, this Patent Document 2 discloses its use as a fertilizer or a soil conditioner.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, although siliceous shale has the above-described various properties, for example, in heating as described in Patent Document 2, for example, in a firing treatment using a kiln or the like, the pH changes from neutral to weakly basic. Therefore, the use is limited only by the treatment of heating.

[0007] Therefore, an object of the present invention is to provide a porous body, a method for manufacturing a porous body, a porous body manufacturing facility, a siliceous shale treatment method, and a siliceous shale treatment facility that expand the uses of siliceous shale.

Means for Solving the Problems

[0008] Therefore, the porous body of the present invention Obtained through a water-containing step of adding liquid water to siliceous shale and a contact treatment step of bringing superheated steam into contact with the siliceous shale containing the water, Fe 3+ with respect to Fe 2+ contains more is formed of reduced siliceous shale.

[0009] The porous body preferably has a pore radius of 10 μm or less even if it is large. In the pore size distribution curve showing the relationship between the pore radius and the pore volume, the porous body has 1 nm or more a first peak exceeding 0.02 cm 3 / g in a first range of 10 nm or less, and a second peak exceeding 0.02 cm 3 / g in a second range of 100 nm or more and 10 μm or less. The first peak is the peak of the pore volume when the pore radius in the first range is divided in 1-nm increments, and the second peak is preferably the peak of the pore volume when, in the second range, the pore radius of 100 nm or more and 1 μm or less is divided in 100-nm increments and the pore radius of 1 μm or more and 10 μm or less is divided in 1-μm increments.

[0010] The porous body is preferably formed in a granular shape.

[0011] The porous body preferably exhibits a redox potential of 513 mV or less even when suspended in deionized water. The suspension has a concentration calculated as (M11 / MW)×100 of 10% when the mass of the porous body is M11 and the mass of deionized water is MW, and the oxidation-reduction potential is a value obtained by correcting the measured value measured using Ag / AgCl as a reference electrode and KCl as an internal solution with the standard hydrogen electrode correction value as the reference electrode (the correction formula is E (N.H.E.) =E(Ag / AgCl) +206 - 0.7(t - 25), E (N.H.E.) is the standard hydrogen electrode correction value, E (Ag / AgCl) is the measured value, and t is the measurement temperature (unit: °C)).

[0012] The method for manufacturing a porous body of the present invention includes a water-containing step and a contact treatment step. In the water-containing step, liquid water is incorporated into siliceous shale. In the contact treatment step, superheated steam is brought into contact with the siliceous shale in a state containing water.

[0013] The siliceous shale is preferably Wakkanai-layer siliceous shale.

[0014] In the water-containing step, it is preferable to incorporate water into the siliceous shale by immersing the siliceous shale in water.

[0015] After the contact treatment step, it is preferable to have a cooling step of cooling the siliceous shale under reduced pressure.

[0016] The temperature of the superheated steam is preferably at least 160°C even if it is low.

[0017] In the contact treatment step, it is preferable to bring the superheated steam into contact with the siliceous shale for at least 10 minutes.

[0018] In the contact treatment step, which has a plurality of through holes penetrating in the thickness direction, it is preferable to bring the superheated steam into contact with the siliceous shale by supplying the superheated steam from below the mounting tool on which the siliceous shale is placed. In the contact treatment step, with the siliceous shale placed on each of a plurality of mounting tools spaced apart in the vertical direction, it is preferable to supply the superheated steam from below the lowermost mounting tool among the plurality of mounting tools.

[0019] The manufacturing equipment for a porous body of the present invention includes a mounting tool and a contact treatment unit. The mounting tool has a plurality of through holes penetrating in the thickness direction, on which siliceous shale containing liquid water is placed. The contact treatment unit has an outlet for superheated steam directed toward the lower surface of the mounting tool, and brings the superheated steam into contact with the siliceous shale on the mounting tool by supplying the superheated steam from below the mounting tool.

[0020] It is provided with a plurality of placing tools arranged at intervals in the vertical direction, and it is preferable that the contact treatment part is arranged with the outlet facing the lower surface of the lowermost placing tool among the plurality of placing tools.

[0021] The method for treating siliceous shale of the present invention has a water-containing step and a contact treatment step. The water-containing step makes the siliceous shale contain liquid water. The contact treatment step brings superheated steam into contact with the siliceous shale in a state containing water.

[0022] The siliceous shale treatment equipment of the present invention is provided with a placing tool and a contact treatment part. The placing tool has a plurality of through holes penetrating in the thickness direction, on which siliceous shale containing liquid water is placed. The contact treatment part has an outlet for superheated steam facing the lower surface of the placing tool, and supplies superheated steam from below the placing tool to bring the superheated steam into contact with the siliceous shale on the placing tool.

Advantages of the Invention

[0023] According to the present invention, the uses of siliceous shale are expanded.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0025] A porous body 11 shown in FIG. 1 is one embodiment of the present invention, is made from siliceous shale 13 (see FIG. 4), and has a plurality of pores (voids) 14. The pores 14 are irregular in shape, and the sizes of the plurality of pores 14 are non-uniform. In FIG. 1, the distances between the pores 14 are greatly exaggerated to avoid complicating the drawing.

[0026] In this example, the particle diameter D is in the range of 1 mm to 10 mm, and is preferably in the range of 2 mm to 5 mm in order to improve the usability (ease of use, handling) when used as a moisture absorbing material in the moisture absorption evaluation described later. However, the particle diameter D is not particularly limited and can be appropriately set according to the application. For example, when the particle diameter D is less than 1 mm in powder form, it tends to fly up during use, and when the particle diameter D is 1 mm or more, the flying up is suppressed. In addition, the porous body 11 may be in the form of a lump (block) with a particle diameter D larger than 10 mm. Note that, whether the porous body 11 is a grain, powder, or lump, the particle diameter D when it is in an irregular shape is the longest dimension among the diameters that can be taken.

[0027] The pores of porous materials are classified by IUPAC (International Union of Pure and Applied Chemistry) as micropores with a pore diameter of 2 nm or less, mesopores with a pore diameter of 2 nm to 50 nm, and macropores with a pore diameter of 50 nm or more. Based on this classification, the porous body 11 has micropores 14a, mesopores 14b, and macropores 14c, which all exist together. It is considered from the pore distribution curve described later that mesopores 14b are formed on the inner wall surface defining the macropores 14c, and micropores 14a are formed on the inner wall surface defining the mesopores 14b. Note that the mesopores 14b and the micropores 14a may exist independently in the porous body 11, and some of the micropores 14a may be formed on the inner wall surface of the macropores 14c.

[0028] The porous body 11 is manufactured from siliceous shale 13 (see Fig. 4), and no special treatment is performed to remove the components of the siliceous shale during the manufacturing process. Therefore, the porous body 11 has a pore radius and pore distribution approximately equal to those of the raw material. Note that microorganisms (such as bacteria, fungi, viruses, etc.) may adhere to the inner wall surface defining the pores in the siliceous shale, and the size of the pores in the siliceous shale cannot be measured considering the presence or absence of these adherents. Therefore, there may be a very slight difference between the measurement result of the pore size of the raw material siliceous shale and the measurement result of the pore size of the pores 14 in the porous body 11. However, the contact treatment with superheated steam described later does not remove the components of the siliceous shale itself even if the adherents such as microorganisms are removed. Therefore, the pore size of the porous body 11 can be regarded as the same as the pore size of the raw material siliceous shale.

[0029] The raw material siliceous shale 13 has a maximum pore radius of 10 μm. As shown in Fig. 2, in the pore distribution curve showing the relationship between the pore radius and the pore volume, the siliceous shale 13 has a first peak exceeding 0.02 cm 3 / g in the first range where the pore radius is greater than 0 nm and less than or equal to 10 nm, and a second peak exceeding 0.02 cm 3 / g in the second range where the pore radius is greater than or equal to 100 nm and less than or equal to 10 μm. Therefore, the porous body 11 also has a maximum pore radius of 10 μm. As shown in Fig. 2, in the pore distribution curve showing the relationship between the pore radius and the pore volume, the siliceous shale 13 has a first peak exceeding 0.02 cm 3 / g in the first range where the pore radius is greater than 0 nm and less than or equal to 10 nm, and a second peak exceeding 0.02 cm 3 / g in the second range where the pore radius is greater than or equal to 100 nm and less than or equal to 10 μm. Note that the pore distribution curve shown in Fig. 2 is data for the pressure-molded siliceous shale 13. In this regard, it has been reported by the (public) Horonobe Geosphere Environment Research Institute that pressure molding has no effect on the pore distribution consisting of macropores, mesopores, and micropores. The vertical axis in Fig. 2 is the pore volume, and the horizontal axis is the pore radius, which is in logarithmic notation.

[0030] Siliceous shale is geographically classified as a type of diatomaceous earth, and it is generally known that diatomaceous earth also has pores. The Wakkanai-layer siliceous shale and the main diatomaceous earth produced in Japan have the pore characteristics shown in Table 1 respectively. The "average specific surface area of diatomaceous earth" in Table 1 is the average value av1 of the specific surface areas x1 of four types of diatomaceous earth, namely Akita diatomaceous earth, Ishikawa diatomaceous earth, Okayama diatomaceous earth, and Oita diatomaceous earth. The "ratio of the specific surface area to the average of diatomaceous earth" is obtained by the calculation formula of x1 / av1. The "average pore volume of diatomaceous earth" in Table 1 is the average value av2 of the pore volumes x2 of the four types of diatomaceous earth, and the "ratio of the pore volume to the average of diatomaceous earth" is obtained by the calculation formula of x2 / av2. The "average pore radius of diatomaceous earth" in Table 1 is the average value av3 of the average pore radii x3 of the four types of diatomaceous earth, and the "ratio of the average pore radius to the average of diatomaceous earth" is obtained by the calculation formula of x3 / av3. Table 1 is an excerpt from a report from Horonobe Sand and Gravel Industry Co., Ltd. (currently Seria Co., Ltd.) to the Horonobe Geosphere Environment Research Institute of the Hokkaido Science and Technology Promotion Center, where Horonobe Sand and Gravel Industry Co., Ltd. requested the analysis of molded siliceous shale from the institute. Also, the Wakkanai-layer hard shale in Kamihoronobe, Horonobe Town has the basic properties shown in Table 2. The source of Table 2 is the above-mentioned report from the (public) Horonobe Geosphere Environment Research Institute. The "Wakkanai-layer siliceous shale" in Table 1 and the "hard shale produced in Kamihoronobe" in Table 2 are the Wakkanai-layer hard shale in Kamihoronobe, Horonobe Town, and it is the siliceous shale 13 used in the production of the porous body 11 described later. In this example, the Wakkanai-layer siliceous shale in Kamihoronobe, Hokkaido is used as the siliceous shale 13. However, the siliceous shale used as the raw material is not limited to the siliceous shale 13 in this example. For example, diatomaceous earth and siliceous shale without the above-mentioned second peak may be used, or diatomaceous earth and siliceous shale with a peak in the first range where the pore radius is larger than 0 nm and less than or equal to 10 nm, but the peak is smaller than 0.02 cm 3 / g may also be used.

[0031]

Table 1

[0032]

Table 2

[0033] The porous body 11 exhibits an ORP (Oxidation-Reduction Potential) of at most 513 mV even when suspended in deionized water. The ORP is the potential determined by the equilibrium state between the oxidizing and reducing substances coexisting in the solution. The suspension has a concentration (unit: %) calculated as (M11 / MW)×100 = 10% when the mass of the porous body 11 is M11 and the mass of the deionized water is MW. The ORP is a value obtained by using Ag / AgCl as the reference electrode (comparative electrode) and KCl as the internal solution, and correcting the obtained value to the standard hydrogen electrode value as the reference electrode (the correction formula is E (N.H.E.) =E (Ag / AgCl) + 206 - 0.7(t - 25), where E (N.H.E.) is the standard hydrogen electrode correction value, E (Ag / AgCl) is the measured value, and t is the measurement temperature (unit: °C). )) and The porous body 11 more preferably exhibits an ORP within the range of 505 mV or more and 513 mV or less. The porous body 11 with such an ORP of the suspension can be regarded as containing more Fe 3+ than Fe 2+ .

[0034] The porous body 11 is formed of a reduced-type siliceous shale containing Fe 2+ . The siliceous shale 13 contains Fe 3+ , but the porous body 11 contains a double salt structure of Fe 3+ reduced to Fe 2+ . The porous body 11 is presumed to contain Fe 3+ and Fe 2+ , and it is also presumed that the amount of Fe 2+ has increased.

[0035] From the X-ray fluorescence diffraction analysis results shown in FIG. 3, the porous body 11 contains Fe 2+ , that is, Fe(II), and Fe 3+That is, it can be considered that Fe(III) is also present. According to "How to Read Fluorescent X-ray Spectra" (Jun Kawaai, Graduate School of Engineering, Kyoto University), the peak detection diffraction angle (2θ) and the center of gravity of the X-ray energy (eV) of Fe(II) and Fe(III) are different from each other. Also, according to this document, compared with the detection position of the double salt compound Fe(III), the detection position of iron oxide FeO(II) shifts to the high energy side (low diffraction angle side), while the double salt compound Fe(III) shifts to the low energy side (high diffraction angle side). In this example, the center of gravity of the Fe characteristic peak measured by a wavelength dispersive fluorescent X-ray analyzer was analyzed using measurement software, and the center of gravity of the Fe characteristic peak of the porous body 11 ("treated siliceous shale (example of the present invention)" in FIG. 3) and the siliceous shale 13 which is the raw material of the porous body 11 ("untreated siliceous shale (control example)" in FIG. 3) was compared. As shown in FIG. 3 and Table 3, a shift in the center of gravity of the Fe characteristic peak was confirmed. In Table 3, "untreated" in the "peak type" column means the siliceous shale 13 which is the raw material, "treated" means the porous body 11, and "B" means the characteristic absorption peak Fe-KB1 peak, and "A" means the Fe-KA peak. Regarding the center of gravity of the characteristic absorption peak of "untreated", that is, the siliceous shale 13, "Pt1" in the "identification" column is the coordinate of the Fe-KB1 peak center of gravity, "Pt2" is the coordinate of the low diffraction side end of the Fe-KA peak, and "Pt3" is the coordinate of the high diffraction side end of the Fe-KA peak. The x coordinate of the Fe-KA peak center of gravity was estimated from the x coordinates of Pt2 and Pt3. Regarding the center of gravity of the characteristic absorption peak of "treated", that is, the porous body 11, "Pt4" is the coordinate of the Fe-KB1 peak center of gravity, "Pt5" is the coordinate of the low diffraction side end of the Fe-KA peak, and "Pt6" is the coordinate of the high diffraction side end of the Fe-KA peak. The x coordinate of the Fe-KA peak center of gravity was estimated from the x coordinates of Pt5 and Pt6. In FIG. 3, the horizontal axis is the diffraction angle (2θ), and the peak position of the porous body 11 is shifted to the high diffraction angle side (low X-ray energy side) (the center of gravity of the KB peak is 0.199005°, and the center of gravity of the KA peak is 0.161692°).From this, it is considered that in the "untreated" state, i.e., not the change of Fe(III) contained in the siliceous shale 13 to FeO(II), but the double salt compound mainly composed of Fe(III) in the siliceous shale 13 changed to the double salt compound mainly composed of Fe(II) by the reduction of Fe(III) to Fe(II). Thus, by wavelength-dispersive X-ray fluorescence analysis, the reduced component of the Fe compound, i.e., Fe. 2+ is more than that in the raw material siliceous shale 13.

[0036] Each sample of the "untreated" siliceous shale 13 and the "treated" porous body 11, which are samples for X-ray fluorescence diffraction analysis, was prepared as follows. The "untreated" siliceous shale 13 was stored in a vacuum pack, then pulverized with a stirrer, and dried at 105 °C for 2 hours. Next, it was press-molded into a disc shape to obtain a sample for X-ray fluorescence diffraction analysis. For the "treated" porous body 11, first, the granular siliceous shale 13 was immersed in water for 12 hours and allowed to stand (the water-containing process described later), and then the excess water was filtered off. In the water-containing process, the water content was generally set to 40%. This granular siliceous shale 13 was spread on a stainless steel mesh tray to a thickness of 2 cm to 3 cm and subjected to a contact treatment process in the manufacturing method described later. The contact treatment process is carried out by supplying superheated steam 43 (see Fig. 6) described later and maintaining the temperature around the mounting tool 58 (see Fig. 6) at 350 °C for 15 minutes, and then maintaining it at 400 °C for 15 minutes. Thereby, the porous body 11 was obtained, and after cooling the porous body 11 by the cooling process described later, it was vacuum-sealed (vacuum-packed) in a container as a sample. After pulverizing the vacuum-packed sample with a stirrer, it was dried at 105 °C for 2 hours, and then press-molded into a disc shape to obtain a sample for X-ray fluorescence diffraction analysis. In the process of press-molding the porous body 11 into a holder after the above-mentioned pulverization and dry heat drying when preparing the sample as described above, a part of the Fe 2+ in the porous body 11 is oxidized to Fe 3+ , and it is considered that the porous body 11 becomes a sample in which Fe(III) is mixed with Fe(II).

[0037] The fluorescence X-ray diffraction analysis and the data in FIG. 3 and Table 3 are by the Hokkaido Research Organization, and a wavelength dispersive fluorescence X-ray analyzer is used. This apparatus has an excellent peak resolution compared to an energy dispersive type.

[0038]

Table 3

[0039] Although details will be described later, the porous body 11 in this example has a hue of 9.4YR, a lightness of 4.5, and a chroma of 1.4 in the Munsell color system. The porous body 11 exhibiting such a color contains more Fe 3+ , specifically Fe 2 O 3 than Fe 2+ , specifically FeO . Therefore, when coexisting with other substances by mixing or the like, oxidation of the other substances is more surely suppressed.

[0040] The porous body 11 can be produced, for example, by a porous body production facility (hereinafter simply referred to as the "production facility") 31 shown in FIG. 4. The production facility 31 is for producing the porous body 11 from siliceous shale 13 as a raw material, and by treating the siliceous shale 13 as an object to be treated (object to be processed), Fe 3+ contained in the siliceous shale 13 is reduced to Fe 2+ . It is a siliceous shale treatment facility.

[0041] It is known that the composition of siliceous shale changes due to long-term weathering. Table 4 shows the composition data of weathered siliceous shale and unweathered siliceous shale. The source of Table 4 is the materials held by the above-mentioned Horonobe Sand Industrial Co., Ltd. In Table 4, "weathered hard shale" is weathered siliceous shale, and "unweathered hard shale" is unweathered siliceous shale, both of which are produced in Horonobe, Hokkaido. The weathered hard shale shown in Table 4 has a striped yellow weathered part, and the unweathered hard shale exhibits gray. It can be seen from this Table 4 that the weathered siliceous shale has more Fe2O3 than the unweathered siliceous shale.

[0042]

Table 4

[0043] As the siliceous shale 13, it is not particularly limited as long as it is a siliceous shale containing Fe 3+ and diatomaceous earth having mesopores of the same degree may also be used. However, from the viewpoint of obtaining the porous body 11 having the pore radius and the pore size distribution curve as described above, it is preferable to use the above-mentioned Wakkanai-layer siliceous shale. Table 5 shows the physical properties of the siliceous shale 13 used in this example. The physical property values shown in Table 5 are a summary list of the analysis results by the Hokkaido Industrial Research Institute and the Hokkaido Central Agricultural Experiment Station (currently within the Hokkaido Research Organization, a local independent administrative agency).

[0044] The "water absorption rate" in Table 5 is the analysis result at the Hokkaido Industrial Research Institute. The analysis method was as follows: after drying the sample, it was allowed to absorb water for 24 hours, the surface moisture was removed, and then the weight of the sample was measured. Thereafter, it was dried for 8 hours using a dryer set at 150°C, and the weight of the dried sample was measured. The water absorption rate was determined from the weight before drying and the weight after drying. Note that the samples were of two types, a sample with a particle size of 1 mm and a sample with a particle size of 8 mm. For the sample with a particle size of 1 mm, it is the average value of the water absorption rates of two samples, and for the sample with a particle size of 8 mm, it is the average value of the water absorption rates of four samples.

[0045] The "moisture absorption rate" in Table 5 is the analysis result at the Hokkaido Industrial Research Institute (Industrial Test Result No. 193123). The test method was as follows: 1 g of a completely dried sample was precisely weighed into a weighing bottle, and in a constant temperature and humidity chamber with a constant temperature of 25°C, the humidity was changed to 90% RH and 50% RH every 24 hours. The mass of the sample in each atmosphere was measured, and the moisture absorption rate was calculated using the following calculation formula. Moisture absorption rate (%) = 100 × Moisture absorption amount / Completely dried mass

[0046] The "cation exchange capacity" in Table 5 is the analysis result at the Hokkaido Central Agricultural Experiment Station (Central Agricultural Environment Protection No. 1-42). The analysis method is based on "Diagnostic Criteria for Soil and Crop Nutrition - Analysis Method (Revised Edition)" (Hokkaido Agriculture and Forestry Department, Hokkaido Central Agricultural Experiment Station, 1992). This analysis method (soil analysis method) uses the ammonium acetate extraction - Schollenberger method - formal titration method.

[0047] The "available water content" in Table 5 is the analysis result at the Hokkaido Central Agricultural Experiment Station (Central Agricultural Environment Protection No. 1-37). The analysis method is based on "Diagnostic Criteria for Soil and Crop Nutrition - Analysis Method (Revised Edition)" (Hokkaido Agriculture and Forestry Department, Hokkaido Central Agricultural Experiment Station, 1992). In this analysis method (soil analysis method), a 100 ml soil sampling tube was filled with the sample as it was. After saturation with water, the gas phase was measured with a three-phase meter. Subsequently, measurements were taken for the pF 3 stages using a centrifuge. Finally, it was dried by heating at 105 °C, and the water content was measured. The water content at pF 0 was taken as the value obtained by adding the water content at saturation and the gas phase ratio.

[0048]

Table 5

[0049] The manufacturing facility 31 includes a crushing device 33, a moisture-containing unit 34, a superheated steam contact treatment device (hereinafter simply referred to as the "contact treatment device") 37, and a cooling device 38. The crushing device 33 is for crushing the siliceous shale 13 into particles of a desired size. The siliceous shale 13 is in an irregular lump shape when mined, and may be large, for example, with a diameter exceeding 200 mm. Although such large lump-shaped siliceous shale 13 may be used as it is as a raw material and supplied to the moisture-containing unit 34, in this example, in order to manufacture the granular porous body 11, the crushing device 33 is used to make the siliceous shale 13 into granular siliceous shale 13A, and the granular siliceous shale 13A is supplied to the moisture-containing unit 34. If the granular siliceous shale 13A of the same size as the target porous body 11 is available, there is no need to crush it, so the crushing device 33 may be omitted. Also, the crushing device 33 may not be omitted when the porous body 11 is manufactured into a large lump shape. In this way, the size of the porous body 11 to be produced can be adjusted by whether or not the siliceous shale 13 is crushed and by the degree of crushing.

[0050] When the siliceous shale 13 is crushed to smaller sizes, the production efficiency in the production facility 31 is improved. For example, the water impregnation step and the superheated steam contact treatment step (hereinafter simply referred to as the "contact treatment step") described below can be carried out in a shorter time. Therefore, from the viewpoint of increasing the production efficiency, it is preferable to crush the shale to smaller sizes, and it is more preferable to size the shale to have uniform particles.

[0051] The pulverizing device 33 is not particularly limited as long as it can pulverize the siliceous shale 13, and a commercially available pulverizing device may be used. Depending on the throughput (the amount to be pulverized) of the siliceous shale 13 and the target particle size of the granular siliceous shale 13A, at least two types selected from a pulverizer (roller mill, jet mill, high-speed rotary pulverizer, container-driven mill, etc.) and a crusher (jaw crusher, bucket crusher, diitret crusher, cone crusher, double roll crusher, impact crusher, etc.) may be used in combination. In this example as well, a commercially available pulverizing device is used, and a combination of an impact type and a twin-shaft type crusher and a high-speed rotary pulverizer manufactured by Horai Co., Ltd. is used to perform pulverization that also serves to adjust the particle size.

[0052] The water-containing unit 34 is for causing the granular siliceous shale 13A to contain liquid water 40 (see Fig. 5). Since the siliceous shale 13 is porous as described above, the granular siliceous shale 13 obtained by merely pulverizing it is also porous. The water-containing unit 34 allows water 40 to enter the pores (voids) of the porous granular siliceous shale 13. When the siliceous shale 13 is supplied to the water-containing unit 34 without being pulverized, it is advisable to let water 40 enter the pores of the siliceous shale 13. Details of the water-containing unit 34 will be described later using another drawing.

[0053] The contact treatment device 37 is for reducing Fe 3+ to Fe 2+ The contact treatment device 37 is composed of a contact treatment section 41, a superheated steam supply section 42, etc. The superheated steam supply section 42 is for supplying superheated steam 43 (see Fig. 6) to the contact treatment section 41 and is connected to the contact treatment section 41. The contact treatment section 41 contacts the superheated steam 43 supplied by the superheated steam supply section 42 with the water-containing granular siliceous shale 13A (contact treatment step), thereby causing heat exchange between the water 40 contained in the granular siliceous shale 13A and the superheated steam, and heat exchange between the steam generated by the heat exchange and the superheated steam, to raise the central temperature of the granular siliceous shale 13A. As a result, Fe 3+ becomes Fe 2+A porous body 11 reduced thereto is generated. The granular siliceous shale 13A that has not been subjected to the water-containing treatment has a water content of around 10%, but even when contacted with superheated steam 43, Fe 3+ is Fe 2+ is not significantly reduced and the porous body 11 is not obtained.

[0054] The superheated steam supply unit 42 is provided in the contact treatment device 37, but the superheated steam supply unit 42 may be an external device provided outside the contact treatment device 37 as long as it is connected to the contact treatment unit 41. The details of the contact treatment device 37 will be described later using another drawing.

[0055] The cooling device 38 is for cooling the porous body 11 generated by the contact treatment device 37 to room temperature (approximately 25°C). By this cooling device 38, the porous body 11 is cooled (cooling step) and the temperature is lowered to room temperature while suppressing, for example, dew condensation in the porous body 11. The manufacturing facility 31 of this example includes the cooling device 38, and the porous body 11 generated by the contact treatment device 37 is cooled by this cooling device 38 to room temperature. However, the manufacturing facility 31 does not necessarily have to include the cooling device 38, and the porous body 11 may be brought to room temperature by natural air cooling. Thus, the manufacturing facility 31 does not necessarily have to include the cooling device 38, and the porous body 11 may be obtained at a temperature higher than room temperature. The details of each of the contact treatment device 37 and the cooling device 38 will be described later using another drawing.

[0056] An example of the aforementioned water-containing unit 34 includes, as shown in FIG. 5, a container 45 for accommodating liquid water 40 and granular siliceous shale 13A, and a water supply unit 46 for supplying liquid water to the container 45. The container 45 has an opening 45o formed at the bottom, and the opening 45o is configured to be opened and closed by a plate-like member 45b. The plate-like member 45b is provided on the bottom surface of the container 45 and is slidable between a closed position for closing the opening 45o (shown by a solid line in FIG. 5) and an open position for opening the opening 45o (shown by a two-dot chain line in FIG. 5). The plate-like member 45b is arranged at the closed position during the water-containing step of allowing the granular siliceous shale 13A to contain water 40, and at the open position when discharging the water 40.

[0057] The granular siliceous shale 13A is accommodated in the container 45 of the water-containing unit 34, and water 40 is put in by the water supply unit 46, so that the granular siliceous shale 13A is immersed in the water 40. Thereby, the water 40 enters into the pores of the granular siliceous shale 13A, and the granular siliceous shale 13A is brought into a water-containing state (water-containing step). In this example, the container 45 is left standing with the granular siliceous shale 13A immersed, and the granular siliceous shale 13A becomes water-containing due to the water absorption property originally possessed by pores such as mesopores.

[0058] The time of the water-containing step, that is, the time for maintaining the immersed state, is not particularly limited as long as the granular siliceous shale 13A is sufficiently water-containing, and may be set according to, for example, the particle size of the granular siliceous shale 13A. However, in the case of normal pressure, it is preferably at least 6 hours, more preferably at least 12 hours, so that the water 40 surely enters into the internal pores in each of the plurality of granular siliceous shales 13A. In this example, it is set to approximately 12 hours so that the water 40 surely enters into the internal pores in each of the plurality of granular siliceous shales 13A. When a granular siliceous shale 13A having a diameter D larger than that in this example (including the siliceous shale 13) is used as the object to be treated in the water-containing step, the time of the water-containing step may be set longer. The water-containing unit 34 makes the granular siliceous shale 13A water-containing under normal pressure, but instead of the water-containing unit 34, a decompression container (not shown) capable of making the inside in a decompressed state may be used. When using a decompression container, the granular siliceous shale 13A may be immersed in the water 40 put in the decompression container and left standing until the generation of bubbles stops. When performing the water-containing step under reduced pressure in this way, for example, the time of the water-containing step may be set according to the degree of decompression.

[0059] When it is said that the granular siliceous shale 13A contains sufficient water, it means that the granular siliceous shale 13A does not undergo air oxidation in the contact treatment step. When water is contained by immersion, if it is immersed for 6 hours or more as described above, it will be in a state of containing sufficient water. Also, when the mass of the granular siliceous shale 13A subjected to the water-containing step, that is, the mass of the granular siliceous shale 13A before the water-containing step is M13a, and the mass of the granular siliceous shale 13A after water-containing is M13b, if the water content rate (unit: %) obtained by {(M13b - M13a) / M13b}×100 is 35% or more, it may be regarded as sufficiently water-containing. The water content rate is more preferably 38% or more, still more preferably 40% or more, and in this example, it is 40%.

[0060] The temperature of the water 40 is not particularly limited, and in this example, it is room temperature (approximately 25°C). The water 40 is not particularly limited for the reduction of Fe 3+ and it is advisable to consider the cleanliness according to the use of the porous body 11. In this example, considering the case of using it for feed etc., water with a cleanliness level such that it can be ingested by humans as a beverage is used, for example, tap water or deionized water. Other examples of the water 40 include distilled water, ion-exchanged water, RO water purified by an RO (reverse osmosis) membrane, etc.

[0061] A net 45c is provided at the opening 45o. The net 45c is for suppressing the discharge of the granular siliceous shale 13A from the opening 45o, and for this purpose, the mesh (not shown) of the net 45c is sized such that the granular siliceous shale 13A does not pass through. As a result, even when the opening 45o is in an open state, for example, when discharging the used water 40, the granular siliceous shale 13A is captured by the net 45c and remains in the container 45, and is drained. By draining, the treatment time in the subsequent contact treatment step is shortened, and the manufacturing efficiency is improved.

[0062] The water-containing unit for hydrating the granular siliceous shale 13A is not limited to the water-containing unit 34 in this example. For example, a water-containing unit having a double structure of an inner container (not shown) formed of a net with a mesh small enough to prevent the granular siliceous shale 13A from passing through and an outer container that houses the inner container and water 40 can be cited. In the case of this water-containing unit, the inner container containing the granular siliceous shale 13A is placed in the outer container filled with water 40, thereby immersing the granular siliceous shale 13A in the water 40. When the immersion is completed, the inner container may be taken out of the outer container.

[0063] The method for hydrating the granular siliceous shale 13A is not limited to immersion. For example, a method of spraying water 40 onto the granular siliceous shale 13A or a method of pouring water 40 over the granular siliceous shale 13A may be used. However, immersion is more preferable in terms of the certainty of water content and the simplicity of only having to leave it standing.

[0064] The contact treatment device 37 will be described with reference to FIG. 6. The contact treatment device 37 is an example of a siliceous shale treatment device that reduces Fe in the siliceous shale 13 and the granular siliceous shale 13A to Fe 3+ to Fe 2+ The superheated steam supply unit 42 includes a steam generation unit 51 that generates superheated steam 43 from liquid water, a valve 52, and a controller 53 that comprehensively controls the steam generation unit 51 and the valve 52. Liquid water is supplied to the steam generation unit 51, and under the control of the controller 53, the amount of the generated superheated steam 43 and the temperature of the superheated steam 43 are adjusted. Further, the valve 52 is controlled by the controller 53 for its opening degree (including opening and closing), whereby the flow rate (supply flow rate) of the superheated steam 43 supplied to the contact treatment unit 41 is adjusted. Note that the flow rate of the superheated steam supplied to the contact treatment unit 41 may be adjusted by holding the valve 52 at a constant opening degree, such as fully open, and adjusting the generation rate of the superheated steam 43 in the steam generation unit 51.

[0065] The contact treatment unit 41 includes a treatment unit main body 56 and a support base 57 that supports the treatment unit main body 56. The treatment unit main body 56 includes three placement tools 58A to 58C on which the granular siliceous shale 13A is placed, a plate-shaped support member 61 that supports the placement tools 58A to 58C, and a supply pipe 62 that supplies the superheated steam 43 to the placement tools 58A to 58C. The three placement tools 58A to 58C are arranged at intervals in the vertical direction, that is, the up and down direction, and are sequentially labeled 58A, 58B, and 58C from the bottom. In the following description, when the placement tools 58A to 58C are not distinguished, they are referred to as the placement tool 58. When a plurality of placement tools 58 are arranged, it is preferable to install them at intervals in the vertical direction as in this example. The number of the placement tools 58 is not limited and may be determined according to the amount of the granular siliceous shale 13A used in the contact treatment process and the like.

[0066] The support member 61 is for supporting the placement tool 58, and a pair of them are provided. In this example, for the purpose of arranging the supply pipe 62 so that the outlet 62о of the superheated steam 43, which is the tip opening of the supply pipe 62, is located below the placement tool 58A, the support member 61 is provided on the support base 57. The support member 61 is fixed to the support base 57 in an upright posture, and protrusions 61a for supporting the placement tool 58 are formed on the facing walls of the pair of support members 61 that face each other. The heights of the protrusions 61a in the vertical direction of the pair of support members 61 are equal to each other, and by these pair of support members 61, the placement tool 58 is supported in a state where its posture is maintained and in a state floating from the floor surface. The shape of the protrusion 61a is not particularly limited. In this example, it is formed to extend in the horizontal direction, and the placement tool 58 slides along this protrusion 61a and is detachable from the support member 61.

[0067] The placement tool 58 is formed in a box shape with an open top, and includes a generally flat mesh member 58a and a frame 58b that supports the mesh member 58a in a state where tension is applied thereto. The outer dimensions of the placement tool 58 are 60 cm × 40 cm × 8 cm in height, but the size of the placement tool 58 is not particularly limited. The frame 58b stands obliquely with respect to the mesh member 58a, whereby it is supported by the above-described protrusion 61a and suppresses the fall of the placed granular siliceous shale 13A from the placement tool 58. However, since it is difficult to fall when the amount of the granular siliceous shale 13A placed is small, depending on the possibility of falling, instead of the frame 58b, a frame that is flat in the horizontal direction like the mesh member 58a may be used.

[0068] The mesh member 58a is for holding the granular siliceous shale 13A and guiding the superheated steam 43 from below to the granular siliceous shale 13A. The mesh member 58a has a plurality of meshes as through holes penetrating in the thickness direction, and each of these meshes allows the superheated steam 43 to pass through. In this example, the superheated steam 43 is sent out from the outlet 62о of the supply pipe 62 toward the lower surface of the placement tool 58A as described later, and is guided to the upper surface side of the placement tool 58 by the meshes of the mesh member 58a. As a result, the superheated steam 43 contacts the granular siliceous shale 13A on the mesh member 58a. In this way, the placement tool 58 functions as a support member that supports the granular siliceous shale 13A while the superheated steam 43 is in contact, and the mesh serves as a guide path for guiding the sent superheated steam 43 to the granular siliceous shale 13A. Note that the mesh member 58a is rectangular, but it may be, for example, circular other than rectangular.

[0069] The mesh member 58a is a net formed of, for example, metal, and the frame 58b is also formed of metal. The metal is not particularly limited as long as it can maintain its shape without melting even when it comes into contact with the superheated steam 43. The materials of the mesh member 58a and the frame 58b in this example are stainless steel. Since the mesh member 58a functions as a support member for supporting the granular siliceous shale 13A, the mesh size is set to a size through which the granular siliceous shale 13A does not pass. In this example, since the granular siliceous shale 13A is amorphous and the shortest diameter (hereinafter referred to as the short diameter) is about 1 mm, the mesh size is about 0.9 mm, which is smaller than the short diameter of the granular siliceous shale 13A in the largest diameter portion. When the granular siliceous shale 13A passes through, a plurality of mesh members 58a may be stacked in the thickness direction in a state where the meshes of each other are displaced, and a mesh smaller than each mesh of the plurality of mesh members 58a may be formed.

[0070] The mesh member 58a is an example of a porous member, and the porous member is not limited to the mesh member 58a. For example, a perforated plate in which a plurality of holes are formed in a metal plate by, for example, punching may be used. Also, a plurality of perforated plates may be stacked in the thickness direction and used, or a perforated plate and the mesh member 58a may be stacked in the thickness direction and used.

[0071] The supply pipe 62 is connected to the superheated steam supply unit 42, and the tip on the side of the outlet 62о is arranged upward so that the outlet 62о faces the lower surface of the mounting tool 58. When a plurality of mounting tools 58 are provided as in this example, the supply pipe 62 may be installed below each of the plurality of mounting tools 58 and the outlet 62о may be directed to each lower surface. However, since the superheated steam 43 goes upward when it is sent out from the outlet 62о, even if the supply pipe 62 is arranged only on the lowermost mounting tool 58A among the plurality of mounting tools 58, it is sufficient because the superheated steam 43 is guided to the granular siliceous shale 13A on all the mounting tools 58A to 58C.

[0072] In this example, two supply pipes 62 are provided below each of a pair of support members 61 so as to face each other in one of two directions intersecting on a horizontal plane, and each outlet 62о is located inside the support member 61. Thus, the superheated steam 43 discharged from the outlet 62о is guided upward between the pair of support members 61 by the plate-shaped support member 61. Therefore, the discharged superheated steam 43 is guided to and contacts the granular siliceous shale 13A placed on the carriers 58A to 58C, and is utilized without waste in contacting the granular siliceous shale 13A.

[0073] When the superheated steam 43 contacts the granular siliceous shale 13A, the granular siliceous shale 13A is heated, and the liquid water 40 (see FIG. 5) contained in the granular siliceous shale 13A changes into steam. Since the granular siliceous shale 13A to be heated contains water 40, the oxidation of the granular siliceous shale 13A by oxygen in the air and the like is suppressed, and the sudden temperature rise of the granular siliceous shale 13A is suppressed by the evaporation of the water 40, so that the oxidation of the surface is particularly suppressed, and the contained Fe 3+ is reduced to Fe 2+ . In this way, the porous body 11 is formed. As a result, the porous body 11 has recovered various known functions that siliceous shale in nature would have lost due to oxidation by long-term weathering. Further, when microorganisms such as bacteria are present in the pores 14 (see FIG. 1) of the granular siliceous shale 13A, they are killed by being heated by the superheated steam 43. In addition, the water 40 contained in the pores 14 may generate cavitation or cause drift (blowout) due to, for example, sudden heating, and in some cases, the dead microorganisms are released by these forces.

[0074] The temperature of the superheated steam 43 is preferably at least 160°C, i.e., 160°C or higher. From the perspective of the production efficiency of the porous body 11, it is more preferably in the range of 200°C or higher and 600°C or lower, still more preferably in the range of 300°C or higher and 600°C or lower, and particularly preferably in the range of 400°C or higher and 600°C or lower. The upper limit of the temperature of the superheated steam 43 is within the range that can be supplied by the superheated steam supply unit 42 and is not particularly limited. When the temperature of the superheated steam 43 cannot be detected, the temperature around the mounting table 58 may be detected and regarded as the temperature of the superheated steam 43. The temperature around the mounting table 58 can be detected, for example, by providing a temperature sensor (not shown) on the wall surface of the support member 61 on the side where the mounting tool 58 is installed.

[0075] Commercially available devices for treating an object to be treated with superheated steam are evaluated for their processing capacity based on the upper limit (attainable temperature) of the temperature of the generated superheated steam (unit: °C) and the amount of superheated steam generated per hour (unit: kg / h). The same applies to the contact treatment device 37 in this example. The temperature for treatment with superheated steam (treatment temperature) varies depending on the purpose of the treatment, and the amount of steam generated is changed according to the treatment temperature. Therefore, the treatment temperature is important. Although the processing capacity varies depending on the treatment temperature, in the case of a treatment temperature around 400°C, it is preferable to use, as a guide, approximately 60% of the total capacity (total volume) of the mounting tool 58 and the granular siliceous shale 13A as the processing volume (treatment volume) of the contact treatment space where the contact treatment between the superheated steam 43 and the granular siliceous shale 13A is carried out.

[0076] In the case of a commercially available superheated steam treatment device, even when the attainable temperature is 500°C, there are differences in the processing capacity within the range of 20 kg / h or more and 150 kg / h or less in the amount of superheated steam generated per hour depending on the device, and the processing volume of the contact treatment space is limited by the treatment temperature and the amount of superheated steam generated. Although the specific enthalpy, specific heat, and specific volume change according to the temperature of the superheated steam, the temperature of the superheated steam greatly depends on the amount of superheated steam generated per hour. Most superheated steam treatment devices are of a sealed type in which the treatment space is partitioned from the external space, and an open type in which the treatment space is open is applied when the amount of superheated steam generated is large.

[0077] The flow rate of the superheated steam 43 supplied to the main body 56 of the processing unit is set such that the generation amount of superheated steam has an upper limit of 100 kg / h at a superheated steam temperature of 500°C or lower. In order to make the temperature of the processing space before the start of the contact treatment the target processing temperature, superheated steam 43 at a temperature higher than this processing temperature is sent into the main body 56 of the processing unit at a superheated steam generation amount of 100 kg / h. When the processing space in the main body 56 of the processing unit reaches the target processing temperature, the superheated steam generation amount is reduced to about 80% of the above initial setting value (100 kg / h). In the contact treatment step, the granular siliceous shale 13A decreases while the temperature of the processing space in the main body 56 of the processing unit drifts from the target processing temperature due to the heat exchange between the taken-in water 40 and the superheated steam 43. During this period, it is preferable to appropriately increase the flow rate of the superheated steam 43. Also, a plurality of steam generation units 51 may be used, and the flow rate may be made larger than 100 kg / h by the plurality of steam generation units 51. However, it is preferable to increase or decrease the flow rate according to the size of the mesh member 58a of the mounting tool 58 and the height from the outlet 62о of the uppermost mounting tool 58 among the plurality of mounting tools 58.

[0078] The temperature of the supplied superheated steam 43 depends not only on the temperature of the steam adjusted in the steam generation unit 51 but also on the adjustment of the flow rate by controlling the opening degree of the valve 52. Therefore, the temperature of the superheated steam 43 is preferably controlled more precisely by controlling the opening degree of the valve 52, and this is also the case in this example. Specifically, for example, based on the detection result of the aforementioned temperature sensor (not shown) provided on the support member 61, the opening degree of the valve 52 may be adjusted by the controller 53. When increasing the temperature of the superheated steam 43, adjust it in the direction of reducing the opening degree of the valve 52, and when reducing the temperature, adjust it in the direction of increasing the opening degree. The temperature of the superheated steam 43 may drop between the time it is generated in the steam generation unit 51 and the time it reaches the mounting tool 58. In such a case, the temperature of the superheated steam sent out from the steam generation unit 51 may be adjusted by the steam generation unit 51 in consideration of the temperature drop.

[0079] To further improve the contact treatment efficiency by contact with superheated steam 43 and to promote the reduction of Fe in the granular siliceous shale 13A, it is preferable that the distance between the outlet 62о and the lowermost mounting tool 58A be as small as possible. 3+ Fe 2+ For the purpose of promoting the reduction of Fe in the granular siliceous shale 13A, it is preferable that the distance between the outlet 62о and the lowermost mounting tool 58A be as small as possible.

[0080] The plate-shaped support member 61 may be, for example, a columnar (bar-shaped) member in an upright posture from the viewpoint of supporting the mounting tool 58. In the case of such a columnar support member or when the support member 61 of this example is used, since the space between the support members is open, the contact treatment space where the contact treatment between the superheated steam 43 and the granular siliceous shale 13A is performed is an open system. Further, the contact treatment space may be a closed system partitioned from the external space. In the case of a closed system, for example, a box-shaped partition member that partitions the contact treatment space from the external space so as to surround the mounting tool 58 may be used. The lower surface of this partition member may be opened to introduce the superheated steam 43. Further, the upper surface of this partition member may be closed, but in order to promote the discharge of the steam evaporated from the water 40, an opening may be provided on the upper surface of the partition member, and the steam may be naturally discharged from this opening, or a suction mechanism for sucking gas into this opening may be provided to suck the steam.

[0081] The contact time of the superheated steam 43 with the granular siliceous shale 13A, that is, the time of the contact treatment step, is not particularly limited, but it is preferably at least 10 minutes. Thereby, Fe 3+ is surely reduced by Fe 2+ and further, the granular siliceous shale 13A is more surely sterilized to the inside.

[0082] The superheated steam 43 is brought into contact with the granular siliceous shale 13A after dropping from the target treatment temperature as described above and until it recovers to the treatment temperature and reaches it. It tends to be lower than the temperature of the superheated steam sent out from the outlet 62о, and further, by continuing the supply of the superheated steam 43 for 5 minutes thereafter, the time of the contact treatment step is set to 10 minutes.

[0083] In Fig. 7, the cooling device 38 is for cooling the porous body 11 that has been heated to a high temperature in the contact treatment step to room temperature (approximately 25°C). Since condensation may occur due to the temperature difference between the central temperature of the porous body 11, which has increased during the contact treatment step, and the outside air temperature, this cooling device 38 cools the porous body 11 while preventing condensation. The cooling device 38 includes a container 71 that houses the porous body 11, a temperature controller 72 that adjusts the internal temperature of the container 71, and a decompression mechanism 73 that decompresses the inside of the container 71. The container 71 has a container body 71a that houses the porous body 11 and has an open upper surface, and a lid 71b. An opening 71c connected to the decompression mechanism 73 is formed in the lid 72. The decompression mechanism 73 has a suction part (not shown) that sucks the gas inside the container 71 and an inflow part (not shown) that stops the suction and allows gas to flow into the container 71. Thereby, the decompression mechanism 73 decompresses the inside of the container 71 by sucking the air inside the container 71, and also releases the decompression inside the container 71 to restore it to normal pressure. The inflow part allows dry air (hereinafter referred to as dry air) or dry inert gas (hereinafter referred to as dry inert gas) to flow into the container 71 to return the inside of the container 71 to normal pressure.

[0084] When the porous body 11 is housed in the container 71, it is cooled by the internal temperature of the container 71 being cooled by the temperature controller 72. During the cooling process, it is preferable, from the viewpoint of more reliably suppressing condensation, to keep the inside of the container 71 in a decompressed state by the suction part of the decompression mechanism 73, more preferably a state decompressed to a level close to vacuum. After cooling, the suction is stopped by the decompression mechanism 73, and dry air or dry inert gas is allowed to flow in by the inflow part to return to normal pressure. Thereby, the porous body 11 is obtained as one whose temperature has been lowered to room temperature while condensation is more reliably suppressed. Note that the opening 71c may be formed in the container body 71a.

[0085] When adding the porous body 11 to food or feed, if external air is allowed to flow into the inside of the container 71 when returning from a reduced-pressure state to normal pressure, contamination by microorganisms may occur. However, in this example, since dry air or dry inert gas is caused to flow into the container 71 instead of external air as described above, such microbial contamination is prevented. Therefore, it can also be used for the purpose of adding the porous body 11 to food or feed. Thus, the cooling method using the cooling device 38 can also be used even when sterilization by superheated steam treatment of processed food is carried out, and is effective. On the other hand, when microbial contamination is not a problem, the manufacturing facility 31 does not necessarily need to be equipped with the cooling device 38, and the porous body 11 may be brought to room temperature by natural cooling.

[0086] According to the above manufacturing method, Fe contained in the siliceous shale 13 and the granular siliceous shale 13A 3+ decreases, and a porous body 11 in which Fe 2+ increases is obtained (see Fig. 3, Table 3). The color tone of the porous body 11 exhibits the following properties and characteristics. In Table 6, Example 1 is a case where a columnar molded body was produced in the same manner as the sample used for the above-described fluorescent X-ray diffraction analysis, and superheated steam 43 at 350 °C was brought into contact for 15 minutes in the contact treatment step. Example 2 is a case where superheated steam 43 at 400 °C was brought into contact with the molded body for 15 minutes. Comparative Example 1 is data of a porous body obtained by subjecting the granular siliceous shale 13A to a contact treatment step of bringing it into contact with superheated steam 43 at 400 °C for 15 minutes, and the water-containing step was not carried out. Comparative Example 2 is a case where the granular siliceous shale 13A was heated in a temperature range of 300 °C or higher and 500 °C or lower while being rotated using a kiln.

[0087]

Table 6

[0088] pH (hydrogen ion concentration), ORP, and EC (electrical conductivity) were measured by preparing a suspension in the same manner as in the case of obtaining the above-described ORP. Note that EC was measured using an EC meter (Twin COND meter manufactured by AS ONE Corporation). The method for obtaining ORP is as described above.

[0089] From the comparative example and the examples, it can be seen that through the water-containing step and the contact treatment step, the granular siliceous shale 13A has Fe 3+ being Fe 2+ reduced to change the color tone from grayish white to blackish green, the electrolyte mass increases, and the pH and potential decrease. Also, from Comparative Example 1, it can be seen that just performing the contact treatment step without performing the water-containing step only results in a porous body similar to the porous body obtained in Comparative Example 2, the color tone does not change from the granular siliceous shale 13A, and the potential drop is also slight. From the above, for the reduction of Fe 3+ only the contact treatment step using superheated steam 43, or not only heating but also the water-containing step and the subsequent contact treatment step are effective, and cavitation caused by the pressure change due to the contact between superheated steam 43 and water 40 is considered important.

[0090] [Water-soluble nitrogen component adsorption test] Regarding the porous bodies 11 obtained in Examples 1 and 2, a suspension with the same concentration as above was prepared, and a test for the ease of adsorption of the water-soluble nitrogen component (hereinafter referred to as the water-soluble nitrogen component adsorption test) was carried out as follows using this suspension. First, the moisture content of the obtained porous body 11 was measured by a moisture meter (heating loss). Next, the porous body 11 was suspended in deionized water to prepare the above suspension. Also, a 0.1 mol / L solution of ammonium sulfate was prepared and added and mixed to the suspension to make the concentration of ammonium sulfate 0.01 mol / L. After mixing, EC (unit: mS / cm) and pH were measured over time, and the data after 24 hours when an equilibrium state was reached were used as the result data for evaluation. Since it was a suspension, the depth of the measurement target site was made the same between Example 1 and Example 2, and the measurement was carried out under stirring conditions using a 500 ml container. The water-soluble nitrogen component adsorption test was also carried out for the comparative example and Comparative Examples 1 and 2 in the same manner. The results are shown in Table 7.

[0091]

Table 7

[0092] It is known that siliceous shale has the function of capturing nitrate nitrogen and ammonia nitrogen in the water system, and the literature value is 1.6 mg / g. The granular siliceous shale 13A, which is the control example, had a lower capture amount than the literature value. From the results of Example 1 and Example 2, it can be seen that the porous body 11 produced through the water-containing process and the subsequent contact treatment process has a larger capture amount than the control example, and the capture ability has recovered. Also, for the porous bodies obtained in Comparative Example 1 and Comparative Example 2, no recovery of the capture ability as in Example 1 and Example 2 was observed. From the above results, it can be expected that the porous body 11 can be used in applications where the function of capturing nitrate nitrogen and ammonia nitrogen is required and in applications that make use of this function.

[0093] [Hygroscopicity Evaluation] The porous bodies 11 obtained in Example 1 and Example 2 (both having undergone the cooling process) were each vacuum-sealed at the point when the loss on drying became constant and used for evaluation. When the moisture content of the porous body 11 was measured before evaluation, the moisture content was 10%. 40 g of this porous body 11 was placed in a sealed container with a capacity of 4 liters and equipped with a stopper, and a humidity sensor and a temperature sensor were set and sealed. Then, for 120 minutes, the humidity and temperature changes were detected, and the absolute humidity VH (g / m 3 ) was calculated, and the moisture absorption amount per gram was determined. The granular siliceous shale 13A as the control example and the porous body obtained in Comparative Example 2 were also evaluated in the same manner. Table 8 shows the results at 20 minutes, 40 minutes, and 120 minutes from the start of sealing. The moisture contents of the granular siliceous shale 13A as the control example and the porous body of Comparative Example 2 immediately before being placed in the sealed container were 10% and 7% respectively.

[0094]

Table 8

[0095] When the porous bodies 11 of Example 1 and Example 2 were used, compared with the case of using the granular siliceous shale 13A of the control example and the porous body of Comparative Example 2, the initial moisture absorption rate in about 120 minutes from the start was fast and the amount of moisture absorbed at equilibrium was also high. From the above results, it can be expected that the porous body 11 can be used for applications where moisture absorption, particularly the initial moisture absorption from the start of drying, is required, and applications that take advantage of this function.

[0096] [Function of suppressing oxidative rancidity of oils and fats] For each sample of Example 1 and Example 2, the ability to suppress oxidative rancidity by oxygen in the air was assayed using a vegetable oil (perilla oil: manufactured by Koka Foods Co., Ltd.) with a linoleic acid content of 11 w / w%. A sealed container with a capacity of 130 ml was used as the test container, and the sample to be tested was opened and 13 g was placed in the test container. Next, 10 g of perilla oil was weighed into a 20-ml vial and placed in the test container without a stopper. Separately, a certain amount was thinly coated on the detection part of AV-CHECK (manufactured by Advantech Co., Ltd.), placed in a 10-ml vial, and placed in the test container. A test system without the sample to be tested was used as the control example. That is, the control example is the data of oxidation by the air in the container. As comparative examples, untreated siliceous shale, that is, the case of granular siliceous shale 13A, and the case of kiln-treated siliceous shale heat-treated in the aforementioned kiln were conducted. For the test, unopened perilla oil was used, and the measurement was carried out indoors under no illumination at conditions of 32.2 °C to 36.1 °C. For the 10-g portion of perilla oil, the acid value was measured after 10 days, and for the thin film coating, the change in 24 hours was measured. The results of the thin film coating are shown in Table 9, and the results of the vial are shown in Table 10. In addition, in the acid value (AV) of Table 9 and Table 10, 0 to 2 indicates that no deterioration is observed and it is good, 2 to 3 indicates that the deterioration is progressing, and 3 to 4 indicates an evaluation that it is not edible.

[0097]

Table 9

[0098]

Table 10

[0099] The porous body 11 obtained in the examples undergoes lipid oxidation even in a low water activity region where microorganisms do not grow, and lipid oxidation increases even at a water activity of 0.2 or less. As shown in Table 9, it can be seen that the porous body 11 has a function of suppressing lipid oxidation when the oil and fat are in a thin film state. Also, as shown in Table 10, when the porous body 11 is packed in a container, after 10 days, it maintains the evaluation of "no deterioration is observed", and siliceous shale that has changed to reddish-brown is observed, and Fe 2+ is Fe 3+ is oxidized to Fe, and it was confirmed that it has a deoxygenation function by a reduction reaction conjugated with this oxidation. From the above results, the porous body 11 can be expected to be used in applications where suppression of oxidation of the object is required and applications that utilize this function.

[0100] [Water-based freshness retention effect] 30 g of boiled tap water was put into a 30-ml stoppered vial, and for the porous body 11 of Example 2, the porous body of Comparative Example 2, and the non-added group with only boiled tap water as a control example, the standard hydrogen electrode value and the potential drop value were measured as evaluations of the water-based freshness retention effect. In the comparative example and the example, 5 g of the sample was put in each, sealed, and the oxidation-reduction potential was measured after 24 hours. The results are shown in Table 11.

[0101]

Table 11

[0102] As shown in Table 11, in the water-based system using tap water, the porous body 11 has a larger potential drop value than the control example and the porous body of Comparative Example 2. Therefore, it can be seen that the porous body 11 has higher antioxidant activity than other examples. From the above results, the porous body 11 can be expected to be used in applications where freshness retention is required in a water-based system and applications that utilize this function.

[0103] [Freshness retention test] The freshness retention effects of the naturally dried garlic (white six slices) were evaluated for the functions of the porous body 11 of Example 2 and the porous body of Comparative Example 2 using them as humidity regulators by the following method. Since it will crack when natural drying continues at 30°C or higher, the control example was excluded. The results are shown in Table 12. Also, 40 g of the porous body 11 of Example 2 and 40 g of the porous body of Comparative Example 2 were respectively placed as humidity regulators in a sealed container with a capacity of 4 liters, and a humidity sensor and a temperature sensor were set and sealed. The temperature during measurement was set to 27°C to 30°C. When the relative humidity became steady, it was converted to the absolute humidity of each and used as evaluation data for the self-humidity absorption function. Next, 500 g of naturally dried garlic was put in, sealed, and measured until the relative humidity became steady. The results are shown in Table 12.

[0104]

Table 12

[0105] In the evaluation of the self-humidity absorption function, the porous body of Comparative Example 2 maintains a water activity of about 0.1, while the porous body 11 of Example 2 maintains a water activity of 0.2 to 0.25. According to the evaluation of the freshness retention of dried garlic, it was found that in the porous body 11 of Example 2, the relative humidity was adjusted to 60% to 65%, and the absolute humidity decreased compared to the case of Comparative Example 2. From the above results, the porous body 11 can be expected to be used for retaining the freshness of vegetables and the like.

[0106] [Evaluation of the Suitability for Manufacturing a Non-Agglomerated Particle Solution] As an evaluation of the suitability of using the dispersed particle solution of the porous body 11 as a raw material for manufacturing, the suitability for preparing a yeast raw material that precipitates or aggregates during water addition into non-agglomerated yeast microparticles was evaluated. First, commercially available dry yeast for bread making was prepared as the raw material yeast, and commercially available yeast cell wall as the fertilizer was prepared. 90 g of the raw material yeast, 10 g of the porous body 11, and 154 g of deionized water were mixed, filled into a commercially available ice tray (18 holes), covered, and frozen in a freezer.

[0107] Remove the lid of the ice-making tray, place the thawed sample on a stainless steel mesh so that it transfers to the wire mesh, let it stand at a predetermined temperature for a predetermined time, and then bring superheated steam into contact with the sample on the mesh. After the treatment, it was placed in a sealed container containing silica gel and cooled to room temperature. Deionized water was added so that the yeast was 10 w / w%, and a suspension was obtained. The porous body 11 was removed by decantation, and further, a suspension in which the separated liquid passed through a 5A filter paper was obtained. After adjustment, a 1000-fold dilution was prepared and the presence or absence of particle aggregation was confirmed under a microscope. The suspension was allowed to stand at 25 °C for 2 hours, and the presence or absence of particle aggregation with the naked eye and the depth of the upper layer of the interface with respect to the depth of the interface generated between the suspension particles different from aggregation in the container were taken as the dispersion ratio. Also, deionized water was added so that the yeast before the heat treatment was 10 w / w%, and a suspension was obtained. The browning degree was assayed by comparing the color tones of this untreated suspension and the suspension after the superheated steam treatment and standing.

[0108] When dry yeast for bread-making was used as the raw material yeast, the dispersion ratio was 21%, and no aggregation or browning was observed. Also, when yeast cell walls were used as the raw material yeast, the dispersion ratio was 5%, and no aggregation or browning was observed. From these results, it can be seen that the porous body 11 contributes to the production of a non-aggregating fine particle solution.

[0109] Dry yeast containing components in the yeast cell and Torula yeast cell walls (yeast cell wall B) with a high nitrogen content produce browning substances by the Maillard reaction during superheated steam treatment, but by using the porous body 11, aggregation of the suspension particles was suppressed. Also, by adding the porous body 11, suppression of the Maillard reaction and significant suppression of the generation of the upper layer in the formation of a particle interface (the upper layer reacts with oxygen in the headspace) different from the aggregation occurring between the treated particles were observed.

[0110] [Production of water-soluble plant-derived silicic acid from rice husks] 30 g of dried rice husks were finely pulverized, mixed with 30 g of the porous body 11 and 50 g of deionized water, filled into a commercially available ice-making tray (16 holes), covered, and frozen in a freezer. The lid of the ice-making tray containing the frozen sample was removed, and the thawed sample was placed on a stainless-steel mesh such that it transferred to the wire mesh, and left standing at a predetermined temperature for a predetermined time. The hydroformed sample on the mesh was brought into contact with superheated steam at a predetermined temperature for a predetermined time. After treatment with superheated steam, it was placed in a sealed container containing silica gel and cooled to room temperature. Three times the amount of deionized water was added to each sample, and the pH was measured. After the liquid was left standing at a predetermined temperature for a predetermined time, the supernatant was separated by decantation, and solids were removed from the supernatant using 5C filter paper. The filtrate was dehydrated in a desiccator containing silica gel, and the residue was weighed. The shape of the weighed substance was examined under a microscope.

[0111] As a result of the above, the pH was 4.00, the weighed value per 1 g of rice husk was 120 mg, and when the weighed substance was examined under a microscope, it was a (transparent) thin film skeleton. From these results, it was found that the porous body 11 contributed to the production of water-soluble vegetable silicic acid from rice husks.

[0112] Furthermore, two color measurements were carried out on the granular siliceous shale 13A, which is the raw material, and the porous body 11. One is the color difference measurement between the granular siliceous shale 13A and the porous body 11, and the other is microscopic image analysis. Each measurement was carried out by the following method.

[0113] 1. Color difference measurement The test was commissioned to the Kobe Industrial Test Institute Co., Ltd. The test date was March 19, 2021, and the test report issuance date was March 24, 2021. Sample A is the granular siliceous shale 13A pulverized into powder, and sample B is the porous body 11 obtained by treating with superheated steam at 400 °C in the contact treatment step pulverized into powder. The color difference measurement was carried out in the Munsell color system, the measurement conditions are as follows, the measurement results of the color difference are shown in Table 13, and the measurement results of the Munsell values are shown in Table 14. Measuring device: High-speed spectroscopic colorimeter CMS-35SP, Murakami Color Technology Co., Ltd. Light source: C Field of view: 2° Optical condition: S.C.E Measurement method: The sample was placed in a glass petri dish, and the bottom surface side was used as the measurement surface, and the measurement was carried out through the glass on the bottom surface of the glass petri dish.

[0114] [Table 13]

[0115] [Table 14]

[0116] 2. Microscopic image analysis For the microscopic image analysis, in order to evaluate (estimate) the quality of the porous body 11 after 8 months of sealed storage by color difference, granular siliceous shale 13A stored under the same conditions was used as a control (the "raw material group" in the table). Non-destructive measurement of RGB levels was performed on the microscopic images, and conversion to Lab and calculation of the color difference between the two samples were carried out. The analysis method was as follows: First, the non-destructive stored samples were observed under a stereomicroscope. The observation magnifications were 4 times and 100 times, and the image data were acquired respectively. RGB histogram analysis was performed on the acquired image data to measure the RGB values. Then, the Lab values were converted using conversion application software to calculate the color difference. The results are shown in Table 15. The "reduced type group" in the table is the result of the porous body 11, and the "Group (1) analysis" to "Group (4) analysis" are the color difference results based on the control.

[0117] [Table 15]

[0118] It can be seen that the color difference between the granular siliceous shale 13A and the porous body 11 stored in a sealed container for 8 months is greater at higher magnifications and there is a significant difference. Regarding the storage method of the porous body 11, it can be seen from the above results that since it has high hygroscopicity, it is preferable to seal or hermetically seal it, but vacuum storage or inert gas replacement is not a necessary requirement. [Explanation of symbols]

[0119] 11 Porous body 13 Siliceous shale 14 Pore 31 Manufacturing equipment 34 Water-containing unit 37 Contact treatment device 38 Cooling device 40 Water 43 Superheated steam 58A to 58C Mounting tool 58a Mesh member 62 Supply pipe 62о Outlet

Claims

A porous body formed of a reduced siliceous shale obtained through a water-containing step of adding liquid water to siliceous shale and a contact treatment step of bringing superheated steam into contact with the siliceous shale containing the water, wherein the reduced siliceous shale contains more Fe2+ than Fe3+.

2. Even if the pore radius is large, it is 10 μm. In the pore size distribution curve showing the relationship between the pore radius and the pore volume, there is a first peak exceeding 0.02 cm ３ / g in the first range where the pore radius is 1 nm or more and 10 nm or less, and a second peak exceeding 0.02 cm ３ / g in the second range where the pore radius is 100 nm or more and 10 μm or less, and The first peak is a peak of the pore volume when the pore radius in the first range is divided in 1 nm increments, and the second peak is a peak of the pore volume when the pore radius in the second range is divided in 100 nm increments for a pore radius of 100 nm or more and 1 μm or less, and in 1 μm increments for a pore radius of 1 μm or more and 10 μm or less. The porous body according to claim 1.

3. The porous body according to claim 1 or 2, which is formed in a granular shape.

4. When the porous body is suspended in deionized water, the suspension shows a redox potential of at most 513 mV. The suspension has a concentration of 10% calculated as (M11 / MW) × 100, where M11 is the mass of the porous body and MW is the mass of the deionized water. The redox potential is a value obtained by correcting the measured value measured using Ag / AgCl as a reference electrode and KCl as an internal solution with the standard hydrogen electrode correction value for the reference electrode (correction formula: E(N.H.E.) = E(Ag / AgCl) + 206 - 0.7(t - 25), where E(N.H.E.) is the standard hydrogen electrode correction value, E(Ag / AgCl) is the measured value, and t is the measurement temperature (unit: °C)). The porous body according to any one of claims 1 to 3.

5. A water-containing step of adding liquid water to siliceous shale, and a contact treatment step of bringing superheated steam into contact with the siliceous shale containing the water A method for manufacturing a porous body.

6. The method for manufacturing a porous body according to claim 5, wherein the siliceous shale is Wakkanai layer siliceous shale.

7. In the water-containing step, the water is included in the siliceous shale by immersing the siliceous shale in the water. The method for manufacturing a porous body according to claim 5 or 6.

8. The method for manufacturing a porous body according to any one of claims 5 to 7, which has a cooling step of cooling the siliceous shale under reduced pressure after the contact treatment step.

9. The temperature of the superheated steam is at least 160 °C. The method for manufacturing a porous body according to any one of claims 5 to 8.

10. The method for manufacturing a porous body according to any one of claims 5 to 9, wherein the contact treatment step comprises bringing the superheated steam into contact with the siliceous shale for at least 10 minutes.

11. The contact treatment step The method for manufacturing a porous body according to any one of claims 5 to 10, wherein a plurality of through-holes penetrating in the thickness direction are provided, and the superheated steam is supplied from below a mounting tool on which the siliceous shale is placed, so that the superheated steam is brought into contact with the siliceous shale.

12. The contact treatment step The method for manufacturing a porous body according to claim 11, wherein the siliceous shale is placed on each of a plurality of the mounting tools spaced apart in the vertical direction, and the superheated steam is supplied from below the lowermost one of the plurality of mounting tools.

13. A mounting tool having a plurality of through-holes penetrating in the thickness direction, on which siliceous shale containing liquid water is placed, A contact treatment unit having an outlet for superheated steam directed toward the lower surface of the mounting tool, and supplying the superheated steam from below the mounting tool to bring the superheated steam into contact with the siliceous shale on the mounting tool A porous body manufacturing facility comprising:

14. A porous body manufacturing facility according to claim 13, comprising a plurality of the mounting tools spaced apart in the vertical direction, wherein the contact treatment unit is arranged with the outlet directed toward the lower surface of the lowermost one of the plurality of mounting tools.

15. A method for treating siliceous shale, comprising a water-containing step of making the siliceous shale contain liquid water, and a contact treatment step of bringing superheated steam into contact with the siliceous shale in a state containing the water.

16. A mounting tool having a plurality of through-holes penetrating in the thickness direction, on which siliceous shale containing liquid water is placed, A contact treatment unit having an outlet for superheated steam directed toward the lower surface of the mounting tool, and supplying the superheated steam from below the mounting tool to bring the superheated steam into contact with the siliceous shale on the mounting tool A siliceous shale treatment facility comprising:

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