JP2017101133A - Fluidity reduction agent of solid-solution mixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluidity reduction agent of a solid-solution mixture capable of reducing fluidity of the solid-solution mixture while suppressing volume increase by a short time simple works regardless of a chemical composition of the solid-solution mixture.SOLUTION: A fluidity reduction agent of a solid-solution mixture contains a granular article having a structure where fibers are intertwined. In one aspect of the fluidity reduction agent, the granular article has average particle diameter of 300 μm or less and specific surface area by a BET method of 0.25 m/g to 100 m/g. In another aspect of the fluidity reduction agent, the granular article has porosity calculated by (1-bulk density/real density)×100 of 50% or more and specific surface area by the BET method of 0.25 m/g to 100 m/g. The fiber preferably contains a hydrophilic polymer. The hydrophilic polymer is preferably cellulose. The solid-solution mixture is preferably mud.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluidity reducing agent for a solid-liquid mixture.

  Conventionally, in civil engineering work such as river revetment work, when excavated soil that has deteriorated at the embankment site is replaced with improved soil or high-quality soil, the construction process requires a large amount of materials and work, so the strength is As a technique for simplifying replacement of reinforced improved soil, a method of utilizing finely divided waste paper has been proposed (see Patent Documents 1, 2, and 3).

JP 2007-197902 A JP 2008-106088 A JP 2001-121193 A

  However, it is difficult to realize improved soil with strength performance that can be practically used for civil engineering work with the conventional method using finely divided waste paper. If a reinforcing soil for reinforcement having strength can be obtained during a short enforcement period, it is considered that the effectiveness is large.

  The present inventors pay attention to the fact that the degraded excavated soil is a solid-liquid mixture containing soil solid components and water, and if the fluidity of the solid-liquid mixture can be reduced by a simple operation in a short time, We thought that the above difficulties in civil engineering work could be overcome. Further, the present inventors considered that it is necessary to suppress an increase in volume from the viewpoints of volume reduction, cost, etc., when reducing the fluidity of the solid-liquid mixture.

  The present invention has been made in view of the above problems, and reduces the fluidity of the solid-liquid mixture while suppressing the increase in volume by a simple operation in a short time regardless of the chemical composition of the solid-liquid mixture. It is an object of the present invention to provide a fluidity reducing agent for a solid-liquid mixture that can be produced.

  The inventor specifically includes a specific granular material having a structure in which fibers are intertwined by capturing and capturing the solid phase and liquid phase of the solid-liquid mixture in voids formed by the intertwining of fibers. It has been found that the above problem can be solved by using a fluidity lowering agent for a solid-liquid mixture, and the present invention has been completed.

A first aspect of the present invention includes a granular material having a structure in which fibers are entangled, and the granular material has an average particle diameter of 300 μm or less, and a specific surface area by a BET method of 0.25 m ² / g or more and 100 m ^2. / G or less, a fluidity reducing agent for a solid-liquid mixture.

The second aspect of the present invention includes a granular material having a structure in which fibers are intertwined, and the granular material has a porosity calculated by (1-bulk density / true density) × 100 is 50% or more, It is a fluidity reducing agent for a solid-liquid mixture having a specific surface area of 0.25 m ² / g or more and 100 m ² / g or less by the BET method.

  A third aspect of the present invention is a method for producing a low fluidity mixture, comprising mixing a solid-liquid mixture and the fluidity reducing agent to obtain a low fluidity mixture.

  A fourth aspect of the present invention is a method for transporting a low fluidity mixture, which comprises moving the low fluidity mixture obtained by the above method on a moving body.

  The fifth aspect of the present invention is a method for improving the degree of decrease in fluidity of the solid-liquid mixture by allowing the solid phase and liquid phase of the solid-liquid mixture to penetrate into and capture the voids formed by the entanglement of fibers. is there.

  According to a sixth aspect of the present invention, the chemical composition of the solid-liquid mixture subject to fluidity reduction is obtained by allowing the solid phase and liquid phase of the solid-liquid mixture to enter and capture in the voids formed by the entanglement of fibers. This is a method for improving the degree of freedom.

  A seventh aspect of the present invention is a method for suppressing an increase in the volume of a solid-liquid mixture after the fluidity is lowered by allowing the solid phase and the liquid phase of the solid-liquid mixture to enter and capture in voids formed by entanglement of fibers. It is.

  According to the present invention, regardless of the chemical composition of the solid-liquid mixture, the fluidity of the solid-liquid mixture can be reduced by a simple operation in a short time while suppressing the increase in volume while reducing the fluidity of the solid-liquid mixture. Property-reducing agents can be provided.

FIG. 1 is a photograph showing a fluidity reducing agent according to the present invention. FIG. 2 is a photograph showing a state in which soil fine particles are captured in voids formed by entanglement of fibers in the fluidity reducing agent according to the present invention. FIG. 3A and FIG. 3B are graphs showing the results of thermogravimetric / differential analysis for the fluidity reducing agent according to the present invention. FIG. 4 is a graph showing the results of X-ray diffraction analysis for the hot ash content of the fluidity reducing agent according to the present invention.

[Fluidity reducing agent for solid-liquid mixture]
One aspect of the fluidity reducing agent according to the present invention includes a granular material having a structure in which fibers are entangled, and the granular material has an average particle diameter of 300 μm or less and a specific surface area by a BET method of 0.25 m ² / It is a fluidity reducing agent of a solid-liquid mixture which is not less than 100 g ² / g. Moreover, another aspect of the fluidity reducing agent according to the present invention includes a granular material having a structure in which fibers are intertwined, and the granular material has a porosity calculated by (1−bulk density / true density) × 100. Is a fluidity reducing agent for a solid-liquid mixture having a BET method specific surface area of 0.25 m ² / g to 100 m ² / g. In another embodiment, the average particle size of the fluidity reducing agent may be 300 μm or less. In addition, in this specification, an average particle diameter means the average value of the particle diameter of the fluidity reducing agent measured under the optical microscope.

  The fiber is not particularly limited, and examples thereof include those containing a hydrophilic polymer. When the fiber contains a hydrophilic polymer, when the liquid phase in the solid-liquid mixture contains water, the affinity between the fiber and the liquid phase is improved, and the liquid phase is easily captured by the fluidity reducing agent. The degree of fluidity reduction of the solid-liquid mixture is more likely to be improved. The hydrophilic polymer is not particularly limited, and examples thereof include cellulose, polyvinyl alcohol, polyalkylene glycol (for example, polyethylene glycol, polypropylene glycol, etc.), polyacrylic acid, and the like. Biodegradability and neutral pH ( For example, cellulose is preferable because it has a pH of around 8 and is excellent in low environmental impact.

  When the fiber contains a hydrophilic polymer, the content of the hydrophilic polymer in the fluidity reducing agent according to the present invention is preferably 40% by weight or more, more preferably 45% by weight or more, Even more preferably, it is 47% by weight or more. When the content is 40% by weight or more, when the liquid phase in the solid-liquid mixture contains water, the affinity between the fibers and the liquid phase is improved, and the liquid phase is captured by the fluidity reducing agent. It becomes easy to further improve the degree of decrease in fluidity of the solid-liquid mixture. The upper limit of the content may be 100% by weight, but is preferably 80% by weight or less, more preferably 60% by weight or less, considering the degree of fluidity reduction of the solid-liquid mixture, etc. Even more preferred is weight percent or less.

The fluidity reducing agent according to the present invention includes, as optional components, calcium carbonate (CaCO ₃ ), kaolin (Al ₄ Si ₄ O ₁₀ (OH) ₈ ), talc (Mg ₃ Si ₄ ) unless the object of the present invention is impaired. An inorganic filler such as O ₁₀ (OH) ₂ ) may be included.

  It does not specifically limit as a solid-liquid mixture, For example, a mud is mentioned. The content of the liquid phase in the solid-liquid mixture is not particularly limited, and is typically 20 to 90% by weight, more typically 30 to 75% by weight, even more typically 40 to 60% by weight, in particular. Typically 45-55% by weight.

  The manufacturing method of the fluidity reducing agent according to the present invention is not particularly limited, and examples thereof include a method including grinding a piece of material with a mill. As a piece of material, what can form a fiber by the grinding | pulverization by a mill is mentioned, for example, More specifically, paper pieces, such as shredder waste and used paper, are mentioned. By such a method, a granular material having a structure in which fibers are intertwined is formed.

Hereinafter, this fluidity reducing agent will be described along the following properties of the fluidity reducing agent according to the present invention.
(1) Instantaneous (2) Ease of work (3) Versatile (4) Low volume increase rate

(1) Instantaneousness The conventional approach is an approach by solidification accompanying a chemical reaction such as a hydration reaction centering on a cement-based solidified material, and requires a reaction time, that is, a “curing period”. On the other hand, the fluidity reducing agent according to the present invention is based on physical absorption and does not require reaction time. As a result, it is possible to shorten the time from the generation of a solid-liquid mixture having a high fluidity, such as sludge having a high water content, to the completion of the treatment (completion of a low fluidity mixture).

  The fluidity reducing agent according to the present invention has a structure in which fibers are intertwined, and the structure has a cotton-like shape as shown in Examples. This cotton-like structure has many communicating voids, the fluidity reducing agent is added to a solid-liquid mixture having a high liquid content such as sludge, and fine particles constituting water and sludge enter the voids. The internal pressure is difficult to work. As a result, the replacement of the air filling the gap with water and fine particles is performed quickly. In this way, the water and fine particles make the air that has filled the communicating voids in the cotton-like structure of the fluidity reducing agent into a minimum air (bubble), and together with these airs, physically constrained to the communicating voids. Is done.

  In this way, the solid-liquid mixture such as sludge having a high water content, which has liquidity, is restrained from free movement by the fiber structure, and the addition and stirring of the fluidity reducing agent (the fluidity reducing agent Plasticity is brought about immediately after dispersion into the solid-liquid mixture). When the main component of the fiber constituting the fluidity reducing agent is a hydrophilic polymer such as cellulose and the liquid phase of the solid-liquid mixture contains water, the hydrophilic polymer has many hydrophilic groups in the molecular side chain. In addition, an electrical attractive force acts between the water molecules and the fibers constituting the voids, contributing to the difficulty (restraint force) of the water that has entered the communicating voids.

  Moreover, the granular material which comprises the said fluidity reducing agent has the average particle diameter of 300 micrometers or less in one aspect | mode, and its minimum. This contributes to the high dispersibility of the fluidity reducing agent when the fluidity reducing agent is added to the solid-liquid mixture and agitated. Has contributed. From the viewpoint of the dispersibility, the average particle diameter is preferably 250 μm or less, more preferably 200 μm or less. The lower limit of the average particle diameter is not particularly limited, but is typically 3 μm or more, more typically 50 μm or more.

On the other hand, the specific surface area by BET method of the flowable lowering agent is 0.25 m ² / g or more 100 m ² / g or less. The fiber itself constituting the fluidity reducing agent also has fine voids, but silica gel used for a hygroscopic material (specific surface area by BET method: about 500 m ² / g) and activated carbon used for adsorption and the like. Compared with (specific surface area by BET method: about 1000 m ² / g), the specific surface area by BET method is small. Silica gel and activated carbon have innumerable angstrom-order voids (pores) in the material, whereas the fluidity reducing agent has a lot of angstrom-order pores in the particle-constituting fiber itself. Means not. While the pores greatly influence the gas adsorption performance, in the case of liquid absorption, the specific surface area of the fluidity reducing agent is measured considering that the influence of the pores is not so great particularly in a short time. The value confirms the instantaneous liquid absorption principle based on the physical principle of the physical restraint mechanism by the communication gap due to the entanglement of the fibers constituting the fluidity reducing agent.

The specific surface area by the BET method of the fluidity reducing agent is preferably from 0.25 m ² / g to 100 m ² / g, more preferably from 0.5 m ² / g, from the viewpoint of liquid absorption performance by the fluidity reducing agent. above ^{10 m} 2 / g or less, still more preferably 0.75 m ² / g or more ^{5 m} 2 / g or less, more particularly preferably at most ^{1 m} 2 / g or more ^2m 2 / g.

(2) Work simplicity Since the fluidity reducing agent according to the present invention brings plasticity to a liquid-solid mixture by liquid absorption due to physical restraint as described above, the work required for processing is That is, only the addition and stirring of the fluidity reducing agent to the solid-liquid mixture. Therefore, complicated procedures / work / consideration items such as the addition of a plurality of medicines, the order of addition accompanying the addition of the plurality of medicines, and the balance of the blending amount are not required, and the work can be easily performed by anyone.

  In the case of a physical restraint mechanism, it is not necessary to examine the chemical composition of the solid-liquid mixture to be improved in advance, and the effect can be confirmed immediately by addition and stirring. However, it is not necessary to investigate before the work, the solid-liquid mixture is sampled on-site, and the above fluidity reducing agent is added and stirred little by little, and the addition rate that exhibits the desired plasticity can be easily determined. .

(3) Generality Since the fluidity reducing agent according to the present invention brings plasticity to a solid-liquid mixture having liquidity by liquid absorption due to physical restraint as described above, the solid-liquid to be improved It can be used regardless of the chemical composition of the mixture. For example, the solid phase of the solid-liquid mixture may be an inorganic substance or an organic substance. Further, the liquid phase of the solid-liquid mixture may be water, an organic solvent, or a solution. In the case of a solution, for example, the concentration and type of solutes such as an electrolyte and ions are not limited.

(4) Low volume increase rate The fluidity reducing agent according to the present invention has voids as described above. This void is a communication void due to entanglement between fibers constituting the fluidity reducing agent, a fine void included in the fiber itself, or an interparticle void. In one aspect, the fluidity reducing agent according to the present invention has a porosity calculated by (1-bulk density / true density) × 100 of 50% or more. The porosity is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 85% or more from the viewpoint of the liquid absorption performance by the fluidity reducing agent. The upper limit of the porosity is preferably 95% or less, more preferably 93% or less, still more preferably 91% or less, and particularly preferably 89% or less from the viewpoint of the strength of the fluidity reducing agent.

  In the present specification, the bulk density is calculated by filling the fluidity reducing agent into a certain volume of the container and applying the load from the upper part without applying any particular load, and the volume and weight of the filled fluidization reducing agent. Is.

Here, in Example 2, for example, corn having a moisture content of 48 wt% is included in “type 4 treated soil” which is one of the quality categories defined in the “construction sludge treated soil use technical standards”. It has been shown that when improving to an index of 200 kN / m ² or more, it is necessary to add 25 kg of fluidity reducing agent per m ³ . Considering that the true density of the fluidity reducing agent used in Example 2 is 1.9 g / cm ³ , the volume of the fluidity reducing agent added in Example 2 is 25 × 1000 / (1.9 × 100 × 100 × 100) ≈0.013 m ³ . That is, the volume increase rate by the constituent fibers after adding the fluidity reducing agent in Example 2 can be calculated to be about 1%. This volume increase rate is higher than that of the solidification method with hydrate formation by hydration reaction of cement-based solidification materials, etc., and the plasticization approach with a polymer polymer system that expands by incorporating water into the molecule. The rate of increase is very small.

  In addition, the physical restraint to the communication gap constituted by the entanglement of the fibers constituting the fluidity reducing agent has a certain water holding capacity, while the water restrained by the celldron is caused by physical action such as compression. It is possible to extrude. Therefore, for example, while improving the handleability in carrying out construction sludge, etc., it is possible to easily reduce the volume and weight of sludge by physical dehydration such as compression. Compared with the conventional volume reduction method and weight reduction method in a furnace or the like, it is possible to achieve volume reduction and weight reduction at a low cost.

(5) Low environmental impact property The low environmental impact property is demonstrated about the case where the fiber which comprises the fluidity reducing agent which concerns on this invention contains a cellulose. Cellulose is decomposed by cellulase and decomposed by fungi and the like present in the soil. Therefore, the fluidity reducing agent added to the environment returns to the original soil over time. In addition, this biodegradability makes it possible to release water, fine particles, and the like physically constrained by the fluidity reducing agent by the addition of a degrading enzyme such as cellulase. Moreover, since the pH of the fluidity reducing agent is in a neutral region (around pH 8) and the pH of the soil after the addition of the fluidity reducing agent remains in the neutral region, the influence on farmland and surrounding vegetation is small.

[Method for producing low fluidity mixture]
The method for producing a low fluidity mixture according to the present invention includes mixing the solid-liquid mixture and the fluidity reducing agent according to the present invention to obtain a low fluidity mixture. The mixing method is not particularly limited, and may be a known method. The amount of the fluidity reducing agent to be mixed with the solid-liquid mixture is not particularly limited, and is, for example, 1.5 parts by weight with respect to 100 parts by weight of the solid-liquid mixture from the viewpoint of the degree of fluidity reduction of the solid-liquid mixture. Above, preferably 3 parts by weight or more, more preferably 4.5 parts by weight or more, and still more preferably 9 parts by weight or more. The upper limit of the amount is not particularly limited, and is, for example, 50 parts by weight or less, preferably 30 parts by weight or less, more preferably 100 parts by weight or less with respect to 100 parts by weight of the solid-liquid mixture from the viewpoint of easily suppressing volume increase. 20 parts by weight or less, still more preferably 15 parts by weight or less.

[Conveying method of low fluidity mixture]
The conveyance method of the low fluidity mixture which concerns on this invention includes carrying the low fluidity mixture obtained by the manufacturing method of the low fluidity mixture which concerns on this invention on a moving body, and moving it. An example of the moving body is a dump truck. The conveyed low fluidity mixture may be used for construction or the like at the destination, or may be discarded.

[Method for improving the degree of fluidity reduction of a solid-liquid mixture]
Another aspect of the present invention is a method for improving the degree of decrease in fluidity of the solid-liquid mixture by allowing the solid phase and the liquid phase of the solid-liquid mixture to enter and capture in the voids formed by the entanglement of fibers. . In this method, for example, the fluidity reducing agent according to the present invention can be used. This is because the fluidity reducing agent has voids formed by the entanglement of fibers, and the solid phase and the liquid phase of the solid-liquid mixture enter and are trapped in the voids.

[Method for improving the degree of freedom in chemical composition of a solid-liquid mixture subject to fluidity reduction]
Another aspect of the present invention is the freedom of the chemical composition of the solid-liquid mixture that is subject to fluidity degradation by allowing the solid phase and liquid phase of the solid-liquid mixture to enter and capture in the voids formed by fiber entanglement. It is a method to improve the degree. In this method, for example, the fluidity reducing agent according to the present invention can be used. As described above, the fluidity reducing agent according to the present invention can be used regardless of the chemical composition of the solid-liquid mixture, and improves the degree of freedom of the chemical composition of the solid-liquid mixture that is subject to fluidity reduction. Can be made.

[Method for suppressing increase in volume of solid-liquid mixture after fluidity drop]
Another aspect of the present invention is a method for suppressing an increase in the volume of a solid-liquid mixture after the fluidity is lowered by allowing the solid phase and the liquid phase of the solid-liquid mixture to penetrate into and capture the void formed by the entanglement of fibers. is there. In this method, for example, the fluidity reducing agent according to the present invention can be used. As described above, the fluidity reducing agent according to the present invention can suppress an increase in the volume of the solid-liquid mixture after the fluidity reduction.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further more concretely, the scope of the present invention is not limited to these Examples.

[Example 1: Preparation of fluidity reducing agent]
Shredder scrap (specific surface area by BET method 0.23 m ² / g) was ground by mill to obtain an average particle diameter of 200 [mu] m, the fluidity reducing agent comprising a particulate having a specific surface area of 1.6 m ² / g by the BET method . When this granular material was observed with an optical microscope, it had a structure in which fibers were intertwined, and this structure had a cotton-like shape (FIG. 1). It was 1.9 g / cm < ³ > when the true density of this granular material was measured with the Shimadzu dry density meter. Moreover, the bulk density of this granular material was 0.25 g / cm ³ . Therefore, the porosity of this granular material was (1-0.25 / 1.9) × 100≈87%.

[Examples 2 to 5 and Comparative Example 1: Mixing of fluidity reducing agent and mud]
The mud having a water content of 48% by weight and the fluidity reducing agent obtained in Example 1 were mixed at the weight shown in Table 1. Regarding the soil after mixing, the cone index was measured in accordance with JIS A 1228. The results are shown in Table 1. In Table 1, the ratio refers to the weight ratio of the fluidity reducing agent to the mud.

As is clear from Table 1, by mixing the fluidity-reducing agent of 1.6% by weight or more with mud with a moisture content of 48% by weight, the quality classification defined in the “Technology Standards for Construction Sludge Treatment Soil” The range of a cone index of 200 kN / m ² or more possessed by “type 4 treated soil” as one of the above was satisfied, and the fluidity of the mud could be reduced.

  FIG. 2 shows a state after mixing 10% by weight of the fluidity reducing agent with 60% by weight of mud. As shown in FIG. 2, the soil fine particles were trapped in the voids in the cotton-like structure in which the fibers were entangled in the fluidity reducing agent. For photography, the water was evaporated by drying.

[Example 6, Comparative Example 2, and Reference Example 1: Cellulase degradation test]
The following samples were used for the cellulase degradation test.
Example 6: Fluidity reducing agent obtained in Example 1 Comparative Example 2: Shredder waste used to obtain the fluidity reducing agent in Example 1 Reference Example 1: Cellulose Microcrystallin (Merck)

  A cellulase agent (trade name: Cellulase SS, manufactured by Nagase ChemteX Corporation) was diluted with 0.1 M acetate buffer (pH 5.5) to a concentration of 1/50 to prepare an enzyme dilution. 25 mg of a sample was added to 0.5 ml of this enzyme dilution and stirred. At that time, it was observed by visual observation that none of the samples was dissolved. Then, it kept warm at 40 degreeC for 24 hours. Centrifugation (7,000 × g, 5 minutes) was performed on the reaction solution at 0 and 24 hours from the incubation, and the supernatant was collected. The supernatant was boiled for 5 minutes to stop the reaction. The amount of glucose contained in the supernatant was measured with a glucose test Wako CII (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

  As is clear from Table 2, it was confirmed that the fluidity reducing agent according to the present invention can be efficiently decomposed by cellulase as compared with the shredder waste of Comparative Example 2, and is excellent in biodegradability.

[Example 7: pH measurement]
In Example 3, 10 g of a sample obtained by mixing the mud and the fluidity reducing agent was collected in a glass container, 25 ml of pure water was added thereto, and the mixture was stirred and left for 1 hour. About the soil suspension after standing, after stirring lightly, pH was measured by the glass electrode method. As for the test method, “Soil environmental analysis method”, Chapter V, soil chemistry, supervised by the Japan Soil Fertilizer Society. Reference was made to pH (H ₂ O) of pH (glass electrode method).

[Example 8: Physical property analysis of fluidity reducing agent]
1. Content of Analysis The following analysis was performed on the fluidity reducing agent obtained in Example 1.
(1) Loss on ignition (hereinafter also referred to as ig-Loss)
(2) Thermogravimetric / differential analysis (hereinafter also referred to as TG-DTA)
(3) X-ray diffraction analysis of ignition ash (hereinafter also referred to as XRD)

2. Analysis method (1) ig-Loss
About 8 g of the fluidity reducing agent was accurately weighed to 1/100 g in a magnetic crucible, placed in an electric furnace, heated to 1,000 ° C. in about 2 hours, and held for 1 hour. Thereafter, the magnetic crucible that had been cooled to around 100 ° C. in the furnace was taken out of the furnace and placed in a desiccator. It was cooled to room temperature and weighed quickly. Since the fluidity reducing agent is expected to have a large weight loss, the measurement was performed three times. The ignition loss was calculated by the following formula.
Loss on ignition = (weight before heating−weight after heating) / weight before heating

(2) TG-DTA
TG-DTA is a method of examining the state in which a material undergoes a chemical change (including combustion) by heating, using a method of examining exothermic endothermic behavior and weight change. About the fluidity reducing agent obtained in Example 1, TG-DTA was measured using Rigaku's Thermo Plus EVO2 differential type thermometer TG8121. The measurement conditions were a sample weight of 15 mg, a measurement temperature range of 20 to 950 ° C., and a temperature increase rate of 20 ° C./min.

(3) XRD
XRD is an analysis method for performing qualitative and quantitative analysis of substances using the fact that each substance has a unique crystal structure. The ash produced by the above-mentioned (1) ig-Loss is crushed in an agate mortar, the ash produced in the agate mortar is crushed in the agate mortar, and packed in an XRD measurement holder. It was. A Rigaku smart lab was used for the analysis. The measurement conditions were goniometer: MultiFlex + goniometer, X-ray: CuKα, 40 kV / 30 mA, scan mode: continuous mode, scan speed: 2.0 ° / min, scan range: 2θ = 5 to 65 °.

3. Analysis result (1) ig-Loss
The results are shown in Table 3.

(2) TG-DTA
The results are shown in FIGS. 3 (a) and 3 (b). In the figure, the line labeled “TEMP” indicates the heating temperature, the line labeled “TG” indicates the weight change (TG curve), and the line labeled “DTA” indicates the exothermic endotherm (DTA curve). Indicates. Note that FIG. 3B is a diagram in which the drawing scale of the DTA curve in FIG. 3A is changed.

(3) XRD
The results are shown in FIG.

4). Discussion (1) ig-Loss
The measurement of 3 times had almost no variation, and ig-Loss was about 74%. It is considered that the organic component burns and disappears due to this intense heat, and fillers and other inorganic inclusions remain as ash. Details will be discussed in the following TG-DTA and XRD.

(2) TG-DTA
There is a gentle endothermic peak at room temperature to 100 ° C., and the TG curve is slightly lowered (decreased) at the same temperature, indicating that the water adsorbed on the fluidity reducing agent has evaporated. When read from the measured value, the weight ratio of the adsorbed water possessed by the fluidity reducing agent was about 3%.

  Next, it can be seen that a large exothermic peak is observed in the DTA curve when heated to 250 to 350 ° C., and the TG curve also greatly decreases and decreases at the same temperature. This means that the cellulose burned, decomposed into water vapor and carbon dioxide and released into the atmosphere (the amount of heat generated was too large to control the heating, and the line labeled “TEMP” also rose. doing.). The weight loss at this time was about 49%.

  When the combustion of cellulose was completed, a slightly mild exothermic peak appeared at 350 to 570 ° C. The heat generation at this temperature can be lignin, ink carbon, or unburned carbon remaining during combustion at 300-350 ° C., as estimated from the material that the fluidity reducing agent would contain. The wood fiber contains a large amount of hemicellulose and lignin in addition to cellulose. However, since lignin is viscous and causes discoloration, it is removed as much as possible in the papermaking process, so its content is extremely small. Therefore, it is considered as combustion of unburned carbon of cellulose and / or printed carbon. The weight loss at this time was about 7% from the measured value.

  A gentle endothermic peak appears at 700 ° C to 800 ° C, and the weight is reduced at the same temperature. This captures the phenomenon of decarboxylation of the carbonated lucium in the filler contained in the fluidity reducing agent. This decarboxylation loss was about 12%.

Fillers are used for various purposes in the papermaking process. Commonly used fillers include calcium carbonate (CaCO ₃ ), kaolin (Al ₄ Si ₄ O ₁₀ (OH) ₈ ), talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ), and the like. The fluidity reducing agent is also likely to contain fillers other than calcium carbonate. The thermal decomposition of calcium carbonate (reaction formula: CaCO ₃ + ΔH → CaO + CO ₂ , ΔH is calorie) is 700 ° C. or more, and the weight loss (theoretical value 44%) is also large, so it can be clearly detected (depending on the literature, There are reports that the thermal decomposition of calcium carbonate occurs around 600 ° C. and data that it occurs around 900 ° C., but it is 700 to 800 ° C. under the present measurement conditions. On the other hand, the temperature of the thermal decomposition of kaolin and talc (these are dehydration reactions of crystal water) is wide at 350 to 650 ° C. and the weight loss is as small as 10 to 14%, which overlaps with the combustion reaction of cellulose. Detection is difficult with TG-DTA.

The above is summarized in Table 5.

  The total weight loss determined by TG-DTA (heating to 950 ° C.) is 72.12%, which is almost equal to 73.72% of the ignition loss (heating to 1000 ° C.) of (1). Moreover, content of the cellulose contained in the said fluidity reducing agent was about 48 to 56%.

  In addition, about the said fluidity reducing agent, the reduction | decrease in the ashing temperature 575 degreeC prescribed | regulated to JISP8251: 2002 was 61.84% (however, this part also includes the reduction | decrease part of adsorption water). .)

(3) XRD
From the XRD pattern shown in FIG. 4, the ash contains calcium oxide (CaO), gehlenite (Ca ₂ Al (AlSi) O ₇ ), magnetite (iron oxide Fe ₂ 0 ₃ ), calcium hydroxide (Ca (OH) ₂ ). Seems to be included. Assuming from the height of the detection peak, the amount contained in the ash is calcium oxide> gerenite >>magnetite> calcium hydroxide.

  Calcium oxide is a substance produced by decarboxylation of calcium carbonate as a filler by high heat, and was most contained in ash. Note that the calcium hydroxide detected in a trace amount is obtained by reacting calcium oxide in the sample with moisture in the air during measurement. Next, gelenite, which was thought to be produced by dehydration and recrystallization of clay-based fillers such as kaolin, was included. It can be seen that the main components of ash are these two, which are attributed to the filler.

  Moreover, although it is a small amount, magnetite is also seen. This can be attributed to staples, grinding blade wear, ink components, and the like.

Claims (13)

A solid-liquid mixture including a granular material having a structure in which fibers are intertwined, wherein the granular material has an average particle diameter of 300 μm or less and a specific surface area by a BET method of 0.25 m ² / g to 100 m ² / g. Fluidity reducing agent. Including a granular material having a structure in which fibers are intertwined, the granular material has a porosity calculated by (1-bulk density / true density) × 100 or more and a specific surface area by the BET method is 0.25 m. ² / g or more and 100 m ² / g or less, the fluidity reducing agent of the solid-liquid mixture.   The fluidity reducing agent according to claim 2, wherein the average particle size is 300 µm or less.   The fluidity reducing agent according to any one of claims 1 to 3, wherein the fiber contains a hydrophilic polymer.   The fluidity reducing agent according to claim 4, wherein the hydrophilic polymer is cellulose.   The fluidity reducing agent according to claim 4 or 5, wherein the content of the hydrophilic polymer in the fluidity reducing agent is 40% by weight or more.   The fluidity reducing agent according to any one of claims 1 to 6, wherein the solid-liquid mixture is mud.   The manufacturing method of a low fluidity mixture including mixing a solid-liquid mixture and the fluidity reducing agent of any one of Claims 1-6, and obtaining a low fluidity mixture.   The method according to claim 8, wherein the solid-liquid mixture is mud.   A method for transporting a low fluidity mixture, comprising mounting and moving the low fluidity mixture obtained by the method according to claim 8 on a moving body.   A method of improving the degree of decrease in fluidity of the solid-liquid mixture by allowing the solid phase and liquid phase of the solid-liquid mixture to penetrate into and capture the void formed by the entanglement of fibers.   A method for improving the degree of freedom of the chemical composition of a solid-liquid mixture that is subject to a decrease in fluidity by allowing a solid phase and a liquid phase of the solid-liquid mixture to enter and capture in voids formed by entanglement of fibers.   A method of suppressing an increase in the volume of a solid-liquid mixture after fluidity is lowered by allowing a solid phase and a liquid phase of a solid-liquid mixture to enter and capture in voids formed by entanglement of fibers.