JPH10259389A - High-concentration solid-water slurry and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-concn. carbonaceous solid-water slurry having a high flowability and excellent storage and transport stabilities and a process for producing the same. SOLUTION: This slurry exhibits a max. stress of 0.3-10 Pa in a linear zone when measured at a frequency of 1 Hz in the stress sweep test of dynamic viscoelasticity measurement, and the strain giving the max. stress in the linear zone is 2% or higher. In addition, the modulus of Maxwell element obtd. by analyzing values of a creep recovery test measured in a linear elasticity zone in a static viscoelasticity measurement of a slurry on the assumption of a four- constant mathematical model based on Hook's elasticity and Newtonian viscosity is 8-70 Pa, and the modulus of Voigt element is 3-70 Pa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-concentration solid-water slurry and a method for producing the same. More specifically, the present invention relates to a high-concentration solid-water slurry having a solid powder dispersed in water and having high fluidity and excellent storage stability and transport stability even in a high-concentration solid, and a method for producing the same.

[0002]

2. Description of the Related Art In the industry, slurries of coal, cement, paints, various polymers, etc. are widely used. Usually, the slurries have a high concentration, a low viscosity for transportation by pipeline, and a high fluidity. For example, it is required that the dispersoid particles have stability so as not to separate or settle during transportation or storage. In particular, oil, which has been widely used as an energy source in the past, has seen a remarkable rise in price in recent years, and its depletion has been concerned. Therefore, the development of other energy resources that are inexpensive and can be supplied stably has become an issue, and the use of carbonaceous solids such as coal and petroleum coke has been reviewed. However, coal and petroleum coke are solid at room temperature, so they cannot be transported by pipeline, are difficult to handle, and have the disadvantages of causing pollution due to dust scattering and dust explosion. The technology was difficult. Therefore, a fluidizing technology for carbonaceous solids that can fluidize such carbonaceous solids, can be transported by pipeline, is easy to handle, and can prevent the occurrence of pollution and the danger of dust explosion is desired. It is rare. As one of the fluidization techniques, practical application of a liquid fuel conversion technique of forming a high-concentration carbonaceous solid-water slurry in which carbonaceous solids are finely powdered and dispersed in water has been promoted. Generally, in the production of a carbonaceous solid-water slurry, when the concentration of the carbonaceous solid is increased, the viscosity of the slurry becomes extremely high, the fluidity of the slurry is lost, and handling and transportation of the pipeline become difficult. Conversely, when the concentration of the carbonaceous solid is reduced to lower the viscosity of the slurry, not only the transport efficiency and the combustion efficiency are reduced, but also the economy as a liquid fuel is lost. These technical problems of high concentration and low viscosity have been almost solved by the recent development of dispersant technology. However, when the high-concentration carbonaceous solid-water slurry is subjected to severe vibration conditions such as transported by ship or tank lorry, or stored in a tank for a long period of time, sedimentation of carbonaceous solid particles is observed. Such sedimentation of carbonaceous solid particles causes various troubles in practical use of a high-concentration carbonaceous solid-water slurry, and therefore, a stabilization technique for preventing sedimentation of carbonaceous solid particles is required. Generally, in order to stabilize a dispersion system of carbonaceous solid particles, a stabilizer is usually added, and various stabilizers have been studied.
As the stabilizing agent, a cellulose-based semi-synthetic paste, an inorganic mineral, clay, a natural polysaccharide, various ions, and the like have been reported. However, even if these stabilizers are used, there is a problem that sufficient stability cannot be ensured by using an actual line, or the fluidity of a high-concentration carbonaceous solid-water slurry is impaired.

[0003]

That is, an object of the present invention is to provide a high-concentration solid-water slurry having high fluidity and excellent storage stability and transport stability, and a method for producing the same. Another object of the present invention is to provide a high-concentration carbonaceous solid-water slurry having high fluidity and excellent storage stability and transport stability, and a method for producing the same.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have intensively studied a high-concentration carbonaceous solid-water slurry. As a result, the present inventors have found that a high-concentration carbonaceous solid-water slurry having a specific viscoelastic property value shows good fluidity even at a high concentration, and has excellent stability during storage and transportation. Thus, the present invention has been completed. Therefore, the present invention relates to a high-concentration solid-water slurry containing solid particles and water, and in a stress sweep test of a dynamic viscoelasticity measurement method of a slurry, the maximum stress in a linear elastic region observed at a vibration frequency of 1 Hz is obtained. ,
An object of the present invention is to provide a high-concentration solid-water slurry having a strain of 0.3 to 10 Pa and giving a maximum stress in a linear elastic region of 2% or more, and a method for producing the same.

Further, the present invention provides a Maxwell element obtained by analyzing a creep recovery test value measured in a linear elastic region in a static viscoelasticity measurement method assuming a four-constant dynamic model based on hook elasticity and Newtonian viscosity. Has an elastic modulus of 8 to 70 Pa and a Voigt element has an elastic modulus of 3
The present invention provides a high-concentration solid-water slurry having a pressure of up to 70 Pa and a method for producing the slurry.

Further, the present inventors have proposed a (meth) acrylic acid (co) polymer (salt) as an additive capable of easily producing a high-concentration solid-water slurry having the above characteristics.
As a result of diligent study of the polymerization method, by using a specific stirring blade reactor effective for stirring in a wide viscosity range from low viscosity to medium viscosity, industrially efficient, easy and inexpensive production is possible. The present invention has been completed by finding a suitable polymerization method. Accordingly, the present invention further provides a method for measuring the dynamic viscoelasticity of a slurry by using a (meth) acrylic acid-based (co) polymer (salt) polymerized in a specific stirring blade reactor. The maximum stress in the linear elastic region observed at a vibration frequency of 1 Hz is 0.3 to 10 Pa
And the strain giving the maximum stress in the linear elastic region is
The present invention also provides a method for producing a high-concentration solid-water slurry of 2% or more, and the present invention further provides a (meth) acrylic acid-based (co) polymer ( (Salt), the Maxwell element obtained by analyzing the creep recovery test value measured in the linear elastic region in the static viscoelasticity measurement method of the slurry, assuming a four-constant dynamic model based on hook elasticity and Newtonian viscosity And a high-concentration solid-water slurry having an elastic modulus of 8 to 70 Pa and an elastic modulus of the Voigt element of 3 to 70 Pa, and a method for producing the same.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the maximum stress in a linear elastic region observed at a vibration frequency of 1 Hz in a stress sweep test of a dynamic viscoelasticity measurement method of a high-concentration solid-water slurry is 0.
The pressure is preferably 3 to 10 Pa. It is not preferable to limit the maximum stress in the linear elastic region because if the maximum stress in the linear elastic region is less than 0.3 Pa, the stability during storage and transportation is significantly reduced, and the maximum stress in the linear elastic region is not preferable. If the pressure exceeds 10 Pa, the fluidity of the slurry decreases over time, which is not preferable. Further, in the present invention, it is preferable that the strain giving the maximum stress in the linear elastic region is 2% or more. The reason for limiting the strain that gives the maximum stress in the linear elastic region is that if the strain is less than 2%, the stability during storage and transportation decreases.

In the present invention, the maximum stress in the linear elastic region and the strain giving the maximum stress are preferably measured by a rheology measuring device using a stress control method. As a specific example of the device, Rheostress RS100 (HAAKE
Company).

When a stress control type rheology measuring device is used, the maximum stress in the linear elastic region and the strain giving the maximum stress in the linear elastic region are measured by, for example, the following method. The solid concentration or viscosity of the solid-water slurry is adjusted so as to have the property value to be usually used. The slurry is measured based on the following principle, and the maximum stress in the linear elastic region and the strain giving the maximum stress are obtained.
Here, a sinusoidal stress (τ) is applied to the slurry, and the resulting strain (γ) and phase difference (δ) are measured. When the sinusoidal stress represented by the equation (1) is applied to the slurry, the phase of the sinusoidal strain that responds is shifted by δ as shown in the equation (2) according to the magnitude of the viscous property involved.

[0010]

(Equation 1)

The ratio of stress to strain is defined as the modulus of elasticity. Since both stress and strain are complex numbers, the modulus of elasticity is also a complex number. Further, the complex elastic modulus (G ^*) is calculated from the phase difference between the strain and the stress, as shown by the relationship of equation (3), as the elastic component (G ').
And a viscous component (G ″).

[0012]

(Equation 2)

The complex elastic modulus is calculated as the quotient of the maximum value of the stress and the maximum value of the strain, as shown by the relationship of equation (4), and the storage elastic modulus (G ') and the loss elastic modulus (G "). ) Is calculated using a trigonometric function as shown by the relations of Expressions (5) and (6).

[0014]

(Equation 3)

The viscoelastic material exhibits a linear behavior depending on stress up to the critical strain. However, when the viscoelastic material exceeds the critical strain, the viscoelastic material becomes nonlinear due to the destruction of the internal structure, and the storage elastic modulus decreases. By gradually applying a sinusoidal stress of a magnitude from the linear elastic region to the nonlinear region to the slurry, a region where the storage elastic modulus decreases appears, and the maximum stress in the linear elastic region and the strain that gives the maximum stress are determined. . Normally, the relationship between stress (τ) and storage modulus (G ′) as shown in FIG. 1 is obtained, and the intersection of the tangent of the linear elastic region and the tangent of the nonlinear region parallel to the horizontal axis is obtained by the analysis method shown in FIG. Is set as the maximum stress in the linear elastic region, and point b of the strain corresponding to the stress is set as the strain giving the maximum stress.

Further, according to the present invention, in the static viscoelasticity measurement method, a creep recovery test value measured in a linear elastic region is determined by Maxwell in which hook elasticity (spring) and Newtonian viscosity (dashpot) are connected in series. It is preferable that each constant value obtained by analyzing a four-constant dynamic model in which an element and a Voigt element connected in parallel are further arranged in series according to the following rheological equation is within the following range. That is, the elastic modulus of the Maxwell element is 8 to 70 Pa, and the elastic modulus of the Voigt element is 3 Pa.
７０70 Pa. It is not preferable to limit the range of the elastic modulus of each element if the value is smaller than the lower limit because the stability during storage and transportation is significantly reduced, and if the value exceeds the upper limit, the fluidity of the slurry decreases with time. Therefore, it is not preferable.

When a stress control type rheology measuring device is used, the creep recovery test in the linear elastic region is measured by, for example, the following method. The solid concentration or viscosity of the solid-water slurry is adjusted so as to have the property value to be usually used. The magnitude of the stress applied to the slurry in the creep test is not more than the yield stress of the slurry and does not exceed the strain that gives the yield stress during the creep test, and a constant stress is applied to the slurry at the moment to obtain a response. Deformation is measured as a function of time.
The recovery test is performed after the creep test. The stress applied in the creep test is instantaneously reduced to zero, and the recovery is performed until the recoverable deformation is almost recovered. In the creep recovery test, normally, a relationship between the time t and the strain γ as shown in FIG. 3 is obtained. The analysis method of each constant value of the four-constant dynamic model shown in FIG. 5 is analyzed by the following procedure using the analysis method diagram and the rheological equation shown in FIG.

Since the creep stress τ and the creep time t are given as test conditions in advance, the elastic modulus E3 of the Maxwell element is obtained from the initial value γ3 of the strain when the stress is applied, according to the relationship shown in equation (7). .

[0019]

(Equation 4)

Next, the strain γ1 after the recovery is obtained, and the viscosity η1 of the Maxwell element is obtained by the equation (8).

[0021]

(Equation 5)

Next, γ2, which is parallel to the change of γ1, and γ
Then, the delay time λ corresponding to 2 is obtained, and the elastic modulus E2 of the Voigt element is obtained from the relationship shown in Expression (9).

[0023]

(Equation 6)

Next, the viscosity η2 of the Voigt element is determined from the relationship shown in the equation (10).

[0025]

(Equation 7)

In the present invention, the high-concentration solid-water slurry is obtained by dispersing inorganic and / or organic dispersoids in water.

Examples of the dispersoid used in the present invention include inorganic pigments such as calcium carbonate, clay, alumina, zirconia, and titanium oxide, cement, and the like.
There is plaster etc. Organic solids include coal, coke,
Pitch, charcoal, dye, carbon black, paint, microcapsules, various polymers, organic pigments such as anthraquinone, and the like can be mentioned. Among them, coal, regardless of the type, place of origin, moisture content and chemical composition, any coal can be used, for example, anthracite, bituminous coal, sub-bituminous coal, lignite, etc., may be any, There are no particular restrictions on whether these are clean coals or modified coals.

In the present invention, additives may be used for producing a high-concentration solid-water slurry. The additive is not particularly limited, but for example, poly (meth) acrylic acid (co) polymer (salt), ethylene, isobutylene,
Polycarboxylates such as copolymers (salts) of olefins such as amylene, hexene, diisobutylene and α, β-unsaturated dicarboxylic anhydrides represented by maleic anhydride, and polymaleic acid (salts) Coalesce, naphthalenesulfonic acid (salt), ligninsulfonic acid (salt), and formalin condensate thereof, polystyrenesulfonic acid (salt), polyaliphatic dienesulfonic acid (salt), styrenesulfonic acid-maleic anhydride copolymer (Salts), polysulfonate polymers such as styrene-styrenesulfonic acid copolymers (salts), natural polysaccharides such as xanthan gum and guar gum, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, montmorillonite, attapulgite and bentonite Minerals such as, kaolinite, sepiolite, etc. However, a poly (meth) acrylic acid (co) polymer (salt) is preferred.

In the present invention, the (meth) acrylic acid monomer constituting the (meth) acrylic acid (co) polymer (salt) includes, for example, acrylic acid, sodium acrylate, potassium acrylate, acrylic acid Acrylic acid (salt) or methacrylic acid (salt) such as calcium, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, calcium methacrylate, ammonium methacrylate; methyl acrylate, ethyl acrylate, 2-hydroxyethyl Acrylic acid or alkyl esters of methacrylic acid such as acrylate, methyl methacrylate, ethyl methacrylate and 2-hydroxyethyl methacrylate; represented by the following general formula (I)

[0030]

Embedded image

Alkyl polyoxyalkylene (meth) acrylate; 2-sulfoethyl (meth) acrylate,
Sulfoalkyl (meth) acrylates such as 3-sulfopropyl (meth) acrylate and the like can be mentioned,
One or more of these can be used.

Further, if necessary, other copolymerizable monomers can be used in combination with the (meth) acrylic acid monomer as long as the effects of the present invention are not impaired. This other monomer includes vinyl sulfonic acid, styrene sulfonic acid,
Various sulfonic acids such as allylsulfonic acid, methallylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid and their monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts, styrene, p-methylstyrene And vinyl acetate, propenyl acetate, vinyl chloride and the like, and one or more of these can be used.

In the present invention, in order to produce a (meth) acrylic acid (co) polymer (salt), the above monomers may be copolymerized using a polymerization initiator. The copolymerization can be performed by a known method such as polymerization in a solvent, bulk polymerization, suspension polymerization, emulsion polymerization and the like. Polymerization in a solvent can be carried out batchwise or continuously. Examples of the solvent used in this case include water, lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; and aromatic, aliphatic, and heterocyclic aliphatic carbons such as benzene, toluene, cyclohexane, n-hexane, and dioxane. Hydrogen, ester compounds such as ethyl acetate,
Examples thereof include ketone compounds such as acetone and methyl ethyl ketone. Above all, at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms in view of the solubility of the raw material monomers and the resulting water-soluble copolymer and the convenience of using the copolymer. Preferably, a seed is used.

In the case of a polymerization method using water as a solvent, ammonium or alkali metal persulfate, hydrogen peroxide, or 2,2 ′ azobis (2-methylpropionamidine) dihydrochloride is used as a polymerization initiator. And water-soluble polymerization initiators such as azo initiators such as 2,2 'azobis [2-methyl-N- (phenylmethyl) -propionamidine) dihydrochloride.
At this time, an accelerator such as sodium hydrogen sulfite can be used in combination. When a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester compound or a ketone compound is used as a solvent, a peroxide such as benzoyl peroxide or lauroyl peroxide or a hydrochloride such as cumene hydroperoxide is used as a polymerization initiator. Aliphatic azo compounds such as peroxide and azobisisobutyronitrile are used. At this time, an accelerator such as an amine compound may be used in combination. Further, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above various polymerization initiators or a combination of the polymerization initiator and the accelerator. The amount of the polymerization initiator is from 0.01 to 10% by weight, preferably from 0.1 to 10% by weight, based on the monomer mixture.
~ 5% by weight. Also, when using an accelerator together,
It is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the monomer mixture.

The polymerization temperature is appropriately determined depending on the solvent and the polymerization initiator used, but is usually in the range of 0 to 150 ° C., preferably 30 to 120 ° C.

In the present invention, when the (meth) acrylic acid (co) polymer (salt) is used as an additive for a carbonaceous solid-water slurry, the (meth) acrylic acid (co)
The weight average molecular weight of the polymer (salt) is 1000 to 3000
000, preferably 5,000 to 2,000,000, and one or more of these can be used. The molecular weight can be adjusted by a known method.

As a method for adjusting the molecular weight, there are, for example, a method of adjusting with the amount of polymerization initiator, a method of adjusting with a chain transfer agent, a method of adjusting with a polymerization concentration and a polymerization temperature, and the like. The molecular weight can also be adjusted by the method of charging or charging the monomer component, the polymerization initiator and / or the chain transfer agent.

In the present invention, when synthesizing a (meth) acrylic acid-based (co) polymer (salt), the viscosity of the polymerization solution increases with the reaction time depending on the concentration of the polymerization solution, the temperature and the type of the solvent. It varies from centipoise to thousands of centipoise. The increase in the viscosity of the polymerization solution with the progress of the reaction significantly lowers the stirring efficiency and makes (co) polymerization difficult. paddle,
Conventional low-viscosity general blades, such as turbines and three-blade sweep blades, are difficult to apply to medium-viscosity to high-viscosity regions, and high-viscosity stirring blades, such as double helical ribbon blades, are used in low-viscosity regions. Is not suitable for stirring at Generally, the mixing characteristics of the stirring blade are represented by an n · θm-Re curve, and there is a relationship between n and θm as shown in equation (11).

[0039]

(Equation 8)

The specific stirring blade used in the present invention has a mixing characteristic curve represented by a logarithmic axis, that is, an n · θm-Re curve, whose stirring Reynolds number (R) represented by the relationship of equation (12).
e) In a flow region where the mixing time is not more than 50, the time required to complete the mixing (θm) multiplied by the stirring blade rotation speed (n) passes through a region of 400 or less, and n · θm in that region Any configuration may be used as long as the reactor is equipped with a stirring blade having an average rate of change of -1.2 or more. When a reactor equipped with a stirring blade having the above characteristic value is used for the polymerization reaction of the (meth) acrylic acid (co) polymer (salt), the stirring efficiency is significantly reduced in a wide range from low to medium viscosity. Therefore, the (meth) acrylic acid (co) polymer (salt) as an additive for preparing a slurry having the properties defined in the claims is industrially efficient, easy, and inexpensive. Can be manufactured.

Examples of a tank-type reactor equipped with a stirrer that can be used in the present invention are as shown in FIGS. The stirring blade will be described briefly, but does not limit the range of the tank type reactor that can be used in the present invention.

The stirring blade shown in FIG. 6 is symmetrical with respect to a rotation axis provided at the center of the tank, has a substantially flat plate shape, and has a grid-like reactant passage hole in the flat plate. I have.

In the stirring blade shown in FIG. 7, the upper blade is bilaterally symmetric with respect to the rotation axis provided at the center of the tank and is substantially flat, and the lower blade is rotationally symmetric with respect to the rotation axis. The main part of the lower wing and the upper wing are not on the same plane, and are provided with a retreat wing parallel to the rotation axis at the tip of the lower wing and a fin projecting below the tip of the upper wing.

The stirring blade shown in FIG. 8 includes a rotating shaft provided at the center of the upper part of the tank and a pair of spiral band stirring blades supported by a rod-shaped frame extending along the inner wall.

FIGS. 9 and 10 show specific reactors used in the present invention. The stirring blade is provided on a rotating shaft provided at the center of the tank, and a vertically flat paddle portion having no passage hole on the lower side and a grid portion having a lattice-like reactant passage hole on the upper side are arranged in the height direction. It has an integrated shape. The number of agitating blades may be an odd number excluding one as long as the rotation of the shaft can be performed smoothly, but it is desirable to provide about two symmetrically from the viewpoint of ease of manufacture. The length of the lower paddle portion constituting the stirring blade is 1/10 to 2/3, preferably 1/5 to 1/2 of the height of the stirring blade from the lower end of the stirring blade. 0.4 to 0.95 times, preferably 0.5 to 0.9 times. Further, it is preferable that the distance between the lower end of the stirring blade and the bottom of the tank is narrow. The shape of the reactant passage hole in the upper grid portion constituting the stirring blade may be any shape as long as the discharge flow from the tank bottom can be sheared and subdivided and the mechanical strength can be maintained, for example, circular, There are an elliptical shape, a square shape, a rectangular shape, a triangular shape, a star shape, a crescent shape and the like, but a rectangular shape is preferable. The height of the stirring blade is not particularly limited, and is determined in consideration of the height of the tank.

FIGS. 11 and 12 show specific reactors used in the present invention. The stirring blade is provided on the rotating shaft provided at the center of the tank with an upper blade and a lower blade. The upper wing is bilaterally symmetric and substantially made of a flat plate, and its width is usually 0.3 to 0.6 times the inner diameter of the tank,
Preferably it is 0.4 to 0.5 times. A fin projecting upward and / or downward may be provided at the tip of the upper wing, and the fin is symmetrical in shape, and its width is usually １ ／ to の of one side of the upper wing. Further, the upper stage may be in a lattice shape. Although the lower wing is rotationally symmetric with respect to the rotation axis and is substantially a flat plate, a swept wing bent at the tip of the lower wing in parallel with the rotation axis may be formed. The bending degree is symmetrical, and the bending width is usually 1/3 to 1/2 of the lateral width on one side of the lower wing. Bending angle is usually 3
It is 0 to 60 °, preferably about 45 °. The shortest distance of the width of the lower blade is usually 0.3 to 0.7 times, preferably 0.5 to 0.6 times the inner diameter of the tank, and may be equal to or larger than the width of the upper blade. The lower wing may also be provided with a fin protruding upward at the tip, its shape is bilaterally symmetric, and its width is usually 1/4 to 1/1 of one side of the upper wing.
2. The distance between the lower end of the lower blade and the tank bottom is usually 0.01 to 0.06 times the inside diameter of the tank. The height of the upper and lower wings is not particularly limited, and is determined in consideration of the height of the tank. The substantially flat upper and lower blades are not coplanar and usually form an angle of 30 to 90 °, preferably 45 °. When the upper wing has a fin at the lower end, the lower end of the fin of the upper wing is below the upper end of the lower wing, and when the lower wing has a fin at the upper end, the upper end of the fin of the lower wing is above the upper end of the upper wing. It is preferable that both wings are positioned so as to be as follows.

FIGS. 13 and 14 show specific reactors used in the present invention. The stirring blade has a pair of spiral band-shaped blades supported by a substantially rod-shaped frame extending from a rotation shaft provided at the center of the upper portion of the tank to the inner wall of the tank and extending along the inner wall to the center of the tank bottom. The shape of the member constituting the frame may be any shape as long as the spiral band-shaped wing is supported and mechanical strength for stirring the polymerization liquid can be maintained, for example, a plate shape, a square pillar shape, a triangular pillar shape, and the like. May be provided with a plurality of arm-shaped projections directed to the inner wall side and / or the center of the tank or a plurality of beams connecting the frames. The width of the member constituting the frame in the height direction is 0.04 to 0.16 times the inner diameter of the tank, and preferably 0.06 to 0.16 times.
The number is 0.1 times, and the number may be an odd number other than 1 as long as the rotation of the shaft is performed smoothly, but about 2 are provided symmetrically for ease of manufacture. It is desirable. The distance from the center of the tank to the center of the member constituting the frame in the height direction is 0.6 to 0.9 times, preferably 0.7 to 0.8 times, the distance from the center of the tank to the inner wall of the tank. The shape of the spiral wings installed in the straight body section of the reaction tank is almost the same as that of the conventional spiral wings, and the width of the wings is 0.07 to 0.2 times the inner diameter of the tank, and preferably 0.08 to 0.2 times.
It is 0.15 times. Furthermore, the pitch of the spiral is
It is 0.7 to 1.5, preferably 0.9 to 1.3. The shape of the spiral band wing installed on the bottom of the reaction tank is such that it can be connected to the spiral band wing in the straight body section smoothly along the head plate while making a certain angle from the center of the tank bottom to the circumferential direction. The width of the wing is the same as that of the helical wing installed in the straight body section.

In the present invention, the method for producing the high-concentration carbonaceous solid-water slurry is as follows. Used for grinding.
The concentration of the slurry is usually 40% by weight or more, preferably 50 to 90% by weight, based on a fine powdery dry base. If it is less than 40% by weight, it is not practical in terms of economy, transportation efficiency and combustion efficiency.

In the present invention, the use amount of the carbonaceous solid-water slurry additive is not particularly limited, but in order to impart the viscoelastic properties defined in the claims to the carbonaceous solid-water slurry, 0.005 to 2% by weight, preferably 0.01 to 1% by weight, based on the carbonaceous solid weight (dry base)
Is appropriate. When an additive for a carbonaceous solid-water slurry is used, the additive may be mixed with the carbonaceous solid in advance and then slurried, or the additive is dissolved in water in advance. May be used. Of course, a predetermined amount of the additive may be mixed at a time or may be divided and used. Furthermore, due to the nature of the additive, any slurrying device may be used as long as it can slurry carbonaceous solids in water. The scope of the present invention is not limited by these addition methods and slurrying methods.

In the present invention, a chelating agent may be used in combination with the carbonaceous solid-water slurry additive, if necessary. Chelating agents include oxalic acid, malonic acid, succinic acid, lactic acid, malic acid, tartaric acid, citric acid,
Glucuronic acid, glycolic acid, diglycolic acid, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, pyrophosphoric acid, tripolyphosphoric acid, hexametaphosphoric acid, glycine, alanine, etc. and their alkali metal salts, alkaline earth metal salts, ammonium salts And amine salts. In particular, at least one selected from the group consisting of pyrophosphoric acid, tripolyphosphoric acid, hexametaphosphoric acid, glycine, alanine and the like and their alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts is preferred. The addition amount is 0.05% with respect to the carbonaceous solid.
To 3% by weight, preferably 0.1 to 2% by weight.

In the present invention, the carbonaceous solid-water slurry additive may further include a pH adjuster, a rust inhibitor,
Anticorrosives, antioxidants, defoamers, antistatic agents, solubilizers and the like can be added. Carbonaceous solid of the present invention-
When the water slurry additive is used in combination with the pH adjuster,
The pH of the carbonaceous solid-water slurry is usually 4 or more, preferably 7 to 10.

[0052]

Next, the high-concentration solid-water slurry of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, parts and% represent parts by weight and% by weight, respectively, unless otherwise specified.

(Synthesis Example 1) The reactor shown in FIG.
N · θm value at 0: 150). The reaction tank is a cylindrical vertical glass reactor having an inner diameter of 100 mm, a height of 170 mm, a capacity of 1 liter, and equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser. The width of the stirring blade is 75
mm and a height of 140 mm were used. Water 2 in the reaction tank
25 parts, the rotation speed of the stirring blade was set to 250 rpm,
The atmosphere in the reaction vessel was replaced with nitrogen under stirring, and 95 ° C. in a nitrogen atmosphere.
Until heated. Next, a mixture consisting of 71.6 parts of phenoxy polyethylene glycol monoacrylate (average number of moles of ethylene oxide 20), 251.6 parts of acrylic acid and 103 parts of water, 7.6 parts of mercaptopropionic acid as a chain transfer agent and water A mixture consisting of 53 parts and a mixture consisting of 8 parts of ammonium persulfate and 25 parts of water were each added to the reactor by a pump over 3 hours. After the addition was completed, a solution obtained by dissolving 4 parts of ammonium persulfate in 12.5 parts of water was added over 1.5 hours. After completion of the addition, the temperature was maintained at 95 ° C. for 0.5 hour to complete the polymerization reaction. Thereafter, complete neutralization was performed with an aqueous sodium hydroxide solution to obtain a copolymer (a) having a weight average molecular weight of 5000.

(Synthesis Example 2) The reactor shown in FIG.
N · θm value at 0: 35). The reaction tank is a cylindrical vertical glass reactor equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser, having an inner diameter of 100 mm, a height of 170 mm, and a capacity of 1 liter, and has two baffles inside. The stirring blade has an upper blade width of 54 mm and a height of 60 mm.
mm, fin width 8mm, fin protrusion length 15m
m, the overlapping length of the protruding fin and the lower wing is 5 mm, the intersection angle with the lower wing is 45 °, the distance from the center of the axis of the lower wing to the bending point is 20 mm, the bending angle is 45 °, the turning radius of the lower wing is 30 mm, The one having a height of 44 mm was used. The distance between the lower end of the lower blade and the tank bottom is 4 mm. Water 20 in the reaction tank
Five parts were charged, the rotation speed of the stirring blade was set to 200 rpm, the inside of the reaction vessel was replaced with nitrogen under stirring, and heated to 95 ° C. in a nitrogen atmosphere. Next, a mixture of 13.2 parts of phenoxy polyethylene glycol monoacrylate (average number of moles of ethylene oxide 30), 141.2 parts of acrylic acid and 364 parts of water, and 2,2 ′ azobis (2-
Methylpropionamidine) dihydrochloride
A mixture consisting of 1 part and 50 parts of water was pumped into the reactor over 3 hours each. After the addition was completed, a solution prepared by dissolving 0.05 parts of 2,2 ′ azobis (2-methylpropionamidine) dihydrochloride in 25 parts of water was added over 1.5 hours. After the addition is complete,
The temperature was maintained at 95 ° C. for 0.5 hour to complete the polymerization reaction. After that, complete neutralization with potassium hydroxide aqueous solution,
A copolymer (b) having a weight average molecular weight of 1,000,000 was obtained.

(Synthesis Example 3) The reactor shown in FIG.
N · θm value at 0: 45). The reaction tank is a cylindrical vertical glass reactor having an inner diameter of 100 mm, a height of 170 mm, a capacity of 1 liter, and equipped with a thermometer, a stirrer, a gas inlet tube and a reflux condenser. Spiral band width 1
0 mm, a spiral band-shaped blade pitch of 95 mm, a frame width of 8 mm, and a distance between the frames of 65 mm were used. Water 200 in the reaction tank
The reactor was charged, the rotation speed of the stirring blade was set to 170 rpm, the inside of the reaction vessel was replaced with nitrogen under stirring, and heated to 95 ° C. in a nitrogen atmosphere. Then, a mixture of 71.6 parts of stearyloxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide 25), 139.3 parts of methacrylic acid, 116.6 parts of acrylic acid and 103 parts of water, 5 parts of ammonium persulfate and A mixture of 25 parts of water was pumped into the reactor over 3 hours. After the addition was completed, a solution of 2 parts of ammonium persulfate dissolved in 12.5 parts of water was added over 1.5 hours. After completion of the addition, the temperature was maintained at 95 ° C. for 0.5 hour to complete the polymerization reaction. Thereafter, complete neutralization was performed with an aqueous ammonia solution to obtain a copolymer (c) having a weight average molecular weight of 100,000.

(Synthesis Example 4) The reaction vessel was a glass reactor having an inner diameter of 100 mm, a height of 170 mm, a capacity of 1 liter, and provided with a thermometer, a stirrer, a gas inlet tube and a reflux condenser. Three retreating blades (width: 50 mm, height: 10 mm, n · θm value at Re number: 50: 530) were used. Charge 300 parts of water into the reaction tank, and rotate the stirring blade at 3 rpm.
The reaction vessel was purged with nitrogen while stirring, and heated to 95 ° C. in a nitrogen atmosphere. Next, 13.2 parts of lauroyloxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide 15), a mixture of 139.3 parts of methacrylic acid, 116.6 parts of acrylic acid and 103 parts of water, and a chain transfer agent A mixture consisting of 3.6 parts of mercaptopropionic acid and 57 parts of water and a mixture consisting of 2 parts of ammonium persulfate and 25 parts of water were each added to the reactor by a pump over 3 hours. After the addition, 1 part of ammonium persulfate dissolved in 12.5 parts of water was further added over 1.5 hours. After completion of the addition, the temperature was maintained at 95 ° C. for 0.5 hour to complete the polymerization reaction. Thereafter, complete neutralization was performed with an aqueous sodium hydroxide solution to obtain a copolymer (d) having a weight average molecular weight of 30,000.

(Examples 1 to 4, Comparative Example 1) High-concentration coal
Water slurry is manufactured using a stainless steel ball mill as shown in Table 1.
A charcoal, water and each of the obtained copolymers (a) having the properties shown in
After charging a predetermined amount of (d), the slurry was pulverized while measuring the particle size of the slurry with a laser diffraction type particle size distribution meter (FRA manufactured by Nikkiso Co., Ltd.) until the amount of particles having a size of 200 mesh or less became approximately 80%. After pulverization, take out the slurry from the ball mill and use a homomixer (manufactured by Tokushu Kika Kogyo) at 5000r.
The mixture was stirred at pm for 10 minutes to obtain a high-concentration coal-water slurry. The performance of the resulting high-concentration coal-water slurry was determined by the test method of Usui, H., T. Saeki and T. Mori,
Proc, 5th Int.Conf. On Bulk Materials Strage, Han
It was evaluated by dling and Transportaition, Newcastle, 39 (1995) and the like. The evaluation results are shown in Tables 2 to 4.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

[Table 4]

[Test Method for Slurry Performance] (1) Slurry viscosity: The obtained slurry was subjected to a coaxial double cylinder rotational viscometer (RV2 manufactured by HAAKE) at room temperature at 25 ° C. and a shear rate of 100 sec ⁻¹ . Was measured for apparent viscosity.

(2) Method of measuring and analyzing dynamic viscoelasticity by stress sweep test; stress control type viscoelasticity measuring device (HAAK)
Using E100 company RS100), the obtained slurry was set in a measurement container adjusted to 25 ° C., and allowed to stand for 80 minutes.
Stress is gradually applied at a vibration frequency of 1 Hz. The relationship between the stress τ and the storage elastic modulus G ′ as shown in FIG. 1 was measured, and FIG.
The point a of the stress corresponding to the intersection of the tangent of the linear elastic region parallel to the horizontal axis and the tangent of the nonlinear region is defined as the maximum stress in the linear elastic region, and the point b of the strain corresponding to the stress is defined as the maximum stress by the method shown in The distortion was determined.

(3) Measurement and analysis method of static viscoelasticity by creep recovery test; obtained using a stress control type viscoelasticity measuring device (RS100, manufactured by HAAKE) in a measuring container adjusted to 25 ° C. After setting the slurry and allowing it to stand for 80 minutes, the creep test applies a certain amount of stress to the slurry at a moment below the yield stress and not exceeding the strain that gives the yield stress during the test. Measure as a function of time. The recovery test is performed after the creep test, and the stress applied in the creep test is set to zero at the moment, until the recoverable deformation is almost recovered. The relationship between the time t and the distortion γ as shown in FIG. 3 is obtained.
The analysis method of each constant value of the four-constant dynamic model shown in FIG. 5 is analyzed by the following procedure using the analysis method diagram and the rheological equation shown in FIG. Since the creep stress τ and the creep time t are given as test conditions in advance, the elastic modulus E3 of the Maxwell element is calculated from the initial value γ3 of the strain when the stress is applied, according to the relationship shown in Expression (7).

[0065]

(Equation 9)

Next, the strain γ1 after the recovery is obtained, and the viscosity η1 of the Maxwell element is obtained by the equation (8).

[0067]

(Equation 10)

Next, γ2, which is parallel to the change of γ1, and γ
Then, the delay time λ corresponding to 2 is obtained, and the elastic modulus E2 of the Voigt element is obtained from the relationship shown in Expression (9).

[0069]

[Equation 11]

Next, the viscosity η2 of the Voigt element can be obtained from the relationship shown in equation (10).

[0071]

(Equation 12)

[Test Method of Slurry Stability] (1) Evaluation of stability at rest;
mm, sealed in a plastic cylindrical container having a height of 150 mm, allowed to stand at room temperature for one month, and then frozen together with the container. A portion corresponding to 10% by volume of the entire slurry was cut off from the bottom of the container to reduce the concentration of the slurry. It was measured. The stability was determined by evaluating the difference from the slurry concentration at the time of preparation according to the following criteria.

◎: 1.5% or less ○: 1.5 to 2.5% Δ: 2.5 to 3.5% ×: 3.5% or more (2) Evaluation of shear stability; obtained slurry The outer cylinder radius is 55 mm, the outer cylinder height is 180 mm, the inner cylinder radius is 20 mm,
The container was sealed in a coaxial double cylindrical rotary container having an inner cylinder height of 163 mm, sealed, and subjected to shearing at room temperature at a shearing rate of 1 sec ^-1 for 5 days. The height of the sediment at the bottom of the container was measured by a rod penetration method using a test rod weighing 30 g with a brass disk having a thickness of 1 mm. The height of the sediment layer was evaluated according to the following criteria to determine the stability.

：: No sediment Δ: Sediment 1 cm or less ×: Sediment 1 cm or more

[0075]

The high-concentration solid-water slurries exhibiting the viscoelastic characteristic values of the present invention have high fluidity and excellent storage and transport stability. Therefore, the present invention can be effectively applied to various uses such as coal-water slurry, cement slurry, inorganic particle slurry, dye slurry, paint slurry, and polymer particle slurry.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram obtained in a stress sweep test of the dynamic viscoelasticity measurement method of the present invention.

FIG. 2 is an analysis method diagram of characteristic values obtained in a stress sweep test of the dynamic viscoelasticity measurement method of the present invention.

FIG. 3 is a characteristic diagram obtained by a creep recovery test of the static viscoelasticity measurement method of the present invention.

FIG. 4 is a diagram illustrating an analysis method of each constant value of a four-constant dynamic model assumed in the present invention.

FIG. 5 is a four-constant dynamic model of a viscoelastic body assumed in the present invention.

FIG. 6 is a cross-sectional view of an example of a small laboratory reactor equipped with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 7 is a cross-sectional view of an example of a small laboratory reactor equipped with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 8 is a cross-sectional view of an example of a small laboratory reactor equipped with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 9 is a cross-sectional view of an example of a tank reactor provided with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 10 is a cross-sectional view of an example of a tank-type reactor equipped with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 11 is a cross-sectional view of an example of a tank reactor provided with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 12 is a cross-sectional view of an example of a tank reactor provided with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 13 is a cross-sectional view of an example of a tank reactor provided with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

FIG. 14 is a cross-sectional view of an example of a tank-type reactor equipped with a specific stirring blade used for producing an additive capable of easily producing the slurry of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tank reactor 2 rotating shaft 3 stirring blade 4 upper stirring blade 5 fin 6 lower stirring blade 7 receding blade 8 spiral band stirring blade 9 reactant passage hole 10 frame 11 arm 12 beam 13 baffle 14 jacket 15 thermometer 16 gas introduction Pipe 17 Monomer introduction pipe 18 Initiator introduction pipe 19 Chain transfer agent etc introduction pipe 20 Reflux cooler 21 Stirrer QbQ heating bath

Claims (7)

[Claims] 1. A high-concentration solid-water slurry containing solid particles and water, wherein a maximum stress in a linear region measured at a vibration frequency of 1 Hz in a stress sweep test of a dynamic viscoelasticity measurement method of the slurry is 0.3. A high-concentration solid-water slurry having a pressure of ス ラ リ ー 10 Pa and a strain that gives a maximum stress in a linear region of 2% or more. 2. A high-concentration solid-water slurry containing solid particles and water, wherein a creep-recovery test value measured in a linear elastic region in a static viscoelasticity measurement method of a slurry is determined by a hook elasticity and a Newtonian viscosity. The elastic modulus of Maxwell elements analyzed assuming a four-constant dynamic model by
70 Pa, and the elastic modulus of the Voigt element is 3 to 7
High concentration solid-water slurry with 0 Pa. 3. The high-concentration solid-water slurry according to claim 1, wherein the solid particles are carbonaceous solid particles. 4. An n · θm-Re curve represented by a logarithmic axis shows that the stirring Reynolds number Re is 50 or less and n · θm is 4
(Meth) acrylic acid system obtained by polymerization in a reactor equipped with a stirring blade having a characteristic value of -1.2 or more, which passes through a region of not more than 00 and has an average rate of change of a curve of not less than -1.2 in that region. A method for producing a high-concentration solid-water slurry, comprising using a (co) polymer (salt). 5. A (meth) acrylic acid obtained by polymerization in a reactor provided with a stirring blade having a stirring blade having a reactant passage hole in the flat plate which is bilaterally symmetric with respect to the rotation axis and has a reactant passage hole in the flat plate. A method for producing a high-concentration solid-water slurry, comprising using a system (co) polymer (salt). 6. The upper wing is symmetrical with respect to the rotation axis and substantially in the form of a flat plate, the lower wing is rotationally symmetric with respect to the rotation axis, and the main part of the lower wing and the upper wing are in the same plane. Use a (meth) acrylic acid-based (co) polymer (salt) obtained by polymerization in a reactor equipped with a two-stage wing that has a retreat wing at the tip and the lower wing is not on the top A method for producing a highly concentrated solid-water slurry. 7. A polymer obtained by polymerization in a reactor provided with at least one pair of spiral band-like stirring blades supported by a rotating shaft provided at the center of the upper part of the reactor and a rod-like frame extending along the inner wall ( A method for producing a high-concentration solid-water slurry, comprising using a (meth) acrylic acid (co) polymer (salt).