JPH0445554B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a dispersant used in an aqueous slurry of carbonaceous fine powder such as coal or petroleum coke. BACKGROUND ART In recent years, the use of coal has been attracting attention from the viewpoint of soaring oil prices and diversification of energy resources. Since coal is a solid fuel and is difficult to handle, it has been proposed to pulverize it into a water slurry. By turning solid fuels such as coal or petroleum coke into a water slurry, it becomes possible to transport them through pipes and handle them in the same way as liquid fuels. The water slurry needs to be burned as it is in a boiler or the like without being dehydrated, or it needs to be highly concentrated from the viewpoint of transportation efficiency. However, it is difficult to obtain a slurry with a high concentration of 50% or more by simply dispersing carbonaceous fine powder such as coal or petroleum coke in water, and if left standing, the carbonaceous fine powder will settle. It becomes non-uniform and there is also a problem in terms of storage stability. Therefore, it has been proposed to add a dispersion stabilizer to the slurry to increase the concentration and improve the dispersion stability. Such dispersion stabilizers include:
For example, naphthalene sulfonic acid formalin condensate (JP 56-21636), copolymer of acrylic acid or methacrylic acid with other vinyl monomers (JP 56-57890), acrylic acid and maleic acid. (Japanese Patent Application Laid-Open No. 56-57890), crosslinked polyether compounds obtained by crosslinking alkylene oxide adducts of compounds having active hydrogen groups in the molecule (Japanese Patent Application Laid-Open No. 118893/1982), sulfonated Coal tar or formaldehyde condensate
23889), water-soluble aromatic polymers such as salts of copolymers of styrene sulfonic acid and vinyl compounds, and water-soluble aromatic polymers such as copolymers of α-olefin with maleic anhydride, acrylic acid, etc. An additive containing a fatty polymer has been reported (Japanese Unexamined Patent Publication No. 166591/1983). However, although these conventional dispersants have been shown to have a corresponding effect, they are still insufficient in terms of increasing the concentration of slurry and static stability, and improvements have not yet been made. Purpose of the Invention The present invention provides that when carbonaceous fine powder is added to an aqueous slurry, it is possible to achieve a high concentration by reducing the viscosity of the slurry and improving fluidity, and furthermore, it has stable stability over a long period of time. The purpose of the present invention is to provide a dispersant that provides the following. Structure of the Invention The dispersant for water slurry of carbonaceous fine powder of the present invention is characterized by containing the following components (A) and (B). Component (A): One or more sulfonic acid group-containing aromatic hydrocarbon polymers selected from the following polymers (A ¹ ) and (A ² ) (A ¹ ): (a) A polymer obtained by polymerizing one or more monomers selected from the group of polymerizable aromatic sulfonic acid monomers and (b) the group of polymerizable hydrocarbon monomers, said (a)
A polymer containing the following components as essential components. (A ² ): A polymer obtained by polymerizing one or more monomers selected from the group of polymerizable hydrocarbon monomers, which contains at least one polymerizable aromatic monomer as an essential component. Polymer (B) component obtained by sulfonating the containing polymer: Polymer of polymerizable aliphatic unsaturated sulfonic acid monomer The present invention will be described in more detail below. The polymer of component (A) contains an aromatic hydrocarbon containing a sulfonic acid group in the molecule as a structural unit. The polymer (A ¹ ) is one in which the sulfonic acid group is derived from a monomer, that is, one in which an aromatic hydrocarbon monomer containing a sulfonic acid group is polymerized alone or together with other monomers. On the other hand, the polymer (A ¹ ) is obtained by polymerizing monomers to obtain a polymer, and then introducing sulfonic acid groups into the aromatic groups in the polymer. The polymer (A ¹ ) is a polymer consisting of one or more monomers selected from the following groups (a) and (b), and includes at least a structural unit derived from the monomers of group (a). This includes: (a) Polymerizable aromatic sulfonic acid monomer (b) Polymerizable hydrocarbon monomer The proportion of the aromatic sulfonic acid monomer of group (a) in the polymer of (A ¹ ) is 40 to 100 mol%. is preferable, and more preferably 50 to 100 mol%. In this way, without using the monomers of group (b), only the aromatic sulfonic acid monomers of group (a) can be used.
It is also possible to constitute a polymer of (A ¹ ). Specific examples of group (a) monomers include styrene sulfonic acid, α-methylstyrene sulfonic acid, vinyltoluenesulfonic acid, vinylnaphthalenesulfonic acid, or salts thereof. Counterions that form salts include monovalent metals such as sodium and potassium, and divalent metals such as magnesium and calcium.
Examples include valent metals, trivalent metals such as aluminum, ammonium, and organic amines, and among these, sodium, potassium, and ammonium are preferred. Specific examples of group (b) monomers include styrene, α
-methylstyrene, vinyltoluene, ethylene,
Examples include butene, butadiene, and diisobutylene. Copolymers of group (a) monomers and group (b) monomers include styrene sulfonic acid/styrene copolymers,
Examples include styrenesulfonic acid/butadiene copolymer, styrenesulfonic acid/butene copolymer, α-methylstyrenesulfonic acid/ethylene copolymer, and α-methylstyrenesulfonic acid/diisobutylene copolymer. The weight average molecular weight of the polymer (A ¹ ) is suitably 700 to 700,000, preferably 1000 to 500,000. The polymer (A ² ) is a sulfonated product of at least one type of hydrocarbon monomer and includes at least one aromatic monomer as an essential component, or a salt thereof. Examples of aromatic monomers include styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, and indene. Examples of non-aromatic hydrocarbon monomers include ethylene, butene, butadiene, and diisobutylene. Can be mentioned. The appropriate proportion of aromatic monomers in the polymer of these monomers is 30 to 100 mol%,
Preferably it is 50 to 100 mol%. Specific examples of this polymer include petroleum resins such as polystyrene, styrene/ethylene copolymer, styrene/diisobutylene copolymer, and styrene/vinyltoluene/α-methylstyrene/indene copolymer. By sulfonating such a polymer or further converting it into a salt, the polymer (A ² ) can be obtained. Sulfonation can be carried out by applying any sulfonation method using a sulfonating agent such as sulfuric anhydride, chlorosulfonic acid, or a sulfuric anhydride/Lewis base complex. The weight average molecular weight of the polymer (A ² ) is suitably 700 to 700,000, preferably 1000 to 500,000. Examples of the salt of the polymer (A ² ) include the same salts as the polymer (A ¹ ). The sulfonic acid group-containing aromatic hydrocarbon polymer of component (A) can also be used by mixing the polymer of (A ¹ ) and the polymer of (A ² ) in any ratio. The polymer of component (B), a polymerizable aliphatic unsaturated sulfonic acid monomer, has a molecular weight of 700 to 200,000, preferably 1,000 to 100,000. Specific examples of this monomer include olefin sulfonic acids such as allylsulfonic acid and methallylsulfonic acid, unsaturated monocarboxylic acids containing sulfonic acid groups such as 2-sulfoethyl acrylate, 2-sulfoethyl methacrylate, and 3-sulfopropyl acrylate. acid ester, unsaturated monocarboxylic acid amide containing a sulfonic acid group such as 2-acrylamidoethanesulfonic acid, 2-acrylamidoethanesulfonic acid, allyloxyethanesulfonic acid,
Included are sulfonic acid-containing allyl ethers such as allyloxypropanesulfonic acid and salts thereof. The counter ion constituting the salt of aliphatic unsaturated sulfonic acid is the same as the counter ion in component (A). The composition of component (A) and component (B) is the weight ratio of component (A)/(B).
A suitable range of components is 1/9 to 20/1, preferably 1/5 to 15/1. If this ratio is less than 1/9, dispersibility will deteriorate, and 15/
If it is larger than 1, the static stability will be poor. For component (A) or component (B) of the present invention, a crosslinking agent may be used during polymerization, and examples of the crosslinking agent include divinylbenzene, methylene bisacrylamide, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, Examples include trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, and diallyl phthalate. In both components (A) and (B), it is appropriate to use the crosslinking agent in an amount of 0 to 5 mol%, preferably 0.01 to 3 mol%. If the amount of the crosslinking agent is too large, the water solubility will decrease, which is not preferable. The dispersant of the present invention is suitably added to the aqueous slurry of carbonaceous fine powder in an amount of 0.05 to 3% by weight, preferably 0.1 to 2% by weight. Examples of carbonaceous fine powder include coals such as anthracite, bituminous coal, subbituminous coal, and lignite; petroleum coke, carbon black by-produced from chemical plants, carbon black obtained by carbonizing organic matter, and charcoal used as energy sources. is used. In addition, it is preferable to clean coal containing a large amount of ash by deashing and desulfurizing it by flotation, oil agglomeration, or the like. These carbonaceous materials are pulverized so that they do not substantially contain anything larger than 1 mm, but in consideration of combustibility as a fuel, it is preferable that the content of carbon particles below 74 μm is 50% by weight or more. Preferably it is 60 to 100% by weight. A water slurry of carbonaceous fine powder can be obtained by pulverizing carbonaceous material into a water slurry using a dry pulverization method or a wet pulverization method, and the dispersant is added in an appropriate step so as to be included in the final water slurry. Can be added. For example, when carbonaceous fine powder is obtained by dry pulverization, a dispersant may be dissolved or dispersed in water, the fine powder may be added thereto, and a highly concentrated water slurry may be prepared using an appropriate mixing device. In addition, when adopting a wet pulverization method, a dispersant may be added in advance to the water used for wet pulverization, or
It may be added during or after wet milling. Although the concentration of carbonaceous fine powder in the water slurry depends on the type of fine powder, average particle size, particle size distribution, etc., it can be sufficiently increased by adding the dispersant of the present invention, for example, 80% by weight. It is possible to some extent. Effects of the Invention According to the dispersant of the present invention, carbonaceous The fluidity and static stability of the fine powder water slurry can be mutually improved. Therefore, a water slurry with a higher concentration than before can be obtained and can be stored stably for a long period of time. The carbonaceous fine powder water slurry to which the stabilizer of the present invention has been added can be used not only as a boiler fuel for electric power and general industries, but also as a combustion improver to reduce coke used in blast furnaces and metallurgical furnaces in the steel manufacturing field. is also useful. Example A predetermined dispersant was dissolved in water, and carbonaceous fine powder was added little by little at room temperature to a predetermined amount (dry basis). After adding the entire amount, the mixture was stirred for 10 minutes at 3000 rpm using a homo mixer (manufactured by Tokushu Kika Kogyo) to prepare approximately 500 g of highly concentrated water slurry. Next, the fluidity and static stability of this slurry were evaluated. (1) Fluidity Viscosity was measured at 25°C. ○: Good △: Insufficient ×: Poor (2) Static stability Pour the entire slurry into a 500 ml cylinder with an inner diameter of 6 cm, and insert a glass rod with a diameter of 5 mm, a length of 40 cm, and a weight of 50 g from the surface of the slurry. The time required for the rod to reach the bottom of the cylinder was measured twice, immediately after preparation and after being left at room temperature for one month, to determine the rod penetration time. The maximum measurement time is 180 seconds, and if it takes longer than that, the height from the bottom at this time,
It was measured as the height of the consolidated layer. ○: Good ×: Poor Table 1 shows the particle size distribution of the carbonaceous fine powder used for preparing the water slurry, and Table 2 shows the analysis values of the coal. The properties of component (A) of the dispersant of the present invention are shown in Table 3, and the properties of component (B) are shown in Table 4. Table 5 shows the measurement results of the water slurry using the dispersant of the present invention containing component (A) and component (B). In addition, Table 6 shows, as comparative examples, those without the addition of a dispersant (Experiment No. 65), those using component (A) or (B) of the present invention alone (Experiment No. 66, 67), Measurement results for representative examples of known dispersants (Experiment Nos. 68 to 70) are shown.

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Claims (1)

[Scope of Claims] 1 (A): One or more sulfonic acid group-containing aromatic hydrocarbon polymers selected from the following polymers (A ¹ ) and (A ² ) (A ¹ ): A polymer obtained by polymerizing one or more monomers selected from (a) a group of polymerizable aromatic sulfonic acid monomers and (b) a group of polymerizable hydrocarbon monomers. The above (a)
A polymer containing the following components as essential components. (A ² ): A polymer obtained by polymerizing one or more monomers selected from the group of polymerizable hydrocarbon monomers, which contains at least one polymerizable aromatic monomer as an essential component. 1. A dispersant for an aqueous slurry of carbonaceous fine powder, comprising: a polymer obtained by sulfonating a polymer containing the same; and (B): a polymer of a polymerizable aliphatic unsaturated sulfonic acid monomer.