JPH0832900B2 - Additive for water slurry of carbonaceous fine powder - Google Patents

Description

TECHNICAL FIELD The present invention relates to an additive used for an aqueous slurry of carbonaceous fine powder represented by coal or petroleum coke.

2. Description of the Related Art Utilization of coal has been drawing attention in recent years from the viewpoint of soaring oil prices and diversification of energy resources. Since coal is a solid fuel and has a difficulty in handling, it has been proposed to pulverize it into an aqueous slurry. By making solid fuel such as coal or petroleum coke into water slurry, pipe transportation becomes possible and it can be handled in the same way as liquid fuel, but it is necessary to raise the rate of rise in order to improve transportation efficiency. . However, it is difficult to obtain a high-concentration slurry of 50% or more simply by dispersing carbonaceous fine powder such as coal or petroleum coke in water as it is, and if left standing, the carbonaceous fine powder will settle out. There is also a problem in storage stability.

Therefore, it has been proposed to add a dispersion stabilizer to the slurry to improve the concentration and improve the dispersion stability. Examples of such additives include polystyrene sulfonate (JP-A-62-590), a polyether compound obtained by adding ethylene oxide to a compound having one or more active hydrogen atoms in the molecule, or a derivative thereof. Two-component system of styrene sulfone powder / styrene copolymer (JP-A-60-250096), two-component system of amphoteric surfactant and naphthalene sulfonate formalin condensate or lignin sulfonate (JP-A-60-250096). 59-500520) and the like are known.

However, although these conventional additives are found to have a corresponding effect, they are still insufficient in terms of both the high concentration of the slurry and the stability upon standing, and further improvements have been made.

OBJECT OF THE INVENTION The present invention provides an additive which, when added to an aqueous slurry of carbonaceous fine powder, can achieve a high concentration of the slurry, and further, share resistance, and stability upon standing for a long period of time. Is.

Constitution of the Invention The additive for a water slurry of carbonaceous fine powder of the present invention is characterized by using the following components (A) and (B) together.

(A): One or more sulfonic acid group-containing aromatic hydrocarbon polymers or salts thereof selected from the following polymers (A ¹ ) and (A ² ).

(A ¹ ) A polymer obtained by polymerizing one or more monomers selected from the group of (a) polymerizable aromatic sulfonic acid-based monomers and (b) polymerizable hydrocarbon-based monomers. And a polymer containing the group (a) monomer as an essential component.

(A ² ) 1 selected from the group of polymerizable hydrocarbon monomers
A polymer obtained by polymerizing one or more monomers, which is obtained by sulfonation of a polymer containing at least one polymerizable aromatic monomer as an essential component.

(B): Amphoteric surfactant.

The polymer of the component (A) of the present invention contains an aromatic hydrocarbon containing a sulfonic acid group in its molecule as a constituent unit. Then, a polymer in which the sulfonic acid group is derived from a monomer, that is, a polymer obtained by polymerizing an aromatic hydrocarbon monomer containing a sulfonic acid group alone or together with another monomer is the polymer (A ¹ ). On the other hand, a polymer of (A ² ) is obtained by polymerizing a monomer to obtain a polymer and then introducing a sulfonic acid group into an aromatic group in the polymer.

The polymer of (A ¹ ) is a polymer composed of at least one monomer selected from the following (a) group and (b) group, and is a structural unit derived from at least a (a) group monomer: Is included.

(A) Polymerizable aromatic sulfonic acid-based monomer (b) Polymerizable hydrocarbon-based monomer The proportion of the aromatic sulfonic acid-based monomer of group (a) in the polymer of (A ¹ ) is 40 to 100 mol%. Is preferable, and more preferably 50 to 100 mol%. As described above, the polymer of (A ¹ ) can be composed only of the aromatic sulfonic acid type monomer of the group (a) without using the monomer of the group (b).

Specific examples of the (a) group monomer include styrenesulfonic acid, α-methylstyrenesulfonic acid, vinyltoluenesulfonic acid, and vinylnaphthalenesulfonic acid.

Specific examples of the (b) group monomer include styrene and α-
Methylstyrene, vinyltoluene, ethylene, butene,
Examples thereof include butadiene, diisobutylene, cyclopentadiene and dicyclopentadiene.

As the copolymer of the (a) group monomer and the (b) group monomer, styrene sulfonic acid / styrene copolymer, styrene sulfonic acid / butadiene copolymer, styrene sulfonic acid / butene copolymer, α-methylstyrene Sulfonic acid / ethylene copolymer, α-methylstyrene sulfonic acid /
A diisobutylene copolymer is illustrated.

The polymer (A ² ) is a sulfonated polymer of at least one kind of hydrocarbon monomer, which contains at least one kind of aromatic monomer as an essential component.
Or its salt. As this aromatic monomer,
Styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, indene and the like, and as the hydrocarbon monomer other than aromatic, ethylene, butene, butadiene, diisobutylene, cyclopentadiene, dicyclopentadiene. To be The ratio of aromatic monomers in the polymer of these monomers is 30 to 10
0 mol% is suitable, preferably 50 to 100 mol%. Specific examples of this polymer include polystyrene, styrene / ethylene copolymer, styrene / diisobutylene copolymer, styrene / dicyclopentadiene copolymer, styrene / vinyltoluene / α-methylstyrene / indene copolymer. Such petroleum resins can be mentioned. The polymer of (A ² ) can be obtained by sulfonating such a polymer or further converting it into a salt. The sulfonation can be carried out by using a sulfonating agent such as sulfuric anhydride, chlorosulfonic acid, sulfuric anhydride / Lewis base complex, etc. and applying an arbitrary sulfonation method.

The molecular weight of the sulfonic acid group-containing aromatic hydrocarbon polymer as the component (A) is preferably 1,000 to 200,000 in terms of weight average molecular weight.

In the polymer of (A ¹ ) or (A ² ) of the present invention, a crosslinking agent can be used during the polymerization, and as the crosslinking agent, divinylbenzene, methylenebisacrylamide, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol. Examples thereof include dimethacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate and diallyl phthalate. In both cases of the (A ¹ ) and (A ² ) polymers, it is appropriate to use the crosslinking agent in an amount of 0 to 5 mol%, preferably 0.01 to 3 mol%. If the blending amount of the cross-linking agent is too large, the water solubility decreases, which is not preferable.

In the additive of the present invention, these sulfonic acid group-containing aromatic hydrocarbon polymers are used in the form of free acid or salt.

As the salt in the component (A), as a monovalent salt, an alkali metal salt such as lithium, sodium and potassium, an ammonium salt, or monoethanolamine, diethanolamine, triethanolamine, morpholine, ethylamine, butylamine, coconut oil amine, beef tallow. Organic amine salts such as amines; divalent salts such as calcium, magnesium, barium and other alkaline earth metal salts, organic amine salts such as ethylenediamine and hexamethylenediamine salts; trivalent salts such as aluminum salts and diethyltriamine Organic amine salts; or polyvalent organic amine salts such as polyethyleneimine.

Although the sulfonic acid group-containing aromatic hydrocarbon-based polymer of the component (A) alone is added as an additive, although the concentration of the carbonaceous fine powder water slurry can be increased to some extent,
It is still insufficient.

As the component (B), one or more amphoteric surfactants are used.

The amphoteric surfactant as the component (B) is a betaine type,
Examples of the amphoteric surfactant include glycine type, alanine type, sulfobetaine type, and imidazoline type, and typical structural examples thereof are as follows. Generally, lecithin and the like are well known.

(1) Betaine type amphoteric surfactant (For example, R ₁ , R ₂ = short-chain alkyl such as methyl group, R ₃ =
Long-chain alkyl group) (2) Glycine-type amphoteric surfactant [For _{example, R 6 NH-CH 2 -CH} 2 2 NH-CH 2 -COOH, (R 6 is an alkyl _{group) (C 8 H 17 -NH-} CH 2 -CH 2 2 N-CH 2 -COOH ] (3 ) Alanine-type amphoteric surfactant (For example, R ₇ = long-chain alkyl, R ₈ = H) (4) Sulfobetaine-type amphoteric surfactant (For example, R ₃ , R ₁₁ = H, R ₁₀ = long-chain alkyl, n = 2) (5) Imidazoline-type amphoteric surfactant (R = long-chain alkyl group) When the component (B) is used alone as an additive, it is difficult to increase the concentration of the carbonaceous fine powder water slurry, and
Inferior share resistance. Such a slurry is not preferable because it is viscous during transfer by pumping and the fluidity deteriorates.

The sulfonic acid group-containing polymer as the component (A) and the amphoteric surfactant as the component (B) may form a complex when the two components are mixed in a high concentration state in advance. In that case, it is preferable to separately add each component separately to the carbonaceous fine powder water slurry, preferably, first, the amphoteric surfactant of the component (B) is added, and then the sulfonic acid group of the component (A) is added. Add the containing polymer. Further, when both components are mixed and dissolved, they may be added as a mixture or may be dividedly added as described above.

The additive of the present invention contains 0.05 to 3% by weight of component (A), preferably 0.1 to 2% by weight, and 0.001 to 2% by weight of component (B), and preferably 0.005 to 10% by weight, in an aqueous slurry of carbonaceous fine powder.
It is suitable to add it so as to be included in the range of 1.5% by weight.

Further, the combined ratio of both components (A) and (B) is preferably (A) / (B) = 99/1 to 50/50 in weight ratio, which makes it possible to increase the carbonaceous fine powder water slurry. Concentration and stability can be further improved.

As carbonaceous fine powder, anthracite, bituminous coal, subbituminous coal,
Coal such as brown coal; petroleum coke, carbon black produced as a by-product from a chemical plant, carbon black obtained by carbonizing an organic matter, charcoal, and other energy sources are used.

In addition, as for coal that contains a large amount of ash, the flotation method,
It is preferable to apply an underwater granulation method (Oil Agglomeration method) or the like to carry out deashing and desulfurization treatments for cleaning. These carbonaceous materials are pulverized so that the carbonaceous material does not substantially contain 1 mm or more, but in consideration of combustibility as a fuel, the content of 74 μm or less is preferably 50% by weight or more. It is preferably 60 to 100% by weight.

Effects of the Invention According to the additive of the present invention, carbonaceous fine powder water is obtained by using (A) a sulfonic acid group-containing aromatic hydrocarbon polymer or a salt thereof and (B) an amphoteric surfactant in combination. The fluidity and stability of the slurry can be continuously improved, and the shear resistance is also excellent. Therefore, it is possible to obtain a water slurry having a higher concentration than that of the conventional one and to stably store the slurry for a long period of time.

The carbonaceous fine powder water resistant slurry to which the additive of the present invention is added is not only used as a boiler fuel for electric power and general industries, but also as a combustion improver for saving coke used in blast furnaces and metallurgical furnaces in the field of iron making. It is useful.

Example The component (B) of the additive was dissolved in water, and coal and the component (A) were added thereto little by little so that a predetermined amount (dry basis) was obtained. After the addition of the entire amount was completed, the mixture was stirred at 3,000 rpm for 10 minutes with a homomixer (made by Tokushu Kika Kogyo Co., Ltd.) to prepare about 600 g of a high-concentration water slurry.

Next, the fluidity, static stability and shear resistance of this slurry were evaluated.

(1) Fluidity Using a Brookfield viscometer, the viscosity was measured at 25 ° C (rotor No. 3,60 rotations, 1 minute later). From the obtained results, the fluidity was evaluated as follows.

◯: Good Δ: Insufficient x: Poor (2) Stability upon standing The above high-concentration water slurry (500 g) was placed in a 500 ml plastic cylinder having an inner diameter of 6 cm and stored and stored at 25 ° C. After 30 days, the cylinder was cooled to −10 ° C. to freeze the slurry, horizontally cut at a height of 2 cm from the bottom of the cylinder, and the coal concentration of the lower (lower layer) slurry was measured to determine the concentration immediately after preparation. Compared. From the obtained results, the stationary stability was evaluated as follows.

○: Good Δ: Insufficient ×: Poor (3) Shear resistance Put 500 g of the high-concentration slurry in a beaker and use a homomixer (TK Auto Homomixer, low viscosity type, manufactured by Tokushu Kika Kogyo) at 4,000 rpm. Stir for 10 minutes while circulating.

From the state of the slurry after stirring, the shear resistance was evaluated as follows.

◯: The fluidity was not changed even after the stirring, and was good. X: The fluidity was poor after the stirring or during the stirring, resulting in poor fluidity.

Table 1 shows the properties of the coal powder used to prepare the water slurry.
Table 2 shows the evaluation results of the water slurry.

Claims (1)

[Claims] 1. (A): One or more sulfonic acid group-containing aromatic hydrocarbon polymers or salts thereof selected from the following polymers (A ¹ ) and (A ² ): A ¹ ): a polymer obtained by polymerizing one or more monomers selected from the group of (a) polymerizable aromatic sulfonic acid-based monomers and (b) polymerizable hydrocarbon-based monomers. A polymer (A ² ) containing the above-mentioned (a) group monomer as an essential component: a polymer obtained by polymerizing one or more monomers selected from the group of polymerizable hydrocarbon monomers. And at least one polymerizable aromatic monomer
Polymer (B) obtained by sulfonation of a polymer contained as a seed essential component: an additive for water slurry of carbonaceous fine powder, which is used in combination with an amphoteric surfactant.