JPH06299172A - Dispersion-stabilizing agent for aqueous slurry of coal powder - Google Patents

Abstract

PURPOSE:To provide a dispersion-stabilizing agent excellent in dispersibility and stability and enhancing the high concentration transportation and storability of the coal powder aqueous slurry by subjecting a phenylglycol, a (sulfomethylated)melamine, a phenol compound, etc., and formaldehyde, to addition-condensation. CONSTITUTION:The dispersion stabilizing agent excellent in dispersibility and stability and improving the high concentration transportation and storability of a coal powder aqueous slurry is characterized by containing a cocondensation product as an essential component, the cocondensation product being produced by subjecting (A) a phenylglycol of formula I (RO1 is 2-3C oxyalkylene; n is 1-100; R1 is 1-9C alkyl; X1 is sulfo group or its alkali metal salt) and one kind or more of (B) a (sulfomethyl group-containing) melamine compound of formula II [Y is H, CH2SO3Z (Z is alkali metal salt) and/or (C) a (sulfomethyl group- containing) urea of formula III, and (D) a phenol compound of formula IV (R2 is the same as R1; X2 is the same as X1) and formaldehyde to addition- condensation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dispersion stabilizer for an aqueous slurry of coal powder. More specifically, it relates to a dispersion stabilizer that disperses and stabilizes coal powder in water so that it can be transported by pipeline.

[0002]

2. Description of the Related Art In recent years,
The depletion of petroleum resources has re-recognized the use of coal resources that have large reserves and are not unevenly distributed all over the world. However, in the case of coal, unlike oil, it is a solid and cannot be transported by pipeline, which is a significant disadvantage in handling. Under these circumstances, various methods have been studied for pulverizing coal, dispersing it in water and using it in the form of a slurry in order to improve handling defects.

However, also in this case, when the coal concentration is increased, the viscosity is remarkably increased and the fluidity is lost. This is because coal particles in the water slurry of coal powder aggregate in water, which causes an increase in viscosity and a decrease in fluidity. Further, if the coal concentration is lowered, the transportation efficiency is lowered, and further the dehydration process is expensive, which is not practical.

As a countermeasure against this, various dispersants are used. This is because, by adding a dispersant that is a surfactant, it is known that the dispersant is adsorbed on the coal particles to loosen the coal particles into pieces and to prevent the coal particles from aggregating with each other. . However, sodium naphthalene sulfonate formaldehyde condensate (hereinafter referred to as naphthalene type), sodium polystyrene sulfonate (hereinafter referred to as polystyrene type), etc., which are used today, should be practically satisfactory in terms of dispersion stability and fluidity. It wasn't kimono.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made diligent studies to improve the dispersion stability and the fluidity, which are the drawbacks of the conventional water slurry of coal powder, and as a result, the dispersion stability and the fluidity have been improved. The present invention has been completed by finding a dispersion stabilizer having an excellent property.

That is, the present invention comprises a compound represented by the following general formula (A) and one or more compounds selected from the compounds represented by the following general formulas (B) to (D). The present invention relates to a dispersion stabilizer for an aqueous slurry of coal powder, which contains a co-condensate which is addition-condensed with formaldehyde as an essential component.

[0007]

[Chemical 2]

(Wherein RO _{1 is an} oxyalkylene group having 2 to 3 carbon atoms n; an integer of _{1 to} 100 R ₁ and R ₂ ; H or an alkyl group having 1 to 9 carbon atoms, X ₁ and X ₂ ; H and sulfone. Group or its alkali metal salt Y; H or CH ₂ SO ₃ Z (Z is an alkali metal salt), provided that Y
At least two of these are H. ) The formaldehyde co-condensate in the present invention has a three-dimensional molecular structure, which is adsorbed on coal particles to enhance the steric repulsive force, thereby improving the fluidity and dispersion stability, and moreover the oxy group in the structure. It is presumed that these effects are enhanced by the alkylene group having a graft structure.

The compound represented by the general formula (A) used in the present invention is obtained by adding 1 to 100 mol of ethylene oxide or propylene oxide to phenol or alkylphenol, or its sulfonic acid or its sulfonic acid alkali metal. It is salt.

Examples of the metal salt include sodium, potassium and lithium. As the alkyl group, methyl,
1 carbon atom such as ethyl, propyl, isopropyl and nonyl
~ 9 straight or branched chain alkyl groups are used.

The number of moles of alkylene oxide added to the compound represented by the general formula (A) is in the range of 1 to 100 on average, and the fluidity is excellent in this range. When it is 100 or more, cocondensation becomes difficult.

The compound represented by the general formula (B) is melamine or a sulfomethyl group-containing melamine. The compound represented by the general formula (C) is urea or a sulfomethyl group-containing urea. In the present invention, the general formulas (B) and (C)
Either one or both of the compounds represented by In the present invention, it is preferable that the compound represented by the general formula (B) and / or (C) is essential.

Of the compounds represented by the general formulas (B) and (C), the compound having a sulfomethyl group can be obtained by introducing a sulfomethyl group into the corresponding raw material. It may be carried out at the stage of, or may be carried out to the resulting co-condensate.

The method of introducing a sulfomethyl group into melamine can be obtained by a known method, that is, by adding and condensing formaldehyde into melamine to introduce a methylol group, and then replacing the hydroxyl group with a sulfonating agent. There are 6 possible bonding sites, but at least 2 of them are considered to be used for forming the cocondensate according to the present invention. Therefore, it is possible to introduce sulfomethyl groups within 4 sites per melamine. The invention does not exclude either case.

The same applies to the case of urea, and an introduction product having 1 to 2 sulfomethyl groups per urea is used.

As the sulfonating agent, known sulfonating agents such as sodium sulfite, sodium pyrosulfite, sodium hydrogen sulfite and the like are used.

The compound represented by the general formula (D) is phenol or alkylphenol, or its sulfonic acid or its alkali metal salt.

Examples of the metal salt include sodium, potassium and lithium. As the alkyl group, methyl,
1 carbon atom such as ethyl, propyl, isopropyl and nonyl
~ 9 straight or branched chain alkyl groups are used.

The formaldehyde used to produce these formaldehyde addition cocondensates preferably uses formalin at a concentration of 30-40% by weight in its aqueous solution. The amount of formaldehyde used is appropriately 1 to 3 times the total moles of the compounds represented by formulas (A) to (D), which are monomers.

The formaldehyde addition co-condensation reaction is carried out in the range of pH 4 to 11 in the weak acid region to the basic region, such as phenyl glycol (or sodium phenyl glycol sulfonate), (sulfomethyl group-containing) melamine and / or Or (containing a sulfomethyl group) urea,
And phenol (or phenol sulfonic acid) formalin dripping reaction, or phenyl glycol (or sodium phenyl glycol sulfonate) and phenol are added in advance with methylol (sulfomethyl group containing) melamine and / or (sulfomethyl group containing) urea There is no particular limitation.

The formaldehyde addition cocondensate in the present invention is a compound represented by the general formula (A) and a general formula (B).
The inclusion of one or more compounds selected from the compounds represented by (D) to (D) exhibits dispersibility that cannot be exhibited by conventional coal dispersants. In particular, the constitutional molar ratio of the compound is (A): [(B) + (C)] = 0.1 to 1.0
: 0.1 to 1.0, or (A): [(B) + (C)]:
(D) = 0.1 to 1.0: 0.1 to 1.0: The range of 0.1 to 1.0 shows excellent effects.

The standard method for producing the formaldehyde addition cocondensate in the present invention is shown below, but the present invention is not limited thereto. Predetermined amount of phenyl glycol, (containing sulfomethyl group) melamine and / or
(Sulfomethyl group-containing) Urea, sodium phenolsulfonate and water were weighed and adjusted to pH (7 to 8.5) and solid content concentration, then charged to a reaction vessel, and 1% of 37% formalin water was added at 80 to 90 ° C. Add dropwise over 3 hours. After the dropping, the dispersion stabilizer of the present invention can be obtained by stirring under reflux for 3 to 30 hours and cooling.

The average molecular weight of the cocondensate of the present invention is preferably 3,000 to 50,000, more preferably 10,000 to 30,000. (The average molecular weight is calculated by gel permeation chromatography / molecular weight conversion based on sodium polystyrene sulfonate.) If the average molecular weight is less than 3,000 or more than 50,000, the fluidity is poor.

The amount of the dispersion stabilizer of the present invention added to coal is preferably 0.05 to 3.0% by weight based on the solid content of coal.
0.5 to 1.0% by weight is more preferable.

[0025]

EXAMPLES The present invention will be specifically described below, but the present invention is not limited to these examples. In addition,% in the following examples is% by weight.

The average molecular weight of the condensate or co-condensate shown in the examples is obtained from the molecular weight by gel permeation chromatography / sodium polystyrene sulfonate conversion.

Preparation Example of Cocondensate (1) Phenyl glycol, sulfomethyl group-containing melamine (1 mol of melamine skeleton is a sulfomethylation reaction product) and sodium phenolsulfonate are charged in a reaction vessel equipped with a stirrer in a predetermined amount, and 1N The solution is adjusted to pH 8.0 and the solid content concentration is adjusted to 45% by weight by adding sodium hydroxide aqueous solution and water. Then, the adjusted solution is heated to 85 ° C., 37% formalin is added with stirring, and the reaction mixture is stirred under reflux for 3 to 30 hours. Then, the mixture is cooled to 30 ° C. and water is added to adjust it to 25% by weight to obtain the dispersion stabilizer of the present invention. Table 1 below shows the content of the cocondensate of the present invention produced according to Production Example (1). The contents of the phenyl glycol used (number of moles of ethylene oxide added) are shown below. Further, the number of moles of formalin in the table is the number of moles as formaldehyde (the same applies to the production examples below).

Symbols and contents of phenyl glycol used in Production Example (1) PG-1; phenyl glycol ethylene oxide addition average number of moles = 1.2 PG-2; phenyl glycol ethylene oxide addition average number of moles = 5.1 PG-3; phenyl Glycol ethylene oxide addition average number of moles = 20.5 PG-4; phenyl glycol ethylene oxide addition average number of moles = 92.3 PG-5; sodium phenyl glycol sulfonate ethylene oxide addition average number of moles = 5.1 PG-6; methylphenylglycol ethylene oxide addition Average number of moles = 5.1 PG-7; Nonylphenylglycol ethylene oxide addition average number of moles = 5.1

[0029]

[Table 1]

Production Example of Cocondensate (2) Phenyl glycol (PG-2) in a reaction vessel equipped with a stirrer,
Melamine, sulfomethyl group-containing urea (1 mol of the urea skeleton is a sulfomethylation reaction product) and sodium phenolsulfonate were charged in a predetermined amount, and 1N sodium hydroxide aqueous solution and water were added to bring the solution to pH 8.0. Adjust the solids concentration to 45% by weight. Next, prepare this solution 85
The temperature is raised to ℃, 37% formalin is added with stirring, and the reaction mixture is stirred under reflux for 3 to 30 hours. Then, the mixture is cooled to 30 ° C. and water is added to adjust it to 25% by weight to obtain the dispersion stabilizer of the present invention. Table 2 below shows the content of the cocondensate of the present invention produced according to Production Example (2). The content of the phenyl glycol used (number of moles of ethylene oxide added) is the same as in Production Example (1).

[0031]

[Table 2]

Preparation Example of Cocondensate (3) Sodium phenylglycolsulfonate (PG-5) and sulfomethyl group-containing melamine (3 mol of methylol addition, 1 mol of which is a sulfomethylation reaction product) and methyl in a reaction vessel equipped with a stirrer. Charge phenol in a specified amount and add 1N aqueous sodium hydroxide solution and water to adjust the pH to 8.0.
Then, the solid content concentration is adjusted to 45% by weight. Then, the adjusted solution is heated to 85 ° C., 37% formalin is added with stirring, and the reaction mixture is stirred under reflux for 3 to 30 hours. Then, the mixture is cooled to 30 ° C. and water is added to adjust it to 25% by weight to obtain the dispersion stabilizer of the present invention. Hereinafter, Production Example (3)
Table 3 shows the content of the cocondensate of the present invention produced according to the above. The content of the phenyl glycol used (number of moles of ethylene oxide added) is the same as in Production Example (1).

[0033]

[Table 3]

Preparation Example of Cocondensate (4) A reaction vessel equipped with a stirrer was charged with sodium phenylglycolsulfonate (PG-5), melamine and sodium phenolsulfonate in predetermined amounts, and 1N aqueous sodium hydroxide solution and water were added. In addition, the solution is adjusted to pH 8.0 and the solid content concentration is adjusted to 45% by weight. Then, the adjusted solution is heated to 85 ° C., 37% formalin is added with stirring, and the reaction mixture is stirred under reflux for 3 to 30 hours. Then, the mixture is cooled to 30 ° C. and water is added to adjust it to 25% by weight to obtain the dispersion stabilizer of the present invention. Table 4 below shows the content of the cocondensate of the present invention produced according to Production Example (4). Contents of phenyl glycol used (number of moles of ethylene oxide added)
Is the same as in Production Example (1).

[0035]

[Table 4]

The comparative dispersants used in the examples and their symbols are shown below. Reference symbol NS in the Examples: naphthalene-based dispersant (Mighty 150
Manufactured by Kao Corporation, symbol PS in the examples; polystyrene-based dispersant (molecular weight 860
0).

The production examples (1) to (4) are as follows.
Performance tests of the dispersion stabilizer and the comparative dispersant obtained in (3) were conducted.

Preparation of Coal Powder Water Slurry A 5 liter magnetic ball mill (inner diameter 20 cm) was filled with 30% stainless steel balls, and 660 g of coal and water (including dispersion stabilizer).
Put 340g, 80 mesh for 200 mesh (74μm) or less at 50rpm
Grinded to 81%. After crushing, the slurry was extracted from the ball mill and stirred at 4000 rpm for 10 minutes using a TK Auto Homo Mixer (made by Tokushu Kika Kogyo).

Evaluation of fluidity The water slurry of the coal powder obtained by the above-mentioned preparation method is brought to a predetermined temperature, and shear stress is applied up to a maximum shearing rate of 150 sec ^-1 with a Haake Rheometer (measuring head; MK-500, rotor MV2P). The viscosity was measured and the apparent viscosity was calculated from the shear stress at 100 sec ⁻¹ to obtain the slurry viscosity.

Evaluation of Stability A slurry of coal powder in water was allowed to stand for 30 days, and then a stainless rod having a diameter of 5 mm (weight: 50 g) was gently put into the slurry, and its sedimentation state was observed. ◯: Good stability (no coal consolidation) X: Poor stability (coal consolidation was high) Table 5 shows the measurement results.

[0041]

[Table 5]

[0042]

EFFECT OF THE INVENTION The dispersion stabilizer for water slurry of coal powder of the present invention exhibits excellent dispersibility as is clear from the results of Examples. Therefore, it is possible to transport the slurry at a high concentration, and further, it is possible to improve the storability because it is excellent in long-term stability.

Claims (4)

[Claims] 1. Addition condensation of a compound represented by the following general formula (A) and one or more compounds selected from compounds represented by the following general formulas (B) to (D) with formaldehyde. A dispersion stabilizer for an aqueous slurry of coal powder containing the co-condensate thus obtained as an essential component. [Chemical 1] (In the formula, RO ₁ ; an oxyalkylene group having 2 to 3 carbon atoms n; an integer _{1 to} 100, R ₁ and R ₂ ; H or an alkyl group having 1 to 9 carbon atoms, X ₁ and X ₂ ; Alkali metal salt Y; H or CH ₂ SO ₃ Z (Z is an alkali metal salt), provided that Y
At least two of these are H. ) 2. A compound represented by the general formula (B) and / or (C) is essential as at least one compound selected from the compounds represented by the general formulas (B) to (D). The dispersion stabilizer for an aqueous slurry of coal powder according to claim 1. 3. General formulas (A), (B) and / or (C)
The constituent molar ratio of the compound represented by (A): [(B) +
(C)] = 0.1-1.0: 0.1-1.0 The dispersion stabilizer for an aqueous slurry of coal powder according to claim 1 or 2. 4. The constitutional molar ratio of the compounds represented by formulas (A), (B) and / or (C), (D) is (A): [(B) + (C)] :( D ) = 0.1 to 1.0:
0.1 to 1.0: 0.1 to 1.0, any one of claims 1 to 3.
Item 6. A dispersion stabilizer for an aqueous slurry of coal powder according to the item.