JPS61225294A - Additive for coal-water slurry - Google Patents

Abstract

PURPOSE:The titled additive capable of providing a coal-water slurry which is low in viscosity and excellent in storage stability, which comprises a polyoxyalkylene ether of a polyamide and an alkaline substance. CONSTITUTION:0.01-5wt% (based on a coal used) polyoxyalkylene ether, which has 50wt% or more oxyethylene group, a 3C or higher oxyalkylene group, a molecular weight of 45,000-800,000 and at least 900 oxyalkylene units, of a polyamide [e.g.: polyamide obtained by reacting an (alkyl)alkylenepolyamine and/or an (alkyl)alkylenediamine with a polycarboxylic acid] having at least 5 active hydrogens (A) is mixed with 0.01-2wt% (based on a coal used) alkaline substance (B) selected from hydroxides, carbonates and/or silicates of alkaline metals, hydroxides of alkaline earth metals, NH4OH and amines in an (A)/(B) weight ratio of 999-1:1-999 to obtain the titled additive.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an additive for coal-water nuraries.

[Conventional technology]

Traditionally, as an additive for highly concentrated coal-water slurries, the active hydrogen-containing compound alkylene oxide has been used as an average of 80
Additives of up to 0 mol are known, and it is said that handling is difficult when the amount exceeds 800 mol.

For certain types of coal, it has been difficult to obtain a coal-water slurry with low viscosity and good storage stability.

[Problems to be solved by the present invention]

As a result of extensive research aimed at obtaining an additive for coal-water slurry that provides a coal-water slurry with low viscosity and good storage stability regardless of the type of coal, the inventors discovered that, contrary to expectations, The present invention was achieved by discovering that the desired additive could be obtained by increasing the number of moles to 900 moles or more.

[Means to solve the problem]

The present invention is an additive for coal-water slurry characterized by containing a polyoxyalkylene ether of polyamide and an alkaline substance.

In the present invention, the polyamide in the polyoxyalkylene ether is formed by dehydration condensation of a polycarboxylic acid component (which may partially contain mono-9nocarboxylic acid) and a polyamine component (which may partially contain monoamine). Examples include polyamides in the form of

As the polycarboxylic acid component, an aliphatic group which may have an ether oxygen atom, a ketone group or/and a hydroxyl group,
Alicyclic or aromatic polycarboxylic acids (usually divalent to pentavalent, preferably divalent or trivalent) can be used. Specifically, aliphatic polycarboxylic acids [aliphatic saturated polycarboxylic acids such as oxalic acid].

Malonic acid, succinic acid, glutaric acid, adipic acid.

Glutaconic acid, etc.; aliphatic unsaturated polycarboxylic acids, evamaleic acid, fumaric acid,
0 alkenyltoe, dodecenylsuccinic acid, octadecenylsuccinic acid, ξalicyclic polycarboxylic acids (cyclopropanedicarboxylic acid, cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, etc.), aromatic polycarboxylic acids (phthalic acid, terephthalic acid, etc.) , isophthalic acid, trimellitic acid, etc.), polymerized aliphatic acids (dimer acids obtained by polymerization of unsaturated fatty acids, etc.).

Oxycarboxylic acids (malic acid, tartaric acid, sodium citrate)
, ether oxygen-containing polycarboxylic acids (such as diglycolic acid) and ketopolycarboxylic acids (acetonedicarboxylic acid,
phthalonic acid, etc.). Among these, preferred are polymerized fatty acids.

Aliphatic polycarboxylic acids and aromatic polycarboxylic acids, particularly preferred are dimer acid, oxalic acid, succinic acid, adipic acid, maleic acid, phthalic acid and terephthalic acid.

Two or more of these may be used in combination; for example, a mixture of an aliphatic polycarboxylic acid (oxalic acid, malonic acid, maleic acid, etc.) and a polymerized fatty acid (dimer acid, etc.) may be used.

Furthermore, as the polyamine component, aliphatic polyamines, aromatic polyamines, and alicyclic polyamines can be used.

The aliphatic polyamine has the general formula: [In the formula, "Melon" is an alkylene group having 2 or more carbon atoms, usually 2 to 10 carbon atoms, preferably 2 to 6 alkylene groups, or 0 or 1 to 10 carbon atoms. ] (Alki/l/) (
Poly) alkylene polyamine, and general formula (wherein R is an alkylene group having 2 or more carbon atoms, usually having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, n2.n3
is an integer of 1 or more, and n2+n3 is usually 2 to 200, preferably 2 to 100).

The (alkyl/L')(poly)alkylene polyamines represented by the general formula (i) include (alkyl)polyalkylene polyamines such as polyethylene polyamines (diethylenetriamine, pentaethylene hexamino, decaethylene undecamine, etc.), polypropylene polyamines (
Dipropylenetriamine, tripropylenetetramine,
nonapropylene decamino, etc.), polybutylene polyamines (diethylene triamine, etc.), poly(pentamethylene) polyamines [binu(pentamethylene) triamine, etc.], poly(hexamethylene) polyamines [binu(hexamethylene) triamine, etc.], ( Alk)V) Alkylene diamines such as ethylene diamine, propylene diamine, butylene diamine.

Pentamethylene diamine and hexamethylene diamine and N-alkyl substituted products of these polyamines, [N
-Hexyρ-,N-(2-ethylhexy/L/)-
, and N-nonyl-tetraethylenepentamine].

Among these, preferred are polyethylene polyamine, polypropylene polyamine and alkylene diamine, and particularly preferred are ethylene diamine,
Diethylenetriamine, triethylenetetramine, tetraethylenepentamine.

They are pentaethylene hexamino, propylene diamine and dipropylene triamine.

In general formula (2), the common alkylene group is an alkylene group having 2 to 4 carbon atoms, for example, an ethylene group.

Examples include propylene groups. Among the alkylene groups, ethylene is preferred.

A specific example of the compound represented by the general formula (2) is 8th class nitrogen-containing polyethyleneimine (trade name: Epomino, grade SP, e.g. 5P-018, manufactured by Nippon Shokubai Chemical Co., Ltd.).

Examples of the aromatic or alicyclic polyamine include the general formula % (3) or an alicyclic hydrocarbon group. n4 is an integer of 2 or more,
Usually 2 to 10, preferably 2 or 3. ] are listed.

In general formula (3), X is (R″+rrAr−
and a group represented by (R/'i ay-) (snoring is an aromatic nucleus,
Cy is an alicyclic hydrocarbon group having usually 3 to 20 carbon atoms, preferably 5 to 12 carbon atoms, and W' is usually an alicyclic hydrocarbon group having 1 to 20 carbon atoms, preferably a benzene nucleus or a naphthalene nucleus.

R'' is methyl, ethyl, n- or i-propyl, n-'-, +, s or t-butyl, hexyl,
Straight chain or branched saturated alkyl groups such as noni ~, dodecyl p; and unsaturated such as vinyl and octenyl; +': H
Examples include an X alkenyl group.

Examples of aromatic polyamines include m- or P-xylylenediamine, 2,4-92,6- or 8,4-tolylenediamine, diaminobenzene, diaminonaphthalene, diphenylmethanediamine, polymethylenepolyphenylpolyamine (aniline- Examples include formaldehyde condensates, triaminobenzene, and the like.

Examples of the alicyclic polyamine include cyclohexylene diamine, cyclohebutylene diamine, 9 dicyclohexylene methanediamine, isophorone diamine, and cyclohexyl triamine.

Among these polyamine components, preferred are aliphatic polyamines, and particularly preferred are (alkylv)
It is a polyalkylene polyamine.

Two or more of these polyamine components may be used in combination; for example, (alkyl)(poly)alkylene polyamines (ethylene diamine, pentaethylene hexamino, etc.)
and aromatic polyamines (diaminobenzene, m- or p-
xylylene diamine, etc.) may also be used.

In addition to polycarboxylic acids, and polyamines, if necessary, monocarboxylic acids as part of the acid component.

A monoamine can also be used as part of the amine component. Monocarboxylic acids include aliphatic monocarboxylic acids (acetic acid, propionic acid, hexanoic acid, lauric acid,
Stearic acid, oleic acid.

Coconut oil fatty acids, beef tallow fatty acids, 2-ethylhexanoic acid, etc.), aromatic monocarboxylic acids (benzoic acid, pheni/L'acetic acid 1β-phenipropionic acid, etc.); monoamines include aliphatic monoamines (butylamine, laurylamine, stearylamine.

oleylamine, etc.), alicyclic monoamines (cyclohexylamine, etc.), aromatic monoamines (aniline, etc.)
Examples include. Monocarboxylic acids and monoamines are
It is used within the range that provides a polyamide having 5 or more active hydrogen atoms.

It is possible to adjust the number of active hydrogens in a polyamide to 5 or more with relative freedom; for example, the number of amide synthesized from 2 moles of dimer acid and 8 moles of pentaethylene hexamine is theoretically 20, An amide synthesized from mol and 6 mol of pentaethylene hexamine can have 38 active hydrogen atoms.

The method for synthesizing polyamide is not particularly limited and may be any conventional method, and can usually be obtained by a condensation reaction between a polycarboxylic acid component and a polyamine component.

Specific manufacturing methods and examples of polyamide are described in Japanese Patent Publication No. 51-44275 and U.S. Patent No. 899281.
It is described in the specification of No. 2.

In addition, sulfur-containing polyamides manufactured using an acid component containing sulfur, an amine component containing sulfur, etc. as at least a part of the acid component and/or amine component, as described in JP-A-54-129257, You can also use

Furthermore, in place of (or together with) the polyamide in the form of condensation of a polycarboxylic acid component and a polyamine component, a lactam (such as caprolactam) made by full ring-opening polymerization (
It is also possible to use the aforementioned polyamines and/or polycarboxylic acids as initiators). Examples of such polyamides include those described in British Patent No. 799,158 and German Patent No. 1,224,081.

The number of active hydrogen atoms in the polyamide in the polyoxyalkylene ether used in the present invention is 15 or more, usually 5 to 120, preferably 5 to 60, particularly preferably 5 to 30. The molecular weight of polyamide is usually 17
4-7QOO, preferably 174-8500. The degree of polymerization (degree of condensation) is usually 2 to 60, preferably 2 to 80.

The oxyalkylene units constituting the polyoxyalkylene ether in the present invention include oxyethylene groups, oxyalkylene groups having 3 or more carbon atoms, such as oxypropylene groups, oxybutylene groups (i.2-92.8-1
1,8- or 1,4-), phenyl-substituted oxyethylene groups (oxystyrene groups), hero-substituted oxyethylene groups (oxychloroethylene groups, etc.), and these 2
An example is a system in which more than one species is used in combination.

A particularly preferred polyoxyalkylene ether is a polyoxyalkylene ether of an oxyethylene group and an oxyalkylene group having 8 or more carbon atoms, and a particularly preferred polyoxyalkylene ether is a polyoxyalkylene ether of an oxyethylene group and an oxypropylene group. It is.

The content of oxyethylene groups in the above polyoxyalkylene ether is usually 50% by weight or more, preferably 50 to 50% by weight.
99.7% by weight, particularly preferably 60 to 90% The ratio of oxyethylene groups to oxyalkylene groups having 3 or more carbon atoms in the oxyalkylene ether is usually 1:1 to 9.
99:1, preferably 3:2 to 99:1.

The number of oxyalkylene units in the polyoxyalkylene ether in the present invention is 900 or more, preferably 92
0 to 20,000, particularly preferably 950 to 1,000
It is 0. If the number of oxyalkylene units is less than 900, depending on the type of coal, the coal may not be dispersed and cannot be formed into a slurry, or the storage stability may deteriorate. Also, 200
If it exceeds 00, the viscosity of the coal-water slurry will not be reduced sufficiently.

In the polyoxyethylene ether μ in the present invention,
The number of moles of oxyethylene group in 1 active hydrogen pb is usually 1
It is 0 or more, preferably 20 to 750.

Polyoxyoxyalkylene chains in polyoxyalkylene ether include -Q-E-, -E-Q-, -E
-Q-E- and -Q-E-Q'- (E, B/ are hydrophilic polyoxyalkylene chains, Q, Q' are hydrophobic polyoxyalkylene chains.) Block addition type polyoxy Examples include alkylene chains and randomly added polyoxyalkylene chains.

The hydrophobic polyoxyalkylene chains Q, Q' and the hydrophilic polyoxyalkylene chains E, E/ in the block-added polyoxyalkylene chain include the hydrophobic polyoxyalkylene chains Q, Q' and the polyoxypropylene chain -
(C,H60)s- and oxygen/carbon atomic ratio is 0.4
3 or less mixed polyoxyalkylene chains (especially those mainly composed of oxypropylene groups), hydrophilic polyoxyalkylene chains E and E' include polyoxyethylene chains -(02H,0)t- and oxygen/carbon atoms The number ratio is 0.
Mixed polyoxyalkylene chains larger than 48 (particularly polyoxyethylene/oxypropylene chains mainly composed of oxyethylene groups) are included. E, Q, E/;Q' bonded to five or more active hydrogens may be the same or different. E that binds to 5 or more active hydrogens
, Q, E/, and Q', some of them may not exist. (It is sufficient if the average composition has the above structure.

) Preferred among the block addition type polyoxyalkylene chains are -Q-E- and -E-Q-E'-.

The oxygen/carbon atom ratio of all polyoxyalkylene chains is 0.
4 or more is preferable.

Random addition type mixed polyoxyalkylene chain (MA)
Examples include adducts of mixed alkylene oxides of ethylene oxide and alkylene oxides having 3 or more carbon atoms excluding ethylene oxytra.

Mixed alkylene oxides include, for example, a mixture of ethylene oxide and propylene oxide, a mixture of ethylene oxide, propylene oxide and 1,2-butylene oxide, a mixture of ethylene oxide and styrene oxide, a mixture of ethylene oxide and 1,3-butylene oxide, etc. A mixture of ethylene oxide and propylene oxide is preferred. The oxygen/carbon atom ratio of the mixed alkylene oxide is preferably 0.4 or more.

MAs bonded to five or more active hydrogens may be the same or different.

Among block addition type polyoxyalkylene chains and random addition type polyoxyalkylene chains, block addition type polyoxypropylene groups are preferred.

The molecular weight of the polyoxyalkylene ether of the polyamide in the present invention is usually 4500 k8000017,
Preferably it is 50,000 to 500,000. The molecular weight of the polyoxyalkylene ether is 45,000
If it is less than 100 ml, depending on the type of coal, the coal may not be dispersed in water and cannot be made into a slurry, or the viscosity of the coal-water slurry may not be sufficiently reduced.

Specific examples of the polyoxyalkylene ether in the present invention include compounds shown in Table 1.

Table-1 The abbreviations in Table-1 are Y2, which represents active hydrogen in the present invention, and 5
polyamide residue having AO nioxyalkylene group or substituted oxyalkylene group; l: number of active hydrogen;
PO: Propylene oxide; BO near "tylene oxy"
F'; EO: ethylene oxide; TETA-PA:
) Amidation product of polyethylenetetramine and terephthalic acid: PEHA-AA, Amidation product of pentaethylenehexamino and adipic acid: DETA-DA Amidation product of diethylenetriamine and dimer acid; PEH
A-PA: amidation product of pentaethylene hexamino and terephthalic acid; TEPA-AA, amidation product of tetraethylenepentamine and adipic acid; PO-EQ: block adduct in which propylene oxide is added and then ethylene oxide is added. ; PO/EO: indicates a random adduct of propylene oxide and ethylene oxide.

The above-mentioned polyoxyalkylene ether can be produced using a known method such as adding an alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, styrene oxide, shrimp chlorohydrin, etc.) to a polyamide having 5 or more active hydrogen atoms as a catalyst (basic catalyst such as caustic potash, trimethylamine, etc.). or an acidic catalyst such as boron fluoride). Addition of alkylene oxide can be carried out by single addition, addition by mixing two or more types (random addition), sequential addition (block addition), or a combination of random addition and block addition, but block addition (or A combination of this and random addition) is preferred.

Polyoxyalkylene ethers of polyamides having five or more active hydrogen atoms are described in JP-A-58-8011.

The alkaline substances in the present invention include 1) alkali metal hydroxides, carbonates and/or silicates, II
) hydroxides of alkaline earth metals, II) ammonium hydroxide, 1v) amines, and mixtures of two or more thereof. Examples of alkali metals include potassium, sodium, and lithium.

Examples of alkali metal hydroxides include potassium hydroxide, sodium hydroxide, and lithium hydroxide.

Sodium carbonate is an alkali metal carbonate.

Examples include potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

As an alkali metal silicate, sodium silicate (
sodium metasilicate and its hydrates in various proportions,
Examples include sodium orthosilicate, sodium disilicate, sodium tetrasilicate, etc.), potassium silicate (potassium metasilicate, potassium hydrogen disilicate, etc.).

Examples of alkaline earth metal hydroxides include μsium hydroxide and magnesium hydroxide.

As the amine, lower alkyl/I/(01-4) amine (
Mono-, di- or trimethylamine, ethylamine.

(propylamine, etc.), alkanolamines (mono-di- or triethano-μ-amine, propano-μ-amine, butanolamine, etc.), tetraalkyμ-ammonium hydroxide (tetramethyμ-ammonium hydroxide, etc.), and the like.

Two or more types of these can also be used.

7/I/ Preferred among the potassium substances are alkali metal hydroxides, carbonates and silicates, and particularly preferred are alkali metal hydroxides.

The coal used in the present invention is anthracite! ! Blue coal.

Examples include sub-bituminous coal and lignite. The particle size of the coal is usually 3 mm or less, preferably 9.51 m or less.

The concentration of coal is usually 5 based on the weight of the coal-water nullary.
0 to 85 inches, preferably 60 to 85 inches.

In the additive of the present invention, the amount of the polyoxyalkylene ether added is usually 0.01 to 5 inches, preferably 0.05 to 2 inches, based on the weight of coal in the coal-water slurry.
The amount of alkaline substances added is usually 0.01 to 2.
%, preferably 0.05 to 2.

The weight ratio of the polyoxyalkylene ether to the alkaline substance is usually 999:1 to 1:999, preferably 50:50 to 1:999. '? :'J.

The additive of the present invention may be used as required in JP-A-56-21686, JP-A-56-20.090, JP-A-54-
aasoa publication, JP 56-57889, JP 56-57890, JP 58-42695
No. 1, JP-A-58-45729, JP-A-58-
Dispersants described in Japanese Patent No. 49794 and the like can be used in combination. The amount of these dispersants used may typically be between 0 and 2 inches based on the weight of coal in the coal-water slurry. Further, the amount may be usually 0 to 80 inches based on the weight with the polyoxyalkylene ether.

In addition, if foam is generated in the slurry depending on the particle size of the coal type or the coal-water slurry manufacturing method, add an appropriate antifoaming agent (
(mineral oil type, silicone type, etc.) can be used in small amounts if necessary. The amount of antifoam agent used is usually 0.001 to 0.5 inches, based on the weight of the coal-water slurry.

The method for producing a coal-water slurry using the additive of the present invention may be any conventional method, such as coal.

The polyoxyalkylene ether is added to an aqueous solution of an alkaline substance (concentration usually 0.02% to 5%) in any order with additives and water, dissolved or dispersed, and then coal is added and mixed with a suitable mixing device or pulverizing device ( Alternatively, the polyoxyalkylene ether can be dissolved or dispersed in water, then 1 coal and an alkaline substance can be added thereto, and can be prepared in the same manner as above. can give.

[Example] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

Examples 1-5. Comparative Example 1.2 Additives of the present invention (Examples 1 to 5) and additives of comparative examples (Comparative Examples 1 to 8) are shown in Table-2.

@3 DEA diethanolamine N5FNa: Formalin condensate of naphthalene sulfonic acid sodium salt (degree of condensation: 4) [1] Preparation of coal-water slurry and evaluation of slurry (i
) Preparation of slurry ■ Test coal: South African bituminous coal (thermal coal) and Australian bituminous coal (thermal coal) Analysis values are as shown in Table 3 ■ Slurrying equipment: Ball mill (capacity 81) ■ Batch size 1 tcg as Nis slurry ■Operation method: A predetermined amount of tap water and the additives shown in Table 2 were placed in a beaker and mixed uniformly. Next, a predetermined amount of coal was added and mixed uniformly. The entire amount was transferred to a ball mill and mixed for 2 hours to obtain a slurry.

(2) Slurry evaluation - Viscosity The varnish slurry was placed in a beaker, the temperature was adjusted to 20°C, and then measured using a B-type viscometer.

■Stability test Varnish slurry with inner diameter 5 cm 1 height 25α
It was placed in a cylinder up to a height of 18 (m) from the bottom, sealed tightly, and the cylinder was left at room temperature for a certain period of time. After a certain period of time, the cylinder had a diameter of 5+++ m.

A rod of weight 209 is inserted into the above cylinder. It naturally falls into the slurry of and reach the bottom of the cylinder. Measure lag time to check stability Examined. slurry stability The standards were established as shown in Table-4.

Table 4 (3) Evaluation results of slurry Table 5 shows the evaluation results when South African bituminous coal was used, and Table 6 shows the evaluation results when Australian bituminous coal was used.

〔Effect of the invention〕

■The additive of the present invention has a lower molarity and better storage stability regardless of the type of coal, compared to conventional additives such as active hydrogen-containing compounds with oxyalkylene groups added by 800 mo/l/dimensions. It is possible to obtain a coal-water slurry.

(2) The viscosity of the coal-water slurry prepared using the additive of the present invention is usually below 4000 cp1, particularly below 2000 cp1, at a coal concentration of 70 cm or more.

(2) The storage stability of the coal-water slurry produced using the additive of the present invention is generally good for more than one week, especially for more than 41 days.

(2) The coal-water slurry produced using the additive of the present invention can be transported by ordinary pipelines. In addition, the sent coal-water slurry can be directly burned as fuel in a conventional pulverized coal boiler.

(2) The coal-water slurry produced using the additive of the present invention can be dehydrated or directly gasified or liquefied.

Claims (1)

[Scope of Claims] 1. An additive for coal-water slurry characterized by containing a polyoxyalkylene ether of polyamide having 5 or more active hydrogen atoms and an alkaline substance. 2. Polyoxyalkylene ether of polyamide is 90
The additive according to claim 1, which has zero or more oxyalkylene units. 3. The alkaline substance is (i) an alkali metal hydroxide,
carbonates and/or silicates, (ii) alkaline earth metal hydroxides, (iii) ammonium hydroxide, and (iv)
) The additive according to claim 1 or 2 selected from the group consisting of amines. 4. The amount of alkaline substances added is 0 based on the weight of coal.
．． 01-2% of the additive according to any one of claims 1 to 3. 5. The additive according to any one of claims 1 to 4, wherein the amount of polyoxyalkylene ether added to the polyamide is 0.01 to 5% based on the weight of the coal. 6. Claims 1 to 5, wherein the polyoxyalkylene ether is a polyoxyalkylene ether of an oxyethylene group and an oxyalkylene group having 3 or more carbon atoms.
Additives according to any one of paragraphs. 7. The polyoxyalkylene ether is 45,000 to 8
An additive according to any one of claims 1 to 6 having a molecular weight of 00,000. 8. The polyoxyalkylene ether has at least 50
Additive according to any one of claims 1 to 7, containing % by weight of oxyethylene groups. 9. The additive according to any one of claims 1 to 8, wherein the polyamide is an amidated product of (alkyl) alkylene polyamine and/or (alkyl) alkylene diamine and polycarboxylic acid.