JPS61225293A - 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 polyamine and an alkaline substance. CONSTITUTION:0.01-5wt% (based on a coal used) polyoxyalkylene ether, which has 50wt% or more oxyethylene group and a 3C or higher oxyalkylene group, a molecular weight of 40,000-300,000 and at least 900 oxyalkylene units, of a polyamine [e.g.: (alkyl)polyalkylene polyamine] 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. The additive and optionally, a dispersant and an antifoamer are added to a water slurry of a 50-80wt% coal having a particle diameter of 3mm or less.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an additive for coal-water slurry. [Prior Art] Conventionally, as an additive for high-concentration coal-water slurry, an active hydrogen-containing compound alkylene oxide with 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 Invention] The present inventors aimed to obtain 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. As a result of intensive studies, it was unexpectedly discovered that the desired additive could be obtained by increasing the number of moles added to 900 or more, and the present invention was achieved. [Means for solving the problems] The present invention provides 900 polyamines having 5 or more active hydrogen atoms.
This is an additive for coal-water slurry characterized by containing a polyoxyalkylene ether having the above oxyalkylene units and an alkaline substance. In the present invention, examples of polyamines having 5 or more active hydrogens include (alkyl) polyalkylene polyamines, 8th class nitrogen-containing polyalkylene imines, and aromatic or alicyclic polyamines. The (alkyl) polyalkylene polyamine has the general formula [wherein R2 is an alkylene group having 2 or more carbon atoms, and usually has 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms]. ]
Examples of the compounds shown are: Examples of the (alkyl) polyalkylene polyamine represented by the above general formula (i) include polyethylene polyamines having nl of 1 to 10 (diethylene triamine, pentaethylene hexamine, decaethylene undecamine, etc.);
Polypropylene polyamine (dipropylene triamine,
tripropylenetetramine, nonapropylene decamine, etc.), polybutylene polyamine (diethylenetriamine, etc.), poly(pentamethylene) polyamine [bis(pentamethylene)triamine, etc.], poly(hexamethylene) polyamine

[Bis[hexamethylene]triamine, etc.; and N of these polyalkylene polyamines
-alkyl substituents, (N-hexyl-, N-(2-ethylhexyl)-1 and N-nonyl-tetraethylenepentamine, etc.). Among these, preferred are polyethylene polyamines and polypropylene boria substitutes, Particularly preferred are diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and dipropylenetriamine.Two or more of these (alkyl)polyalkylenepolyamines may be used in combination.Tertiary nitrogen-containing polyamine As an alkylene imine, the general formula % formula % (2) (in the formula, R is an alkylene group having 2 or more carbon atoms and usually has 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms e n2 +
na is an integer greater than or equal to 1, and r12+13 is usually 2 to 20
0, preferably 2-100. ) can be mentioned. In general formula (2), the alkylene group for R 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 tertiary nitrogen-containing polyethyleneimine (trade name: Epomin, grade SP, e.g. 5P-018, manufactured by Nippon Shokubai Chemical Co., Ltd.). Aromatic or alicyclic polyamines have the general formula X +NHz ) n,
(The number is 33, usually 8 to 10, preferably 8.) In the general formula (3), ) and (R')HCy- (Ar is an aromatic nucleus. cy is an alicyclic hydrocarbon group having usually 8 to 20 carbon atoms, preferably 5 to 12 carbon atoms, R# usually has 1 to 20 carbon atoms, preferably pen, zene, and naphthalene.R' is methyl, ethyl, n- or i-propyl, n-, f-, s- or t-butyl, hexyl. linear or branched saturated alkyl groups such as , nonyl, dodecyl; and unsaturated alkenyl groups such as vinyl and octenyl. Condensates, etc.) such as triaminobenzene. Examples of the alicyclic polyamines include cyclohexyltriamine. Two or more of these polyamines may be used in combination; for example, (alkyl) polyalkylene polyamines (polyethylene A mixture of polyamine, polypropylene polyamine, etc.) and aromatic amine (triaminobenzene, etc.) can also be used. The number of active hydrogens of the polyamine having 5 or more active hydrogens is usually 6 to 24, preferably 6 to 14. Among these polyamines, preferred are (alkyl)
Polyalkylene polyamines are particularly preferred, and polyethylene polyamines and polypropylene polyamines are particularly preferred. The oxyalkylene units constituting the polyoxyalkylene ether in the present invention include oxyethylene groups, oxyalkylene groups having 8 or more carbon atoms, such as oxypropylene groups, oxybutylene groups (i,2-, 2,8-,
1,8- or 1.4-). Examples include phenyl-substituted oxyethylene groups (such as oxystyrene groups), halo-substituted oxyethylene groups (such as oxychloroethylene groups), and combination systems of two or more of these. Among the polyoxyalkylene ethers, preferred are polyoxyalkylene ethers of an oxyethylene group and an oxyalkylene group having 8 or more carbon atoms, and particularly preferred are polyoxyalkylene ethers of an oxyethylene group and an oxypropylene group. The content of oxyethylene groups in the polyoxyalkylene ether is usually 60% by weight or more, preferably 50 to 50% by weight.
99.7, and (preferably 60 to 90 weight xyethylene group and carbon number 8 in xyalkylene ether)
The IFIJ combination of the above oxyalkylene groups is usually 1:1
˜999:l, preferably 8:2 to 99:1. The number of oxyalkylene units in the polyoxyalkylene ether in the present invention is 900 or more, preferably 92
0-20000, particularly preferably 950-1000G
It is. 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, 2000
If it exceeds 0, the viscosity of the coal-water slurry will not be reduced sufficiently. In the polyoxyalkylene ether of the present invention, the number of moles of oxyalkylene groups per active hydrogen is usually 10 or more, preferably 20 to 750. As polyoxyalkylene groups in polyoxyalkylene ether, -Q-E-, -E-Q-, -E-Q-
Block-added polyoxyalkylene chains such as E'- and -Q-E-Q'- (E, E' are hydrophilic polyoxyalkylene chains, Q, Q' are hydrophobic polyoxyalkylene chains); Examples include random addition type polyoxyalkylene chains. In the block addition type polyoxyalkylene chain (7) hydrophobic polyoxyalkylene chain Q9g and hydrophilic polyoxyalkylene chains E and E', hydrophobic polyoxyalkylene chain Q , Q' has a polyoxypropylene chain -(C3HsO)s and an oxygen/carbon atom ratio of 0.4
Mixed polyoxyalkylene chains of 8 or less (especially those mainly composed of oxypropylene groups), hydrophilic polyoxyalkylene chains E and E' include polyoxyethylene chains -(CzLO)t- and oxygen/carbon atom ratio is 0,4
Mixed polyoxyalkylene chains larger than 3 (especially polyoxyethylene/oxypropylene chains mainly composed of oxyethylene groups) are included. E, Q that binds to 5 or more active hydrogens. rlg may be the same or different. Some of E, Q, E', and Q' bonded to five or more active hydrogens may not be present. (It is sufficient if the average composition is the above structure.) Among the block addition type polyoxyalkylene chains, -Q-E- and -E
-QE'-. The oxygen/carbon atom ratio of all polyoxyalkylene chains is preferably 0.4 or more. 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 oxide. 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 1,8-butylene oxide, and the like. , preferred is a mixture of ethylene oxide and propylene oxide. The oxygen/carbon atom ratio of the mixed alkylene oxide is preferably 0.4 or more. Kites that bind 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 polyoxyalkylene chains are preferred. The molecular weight of the polyoxyalkylene ether of the polyamine in the present invention is usually 40,000 to 300,000, preferably 45,000 to 20,000G. If the molecular weight of the polyoxyalkylene ether is less than 40,000, depending on the type of coal, the coal will not be dispersed in water and cannot be made into a slurry, or the viscosity of the coal-water slurry will be insufficient, and if it exceeds 300,000, the viscosity of the coal-water slurry will be It doesn't drop enough. 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
Polyamine residue having 3 or more; e: number i of active hydrogen;
AO nioxyalkylene group or substituted oxyalkylene group; po: brobylene oxide; BO: butylene oxide; EO=ethylene oxide; DETA diethylenetriamine: TEPA: tetraethylenepentamine; PEHA: pentaethylenehexamine; PO・E
O: A block adduct in which propylene oxide is added and then ethylene oxide is added; PO/EO: A random adduct of propylene oxide and ethylene oxide. The above polyoxyalkylene ether can be prepared by a known method, for example, by adding an alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, etc.) to a polyamine having 5 or more active hydrogen atoms as a catalyst (a basic catalyst such as caustic potash, trimethylamine, etc.) or a fluorinated polyamine. It can be produced by addition in the presence of an acidic catalyst (such as boron). 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. Random (combination with addition) is preferred. Polyoxyalkylene ethers of polyamines having five or more active hydrogen atoms are described in JP-A-58-80891. The alkaline substances in the present invention include (i) alkali metal hydroxides, carbonates, and silicates, (i+) alkaline earth metal hydroxides, GiD ammonium hydroxide IV) amines, and two or more of these. A mixture can be mentioned. Potassium and sodium are alkali metals. Examples include 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 (
Examples include sodium metasilicate and its hydrates in various proportions, sodium orthosilicate, sodium disilicate, sodium tetrasilicate, etc.), potassium silicate (potassium metasilicate, potassium hydrogen disilicate, etc.), and the like. Examples of alkaline earth metal hydroxides include calcium hydroxide and magnesium hydroxide. Examples of amines include lower alkyl CC, ~4) amines (mono, di, or trimethylamine, ethylamine, propylamine, etc.), alkanolamines (mono, di, or triethanolamine, propatoolamine, butanolamine, etc.), tetraalkylammonium hydroxide ( Examples include tetramethylammonium hydroxide, etc.). Two or more types of these can also be used. Preferred among the alkaline substances are alkali metal hydroxides, carbonates, and silicates, and particularly preferred are alkali metal hydroxides. Coal used in the present invention includes anthracite and bituminous coal. Examples include sub-bituminous coal and lignite. The particle size of the coal is usually 8 mm or less, preferably 0.5 mm or less. The concentration of coal is usually 50% based on the weight of the coal-water slurry.
~85%, preferably 60-85%. In the additive of the present invention, the amount of the polyoxyalkylene ether added is usually 0.01 to 5%, preferably 0.05 to 2%, 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. ? It is two. The additive of the present invention may be used as required in JP-A-56-21616, JP-A-56-20090, and JP-A-54-a.
asoa, JP 56-57889, JP 56-57890, JP 58-42695, JP 58-45729, JP 58-4
Dispersants described in Japanese Patent No. 9794 and the like can be used in combination. The amount of these dispersants used may typically be between θ and 2% based on the weight of coal in the coal-water slurry. Further, the amount may be usually 0 to 30% based on the weight of the polyoxyalkylene ether. In addition, if foam is generated in the slurry due to 1 type of coal, 2 particle sizes, 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 antifoaming agent used is usually 0.001-0.5% 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. Additives can be added in any order, for example, to an aqueous solution of an alkaline substance (concentration usually 0.02% to 5%), the polyoxyalkylene ether is dissolved or dispersed, and then coal is added and a suitable mixing device or pulverizing device [ball mill, rod mill, etc. (sand mill, etc.), or after dissolving or dispersing the polyoxyalkylene ether in water,
An example of this method is to add coal and an alkaline substance and prepare in the same manner as above. [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 comparative additives (Comparative Examples 1 to 8) are shown in Table-2. Table 2 (Note) NSFNa': Formalin condensate of sodium naphthalene sulfonate (degree of condensation: 4) (i) 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 Table 8 Dog ■ Slurrying equipment: Ball mill (capacity all) ■ Batch size Nissurari - 1 kg ■Procedure 2 A predetermined amount of tap water and the additives shown in Table 2 were placed in a beaker and mixed uniformly, and then 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) Evaluation of slurry ■ Viscosity Take the slurry in a beaker and set the temperature to 20
After adjusting the temperature to .degree. C., the temperature was measured using a B-type viscometer. ■Stability test Nisslary with an inner diameter of 5cm and a height of 25cm
1: Pour into a cylinder to a height of 18 cm from the bottom, seal it tightly, and leave the cylinder at room temperature for a certain period of time. After a certain period of time, a rod with a diameter of 5 mm and a weight of 20 g was allowed to fall naturally into the slurry of the cylinder, and the time taken to reach the bottom of the cylinder was measured to examine stability. The standards for slurry stability were determined 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. Table 5 Table 6 After 1]] ] [Effects of the invention] ■The additive of the present invention is more effective for coal types than conventional additives, such as compounds in which 800 moles of oxyalkylene group are added to an active hydrogen-containing compound. Regardless of the method used, it is possible to obtain a coal-water slurry with low viscosity and good storage stability. (2) The viscosity of the coal-water slurry produced using the additive of the present invention is usually 4000 cp or less at a coal concentration of 70% or more, and particularly 2000 cp or less. (2) The storage stability of the coal-water slurry produced using the additive of the present invention is usually good for one week or more, particularly for four weeks or more. (2) The coal-water slurry produced using the additive of the present invention can be transported by ordinary pipelines. Also, the delivered 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 is dehydrated or directly gasified. It can be used for various purposes such as liquefaction or coke production.

Claims (1)

[Claims] 1. An additive for coal-water slurry characterized by containing a polyoxyalkylene ether having 900 or more oxyalkylene units of a polyamine having 5 or more active hydrogens, and an alkaline substance. . 2. The alkaline substance is (i) an alkali metal hydroxide,
carbonates and/or silicates, (ii) alkaline earth metal hydroxides, (iii) ammonium hydroxide, and (iv)
An additive according to claim 1 selected from the group consisting of amines. 8. The amount of alkaline substances added is 0 based on the weight of coal.
．． The additive according to claim 1 or 2, which has a content of 0.01 to 2%. 4. The additive according to any one of claims 1 to 3, wherein the amount of the polyoxyalkylene ether added is 0.01 to 5% based on the weight of the coal. 5. Claims 1 to 4, 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. 6. The polyoxyalkylene ether is 40,000 to 3
An additive according to any one of claims 1 to 5 having a molecular weight of 00,000. 7. The polyoxyalkylene ether has at least 50
Additive according to any one of claims 1 to 6, containing % by weight of oxyethylene groups. 8. The additive according to any one of claims 1 to 7, wherein the polyamine is an (alkyl) polyalkylene polyamine.