JPS62125842A - Coal ash-aqueous slurry composition - Google Patents

Abstract

PURPOSE:To remarkably enhance the fluidity and storage stability of an aq. coal ash slurry by mixing a coal ash component, water, and a water-soluble polycarboxylate to prepare the titled coal ash-aq. slurry composition. CONSTITUTION:The coal ash component such as fly ash and bottom ash, a water-soluble polycarboxylate, and water are mixed to prepare the coal ash-aq. slurry composition. The water-soluble polycarboxylate is the water-soluble salt of the polymer of an alpha,beta-unsaturated carboxylic acid monomer or of the copolymer with the copolymerizable monomer, and 0.01-5.0pts.wt., based on the solid component, of the water-soluble salt is ordinarily used with 100pts.wt. coal ash component. The water-soluble polycarbonate, water, and coal ash component are simultaneously mixed, or the polycarbonate is added to a mixture of the coal ash component and water.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a coal ash-water slurry composition, and more particularly, to a coal ash-water slurry composition, a water-soluble polycarmenate is blended into a water slurry consisting of a coal ash component to improve fluidity. and a coal ash-water slurry composition with improved stability.

(Prior Art) In recent years, there has been progress in replacing petroleum with coal as an energy source for electric power, cement, iron manufacturing, paper manufacturing, etc. It is desired to develop a method for processing and utilizing coal ash that is generated due to the increased use of coal IB materials. Currently, coal ash is used as cement admixture, soft ground improvement material, civil engineering material, embankment material,
Although it is used as road material and filler, most of it is disposed of as landfill in the Pacific Ocean. When processing and using coal ash, including landfilling, it is necessary to economically transport large amounts of coal ash over long distances, and water slurry transport is attracting attention as one means of doing so.

In water slurry transportation, it is necessary to prepare a coal ash-water slurry that is highly concentrated, has high fluidity, and has excellent storage stability. Conventionally, naphthalene sulfone (12m formalin condensate,
Methods of adding high-performance cement water reducing agents such as melamine sulfonate formalin condensate and lignin sulfonate are known, but these methods are not necessarily satisfactory in terms of fluidity and storage stability. It wasn't.

(Problems to be Solved by the Invention) Therefore, the present inventors have attempted to solve these drawbacks of the prior art.
As a result of extensive research, we discovered that when a specific polymer compound is added to a water slurry consisting of coal ash components, the fluidity and storage stability of the water slurry are significantly improved, and we have completed the present invention. .

(Means for Solving the Problems) According to the present invention, 1 coal ash component, water and a water-soluble polycarbonate are used. A coal ash-water slurry composition is provided containing a phosphate salt.

Coal ash m- in the present invention refers to combustion residue generated by combustion of coal, specific examples of which include fly ash,
&) Muassi etc.

The water used in the cage of the present invention may be tap water, underground water, seawater, etc., but is not particularly limited.

The water-soluble polycarginates A used in the present invention are α, β
- A water-soluble salt of a copolymer of an unsaturated unsaturated carbenoic acid monomer or a copolymerizable ethylenically unsaturated monomer, and usually has a number average molecular weight of 500 to so, ooo
, preferably 1. OOO~25, OOO. If the molecular weight becomes too large, the dispersibility decreases, and conversely, thickening and aggregation effects occur, which is not preferable.

The α, β to unsaturated carbenoic acid monomers in the polymer can be selected as appropriate, but are usually 10 molti or more, preferably 20 molti or more. Here α.

β-Ill carboxylic acid monomer refers to an unsaturated carboxylic acid having a carboxyl group or an acid anhydride group, or its anhydride, and specific examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Examples include maleic anhydride, itaconic anhydride, and citraconic acid.

Further, the copolymerizable ethylenically unsaturated monomer is the α,β-unsaturated monomer mentioned above. Any material that can be radically polymerized with the phosphoric acid monomer may be used.
For example, ethylene, propylene, buty/, 2-methyl-butene-1,2-methyl-butene-2, hexene, octene, diisobutylene, decene, cyclointene, cyclohexene, styrene, vinyltoluene, α-methylstyrene, coumaron, Indene, methyl vinyl ether, ethyl acrylate, methyl methacrylate, vinyl acetate,
Examples include polar or non-selectable vinyl monomers such as vinylpyrrolidone. Among these, a comonomer of onfin having 4 to 6 carbon atoms and maleic anhydride is preferred from the viewpoint of dispersibility.

The polymer used in the present invention is not limited in its production method, but is usually produced by radical polymerization according to a conventional method.

In accordance with the present invention, a water-soluble salt of the polymer is used as a component of a coal ash-water slurry composition. The salt of the polymer may be one in which at least a part of the carboxyl group or acid anhydride group present in the molecule is converted into a salt within the range that allows the polymer to be water-solubilized, and in particular, 50 mol or more forms a salt. Preferably, it is a book that is easy to read.

Specific examples of such salts include salts of alkali metals such as sodium, potassium, magnesium, calcium, and barium, or alkaline earth metal salts, ammonium salts, and amine salts. is preferred.

The method for producing these polymer salts is not particularly limited, and either a method in which monomers are neutralized and then polymerized, or a method in which a polymer is synthesized and then neutralized in the presence of a base according to a conventional method can be adopted. Moyo.

The water-soluble polycarbic acid salt of the present invention may be in the form of a solid or an aqueous solution, but it is usually used in the form of an aqueous solution with a solid content concentration of 10 to 50% for ease of handling. . At this time, other dispersants, hardening accelerators, solidifying agents, earth and sand, mud, etc. may be appropriately mixed as long as they do not essentially impair the effects of the present invention.

The method of adding the water-soluble Polycal R/acid salt in the present invention is not limited in any way, and specific examples thereof include: (1) Adding and mixing at the same time as the coal ash component and water; (2) Adding and mixing to the mixture of the coal ash component and water. Methods to do so are listed.

The proportion of water-soluble polycarboxylate used in the present invention is not necessarily uniform depending on conditions such as the type of coal ash component, particle size, particle size distribution, concentration, presence or absence of other additives, etc., but on a solid content basis. Usually 0.01 per 100 parts by weight of coal ash component
-5.0 parts by weight, preferably 0.05-3.0 parts by weight.

(Effects of the Invention) Thus, according to the present invention, it is possible to improve the dispersibility of a water slurry consisting of a coal ash component, greatly reduce the viscosity, and prepare a mixture with excellent fluidity and storage stability. .

(Example) Next, the present invention will be explained in more detail with reference to Examples. The properties of the polycarboxylic acid salts used in the examples are shown in Table 1, and the test methods are as follows. In addition, parts, parts, and ratios are based on the amount of N unless otherwise specified.

Test method (1) Dissolution of coal ash-water slurry composition Coal ash components, water-soluble polycarboxylic acid salts, and water were mixed in a predetermined ratio in a juice mixer, and the slurry was stirred.

(2) Fluidity test The fluidity of the obtained slurry was measured using a BM type viscometer and a funnel viscometer (F, V, 500cc1500CQ).

(3) Storage stability test The obtained slurry was placed in a 100 CC graduated cylinder.
After leaving the slurry in 00CC overnight, the sedimentation of the slurry was observed and used as a measure of storage stability. The judgment criteria are as follows.

Judgment Situation Example 1 A water bath solution prepared with tap water containing 4% thermal power as coal ash components, 300 parts of locally generated electric fryer, and various polycarboxylic acid salts shown in Table 2 to a predetermined concentration. 7
A coal ash slurry composition was prepared according to the following formulation, and a fluidity test and a storage stability test were conducted. For comparison, other cement water reducing agents were also tested in the same manner.

The results are shown in Table 2.

From Table 2, it can be seen that the examples of the present invention are superior in fluidity and storage stability compared to the control examples.

Claims (1)

[Claims] A coal ash-water slurry composition comprising a coal ash component, water, and a water-soluble polycarboxylate.