CN1101793C

CN1101793C - Additive of powdered coal ash product and its preparing process

Info

Publication number: CN1101793C
Application number: CN00110123A
Authority: CN
Inventors: 唐涛; 孙景宽
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-02-18
Filing date: 2000-02-18
Publication date: 2003-02-19
Anticipated expiration: 2020-02-18
Also published as: CN1263876A

Abstract

The present invention relates to an additive for fly ash products and a preparation method thereof, which is an organic-inorganic nano hybrid material which is composed of organic material acrylate copolymers and inorganic material silicon dioxide. The material has the weight compounding ratio of 25 to 40% of acrylate copolymer, 2 to 10% of sodium metasilicate or silicon dioxide aerosol, 0.5 to 5% of sodium alkyl benzene sulfonate or alkyl sodium sulfate, 1 to 6% of polyethylene glycol oxide alkyl ether 55 to 70% of deionized water, wherein the acrylate copolymer has the components of 35 to 45% of methyl methacrylate, 0 to 55% of hexyl ethylacrylate, 0 to 55% of butyl acrylate and 2.5 to 5% of acrylic acid. The additive has good affinity with the fly ash and can obviously improve the performance of the fly ash products.

Description

Additive of powdered coal ash product and preparation method thereof

Technical field

The present invention relates to a kind of additive of powdered coal ash product and preparation method thereof.

Background technology

Contain the alumina silicate glass microballon in the flyash, spongy vitreum, quartzy, mullite, carbon granules, mineral substance such as vitriol, be a kind ofly can fully utilize the resource that turns waste into wealth, flyash is made a kind of effective means that new construction material is comprehensive utilization, utilize the goods of flyash to have at present: flyash brick (standard JC239-91), fly ash building block (standard JC239-91), flyash concrete (China Railway Press's " flyash concrete " in 1989) etc., but, these powdered coal ash products exist endurance quality (frost resistance, impervious, resistance to fouling) difference etc. problem, because some porous particle in the flyash, water-absorbent is strong, washiness in the granule interior hole, volumetric expansion when icing and cause goods because of freezing destroyed, the way that solves the freeze-thaw resistance of goods is to reduce water cement ratio, the intensity of while powdered coal ash product and the microtexture of itself, particularly porosity and pore texture have very confidential relation, and porosity is subjected to having the greatest impact of water cement ratio, the reduction water cement ratio can reduce the porosity in the flyash brick, improve product strength, but because the frictional force on fly ash grain surface is big, mobile poor, can not improving water cement ratio in powdered coal ash product, but will to improve flowability be a difficult problem, the way of the flowability of batching appears improving by admixture at present, announced a kind of method of adding the powder process coal-dust brick of water-soluble epoxy resin aqueous solution admixture as Chinese patent (application number 91106058.8), Chinese patent (application number 96116318.6) has been announced a kind of brick making from fly-ash, the method of piece, add polyvinyl alcohol (0.3-0.8%), Chinese patent (application number 95119424.0) has been announced improving one's methods of brick making from fly-ash, add ester group carboxylic-acid additive (0.0003-0.0005%), pass through to use admixture in the above goods, the performance of goods is improved, proved that mixing of admixture is successful, but, the also not basic freeze thawing problem that solves of these goods, its intensity is undesirable, weather resistance is unreliable, the freeze thawing index and the intensity index of its goods still do not reach requirement, though the kind of admixture is a lot of at present, single component is arranged, also have compound, compound as inorganic materials and inorganic materials, organic materials and organic materials compound, inorganic materials and organic materials compound, widespread usage in concrete, but select existing admixture can't satisfy the requirement of powdered coal ash product.

Summary of the invention

The objective of the invention is: organic-inorganic composite admixture of a kind of powdered coal ash product use and preparation method thereof is provided, can obviously improves the freeze thawing of powdered coal ash product.

The present invention is achieved in that

The admixture of powdered coal ash product is the organic-inorganic dispersion of materials liquid of the emulsion form of a kind of organic materials acrylate copolymer and inorganic materials silicon-dioxide composition, its weight proportion is: acrylate copolymer 25-40%, Starso or silicon-dioxide aerosol 2-10%, sodium alkyl benzene sulfonate or sodium alkyl sulfate 0.5-5%, polyethylene oxide alkyl ethers 1-6%, deionized water 55-70%, wherein: the acrylate copolymer component is methyl methacrylate 35-45%, 2 ethyl hexyl acrylate 0-55%, butyl acrylate 0-55%, vinylformic acid 2.5-5%.

The preparation method of above-mentioned admixture is: at first add entry in flask; tensio-active agent; sodium bicarbonate; Starso or silicon-dioxide aerosol; the mechanical stirring dissolving; under nitrogen protection, be heated to 80 ℃, with above-mentioned methyl methacrylate; n-butyl acrylate; 2 ethyl hexyl acrylate and Acrylic Acid Monomer are poured in the feed hopper after mixing by formula rate; average rate is added dropwise in the beaker; average rate drips potassium persulfate solution simultaneously, and reinforced finishing in 1.5 hours is after dropping finishes; under uniform temp, continue reaction 1 hour; be cooled to room temperature, regulating pH value with strong aqua is 8-9, organic-inorganic dispersion of materials liquid that can be stable.

Above-mentioned admixture and flyash have good affinity, can significantly improve the performance of powdered coal ash product, have following effect:

(1) water-reduction

Because some porous particle in the flyash, water-absorbent is strong, washiness in the granule interior hole, volumetric expansion when icing and cause goods because of freezing destroyed, the way that solves the freeze-thaw resistance of goods is to reduce water cement ratio, the intensity of while powdered coal ash product and the microtexture of itself, particularly porosity and pore texture have very confidential relation, and porosity is subjected to having the greatest impact of water cement ratio, the reduction water cement ratio can reduce the porosity in the flyash brick, improve product strength, but because water cement ratio reduces, can reduce the flowability of flyash slurry, high molecular component is small ball-like structure in the admixture of the present invention, the flyash slurry had the bearing effect, the flowability of flyash is improved, admixture of the present invention also has the bleed effect, this admixture is mixed in the flyash slurry, can introduce a lot of small bubbles, the bubble existence improves workability, simultaneously, surface-active substance confrontation improvement flyash disperses to have certain effect in this admixture, therefore, and the adding of this admixture, can reduce water cement ratio and guarantee that the flyash slurry has identical flowability, water-reducing rate can reach 15-20%.

(2) endurance quality

High molecular component is evenly distributed in the flyash slurry with small spheroid in the admixture of the present invention, and obstruction flyash contacts with excessive moisture, guarantees that the flyash suction is in undersaturated condition, adds above-mentioned water-reduction, thereby improves anti-freezing property.

(3) enhancement

Admixture of the present invention has the effect that excites the flyash lateral reactivity, and admixture neutral and alkali group makes the (SiO of vitreous surface layer in the flyash ₄) ^4-(AlO ₄) ^4-Tetrahedral network destroys, and the polymerization degree reduces, and the surfactivity center strengthens, and hydration reaction is accelerated, thereby makes flyash and Ca (OH) ₂Gelling thing content such as CSH that reaction generates and CAH increase.

In addition, in the admixture high molecular component contain can with the interactional group of flyash surface hydroxyl, this plays flyash coupling enhancement to a certain extent, and this enhancement is responsive especially to pressure, pressure is big more, this enhancement is strong more.

4. water-retentivity

Admixture of the present invention mixes in the flyash slurry, can introduce a lot of small bubbles, and the gas bubble blockage capillary passageway reduces bleeding, can adopt lower water cement ratio like this, reduces dry shrinkage, even do not carry out water curing for a long time, gain in strength is also very fast.

Embodiment

Embodiment:

Prescription 1:

The component title	Form (Wt%)
The component title	Form (Wt%)	Methyl methacrylate	40
2 ethyl hexyl acrylate	55	Methyl methacrylate	40
2 ethyl hexyl acrylate	55	N-butyl acrylate	0
Vinylformic acid	5	N-butyl acrylate	0
Vinylformic acid	5	Starso	6
Sodium dodecylbenzene sulfonate	3	Starso	6
Sodium dodecylbenzene sulfonate	3	Polyethylene oxide alkyl ethers	2
Sodium bicarbonate	0.4	Polyethylene oxide alkyl ethers	2
Sodium bicarbonate	0.4	Peroxy acid potassium	0.4
Deionized water	150	Peroxy acid potassium	0.4

Regulate n-butyl acrylate, 2 ethyl hexyl acrylate and acrylic acid composition in the above-mentioned prescription, the emulsifying agent Sodium dodecylbenzene sulfonate can be replaced by sodium lauryl sulphate, and Starso can be replaced by the silicon-dioxide aerosol, sees prescription 2-7 for details:

Prescription 2-7:

The component title	Form (Wt%)
	Form (Wt%)						2	3	4	5	6	7
	Methyl methacrylate	40	40	40	40	40	2	3	4	5	6	7	40
2 ethyl hexyl acrylate	Methyl methacrylate	40	40	40	40	40	55	57.5	57.5	37.5	57.5	57.5	40
2 ethyl hexyl acrylate	N-butyl acrylate	0	0	0	20	0	55	57.5	57.5	37.5	57.5	57.5	0
Vinylformic acid	N-butyl acrylate	0	0	0	20	0	5	2.5	2.5	2.5	2.5	2.5	0
Vinylformic acid	Starso	4	4	4	4	8	5	2.5	2.5	2.5	2.5	2.5	0
The silicon-dioxide aerosol	Starso	4	4	4	4	8	0	0	0	0	0	4	0
The silicon-dioxide aerosol	Sodium dodecylbenzene sulfonate	3	3	0	0	0	0	0	0	0	0	4	0
Sodium lauryl sulphate	Sodium dodecylbenzene sulfonate	3	3	0	0	0	0	0	1	1	1	1	0
Sodium lauryl sulphate	Polyethylene oxide alkyl ethers	2	2	2	2	2	0	0	1	1	1	1	2
Sodium bicarbonate	Polyethylene oxide alkyl ethers	2	2	2	2	2	0.4	0.4	0.4	0.4	0.4	0.4	2
Sodium bicarbonate	Peroxy acid potassium	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4
Deionized water	Peroxy acid potassium	0.4	0.4	0.4	0.4	0.4	150	150	150	150	150	150	0.4

Adopt among the preparation method of admixture and drip fast feeding in raw material, the mechanical stirring dissolving can be opened organic particle rapidly, and granularity refinement produces emulsion form organic-inorganic dispersion of materials liquid, and the particle of emulsion is about 0.1-0.2 μ m.

This organic-inorganic dispersion of materials liquid admixture the key technical indexes is as follows:

1. oyster white uniform liquid, blue light slightly, staging life is more than 6 months,

2.PH value is about 8-9,

3. the sphere diameter of high molecular component is less than 0.2 μ m,

4. admixture is stable under alkalescence or solutions of weak acidity,

5. the admixture solid content is 35-42%, (weight)

6. admixture viscosity is the 300-350 centipoise.

The adding of admixture of the present invention can obviously improve the performance of goods brick, also strengthens the cost of goods brick simultaneously, therefore, the add-on of admixture directly influences the technical and economic requirements of goods brick, and test finds that the volume of admixture was at 0.03% o'clock, intensity can reach 10Mpa

The application of above-mentioned admixture in flyash brick, proportioning is as follows:

The component title	Form
The component title	Form	Slag	55
Flyash	35	Slag	55
Flyash	35	Cement	10

Account for the water of said ratio total amount 14% in addition, 0.03% admixture.

Flyash by above-mentioned prescription and explained hereafter is that the every performance index of concrete brick meet or exceed " JC239-91 " flyash brick standard-required, and specific targets see the following form:

Sequence number	Interventions Requested	Measure unit	Standard value	Assay	The individual event evaluation
Sequence number	Interventions Requested	Measure unit	Standard value	Assay	The individual event evaluation	1	Folding strength (mean value)	MPa	≥3.2	4.2	Qualified
	(individual event value)	MPa	≥2.4	3.7	Qualified	1	Folding strength (mean value)	MPa	≥3.2	4.2	Qualified
	(individual event value)	MPa	≥2.4	3.7	Qualified	2	Ultimate compression strength (mean value)	MPa	≥15.0	18.4	Qualified
	(individual event value)	MPa	≥11.0	15.9	Qualified	2	Ultimate compression strength (mean value)	MPa	≥15.0	18.4	Qualified
	(individual event value)	MPa	≥11.0	15.9	Qualified	3	Frost resistance (ultimate compression strength)	MPa	≥12.0	17.9	Qualified
	(dry mass loss)	％	≤2.0	0.7	Qualified	3	Frost resistance (ultimate compression strength)	MPa	≥12.0	17.9	Qualified
	(dry mass loss)	％	≤2.0	0.7	Qualified	4	Drying shrinkage value	mm/m	≤0.85	0.51	Qualified
Meet evaluation	Meet 15 grades of intensity ranks	Remarks	Freeze proof condition :-25 ℃ of 15 circulations			4	Drying shrinkage value	mm/m	≤0.85	0.51	Qualified

From above-mentioned assay as seen, every index of fly ash microconcrete brick has all reached the standard of national flyash brick.

Claims

1. additive of powdered coal ash product, be the organic-inorganic dispersion of materials liquid of the emulsion form of a kind of organic materials acrylate copolymer and inorganic materials silicon-dioxide composition, its weight proportion is: acrylate copolymer 25-40%, Starso or silicon-dioxide aerosol 2-10%, sodium alkyl benzene sulfonate or sodium alkyl sulfate 0.5-5%, polyethylene oxide alkyl ethers 1-6%, deionized water 55-70%, wherein: the acrylate copolymer component is methyl methacrylate 35-45%, 2 ethyl hexyl acrylate 0-55%, butyl acrylate 0-55%, vinylformic acid 2.5-5%.

2. the preparation method of additive of powdered coal ash product as claimed in claim 1 is: at first add entry in flask; tensio-active agent; sodium bicarbonate; Starso or silicon-dioxide aerosol; the mechanical stirring dissolving; under nitrogen protection; be heated to 80 ℃; with above-mentioned methyl methacrylate; n-butyl acrylate; after being mixed in proportion, 2 ethyl hexyl acrylate and Acrylic Acid Monomer pour in the feed hopper; average rate is added dropwise in the beaker; average rate drips potassium persulfate solution simultaneously, and reinforced finishing in 1.5 hours is after dropping finishes; under uniform temp, continue reaction 1 hour; be cooled to room temperature, regulating pH value with strong aqua is 8-9, organic-inorganic dispersion of materials liquid that can be stable.