Impurity-resistant water reducing agent for high-silica-content refractory castable and preparation method thereof
阅读说明：本技术 一种用于高硅灰耐火浇注料的抗杂质减水剂及其制备方法 (Impurity-resistant water reducing agent for high-silica-content refractory castable and preparation method thereof ) 是由 陈娜 黄凯 黄異 包颖 于 2021-07-05 设计创作，主要内容包括：本发明提供了一种用于高硅灰耐火浇注料的抗杂质减水剂,减水剂各组分及质量配比为：羧酸单体500～700份、交联单体20～50份、聚氨酯起始单体50～100份、异氰酸酯单体30～50份、醚类羟基单体100～200份、催化剂1.5～2.5份、引发剂0.5～1.5份、缓释粉体300～500份；其中异氰酸酯单体为甲苯二异氰酸酯、二苯基甲烷二异氰酸酯、异佛尔酮二异氰酸酯、六甲撑二异氰酸酯中的任意一种或者两种以上的混合物。本发明还提供了一种用于高硅灰耐火浇注料的抗杂质减水剂的制备方法,制备方法简单方便。本发明所制得的抗杂质减水剂具有极佳的分散性能,将抗杂质减水剂用于高硅灰耐火浇注料中,浇注料的流动性以及成型性能好。(The invention provides an impurity-resistant water reducing agent for a high-silica-content refractory castable, which comprises the following components in percentage by mass: 500-700 parts of carboxylic acid monomer, 20-50 parts of crosslinking monomer, 50-100 parts of polyurethane starting monomer, 30-50 parts of isocyanate monomer, 100-200 parts of ether hydroxyl monomer, 1.5-2.5 parts of catalyst, 0.5-1.5 parts of initiator and 300-500 parts of slow release powder; wherein the isocyanate monomer is any one or a mixture of more than two of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate. The invention also provides a preparation method of the impurity-resistant water reducing agent for the high silica fume refractory castable, and the preparation method is simple and convenient. The impurity-resistant water reducing agent prepared by the invention has excellent dispersion performance, and the fluidity and the forming performance of the castable are good when the impurity-resistant water reducing agent is used in the high-silica-content refractory castable.)
1. An impurity-resistant water reducing agent for high silica fume refractory castable, which is characterized in that: the water reducing agent comprises the following components in percentage by mass: 500-700 parts of carboxylic acid monomer, 20-50 parts of crosslinking monomer, 50-100 parts of polyurethane starting monomer, 30-50 parts of isocyanate monomer, 100-200 parts of ether hydroxyl monomer, 1.5-2.5 parts of catalyst, 0.5-1.5 parts of initiator and 300-500 parts of slow release powder;
the isocyanate monomer is any one or a mixture of more than two of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate, the polyurethane initial monomer and the isocyanate monomer react with the ether hydroxyl monomer to generate long-chain polyurethane, and the distribution and chain length of alkoxy on the long-chain polyurethane are adjusted by the ether hydroxyl monomer with different molecular weights, so that the winding effect of hydrogen bonds formed by the alkoxy and impurities on the molecular chains is reduced.
2. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the polyurethane initial monomer is any one of isocyanate ethyl acrylate, isocyanate ethyl methacrylate and ethoxylated isocyanate ethyl acrylate.
3. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the ether hydroxyl monomer is polyethylene glycol ether with the molecular weight of 300-800.
4. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the crosslinking monomer is any one or a mixture of more than two of trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate and dipentaerythritol pentaacrylate.
5. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the carboxylic acid monomer is any one or a mixture of more than two of methacrylic acid, acrylic acid, maleic anhydride and fumaric acid.
6. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the catalyst is any one or a mixture of two of dibutyltin dilaurate and tin acetate.
7. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the initiator is a mixture of triarylsulfonium salt and cumen ferrocenyl hexafluorophosphate according to a mass ratio of 2: 1-4: 1.
8. The impurity-resistant water reducing agent for high silica fume refractory castable of claim 1, wherein: the slow release powder has a specific surface area of 100-300 m2In g of fumed alumina.
9. The preparation method of the impurity-resistant water reducing agent for the high silica fume refractory castable according to claim 1, characterized by comprising the steps of: adding a carboxylic acid monomer, a polyurethane initial monomer, an ether hydroxyl monomer, a crosslinking monomer and an initiator into a reaction kettle, starting stirring, uniformly stirring and mixing, then opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 40-50 ℃, setting the stirring speed at 15-30 rpm, keeping the stirring speed for 30-60 min, then closing the ultraviolet lamp, then adding an isocyanate monomer and a catalyst, stirring for 15-20 min, then heating to 90 ℃, keeping the temperature for 3-5 h, finally directly pouring into a granulator and slowly adding slow release powder, and keeping the slow release powder for 10-20 min for discharging.
Technical Field
The invention belongs to the technical field of refractory castable, relates to a water reducing agent, and particularly relates to an impurity-resistant water reducing agent for a high-silica-content refractory castable.
Background
The refractory castable is composed of refractory aggregate, powder, a bonding agent, an additive, water or other liquid materials, has high fluidity, can be molded by methods such as pouring, vibration, tamping and the like, can also be directly made into prefabricated parts, and can be hardened without heating. The raw materials are as follows: the castable mainly comprises different refractory raw materials such as clay castable, high-alumina castable, siliceous castable, mullite castable, corundum castable, magnesium castable, silicon carbide castable and the like. The refractory castable has the advantages of low cost, simple process, convenient construction and the like, and can be used for casting linings of high-temperature kilns, boilers, thermal equipment and the like. After the refractory castable is stirred by adding water, a water molecular layer can be formed on the surfaces of castable particles due to hydration, and in addition, association is generated among the particles due to anisotropic charges carried on the surfaces of the particles, so that a flocculation structure is formed in the castable. Therefore, a portion of the mixing water is entrapped in the particles and cannot participate in free flow and lubrication, thereby affecting the flowability of the casting material.
The water reducing agent is an anionic surfactant, and is added into the refractory castable, and is adsorbed on the surfaces of castable particles, so that the castable particles are charged with the same kind of charges to form an electrostatic repulsion effect, the castable particles are mutually dispersed, the flowability of the castable particles is improved, the unit water consumption is reduced, and the construction is facilitated. In addition, the structure of the water reducing agent has hydrophilic branched chains, and the hydrophilic branched chains extend in an aqueous solution, so that a hydrophilic three-dimensional adsorption layer with a certain thickness can be formed on the surfaces of the adsorbed castable particles. When the castable particles approach, the adsorption layers begin to overlap, steric hindrance effect is generated among the particles, the more the overlapping is, the larger the steric hindrance repulsive force is, the larger the obstruction to the condensation effect among the castable particles is, and the slump of the castable is kept good.
The water reducing agent contains polycarboxylic acids, phosphates, polyacrylates and the like which can achieve better dispersing and anti-flocculation effects on the refractory castable. And the organic component polycarboxylic acid molecules of the ether polycarboxylic acid water reducing agent have good water solubility, and the main chain is adsorbed on the surface of the casting material after being dissolved in water, so that the casting material particles carry the same charge to form an electrostatic repulsion effect, and in addition, the branched chains of the ether polycarboxylic acid water reducing agent surround the periphery of the casting material to play a steric hindrance effect. Therefore, the ether polycarboxylic acid water reducing agent has two flocculation resistance repulsion functions of electrostatic repulsion and steric hindrance, and is widely used in refractory castable.
However, researches show that the ether polycarboxylic acid water reducer is sensitive to raw materials of the refractory castable, for example, the content and purity of silica powder in the raw materials and the purity of alumina can influence the dispersing effect of the ether polycarboxylic acid water reducer. The impurity elements contained in the silicon micropowder and the alumina can generate hydrogen bonding with alkoxy in the ether water reducer, and the hydrogen bonding can cause the winding of alkoxy chain links along with the increase of the alkoxy chain links, so that the inactivation of the water reducer is caused, and the dispersion effect of the high-silica-content refractory castable is influenced. Therefore, the technical scheme which can reduce the influence of impurities in the raw materials of the high-silica-content refractory castable on the dispersion effect and has good dispersion and flocculation resistance effects is urgently needed in the field.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the impurity-resistant water reducing agent for the high-silica-content refractory castable, the impurity-resistant water reducing agent has excellent dispersion performance, and the fluidity and the forming performance of the castable are good when the impurity-resistant water reducing agent is used in the high-silica-content refractory castable.
The technical scheme adopted for realizing the above purpose of the invention is as follows:
an impurity-resistant water reducing agent for a high-silica-content refractory castable material comprises the following components in parts by mass: 500-700 parts of carboxylic acid monomer, 20-50 parts of crosslinking monomer, 50-100 parts of polyurethane starting monomer, 30-50 parts of isocyanate monomer, 100-200 parts of ether hydroxyl monomer, 1.5-2.5 parts of catalyst, 0.5-1.5 parts of initiator and 300-500 parts of slow release powder;
the isocyanate monomer is any one or a mixture of more than two of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate, the polyurethane initial monomer and the isocyanate monomer react with the ether hydroxyl monomer to generate long-chain polyurethane, and the distribution and chain length of alkoxy on the long-chain polyurethane are adjusted by the ether hydroxyl monomer with different molecular weights, so that the winding effect of hydrogen bonds formed by the alkoxy and impurities on the molecular chains is reduced.
The polyurethane initial monomer is any one of isocyanate ethyl acrylate, isocyanate ethyl methacrylate and ethoxylated isocyanate ethyl acrylate.
The ether hydroxyl monomer is polyethylene glycol ether with the molecular weight of 300-800.
The crosslinking monomer is any one or a mixture of more than two of trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate and dipentaerythritol pentaacrylate.
The carboxylic acid monomer is any one or a mixture of more than two of methacrylic acid, acrylic acid, maleic anhydride and fumaric acid.
The catalyst is any one or a mixture of two of dibutyltin dilaurate and tin acetate.
The initiator is a mixture of triarylsulfonium salt and cumen ferrocenyl hexafluorophosphate according to a mass ratio of 2: 1-4: 1.
The slow release powder has a specific surface area of 100-300 m2In g of fumed alumina.
The invention also provides a preparation method of the impurity-resistant water reducing agent for the high silica fume refractory castable, which comprises the following steps: adding a carboxylic acid monomer, a polyurethane initial monomer, an ether hydroxyl monomer, a crosslinking monomer and an initiator into a reaction kettle, starting stirring, uniformly stirring and mixing, then opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 40-50 ℃, setting the stirring speed at 15-30 rpm, keeping the stirring speed for 30-60 min, then closing the ultraviolet lamp, then adding an isocyanate monomer and a catalyst, stirring for 15-20 min, then heating to 90 ℃, keeping the temperature for 3-5 h, finally directly pouring into a granulator and slowly adding slow release powder, and keeping the slow release powder for 10-20 min for discharging.
Compared with the prior art, the impurity-resistant water reducing agent for the high-silica-content refractory castable provided by the invention has the following advantages: 1. the preparation method of the impurity-resistant water reducing agent provided by the invention is simple and convenient, and the water reducing agent is powdery, uniform in powder and convenient and simple to use; 2. according to the invention, isocyanate groups in polyurethane initial monomer chain segments react with ether hydroxyl monomers and hydroxyl groups in crosslinking monomers to generate long-chain polyurethane, and the chain segments of the polyurethane initial monomers contain propenyl chain segments, so that the reactivity and selectivity of the polyurethane initial monomers are higher, the requirements on equipment and environmental conditions are reduced, the molecular weight distribution of reaction products is narrowed due to the accurate condensation control, the chain length regularity of side chains is improved, and the performance of the effective molecular weight products of the products is improved and is closer to the theoretical design range. 3. According to the invention, the polyurethane initial monomer, the isocyanate monomer and the ether hydroxyl monomer react to generate long-chain polyurethane, and the distribution and chain length of alkoxy groups on the long-chain polyurethane are adjusted by the polyglycol ethers with different molecular weights, so that the hydrogen bond effect between impurities and the alkoxy groups contained in the silica powder is greatly reduced, the winding effect on the molecular chains is reduced, and the probability of flocculation or influence on the fluidity is reduced. 4. The poor polarity between the polyurethane functional group and the ethoxy group can generate an association effect, so that the workability of the product is improved, the mud separation phenomenon is not easy to occur, the water reducing agent can generate better fluidity in a high silica fume system, and the sensitivity to the powder quality and the water adding amount is reduced. 5. The polycarboxylic acid molecule has good water solubility, the main chain is adsorbed on the surface of cement after being dissolved in water, and the branched chain surrounds the periphery of the cement, so that the polycarboxylic acid molecule has double effects of steric hindrance and electrostatic repulsion, and has good dispersion effect and water reducing effect.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention is further described in detail with reference to the following examples.
Example 1
The impurity-resistant water reducing agent for the high silica fume refractory castable provided in the embodiment is prepared by the following method:
adding 500 parts of maleic-rich acid, 80 parts of ethyl isocyanate acrylate, 100 parts of polyethylene glycol ether with molecular weight of 350, 20 parts of trimethylolpropane trimethacrylate, 0.5 part of a mixture of triarylsulfonium salt and cumeneferrocene hexafluorophosphate according to a ratio of 2:1 into a reaction kettle, starting stirring, uniformly stirring, then opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 45 ℃, setting the stirring speed at 25rpm, keeping the stirring speed for 60min, then closing the ultraviolet lamp, then adding 30 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate, stirring for 15min, heating to 90 ℃, keeping the temperature for 5h, finally directly pouring into a granulator, slowly adding 300 parts of polyethylene glycol ether with specific surface area of 100m2The gas phase alumina of per gram is kept for 10min after being added completely and then is discharged.
Comparing the impurity-resistant water reducing agent for the high-silica-content refractory castable material obtained in the embodiment with other water reducing agents, and using the water reducing agent and the other water reducing agents obtained in the embodiment in a cement-bonded high-purity system, the formula of each group is shown in the following table, wherein the water reducing agent used in the No. A1 is sodium tripolyphosphate, the water reducing agent used in the No. A2 is an ether polycarboxylic acid water reducing agent A of a certain company, and the water reducing agent used in the No. A3 is the water reducing agent obtained in the embodiment.
The results of the tests performed on the products obtained in the three experiments are shown in the table below.
Testing performance
A1
A2
A3
Flow value/mm
105
130
175
24h demoulding rupture strength/MPa
5.5
4.8
7.3
Bending strength/MPa at 110 deg.C for 24h
12.5
12.3
13.9
As can be seen from the above table, in the cement-bonded high-purity system, the water reducing agent in the example has good fluidity, 24h demold breaking strength and 110 ℃ x 24h breaking strength compared with other water reducing agents applied to the system.
Example 2
The impurity-resistant water reducing agent for the high silica fume refractory castable provided in the embodiment is prepared by the following method:
adding 300 parts of maleic anhydride, 300 parts of acrylic acid, 100 parts of ethyl acrylate, 150 parts of polyethylene glycol ether with the molecular weight of 800, 30 parts of ethoxylated trimethylolpropane triacrylate and 0.5 part of a mixture of triarylsulfonium salt and cumen ferrocenyl hexafluorophosphate according to the ratio of 2:1 into a reaction kettle, starting stirring, uniformly stirring, opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 50 ℃, setting the stirring speed at 25rpm, closing the ultraviolet lamp after keeping for 60min, then adding 45 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate, stirring for 15min, heating to 90 ℃, keeping the temperature for 5h, finally directly pouring into a granulator, slowly adding 300 parts of a mixture with the specific surface area of 300 parts200m2The gas phase alumina of per gram is kept for 10min after being added completely and then is discharged.
The anti-impurity water reducing agent for the high silica fume refractory castable obtained in the embodiment is compared with other water reducing agents, the water reducing agent and the other water reducing agents obtained in the embodiment are used in the high silica fume cement combined high alumina castable, the formula of each group is shown in the following table, wherein the water reducing agent used in the No. B1 is sodium tripolyphosphate, the water reducing agent used in the No. B2 is an ether polycarboxylic acid water reducing agent B of a certain company, and the water reducing agent used in the No. B3 is the water reducing agent obtained in the embodiment.
The results of the tests performed on the products obtained in the three experiments are shown in the table below.
Testing performance
B1
B2
B3
Flow value/mm
108
150
210
24h demoulding rupture strength/MPa
2.5
3.1
3.3
Bending strength/MPa at 110 deg.C for 24h
11.5
11.8
13.1
As can be seen from the above table, in the high silica fume cement combined high alumina castable, the water reducing agent in the embodiment has good fluidity, 24h demoulding rupture strength and 110 ℃ x 24h rupture strength compared with other water reducing agents applied to the system.
Example 3
The impurity-resistant water reducing agent for the high silica fume refractory castable provided in the embodiment is prepared by the following method:
adding 300 parts of maleic anhydride, 400 parts of acrylic acid, 75 parts of ethoxylated isocyanate ethyl acrylate, 200 parts of polyethylene glycol ether with the molecular weight of 800, 50 parts of ethoxylated trimethylolpropane triacrylate and 1.5 parts of a mixture of triarylsulfonium salt and cumin cyclopentadienyl iron hexafluorophosphate according to the ratio of 4:1 into a reaction kettle, starting stirring, uniformly mixing, then opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 50 ℃, setting the stirring speed at 25rpm, keeping the stirring speed for 30min, then closing the ultraviolet lamp, then adding 30 parts of diphenylmethane diisocyanate and 2 parts of tin acetate, stirring for 15min, heating to 90 ℃, keeping the temperature for 5h, finally directly pouring into a granulator, slowly adding 500 parts of mixture with the specific surface area of 200m2The gas phase alumina of per gram is kept for 10min after being added completely and then is discharged.
The impurity-resistant water reducing agent for the high silica fume refractory castable material obtained in the embodiment is compared with other water reducing agents, and the water reducing agent obtained in the embodiment and other water reducing agents are used for MgO-SiO2-H2In the O-bonded high-alumina castable, the water reducing agent used in the number C1 is sodium tripolyphosphate, the water reducing agent used in the number C2 is an ether polycarboxylic acid water reducing agent C of a certain company, and the water reducing agent used in the number C3 is the water reducing agent obtained in the embodiment.
The results of the tests performed on the products obtained in the three experiments are shown in the table below.
Testing performance
C1
C2
C3
Flow value/mm
125
155
195
24h demoulding rupture strength/MPa
1.2
1.2
1.3
Bending strength/MPa at 110 deg.C for 24h
9.8
9.6
10.5
As can be seen from the above table, in MgO-SiO2-H2In the O-bonded high-alumina castable, compared with other water reducers applied to the system, the water reducer in the embodiment has good performanceThe 24h demolding rupture strength and the 110 ℃ multiplied by 24h rupture strength.
Example 4
The impurity-resistant water reducing agent for the high silica fume refractory castable provided in the embodiment is prepared by the following method:
adding 300 parts of maleic anhydride, 400 parts of acrylic acid, 50 parts of ethoxylated isocyanate ethyl acrylate, 180 parts of polyethylene glycol ether with the molecular weight of 500, 50 parts of ethoxylated trimethylolpropane triacrylate and 1.5 parts of a mixture of triarylsulfonium salt and cumin cyclopentadienyl iron hexafluorophosphate according to the ratio of 4:1 into a reaction kettle, starting stirring, uniformly mixing, then opening a reaction ultraviolet lamp, simultaneously heating and keeping the temperature at 50 ℃, setting the stirring speed at 25rpm, keeping the stirring speed for 60min, then closing the ultraviolet lamp, adding 35 parts of diphenylmethane diisocyanate and 2 parts of tin acetate, stirring for 15min, heating to 90 ℃, keeping the temperature for 5h, finally directly pouring into a granulator, slowly adding 500 parts of mixture with the specific surface area of 200m2The material is discharged after all the gas phase alumina is added for 20 min.
The anti-impurity water reducing agent for the high silica fume refractory castable obtained in the embodiment is compared with other water reducing agents, the water reducing agent and the other water reducing agents obtained in the embodiment are used in a cement-bonded inactive alumina castable, and the formula of each group is shown in the following table, wherein the water reducing agent used in the number D1 is sodium tripolyphosphate, the water reducing agent used in the number D2 is an ether polycarboxylic acid water reducing agent D of a certain company, and the water reducing agent used in the number D3 is the water reducing agent obtained in the embodiment.
The results of the tests performed on the products obtained in the three experiments are shown in the table below.
Testing performance
D1
D2
D3
Flow value/mm
110
145
200
24h demoulding rupture strength/MPa
1.7
2
2.2
Bending strength/MPa at 110 deg.C for 24h
9
9.2
10.4
As can be seen from the above table, in the cement-bonded inactive alumina castable, the water reducer in the embodiment has good fluidity, 24h demolding rupture strength and 110 ℃ x 24h rupture strength compared with other water reducers applied to the system.
Example 5
The impurity-resistant water reducing agent for the high silica fume refractory castable provided in the embodiment is prepared by the following method:
adding 600 parts of acrylic acid, 90 parts of isocyanate ethyl methacrylate, 100 parts of polyethylene glycol ether with molecular weight of 800, 50 parts of ethoxylated trimethylolpropane triacrylate and 1.5 parts of a mixture of triarylsulfonium salt and cumenmetallocene iron hexafluorophosphate according to a ratio of 3: 1 into a reaction kettle, starting stirring, uniformly mixing, openingReacting an ultraviolet lamp, simultaneously heating and keeping the temperature at 50 ℃, setting the stirring speed at 25rpm, keeping the stirring speed for 60min, then turning off the ultraviolet lamp, then adding 50 parts of diphenylmethane diisocyanate and 2 parts of tin acetate, stirring for 15min, heating to 90 ℃, keeping the temperature for 5h, finally directly pouring into a granulator, and slowly adding 500 parts of the mixture with the specific surface area of 200m2The material is discharged after all the gas phase alumina is added for 20 min.
The impurity-resistant water reducing agent for the high silica fume refractory castable material obtained in the embodiment is compared with other water reducing agents, and the water reducing agent obtained in the embodiment and other water reducing agents are used for MgO-SiO2-H2In the combination of O and the pure magnesium castable, the following tables are shown in the formulas, wherein the water reducing agent used in the code E1 is sodium tripolyphosphate, the water reducing agent used in the code E2 is an ether polycarboxylic acid water reducing agent E of a certain company, and the water reducing agent used in the code E3 is the water reducing agent obtained in the embodiment.
The results of the tests performed on the products obtained in the three experiments are shown in the table below.
Testing performance
E1
E2
E3
Flow value/mm
100
155
200
24h demoulding rupture strength/MPa
0.5
0.8
1
Bending strength/MPa at 110 deg.C for 24h
10.5
10.2
11.4
As can be seen from the above table, in MgO-SiO2-H2In the O-bonded pure magnesium castable, compared with other water reducers applied to the system, the water reducer in the embodiment has good fluidity, 24-hour demoulding rupture strength and 110 ℃ x 24-hour rupture strength.
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