JPH10167791A - Additive for alumna cement, alumina cement composition containing the same and amorphous refractory material by using the same composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an alumina cement composition aiming at the improvement of self flowing property without causing a separation of materials by including alumina cement, a thickening agent containing a polyethylene oxide and/or a protein, a fluidizing agent and a coagulation retarder. SOLUTION: This alumina cement composition is obtained by blending 100 pts.wt. alumina cement, 0.1-10 pts.wt. thickening agent containing 0.05-6 pts.wt. polyethylene oxide and/or protein such as casein, gelatin, petroleum artificial protein, etc., 0.05-5 pts.wt. fluidizing agent such as a salt of the condensation product of naphthalenesulfonic acid with formalin, a salt of a condensation product of a melamine resin sulfonic acid with formalin, etc., and 0.01-2 pts.wt. coagulation retarder such as an oxycarboxylic acid or its alkali salt, etc. The prepared unshaped refractory material is obtained by mixing 80-99 pts.wt. above composition, a silica fume, a noncrystalline silica and refractory aggregate such as a clay, and 2-10 pts.wt. water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alumina cement additive, an alumina cement composition containing the same, and an amorphous refractory using the alumina cement composition. The present invention relates to an alumina cement additive for ensuring fluidity, an alumina cement composition containing the same, and an amorphous refractory using the same.

[0002] The product of the present invention is used in the field of refractories in which alumina cement is used, lining of chemical plants, corrosion-resistant materials,
And it can be used in the field of civil engineering and construction.

[0003]

2. Description of the Related Art In the field of refractories, which is one of the major fields of use of alumina cement, the conventional furnace construction method using fixed refractories has recently been required to save labor and labor by mechanization. In addition, in order to save resources for endless repairs, the construction method has been converted to a furnace construction method using irregular-shaped refractories. In addition, due to the rapid conversion to a furnace construction method using an amorphous refractory in recent years, the necessity of mass construction using a pressure pump has also arisen.

On the other hand, casting is performed as one of the methods of applying irregular-shaped refractories. However, there is a problem that it is necessary to prevent poor filling and poor casting at the time of pouring. In other words, in order to enhance the fluidity of the material and improve the filling property, a vibrator, for example, a vibrating operation of applying a vibration with a rod-shaped vibrator or the like is performed. However, there is a problem that material filling failure occurs. In addition, the vibration work using a vibrator or the like is a very heavy work involving noise, vibration, and heat.In terms of labor saving, the work is improved, that is, the vibration work process is not required. The development of a good casting material was desired.

In recent years, there has been proposed a non-vibration, that is, an amorphous refractory which can be constructed in a self-flowing manner, using general alumina cement and an aggregate having a specific particle size (Japanese Patent Laid-Open No. 4-2606).
No. 73, JP-A-5-180689, JP-A-7-237977
And JP-A-8-133850. However, in these technologies, ordinary alumina cement is used, and only by the particle size composition of the aggregate, which is another constituent material, the combined use of additives such as a thickener and a fluidizing agent, and the minute adjustment thereof, the irregular shape is not obtained. The fluidity of the refractory cannot be improved,
In addition, there is a problem that material separation such as breathing occurs due to an increase in the amount of water used in order to improve fluidity.

The present inventor has conducted various studies to solve the above-mentioned problems, and as a result, by using a specific material, the fluidity of alumina cement itself, which is one of the constituent materials of the amorphous refractory, can be improved. As a result, the above problem can be solved, and in particular, the present invention has been completed by obtaining the knowledge that fluidity can be obtained without material separation required for a self-flowing amorphous refractory.

[0007]

That is, the present invention provides a thickener containing polyethylene oxide and / or protein,
A fluidizing agent, and an additive for alumina cement containing a setting retarder, an alumina cement composition containing alumina cement and the additive for alumina cement, the alumina cement composition comprising An amorphous refractory containing refractory aggregate.

Hereinafter, the present invention will be described in detail.

The thickener used in the present invention has an effect of preventing material separation by increasing the viscosity of the alumina cement composition obtained by kneading the alumina cement composition, the refractory aggregate and the water of the present invention. And containing polyethylene oxide and / or protein in its components.

[0010] Here, polyethylene oxide is produced by subjecting ethylene oxide, which is one of cyclic ethers, to ring-opening polymerization with a Friedel-Crafts catalyst or an acid or alkali catalyst. When the pH value is within the range of 4 to 13, the viscosity is stabilized. The amount of polyethylene oxide used is from 0.05 to 100 parts by weight of alumina cement.
It is preferably 5 parts by weight, more preferably 0.1 to 2 parts by weight.
If the amount is less than 0.05 part by weight, bleeding may occur. If the amount exceeds 5 parts by weight, setting delay may be caused to adversely affect strength development.

The protein has an effect of preventing the bleeding of the kneaded material of alumina cement at a low viscosity. In the present invention, proteins such as casein, gelatin, and artificial petroleum protein can be used. The amount of protein used is 0.1% for 100 parts by weight of alumina cement.
It is preferably 1 to 10 parts by weight, more preferably 0.5 to 3 parts by weight. If the amount is less than 0.1 part by weight, good fluidity may not be obtained, and if it exceeds 10 parts by weight, setting delay may occur, which may adversely affect strength development.

[0012] The fluidizing agent used in the present invention refers to the application of a potential to the alumina cement particles to utilize the electrostatic repulsion, or to adsorb to the surface of the alumina cement particles to form a thickener or the like. It enhances the dispersibility of the alumina cement particles by forming a steric hindrance of the polymer. Examples of those which apply a potential to alumina cement particles and utilize the electrostatic repulsion thereof include salts of naphthalenesulfonic acid formalin condensate (naphthalene type), salts of melamine resin sulfonic acid formalin condensate (melamine type), and lignin type. The olefin / maleic acid copolymer salt (a carboxylic acid type) or the like can be used as a material that forms a steric hindrance of a polymer by adsorbing on the surface of alumina cement particles. Specific examples include sodium salts of highly condensed β-naphthalenesulfonic acid, sodium salts of creosote oil sulfonic acid condensates, sodium salts of low-condensed β-naphthalenesulfonic acid, and polyoxyethylene nonylphenyl ether. Can be The amount of the fluidizing agent is not particularly limited, but is preferably 0.05 to 5 parts by weight, more preferably 0.5 to 2 parts by weight based on 100 parts by weight of the alumina cement. If the amount is less than 0.05 part by weight, good fluidity may not be obtained, and if it exceeds 5 parts by weight, setting delay may occur, which may adversely affect strength development.

[0013] The setting retarder used in the present invention refers to a setting retarder which is temporarily adsorbed on the surface of alumina cement particles.
It delays or temporarily stops the hydration reaction. Specifically, citric acid, tartaric acid, gluconic acid,
Succinic acid, lactic acid, salicylic acid, and oxycarboxylic acids such as malic acid or their sodium salts, potassium salts, and alkali salts such as calcium salts, and calcium hydroxide,
One or more inorganic salts such as calcium oxide, sodium aluminate, sodium carbonate and potassium carbonate can be used. The amount of the setting retarder used can be appropriately determined according to the purpose, usually, alumina cement 100
0.01 to 2 parts by weight, preferably 0.2 to 1 part by weight, per part by weight.
Parts by weight are more preferred. If the amount is less than 0.01 part by weight, the setting may be accelerated. If the amount is more than 2 parts by weight, poor curing may occur, and the strength development may be deteriorated.

The method of mixing the alumina cement additive containing the thickener, the fluidizing agent and the setting retarder used in the present invention with the alumina cement is not particularly limited. Individually to alumina cement,
A method of adding at the time of kneading alumina cement, after previously mixing the individual additives, to the alumina cement,
A method of mixing at the time of kneading the alumina cement is possible.

As the alumina cement used in the present invention, a calcining method and / or a calcining source such as quicklime or limestone from an alumina source such as bauxite or Bayer alumina are used.
Or clinker synthesized by the electrofusion method, which is pulverized by a pulverizer such as a tube mill, a vibration mill, and a roller mill, and as a mineral composition, CaO.Al ₂ O ₃ , CaO.2A
l ₂ O ₃ , 12CaO 7Al ₂ O ₃ , 2CaO Al ₂ O ₃ SiO ₂ , and 4Ca
It is not particularly limited as long as it is a calcium aluminate such as O ₂ Al ₂ O ₃ .Fe ₂ O ₃ or a main component thereof and an amorphous calcium aluminate.

The refractory aggregate used in the present invention is preferably used for alumina cement castables, but is not particularly limited as long as it is a refractory aggregate used for ordinary amorphous refractories. is not. Specifically, as magnesia refractory aggregate, molten magnesia, sintered magnesia, natural magnesia, light-burned magnesia, etc., as magnesia spinel refractory aggregate, molten magnesia spinel, sintered magnesia spinel, etc., further alumina Examples of high-quality refractory aggregates include fused alumina, sintered alumina, lightly sintered alumina, easily sintered alumina, and the like, and ultrafine powders such as silica fume, amorphous silica, colloidal silica, chromium oxide, and titanium oxide.
In addition, fused silica, calcined mullite, chromium oxide, bauxite, andalusite, siliconite, chamotte, quartzite, rubite, clay, zircon, zirconia, dolomite, perlite, vermiculite, brick waste, pottery waste, silicon nitride, boron nitride, It is possible to use silicon carbide and silicon nitride iron. The amount of the refractory aggregate used is 100 irregular shaped refractories consisting of the alumina cement composition and the refractory aggregate.
In the weight part, 80 to 99 parts by weight of the refractory aggregate is preferable, and 90 to 97 parts by weight is more preferable. If the amount is less than 80 parts by weight, sufficient fire resistance may not be obtained. If the amount exceeds 99 parts by weight, adhesion of the refractory aggregate may be weakened, and poor curing or collapse may occur.

The water used in the present invention is not limited in particular, tap water, natural water, and the water used for general concrete river water or the like can be used, Na ^{+,
K +, Mg 2+, Ca 2+} , and Cl ^- use of less water soluble components are preferred. The amount of water used is appropriately determined depending on the intended amorphous refractory, and is not particularly limited, but is preferably 2 to 10 parts by weight based on 100 parts by weight of the amorphous refractory. If the amount of water used is large, breathing may occur or strength may decrease. The method of adding water is not particularly limited, and when kneading the alumina cement kneaded material with a mixer or the like, a method of adding the alumina cement composition and the refractory aggregate after mixing, adding an alumina cement additive to water in advance. There is a method of adding a dissolved substance at the time of kneading. When adding water, it is preferable to use a metering pump or the like that can be added at a constant speed so that the water can be added evenly.

Although the method for producing the amorphous refractory of the present invention is not particularly limited, each component is blended so as to have a predetermined ratio according to the usual method for producing an amorphous refractory. A method of uniformly mixing using a mixer such as a mold blender, a cone blender, a Nauter mixer, a pan mixer, and an omni mixer is possible.

Further, the amorphous refractory of the present invention has the object of preventing explosion that is likely to occur when the cured product is dried.
Metal powders such as metal aluminum and silicon alloys, organic fibers such as vinyl fibers and polypropylene, nitrogen-containing gas products, and explosion-proofing agents such as dextrins can be blended as necessary. The amount of explosion inhibitor used is
It should be determined appropriately according to the intended explosion resistance and cannot be determined uniquely. However, generally, 0.05 to 5 parts by weight is blended with respect to 100 parts by weight of the amorphous refractory. Preferably, 1 to 4 parts by weight is more preferable. If the amount is less than 0.05 part by weight, the effect of preventing explosion may not be obtained, and if it exceeds 5 parts by weight, the fluidity may decrease.

[0020]

The present invention will be further described below with reference to examples.

Example 1 To easily evaluate a refractory, 1 part by weight of a fluidizing agent a and 100 parts by weight of a setting retarder α0.5 were used for 100 parts by weight of alumina cement.
Parts by weight, thickener A shown in Table 1, 200 parts by weight of fine aggregate, and 60 parts by weight of water are kneaded with a mortar mixer to prepare a kneaded product, which is molded and cured, and is subjected to refractory test method JIS R 2521. A mortar specimen similar to the above was prepared. The curing time, curing strength, and dry strength of the prepared mortar specimen were measured together with the flow value and material separation of the kneaded material. The results are also shown in Table 1.

<Materials used> Alumina cement: 80% by weight of main mineral composition CaO.Al ₂ O _{3
2CaO · Al 2 O 3 · SiO} 2 20 wt%, commercially available thickener A: polyethylene oxide, commercially available fluidizing agents a: a lignin-based dispersant, commercially available retarder alpha: sodium gluconate, Wako Pure Chemical First grade reagent fine aggregate: JIS standard sand

<Measurement method of physical properties> Flow value: Evaluation of fluidity, place a flow cone used for JIS R 2521 flow test on a horizontally supported smooth acrylic plate in a constant temperature room at 20 ° C. After filling the mortar into the mortar and smoothing the surface, immediately remove the flow cone to the top, leave it still for 1 minute, and measure the maximum diameter of the mortar and the diameter in the direction perpendicular to this with a vernier caliper. , And the average value in mm. Material separation: After measuring the flow value, visually confirm the mortar separation state. As a measurement standard, ○ indicates no material separation, Δ indicates slight separation, and × indicates complete separation. Curing time: Using a temperature recorder, in a 20 ° C constant temperature room,
The time from when the mortar specimen is made to when the exothermic temperature reaches the maximum. Curing strength: Normal temperature strength: Compressive strength after mortar specimens are packed in a mold frame of 4 × 4 × 16 cm and cured in a constant temperature room at 20 ° C. for 24 hours. Drying strength: A mortar specimen is packed in a 4 × 4 × 16 cm formwork, cured for 24 hours in a constant temperature room at 20 ° C., and further cured at 110 ° C. for 24 hours.
Compressive strength after drying for hours.

[0024]

[Table 1]

From Table 1, it is evident that the use of polyethylene oxide as a thickener provides good fluidity, no material separation, a stable curing time, and improved compressive strength.

Example 2 Example 1 was repeated except that 1 part by weight of a fluidizing agent b, 0.5 part by weight of a setting retarder β, and a thickener B shown in Table 2 were added to 100 parts by weight of alumina cement. Performed similarly. The results are also shown in Table 2.

<Materials used> Fluidizing agent b: naphthalene-based, commercially available setting retarder β: tartaric acid, first grade reagent manufactured by Wako Pure Chemical Co., Ltd. Thickener B: milk casein, commercially available product

[0028]

[Table 2]

From Table 2, it is clear that the use of protein as a thickener provides good flowability, no material separation, stable curing time, and improved compressive strength.

Example 3 The procedure was carried out except that 1 part by weight of a fluidizing agent c, 0.5 part by weight of a setting retarder γ, and thickeners A and B shown in Table 3 were mixed with 100 parts by weight of alumina cement. It carried out like Example 1. The results are also shown in Table 3.

<Materials used> Superplasticizer c: melamine-based dispersant, commercially available setting retarder γ: sodium tartrate, first-class reagent manufactured by Wako Pure Chemical Industries, Ltd.

[0032]

[Table 3]

From Table 3, it can be seen that the combined use of polyethylene oxide and protein as a thickener provides good flowability, no material separation, and a stable curing time.
It is clear that the compressive strength has also been improved.

Example 4 1 part by weight of thickener A, 0.5 part by weight of set retarder α, and
The procedure was performed in the same manner as in Example 1 except that the fluidizing agent a shown in (1) was used. The results are also shown in Table 4.

[0035]

[Table 4]

It is clear from Table 4 that the use of a fluidizing agent can provide a stable curing time without material separation, good fluidity.

Example 5 The procedure of Example 1 was repeated except that 1 part by weight of the thickener B, a fluidizing agent b, and a setting retarder α shown in Table 5 were used.
The results are also shown in Table 5.

[0038]

[Table 5]

From Table 5, it is clear that the use of the setting retarder does not cause material separation, has good fluidity, and can provide a stable curing time.

Example 6 100 parts by weight of alumina cement and 2.5 parts by weight of an alumina cement additive consisting of 1 part by weight of a thickener A, 1 part by weight of a fluidizing agent c, and 0.5 part by weight of a setting retarder γ were uniformly mixed. 6 parts by weight of water was mixed with 100 parts by weight of the mixed alumina cement composition, the refractory aggregate shown in Table 6 and the amorphous refractory, and the mixture was kneaded with a mortar mixer. Except having produced, it carried out similarly to Example 1. The results are also shown in Table 6.

<Materials used> Refractory aggregate A: Sintered alumina, particle size 4 to 1 mm, commercial product Refractory aggregate B: Fine powder alumina, particle size 1 mm or less, commercial product Refractory aggregate C: Silica fume, ultrafine powder, commercial product

[0042]

[Table 6]

From Table 6, it is clear that the amorphous refractory of the present invention has good fluidity, no material separation, a stable curing time, and improved compressive strength.

[0044]

The product of the present invention exhibits high fluidity (self-fluidity) unlike conventional products, has no material separation, can secure a stable material, and has a stable curing property.
The strength development was also improved. When the product of the present invention is used in the refractory field, it is possible to cope with labor-saving construction such as pump construction or vibration-free construction, and troubles such as poor curing due to material separation or insufficient filling due to insufficient vibrator found in conventional products. Occurrence can be prevented.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 35/66 C04B 35/66 J // C04B 103: 22 103: 32

Claims (3)

[Claims] 1. An alumina cement additive containing a thickener, a fluidizing agent, and a setting retarder containing polyethylene oxide and / or protein. 2. An alumina cement composition comprising alumina cement and the additive for alumina cement according to claim 1. 3. An amorphous refractory comprising the alumina cement composition according to claim 2 and a refractory aggregate.