JPH0519500B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an inorganic binder. Furthermore,
This invention relates to an inorganic binder containing a boron component-containing calcium silicate fine powder and an activated silica fine powder, and relates to a characteristic inorganic binder having both hydraulic and gelatinous properties. [Prior art] Various metallurgical slags such as blast furnace slag, ferroalloy slag, and metal magnesium slag have basic calcium silicate as their main composition, and their powders, especially granulated slag powders, contain latent water. Because of its hardness, it is well known that it is used as a cement material, such as in blast furnace cement. However, since such slag itself usually has a slow hydraulic reaction, it is not currently put to practical use alone. Therefore, when using such slag as a cement material, it must be used together with cement such as Portland cement or alumina cement, or with alkali stimulants such as quicklime, slaked lime, alkali metal compounds, gypsum, calcium chloride, sulfate, and other adjuvants. A wide variety of such cement compositions have been proposed, and many proposals have been made and put into practical use. [Problems to be Solved by the Invention] Conventionally, in the use of typical blast furnace slag as a cement material, cement compositions made by combining the slag with other components often have drawbacks due to compounding, Compared to Portland cement, it has fewer characteristics and its performance is inferior. Incidentally, the present inventors have discovered that, in connection with the so-called pulverization problem of steelmaking slag, slag is significantly modified by adding boron-containing glass to the molten slag for the purpose of modifying the slag. succeeded in paving the way for its use in cement (Patent Application No. 312481/1981). However, the hydraulic properties of this material are insufficient in terms of strength and must be improved. Furthermore, although the development of cement materials by modifying slag is the most desirable from an economic standpoint, due to the inevitable reasons in the process, significant variations in composition occur, making it impossible to obtain a cement material with a stable composition. There are drawbacks. [Means for solving the problem] In view of the above points, in order to further improve the hydraulic properties of calcium silicate-based fine powder containing a boron component, we have been researching the hydraulic properties and found a composition in which activated silica fine powder is blended with this powder. The present invention was completed based on the discovery that the fire resistance as well as the hydraulic properties of the product were significantly improved. That is, in the present invention, basicity = (CaO + MgO + M ₂ O) / (SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ )
(weight ratio) (in the formula, M represents an alkali metal) is 1.3 to 3.0
and the boron content is 0.1 to _5.0 in terms of _B2O3 .
The present invention relates to an inorganic binder characterized by comprising calcium silicate fine powder and activated silica fine powder containing % by weight. [Function] The calcium silicate fine powder, which is one of the components of the inorganic binder according to the present invention, contains a boron component, and it is important that it has the above composition, and has hydraulic properties by itself. It is. Such a fine powder is advantageously modified by adding a boron-containing substance to a molten material such as steelmaking slag, but its composition must have the above-mentioned basicity. Further, in the present invention, the slag is not related to modified slag, but may be a composite having the above composition. That is, a calcium-containing substance, a silicic acid substance, a boron-containing substance, alumina, magnesia, and a fluorine-containing substance are melted in a predetermined composition, then cooled and pulverized. As described above, the history of calcium silicate-based fine powder must be that of a molten body, and a thermal history comparable to that of a sintered body is not appropriate. Furthermore, after melting, it must be slowly cooled to form a fine powder and crystalline. In this way, if the basicity is outside the range defined above, hydraulic properties do not develop, and even if they develop, they are insufficient and lack strength, lack practicality, and those that are not crystalline have fire resistance. It lacks. The modified slag powder is preferably, for example, steel manufacturing slag such as stainless steel, ferrochrome slag, etc., but is not limited thereto. In addition to the above basicity, it is particularly recommended that the calcium silicate- _based fine powder contains a boron component of 0.1 to 5% by weight as _B2O3 , and more preferably a fluorine component of 3 to 10% by weight as F. . Even if the boron content is small, it significantly modifies the physical properties of calcium silicate, making it impossible to improve the physical properties to hydraulic properties and fire resistance. However, if the boron content is outside the above range, the modification is insufficient. Otherwise, it is unsuitable because it adversely deteriorates the fire resistance. Therefore, boron content is often expressed as B ₂ O ₃
A range of 0.3 to 1% by weight is most preferred. As described above, one of the features of the present invention is that one component of the binder is a material obtained by modifying a highly basic calcium silicate material by containing a small amount of boron component in a uniform structure. It's summery. In general, highly basic calcium silicate causes a powdering phenomenon when slowly cooled, as seen in molten slag, but when it is modified with a boron component, this phenomenon is inhibited, and at the same time, hydraulic properties occur and the modification occurs. The effect can be recognized. The above calcium silicate-based fine powder may have a Blaine specific surface area of 1,500 to 10,000 m ² /g, but in most cases, 2,000 to 6,000 m ² /g is practical and suitable. Next, as another component of the inorganic binder according to the present invention, there is activated silica fine powder, which is essential for improving the physical properties of the binder. Here, activated silica refers to a silica raw material that causes a neutralization reaction, so-called hozolan reaction, with a basicity component such as calcium in a boron component-containing calcium silicate fine powder, such as fluorocon dust. , fumed silica, silica sol, activated clay, etc., and ultrafine powdered silica such as ferrosilicon dust and fumed silica are particularly suitable. The combination of these two components needs to be determined depending on the intended use of the binder, the composition of the calcium silicate-based fine powder, the type of active silica, etc., but in most cases, the active silica is Silica is in the range of 5 to 50 parts by weight, preferably in the range of 7 to 30% by weight. As a matter of course, when using the binder according to the present invention, for example, sand, silica grains, waxite, crushed stone grains, refractory grains such as siyamoto, aggregates such as coarsely crushed slag grains, carbon fibers, organic Synthetic fiber,
Desired reinforcing materials and molded bodies can be obtained by appropriately using various short fibers such as glass fibers or coloring agents. Since the inorganic binder according to the present invention is hydraulic, it can be said to belong to the category of a type of cement in that sense, but unlike ordinary cement compositions, it does not require general steam curing. , after hydraulic hardening and demolding, it is sufficient to perform curing in the air, and the heat of hydration is also extremely small. During hydraulic hardening, the ratio of water to cement is called w/c.
Of course, a smaller value is preferable for increasing strength, but the material according to the present invention is characterized in that this w/c is smaller than that of ordinary cement. For example, a suitable amount of water is 5 to 40 parts by weight, often 6 to 25 parts by weight per 100 parts by weight of binder. In addition, when kneading with water, a known dispersant or foaming agent commonly used in the case of cement can be used in combination, if necessary. Surprisingly, since ordinary cement compositions are hydraulic binders, their strength deteriorates when heated, and they generally have no heat resistance, let alone so-called fire resistance. The binder is heat and fire resistant, and when heated to around 1000°C, it has the property of improving strength rather than causing thermal deterioration. Therefore, for example, when a cured product using the binder according to the present invention is heated at 800 to 1100°C, it can be considered that the hydraulic strength has been converted to sintering strength, and for example, when a molded panel is struck, It can be called ceramics because it emits a porcelain-like sound.
It can be said to be a unique inorganic binder that has both cementitious and ceramic properties. [Examples] Examples are given below to specifically explain the present invention, and all parts and percentages are based on weight. Implementation 1 to 5 A composition containing a predetermined amount of modified stainless steel slag fine powder (Blaine specific surface area 3000 m ² /g) containing a boron component shown in Table 1 and ferrosilicon dust [manufactured by Yakushima Electric Co., Ltd.] were uniformly mixed to form an inorganic binder. These were mixed with coarsely crushed slag (90% or more of 1-5 mm), mixed with an appropriate amount of water with a dispersant, and then vibration-molded to form a test panel (20×
20×10mm) was created. After natural curing, this panel was dried at 150°C and a bending strength test was performed on it before and after firing, and after firing and curing in water.
The results shown in Table 2 were obtained. Table 1 Ingredients % CaO 46.1 SiO ₂ 16.8 Al ₂ O ₃ 14.6 MgO 10.7 Fe ₂ O ₃ 2.2 Cr ₂ O ₃ 2.1 F 6.8 B ₂ O ₃ 0.5

[Table] Examples 6 to 8 Synthetic calcium silicate fine powder having the composition shown in Table 3 (Blaine specific surface area 3500 m ² /g) and Example 1
and a predetermined amount of the same ferrosilicon dust to prepare an inorganic binder. A small amount of water was added to this inorganic binder and kneaded to make a 5cmφ x 10cm cylindrical test rod. After natural curing, the unconfined compressive strength of the rod was measured.
The results in the table were obtained. Table 3 Ingredients % CaO 51.1 SiO ₂ 17.8 Al ₂ O ₃ 13.8 MgO 10.5 Fe ₂ O ₃ 2.7 F 7.0 B ₂ O ₃ 0.6

〔Effect of the invention〕

The inorganic binder according to the present invention is a binder having physical properties different from those of ordinary Portland cement and hydraulic slag cement. That is, it is a characteristic inorganic binder that has both cementitious properties and ceramic properties, has hydraulic properties with a small amount of water, and its cured product is heat resistant and exhibits ceramic properties. Therefore, the inorganic binder according to the present invention can be used to create various characteristic molded bodies, and can be expected to be used in the fields of building materials and ceramics.

Claims (1)

[Claims] 1 Basicity = (CaO + MgO + M ₂ O) / (SiO ₂ + Al ₂ O ₃ + B ₂ O ₃
) (weight ratio) (in the formula, M represents an alkali metal) is 1.3 to 3.0
and the boron content is 0.1 to _5.0 in terms of _B2O3 .
An inorganic binder comprising calcium silicate fine powder and activated silica fine powder containing % by weight. 2. The inorganic binder according to claim 1, wherein the calcium silicate-based fine powder contains 3 to 10% by weight of a fluorine component as F. 3. The inorganic binder according to claim 1 or 2, wherein the calcium silicate-based fine powder is a crystalline fine powder having a Blaine specific surface area of 1,500 to 10,000 m ² /g of the molten and cooled material. 4. The inorganic binder according to claim 1, which contains 5 to 50 parts by weight of activated silica per 100 parts by weight of calcium silicate-based fine powder.