Refractory spray coating material composition for recycling acid-neutral waste refractory material

Abstract

The present invention relates to a refractory spray coating material composition for recycling an acid-neutral waste refractory material, the refractory spray coating material composition being characterized by comprising: 10-80 wt% of an acid-neutral waste refractory material fine aggregate; 5 to 55 wt% of a binder; 5-35 wt% of an endothermic material; 0.3 to 1.7 wt% of an organic fiber; 0.5 to 3.5 wt% of an accelerator; 0.1 to 0.7 wt% of a thickening agent; 0.1 to 0.9 wt% of a fluidizing agent; and an air entraining agent (A.E., air entraining agent) in an amount of 0.05 to 0.15 wt% of the total weight of the composition. Therefore, after being used as blast furnace refractory bricks in an iron and steel plant, most of the acid-neutral waste refractory bricks which are landfilled and discarded in public waters can be recycled and used as a main constituent substance of the refractory spraying and covering material; thus, waste refractory materials are greatly reduced, contributions are made to resource conservation and earth environmental protection, and collapse of the structure can be prevented by preventing concrete burst when a fire occurs in a building and civil engineering site. According to the present invention, the steel frame structure can be prevented from collapsing due to high temperature when a fire occurs, the excellent heat insulation property under the high temperature condition can be ensured due to the small internal pores, and the excellent structural strength can be exhibited when the steel frame structure is suitable for the damaged part of the original concrete structure so as to provide the repairing and reinforcing effect.

Description

Technical Field

[0001] The invention relates to a refractory spray coating material composition, in particular to a refractory spray coating material composition for recycling acid-neutral waste refractory materials. Background Art

[0002] At present, with the increase in the construction of super high-rise buildings, large-scale comprehensive facilities, underground spaces and underground tunnels, and the resulting expansion of the scope of application of the certification system, fire-resistant covering materials and fire-resistant spraying materials have shown an annual growth trend of more than 12%.

[0003] Analysis of the effects of fire temperatures on concrete reveals that dehydration begins at around 250°C, calcium hydroxide decomposes and releases crystallized water at 450-500°C, calcium carbonate decomposes above 600-700°C, and the cement paste completely dehydrates at 900°C. When exposed to high temperatures, concrete properties such as compressive strength and elastic modulus degrade, and the degradation increases with temperature, leading to severe collapse. Furthermore, when exposed to high temperatures, concrete may experience surface layer rupture, resulting in detachment and scattering. Such conditions can cause severe structural damage and lead to rapid collapse. In the event of a large fire, extinguishing the fire can take a long time, potentially resulting in significant damage. As a fire protection measure against large fires like these, a thick layer of refractory mortar can be sprayed onto concrete components to provide protection.

[0004] Generally speaking, in steel mills, various materials are used as interior materials or repair materials for the operating characteristics of various furnaces such as blast furnaces, torpedo ladle cars (TLCs), ladles, converters, vacuum degassing equipment (Ruhrstahl Heraeus), tundishes, heating furnaces, and electric furnaces. Steelmaking refractories are produced in large quantities in shipbuilding and steelmaking processes that handle or process molten iron. Most of these refractories are discarded after a certain period of use, and only a very small portion (approximately 5-6%) is recycled as refractory raw materials.

[0005] Currently, South Korean scrap refractory recycling companies only remove surface impurities after recycling scrap refractory materials and sell them as refractory raw materials. These refractory raw materials can only be recycled as refractory raw materials for steel production. Consequently, recycling these refractory raw materials is subject to numerous restrictions, and to meet demand, low-cost imports must be made, frequently leading to quality degradation.

[0006] Prior art literature

[0007] Patent Literature

[0008] (Patent Document 0001) Registered Patent Gazette No. 10-1492233 Summary of the Invention

[0009] The present invention aims to solve the problems existing in the prior art as described above. The purpose of the present invention is to provide a refractory spray covering material composition that recycles acid-neutral waste refractory materials discarded from steel mills as refractory insulating aggregates to improve their recycling rate and thereby save resources.

[0010] Another object of the present invention is to provide a refractory spray covering material composition for recycling acid-neutral waste refractory materials by incorporating the acid-neutral waste refractory materials into a sprayable hydraulic refractory mortar composition, thereby being suitable for both construction and civil engineering applications and having excellent fire resistance, compressive strength and water retention.

[0011] In order to achieve the purpose of the present invention as described above, a refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention may include: 10 to 80 weight percent of acid-neutral waste refractory fine aggregate; 5 to 55 weight percent of a binder; 5 to 35 weight percent of an endothermic material; 0.3 to 1.7 weight percent of an organic fiber; 0.5 to 3.5 weight percent of an accelerator; 0.1 to 0.7 weight percent of a thickener; 0.1 to 0.9 weight percent of a fluidizer; and 0.05 to 0.15 weight percent of an air entraining agent (AE).

[0012] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the acid-neutral waste refractory material fine aggregate can be one or more of Al-Si-C, plate, inflow material, general castable alumina and T / D alumina.

[0013] In a refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the acid-neutral waste refractory material fine aggregate may include: 10 to 30 weight percent Al-Si-C; 10 to 30 weight percent plate; 10 to 30 weight percent inflow material; 10 to 30 weight percent general castable alumina; and 10 to 30 weight percent T / D alumina.

[0014] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the acid-neutral waste refractory material fine aggregate can be crushed into a particle size of less than 4 mm.

[0015] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the binder may be one or more of Portland cement and high-alumina cement.

[0016] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the melting point of the refractory mortar manufactured using the composition can be above 1200°C, and can prevent damage within 3 hours at 1200°C.

[0017] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the heat absorbing material may include one or more of lime, gypsum and aluminum hydroxide.

[0018] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the organic fiber may include one or more of polypropylene, acrylic acid, rayon, vinylon or polyethylene fiber.

[0019] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the accelerating agent may include one or more of cement minerals, aluminates, silicates or alkali-free agents.

[0020] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention, the thickener may include one or more of methyl cellulose or polyvinyl acetate.

[0021] In the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to the present invention, acid-neutral waste refractory bricks, most of which are landfilled and discarded into public waters after being used as blast furnace refractory bricks in steel plants, can be recycled and used as the main component of refractory mortar for spraying, thereby greatly reducing the discarded waste refractory materials and contributing to resource conservation and protection of the earth's environment.

[0022] In addition, the refractory spray coating material composition for recycling acid-neutral waste refractory materials according to the present invention can prevent the collapse of structures by preventing concrete from bursting when a fire occurs at a construction or civil engineering site, and can also prevent the collapse of steel frame structures due to high temperatures when a fire occurs.

[0023] Lightweight refractory materials may suffer from reduced thermal insulation at high temperatures due to their large internal pores. However, in the refractory spray covering material composition for recycling acid-neutral waste refractory materials according to the present invention, excellent thermal insulation under high temperature conditions can be ensured due to its small internal pores. Moreover, when applied to damaged parts of the original concrete structure, it can also exhibit excellent structural strength and thereby exert a repair and reinforcement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figures 1a to 1d This is a report for inspecting the quality of recycled fine aggregate from acid-neutral waste refractory materials used in a refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention.

[0025] Figure 2 This is a report for inspecting the quality of the refractory mortar composed of the refractory spray covering material composition obtained by recycling acid-neutral waste refractory materials according to one embodiment of the present invention.

[0026] Figures 3 to 17 This is a test report that graphically illustrates the test results of the various items in Table 1 and Table 2 of the refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention. DETAILED DESCRIPTION

[0027] Next, some embodiments of the present invention will be described in detail with reference to the illustrative drawings. It should be noted that in assigning reference numbers to the components in the various drawings, the same reference numbers are used whenever possible for the same components, even if they are shown in different drawings. In addition, when describing the embodiments of the present invention, if it is determined that a detailed description of a related well-known function or structure may hinder understanding of the embodiments of the present invention, the related detailed description will be omitted.

[0028] In addition, in the process of describing the constituent elements of the embodiments of the present invention, terms such as first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish the corresponding constituent elements from other constituent elements, and the nature, order or sequence of the corresponding constituent elements are not limited by the terms. When it is recorded that a certain constituent element is "connected", "combined" or "connected" with other constituent elements, the constituent element can be directly connected or connected with the other constituent elements, but it should be understood that there may be other constituent elements "connected", "combined" or "connected" between each constituent element.

[0029] Next, a refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] According to one embodiment of the present invention, a refractory spray covering material composition for recycling acid-neutral waste refractory materials may include: 10 to 80 weight percent of acid-neutral waste refractory fine aggregate; 5 to 55 weight percent of a binder; 5 to 35 weight percent of a heat-absorbing material; 0.3 to 1.7 weight percent of an organic fiber; 0.5 to 3.5 weight percent of an accelerator; 0.1 to 0.7 weight percent of a thickener; 0.1 to 0.9 weight percent of a fluidizer; and 0.05 to 0.15 weight percent of an air entraining agent (AE). Preferably, the refractory spray covering material composition for recycling acid-neutral waste refractory materials can include 45 weight% of acid-neutral waste refractory fine aggregate, 31 weight% of binder, 20 weight% of endothermic material, 1 weight% of organic fiber, 2 weight% of accelerator, 0.4 weight% of thickener, 0.5 weight% of fluidizer and 0.1 weight% of air entraining agent (AE).

[0031] However, users can modify or delete some of the aforementioned compositions based on their specific circumstances. For example, if only refractoriness is required, the proportion of the acid-neutralized scrap refractory fine aggregate can be increased to 80% by weight, while the proportions of other compositions can be reduced. In other words, users can flexibly adapt to the specific circumstances after understanding the site, thereby modifying or deleting the proportions of the aforementioned compositions.

[0032] Figures 1a to 1d This is a report for inspecting the quality of recycled fine aggregate from acid-neutral waste refractory materials used in a refractory spray covering material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention.

[0033] See Figures 1a to 1d According to the test results of the quality of the acid-neutral waste refractory recycled fine aggregate, it can be confirmed that it is suitable for use in civil engineering or construction.

[0034]

Table 1

[0035]

[0036] Table 1 above lists the types and components of the recycled waste refractory raw materials used in the refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention.

[0037] Referring to Table 1, the acid-neutral waste refractory fine aggregate may include one or more of Al-Si-C, plate, inflow material, general castable alumina, and T / D alumina.

[0038] Meanwhile, the acid-neutralized waste refractory fine aggregate may include 10-30 wt% Al-Si-C, 10-30 wt% plate, 10-30 total wt% inflow material, 10-30 wt% general castable alumina, and 10-30 wt% T / D alumina. In particular, it is preferable to include 20 wt% Al-Si-C, 20 wt% plate, 20 wt% inflow material, 20 wt% general castable alumina, and 20 wt% T / D alumina. That is, the acid-neutralized waste refractory fine aggregate may include Al-Si-C, plate, inflow material, general castable alumina, and T / D alumina in a ratio of 1:1:1:1:1, respectively. However, the acid-neutral waste refractory fine aggregate is not limited to the ratio range mentioned above, and its performance can be satisfied even if it is mixed in various ratios.

[0039] The acid-neutral waste refractory fine aggregate is preferably crushed into a particle size of less than 4 mm.

[0040]

Table 2

[0041]

[0042]

Table 3

[0043]

[0044] Table 1 shows that the acid-neutral scrap refractory material is primarily composed of alumina (Al2O3), with some SiO2 present, making it an aggregate with excellent refractory properties. Therefore, as shown in Tables 2 and 3, the refractoriness of the mortars produced using the acid-neutral scrap refractory fine aggregate as a simple basic component of hydraulic refractory mortars was measured. The term "fine aggregate" is used to refer to the fine aggregate of the acid-neutral scrap refractory material.

[0045] It was confirmed that regardless of whether high-alumina cement or silicate cement was mixed, all aggregates could produce refractory mortar with a melting point of more than 1200°C and high refractoriness.

[0046] Figure 2 This is a report for inspecting the quality of the refractory mortar composed of the refractory spray covering material composition obtained by recycling acid-neutral waste refractory materials according to one embodiment of the present invention.

[0047] See Figure 2 The results of quality inspection of the refractory spray coating material composition produced by mixing fine aggregate, heat-absorbing materials, and other admixtures confirm that the material has sufficient fire resistance and sufficient compressive strength and water retention for civil engineering applications. KSL 5220 is a test for various types of dry cement mortar (spray finishing, general finishing, wall masonry, and flooring) that meet the standards.

[0048] Figures 3 to 17 This is a test report that illustrates the test results of each item in Table 1 and Table 2 of the refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention. Figure 3 The refractoriness of the refractory mortar composed of the composition corresponding to No. 1 in Table 2 is shown in FIG. Figure 4 The refractoriness of the refractory mortar composed of the composition corresponding to No. 2 in Table 2 is shown in FIG. Figure 15 The refractoriness of the refractory mortar composed of the composition corresponding to No. 13 in Table 3 is shown in FIG. Figures 3 to 17 In the other drawings, the refractoriness of the refractory mortar composed of the composition having the corresponding number in Table 2 or Table 3 corresponding to the number obtained by subtracting 2 from the number of each drawing is shown.

[0049] See Figures 3 to 17 The refractory mortar according to one embodiment of the present invention exhibits excellent refractoriness with a melting point of over 1,200° C. regardless of the aggregate composition.

[0050] Since the acid neutral waste refractory fine aggregate has been described in the above content, it will be omitted.

[0051] The bonding material may be one or more of Portland cement or high green cement as shown in Table 2 and Table 3.

[0052] Cement is used to enhance adhesion and strength. Typically, one or more hydraulic cements selected from standard Portland cement, white Portland cement, high-alumina cement, early-strength Portland cement, and ultra-early-strength cement are used as a binder. In the above embodiments of the present invention, Portland cement or blast furnace cement can be used as the binder.

[0053] While using too much cement can improve the adhesion and strength of the refractory covering, it also reduces heat resistance due to increased density and thermal conductivity. Furthermore, the increased amount of hydrates formed increases the amount of water vapor generated when exposed to high heat, increasing the likelihood of explosion in the event of a fire. Using too little cement can reduce thermal conductivity but also decreases adhesion and strength, making it difficult to achieve sufficient strength for the refractory lining. Considering these issues, a cement content of 5-55% by weight relative to the total solids content of the composition is ideal. Optimally, 31% by weight of cement can be used as the binder.

[0054] The heat-absorbing material is a compound contained in the refractory cover material that releases crystal water or carbon dioxide gas during a fire and absorbs heat, thereby preventing a rapid temperature rise in the concrete and cover material. It is added to further enhance the purpose of the present invention. Examples of the heat-absorbing material include limestone aggregate, heavy coal, limes such as slaked lime, gypsums such as dihydrate gypsum and hemihydrate gypsum, and aluminum hydroxide. The amount used is preferably 5 to 35% by weight, and most preferably 20% by weight.

[0055] The organic fiber may include one or more of polypropylene, acrylic, rayon, vinylon, or polyethylene fibers.

[0056] During construction, the organic fibers effectively strengthen the composite's bonding strength, preventing premature detachment or cracking. After curing, they contribute to low-temperature strength improvements. Furthermore, in the event of a fire, the fibers dissolve at a relatively low temperature of approximately 170°C, creating multiple pores within the refractory covering. This provides a path for moisture migration, ultimately reducing water vapor pressure and thermal stress within the refractory covering itself or the concrete surface, thereby preventing surface peeling and cracking. The organic fibers not only provide excellent thermal insulation and fire resistance without damaging the refractory covering in the event of a fire, but also rapidly expel gaseous components such as water vapor generated by heat, preventing a rise in vapor pressure within the concrete and refractory lining, thereby protecting the concrete structure from damage.

[0057] If the amount of organic fiber used is too high, the material's strength may be reduced due to increased bulk, while if the amount is too low, the coating may fall off or crack due to insufficient moisture migration paths, potentially leading to loss of functionality as a refractory lining material. Considering these issues, the organic fiber content is preferably 0.3-1.7% by weight, with 1% being the most preferred.

[0058] The quick-setting agent is used to promote the setting of the bonding material and can prevent the composition from sinking by imparting early strength.

[0059] In one embodiment of the present invention, an accelerator can be used to facilitate both early strength and a fast setting time. The organic fiber can comprise one or more of cement minerals, aluminates, silicates, or alkali-free materials. To impart adhesion, the accelerator is preferably used at a concentration of approximately 0.5 to 3.5% by weight, with 2% being optimal.

[0060] The thickener can maintain the viscosity of the slurry in a state that allows for easy construction, and can also impart early bonding strength after construction. Furthermore, it can also prevent the covering layer from sinking by stably supporting it before hydrating with the hydratable bonding material on the construction surface.

[0061] In one embodiment of the present invention, one or more of methyl cellulose and polyvinyl acetate can be used as the organic thickener, and considering its economy and function, it is appropriate to use an amount of about 0.1 to 0.7 weight %, and most preferably 0.5 weight %.

[0062] The fluidizer is a kind of admixture and is one of the substances added for the purpose of improving workability and reducing and relieving coagulation. In one embodiment of the present invention, it is appropriate to use 0.1 to 0.9 weight % of the fluidizer, and most preferably 0.5 weight % can be used.

[0063] Air entraining agent (AE) is a chemical admixture used to improve concrete's workability and freeze-thaw resistance by forming tiny, independent bubbles within the concrete. In one embodiment of the present invention, an AE concentration of 0.05-0.15% by weight is preferred, with 0.1% being optimal.

[0064] Although referred to as air entraining agent (AE) in the above content, the air entraining agent (AE) may include pure air entraining agent (AE) and a portion of other additives according to the user's intention.

[0065] The refractory mortar manufactured using the refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention has a melting point of over 1200° C. and can prevent damage within 3 hours at 1200° C.

[0066] What is described above is merely an embodiment of a refractory spray coating material composition for recycling acid-neutral waste refractory materials according to one embodiment of the present invention. The present invention is not limited to the embodiment described above. The technical gist of the present invention should be understood as including the scope of arbitrary changes in implementation by persons having general knowledge in the technical field to which the present invention belongs without departing from the gist of the present invention.

Claims

1. A refractory spray coating material composition for recycling acid-neutral waste refractory materials, comprising: 10 to 80% by weight of acid neutral waste refractory fine aggregate; 5 to 55% by weight of a binder; 5 to 35% by weight of heat absorbing material; 0.3-1.7 wt% organic fiber; 0.5 to 3.5 weight percent of an accelerating setting agent; 0.1 to 0.7% by weight of a thickener; 0.1 to 0.9 weight percent of a fluidizing agent; and, 0.05-0.15 wt% of air entraining agent (AE).

2. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The acid-neutral waste refractory fine aggregate is one or more of Al-Si-C, plate, inflow material, general castable alumina and T / D alumina.

3. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The acid-neutral waste refractory fine aggregate comprises: 10 to 30 wt% Al-Si-C; 10 to 30% by weight of plate; 10 to 30% by weight of influent; 10 to 30 wt% of general castable alumina; and, 10-30 wt% T / D alumina.

4. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The acid neutral waste refractory fine aggregate is crushed into a particle size of less than 4 mm.

5. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The binder is one or more of silicate cement and high alumina cement.

6. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The refractory mortar produced using the composition has a melting point of 1200° C. or higher and is prevented from being damaged within 3 hours at 1200° C.

7. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The heat absorbing material includes at least one of lime, gypsum and aluminum hydroxide.

8. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The organic fiber includes at least one of polypropylene, acrylic, rayon, vinylon or polyethylene fiber.

9. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The quick-setting agent includes at least one of cement minerals, aluminates, silicates or alkali-free cement.

10. The refractory spray coating material composition for recycling acid-neutral waste refractory materials according to claim 1, The thickener includes at least one of methyl cellulose and polyvinyl acetate.

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