Characteristics of Refractory Castables Containing Mullite and Spinel Coated Graphites
31 Jan 2012-Materials and Manufacturing Processes (Taylor & Francis Group)-Vol. 27, Iss: 2, pp 177-184
TL;DR: In this article, the performance of high alumina castables containing mullite and spinel coated graphites was investigated to explore their commercial application in carbon containing refractory composites, compared in terms of thermal shock resistance, refractoriness under load, static slag resistance test, pore size distribution, and physical properties, e.g., apparent porosity and cold crushing strength.
Abstract: The performance of high alumina castables containing mullite and spinel coated graphites was investigated to explore their commercial application in carbon containing refractory composites. It was compared in terms of thermal shock resistance, refractoriness under load, static slag resistance test, pore size distribution, and physical properties, e.g., apparent porosity and cold crushing strength. The microstructures of these two castables, along with the other containing uncoated graphites, were also studied. Differential thermal analysis and X-ray diffraction patterns of heat-treated carbon-containing castable composites have also been noted. Castables containing mullite-coated graphite were found to be more resistant to repeated thermal shock cycles, whereas those containing spinel-coated graphites were more encouraging when slag resistance and overall physical properties are concerned.
Citations
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TL;DR: In this article, the performance of alumina-carbon castables containing graphite flakes coated by nanosized Ca-doped γ-Al2O3 phases has been investigated in terms of refractoriness under load (RUL) and oxidation resistance tests.
32 citations
TL;DR: In this paper, a nanostructured sol gel coating of calcium aluminate (CaAl2O4) over flaky graphite has been prepared by a hybrid set of precursors.
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TL;DR: In this paper, the effect of exfoliated graphite (Exf-G) addition on mechanical, thermal, and non-flammability properties of polystyrene, nitro-polystyrene (PS-NO2), and amino-polystylrene (NH2) by solution and melt processing was examined.
Abstract: This work examines the effect of exfoliated graphite (Exf-G) addition on mechanical, thermal, and non-flammability properties of polystyrene, nitro-polystyrene (PS-NO2), and amino-polystyrene (PS-NH2) by solution and melt processing. Exfoliated graphite yielded unique morphology in solution formed PS-NH2/Exf-G composites. Tensile strength of solution PS-NH2/Exf-G (30.1–53.2 MPa) was enhanced compared with melt route. Addition of Exf-G also improved T10 of solution processed PS-NH2/F-G 0.01–0.5 composites as 455–502°C. Cone calorimetry results showed that PS-NH2/Exf-G 0.5 formed by solution route had lower peak heat release rate (PHRR) value (434 kW/m2). Physical properties of solution caste systems were enhanced relative to melt systems depicting advantage of technique used.
26 citations
Cites background from "Characteristics of Refractory Casta..."
...The carbon atoms in adjacent planes are seized together by weak van der Waals forces [1, 2]....
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TL;DR: In this article, the commercial preparation of calcium aluminate has been compared with the sol-gel synthesis by differential thermal analysis (DTA) and X-ray diffraction (XRD) to assess the feasibility of the latter for coating preparation.
21 citations
TL;DR: In this article, a comparison between pore size distribution and thermogravimetric analysis (TGA) of two fired castable refractories with and without uncoated graphite was performed.
17 citations
References
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TL;DR: Theoretical models of these processes, as well as static (sessile drop, dipping, and crucible) and dynamic (rotating finger and rotary slag) experimental tests, along with their practical limitations are considered in this paper.
Abstract: Penetration and dissolution mechanisms are reviewed for predominantly single phase oxide, two phase oxide, and oxide–carbon composite refractories by liquid silicates. Theoretical models of these processes, as well as static (sessile drop, dipping, and crucible) and dynamic (rotating finger and rotary slag) experimental tests, along with their practical limitations are considered. Direct (congruent or homogeneous) attack involves dissolution of a solid into a liquid with no intermediate solid phase leading to active corrosion. Indirect (incongruent or heterogeneous) attack leads to formation of one or more new solid phases at the original solid/liquid interface. This may lead to passive corrosion. Examples of direct and indirect attack in a range of refractory–liquid systems are described highlighting the critical influence of the composition and hence viscosity of the local liquid adjacent to the solid. Penetration and corrosion can be controlled either through the local liquid composition via th...
332 citations
"Characteristics of Refractory Casta..." refers background in this paper
...It is known that corrosion of oxide-carbon refractories follows the stages of decarburization due to oxidation of graphite and the concomitant infiltration of slag in that region [11]....
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...As such, its characteristics along with other oxide-carbon composite refractories are widely discussed in literature [11]....
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Book•
01 Sep 1973
TL;DR: Refractories production and properties, Refractories produce and properties, Refractive properties, and properties of refractories, are discussed in detail in the paper.
Abstract: Refractories production and properties , Refractories production and properties , کتابخانه دیجیتالی دانشگاه علوم پزشکی و خدمات درمانی شهید بهشتی
170 citations
"Characteristics of Refractory Casta..." refers background in this paper
...Since oxidation of carbon proceeds by permeation through the refractory castables, permeability in MCBC increases over G’CBC [32]....
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Journal Article•
TL;DR: Gorka Cement as mentioned in this paper produces concretes and refractory mortars as well as ingredient of construction chemistry products, which are used in the construction of concrete structures.
Abstract: 1.1. Name of substance Calcium Aluminate Cements GORKAL 40, GORKAL 40M,GORKAL 50 1.2. Purpose production of concretes and refractory mortars as well as ingredient of construction chemistry products 1.3. Data concerning manufacturer Manufacturer Gorka Cement Sp. z o.o. Street 22 Lipca 58 Postal code/city 32-540 Trzebinia Country Poland Telephone no. ++48 32 758 10 99 Fax ++48 32 623 34 50 e-mail sekretariat@gorka.com.pl website www.gorka.com.pl
147 citations
Additional excerpts
...(C1⁄4CaO, A1⁄4Al2O3, H1⁄4H2O) are formed in the castable [28]....
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01 Jan 2009
TL;DR: Gorka Cement as discussed by the authors produces concretes and refractory mortars as well as ingredient of construction chemistry products, which are used in the construction of concrete structures.
Abstract: 1.1. Name of substance Calcium Aluminate Cements GORKAL 40, GORKAL 40M,GORKAL 50 1.2. Purpose production of concretes and refractory mortars as well as ingredient of construction chemistry products 1.3. Data concerning manufacturer Manufacturer Gorka Cement Sp. z o.o. Street 22 Lipca 58 Postal code/city 32-540 Trzebinia Country Poland Telephone no. ++48 32 758 10 99 Fax ++48 32 623 34 50 e-mail sekretariat@gorka.com.pl website www.gorka.com.pl
125 citations
TL;DR: Transparent Al2O3, Al 2O3-SiO2 and SiO2 sols were prepared via hydration of TEOS and Al(OC3H7)3 in distilled water and used to coat natural flake graphite as mentioned in this paper.
Abstract: Transparent Al2O3, Al2O3–SiO2 and SiO2 sols were prepared via hydration of TEOS and Al(OC3H7)3 in distilled water and used to coat natural flake graphite. Graphite coated with these sols was dried at 120 °C for 12 h and heat-treated at 500 °C for 2 h to gel the sols. Water-wettability and oxidation resistance of as-received (uncoated) and coated graphites were examined. Al2O3, Al2O3–SiO2 and SiO2 coatings improved graphites water-wettability and SiO2-coated graphite showed the best water-wettability. All the coatings also improved the graphites oxidation resistance, especially at high temperatures (>1100 °C). Addition of Si greatly improved the oxidation resistance of as-received graphite whereas the oxidation resistance of the coated graphites was only slightly improved, suggesting that it is possible to decrease the level of antioxidant used in commercial castable systems.
108 citations
"Characteristics of Refractory Casta..." refers background in this paper
...One of the promising solutions to circumvent such problem is to modify the graphite surface with a thin hydrophilic sol-gel coating of single or binary oxide of ceramics [1, 2]....
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