نوع مقاله : مقاله پژوهشی
نویسندگان
1 داشجوی کارشناسی ارشد، دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف ، تهران، ایران
2 دانشیار دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف، تهران، ایران
3 دانشجوی کارشناسی ارشد، دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف ، تهران، ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Abstract
Magnesia-doloma refractories are alkali products from sintered (or fusion) doloma and magnesia fusion), which have 50-80 wt. % MgO. These refractory have many advantages such as high corrosion resistance against slag, high temperature performance, ability to produce clean meet, and cost-effective (due to the abundance of dolomite and magnesite ores in Iran). However, the use of this type of refractories has been faced with restrictions due to poor hydration resistance in various industries. In this study, the effect of adding zirconium oxide nanoparticles on microstructure and hydration resistance of magnesia – doloma refractories containing 35 wt. % CaO is evaluated. Cylindrical samples were pressed under pressure 90MPa, and after it were dried and fired at 110 ℃ for 24 h and, heated t0 1650℃ with 5min / ℃ the for 3 h. Results show that the positive effect of adding zirconium oxide nanoparticles on the sintering temperature samples, due to the larger atomic radius of Mg than Ca thus lower the bond strength of Mg-O tend replacement Ca2 + with Zr + 4 cations network with CaO greater than Mg2 +in MgO networks and the formation of calcium zirconate phase (CaZrO3). According to the result it can be found thet in doloma free CaO reduced by creating (CaZrO3) phase, as well as cavities formed by replacing the cationic in the network, increased the diffusion and sintering process which it led to creates a more dense structure and hydration resistant improvement.
کلیدواژه‌ها [English]
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