The Effect of Sodium Hexametaphosphate on the Physical and Mechanical Properties of Monolithic Refractories Prepared from the Wastes of Magnesia - Carbon Bricks

Subject Areas : journal of New Materials

سارا Alizadeh ¹ , احمد Monshi ² , ابراهیم Karamian ³

1 - مرکز تحقیقات مواد پیشرفته، دانشکده مهندسی مواد، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایران.
2 - مرکز تحقیقات مواد پیشرفته، دانشکده مهندسی مواد، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایران.
3 - مرکز تحقیقات مواد پیشرفته، دانشکده مهندسی مواد، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف آباد، ایران.

Received: 2016-05-20 Accepted : 2016-05-20 Published : 2015-12-22

Keywords: Magnesia, Carbon, Sodium Hexametaphosphate, Spent Brick, Monolithic Refractories,

Abstract :

Magnesia–carbon (MgO–C) refractories are widely used in basic oxygen furnaces, electric arc furnaces and steel ladles. These refractories have excellent slag resistance and thermal shock resistance due to the good properties of carbon such as low wettability, high thermal conductivity and low thermal expansion. In this context, main problems are erosion of the refractories of slag line, carbon oxidation, chemical corrosion and mechanical wear of refractories by slag and need to repair and replace them with other refractories. In this study, the effect of using sodium hexametaphosphate(SHMP) as a bonding agent was investigated in the presece of water and spent magnesia-carbon refractory aggregates. For this purpose, different compounds composed of 0, 3 and 5 wt. % SHMP are prepared and some parameters such as bulk density, percent of apparent porosity (%AP) and cold crushing strenght (CCS) were measured at different temperatures (200, 500 and 1100 °C) and phase and microstructure studies were performed by XRD and SEM. Results indicated that using of 5% SHMP at different temperature, specially at low temperature causes some phosphate bonds with needle-shape morphology like MgP₂O₇, Mg₃(PO₄)₂ and AlPO₄  and improve physical and mechanical properties, so these monolithic refractories can be used for the cold repairing of ladles.

References:

1- L.A. Diaz, R. Torrecillas, A.H.d. Aza,and P. Pena, "Effect of Spinel Content on Slag Attack Resistance of High Alumina Refractory Castables", Journal of the European Ceramic Society, Vol. 27, pp. 4623–4631, 2007.

2- L.A. Diaz, R. Torrecillas, F. Simonin, and G. Fantozzi, "Room Temperature Mechanical Properties of High Alumina Refractory Castables with Spinel, Periclase and Dolomite Additions", Journal of the European Ceramic Society, Vol. 28, pp. 2853–2858, 2008.

3- ج. عظیمی، د. عظیمی، س. اطرج، ز. نعمتی، "بررسی تاثیر مواد افزودنی ضد انعقاد و مقدار SiC بر خواص دیرگدازهای ریختنی کم سیمان دارای سیستم نوسانی در سیستم Al2O3-SiC، مجله مواد و فناوری‌های پیشرفته، جلد یک، شماره یک، صفحات 86-79، 1391.

4- ا. رحیمی، ا. منشی، ر. عمادی، "بررسی اثر اندازه دانه کاربید سیلسیم در تولید جرم ریختنی نسوز خیلی کم سیمان برای صنایع فولاد"، مجله‌ی مواد نوین، جلد 1، شماره‌ 2، صفحات 27-21، 1389.

5- K.S. Kwong, J.P. Bennett, "Recycling Practices of Spent MgO-C Refractories", Journal of Minerals & Materials Characterization & Engineering, Vol. 1, No.2, pp. 69-78, 2002.

6- F. Arianpour, F. Kazemi, F. Golestani Fard, "Characterization, Microstructure and Corrosion Behavior of Magnesia Refractories Produced from Recycled Refractory Sggregates", Minerals Engineering, Vol. 23, pp. 273–276, 2010.

7- A.N. Conejo, R.G. Lule , F. Lopez , and R. Rodriguez, "Recycling MgO-C Refractory in Electric Arc Furnaces", Resources, Conservation and Recycling , Vol.49, pp. 14–31, 2006.

8- S. Hanagiri, A. Shimpo, T. Inuzuka, S. Sakaki, T. Matsui, S. Aso, T. Matsuda, and H. Nakagawa, Recent Improvement of Recycling Technology for Refractories, Nippon Steel Technical Report, No. 98, 2008.

9- V.G. Rocha, R. Menendez, R. Santamaria, C. Blanco, and M. Granda, "Oxidation Behavior of Magnesia–Carbon Materials Prepared with Petroleum Pitch as Binder", Journal of Analytical and Applied Pyrolysis, Vol. 88, pp. 207–212, 2010.

10- H. UM, K. LEE, J. CHOI, and Y. CHUNG, "Corrosion Behavior of MgO–C Refractory in Ferromanganese Slags", ISIJ International, Vol. 52, pp. 62–67, 2012.

11- T. Zhu, Y. Li, M. Luo, S. Sang, Q. Wang, L. Zhao, Y. Li, and S. Li, "Microstructure and Mechanical Properties of MgO–C Refractories Containing Graphite Oxide Nanosheets (GONs)", Ceramics International, Vol. 39, pp. 3017–3025, 2013.

12- T. Zhu, Y. Li, S. Sang, S. Jin, Y. Li, L. Zhao, and X. Liang, "Effect of Nanocarbon Sources on Microstructure and Mechanical Properties of MgO–C Refractories", Ceramics International, Vol. 40, pp. 4333–4340, 2014.

13- S. Zhang, N.J. Marriott, and W.E. Lee, "Thermochemistry and Microstructures of MgO–C Refractories Containing Various Antioxidants", Journal of the European Ceramic Society, Vol. 21, pp. 1037–1047, 2001.

14- L. Musante, L.F. Martorello, P.G. Galliano, A.L. Cavalieri, and A.G. Tomba Martinez, "Mechanical Behavior of MgO–C Refractory Bricks Evaluated by Stress–Strain Curves", Ceramics International, Vol. 38, pp. 4035–4047, 2012.

15- K. Fisher, "Chemical Bond for Refractory Materials", Journal of the American Ceramic Society, Vol. 12, pp. 51-64, 1989.

16- R.W. Limes, "Bonds for Gunning Materials", Journal of. Metals, Vol. 17, No. 5, pp. 663-666, 1985.

17- H.R. Rezaie, F. Arianpour, and F. Naghizadeh, "An evaluation of the Effects of Different Phosphate Binders on the Properties and Microstructure of Tundish Coating Refractories", Proceeding of 49. International Feuerfest- Kolloquium, pp. 363-368, 2006.

18- M.J. Ohara, J.J. Duga,and H.D. Sheets, "Studies in Phosphate Bonding", Ceramic Bulletin, Vol. 51, No. 7, pp. 245-251, 1970.

19- H.J. RenSburg, J.P. Louw, A.M. Hartman, G.P. Rensburg, and M. Matheba, "The Influence of Pre-Drying on Tropical Soil Testing", 31st Southern African Transport Conference, pp. 445-457, Pretoria, South Africa, 2012.

20- United States International Trade Commission, Sodium Hexametaphosphate From China, Washington. DC, 2008.

21- H. Efendy, C.L. Radiman, A. Ramelan, and A. Nuruddin, "Oxidation Protection of MgO-C Monolithic Refractories with Tar-Resin Binder and Metal Antioxidants", China's Refractories, Vol. 16, No. 3, 2007.

22- H. Efendy, and W. Mohamad, "Effect of Tar-Resin Binder on Properties of MgO-C Monolithic Refractories", China's Refractories, Vol. 19, No. 3, 2010.

23- H. Jansen, S. Dudczig, and C.G. Aneziris, "Magnesia-Carbon Castable with New Properties", 51st Colloquium Refractories, Aachen, pp. 84-87, 2008.

24- A.S. Gokce, C. Gurcan, S. Ozgen, and S. Aydin, "The effect of Antioxidants on the Oxidation Behavior of Magnesia-Carbon Refractory Bricks", Journal of Ceramics International, Vol. 34, pp. 323-330, 2008.

25- م. پاغنده، ا. منشی، ر. عمادی، " بررسی تاثیر استفاده از اتصالات فسفاتی در جرم های کم سیمان"، مجله مواد و فناوری‌های پیشرفته، جلد یک، شماره یک، صفحات 7-1، 1391.