Hydration Resistance Improvement of MgO-CaO Refractories by the Addition of Nano-ZrO2

Subject Areas : journal of New Materials

سلمان Ghasemi-Kahrizsangi ¹ (داشجوی کارشناسی ارشد، دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف ، تهران، ایران)
علی Nemati ² (دانشیار دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف، تهران، ایران)
عزیز Shahraki ³ (دانشجوی کارشناسی ارشد، دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف ، تهران، ایران)
محمد Farooghi ⁴ (دانشجوی کارشناسی ارشد، دانشکده مهندسی و علم مواد، دانشگاه صنعتی شریف ، تهران، ایران)

Received: 2015-07-31 Accepted : 2017-11-16 Published : 2017-08-23

Keywords: Magnesi-Doloma, Refractories, Hydration Resistance, Nano-ZrO2,

Abstract :

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 Ca^{2 +} with  Zr ^{+ 4} cations network with CaO  greater than Mg^{2 +}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.

References:

[1] Salman Ghasemi-Kahrizsangi, Ebrahim Karamian, Hassan Gheisari Dehsheikh, Ahmad Ghasemi-Kahrizsangi, “A Review on Recent Advances on Magnesia-Doloma Refractories by Nano-Technology”, Journal of Water and Environmental Nanotechnology, 2, (3) 206-222, 2017.

[2] Salman Ghasemi-Kahrizsangi, Aziz Shahraki, Mohammad Farooghi, “Effect of Nano-TiO₂ Additions on the Densification and Properties of Magnesite–Dolomite Ceramic Composites”, Iranian Journal of Science and Technology, Transaction A, 1-9, 2016.

[3] Salman Ghasemi-Kahrizsangi, Ebrahim Karamian, Ahmad Ghasemi-Kahrizsangi, Hassan Gheisari Desheikh, Ali Soheily,“The impact of trivalent oxide nanoparticles on the microstructure and performance of magnesite-dolomite refractory bricks", Materials Chemistry and Physics, 193, 413-420, (2017).

[4] S. Ghasemi –Kahrizsangi, A.Nemati, A. Shahraki and M. Farooghi, “Densification and properties of Fe₂O₃ nanoparticles added CaO refractories”, Ceramics International journal, 42, pp. 12270-12275, 2016.

[5] S. Ghsemi kahrizsangi, A.Nemati, A. Shahraki and M. Farooghi, “Effect of nano-sized Fe₂O₃ on microstructure and hydration resistance of MgO-CaO refractories”, International Journal of Nanoscience and Nanotechnology, 12, No. 1, pp. 19-26, 2016.

  [6] Aziz Shahraki, Salman Ghasemi-kahrizsangi, Ali Nemati,"  Performance improvement of MgO-CaO refractories by the addition of Nano-sized Al₂O₃", Materials Chemistry and Physics, 198, 354-359(2017).

 [7]Salman Ghasemi- Kahrizsangi, Hassan Gheisari Dehsheikh, Mehdi Boroujednia, “MgO-CaO-Cr₂O₃ composition as a novel refractory brick: use of Cr₂O₃ nanoparticles”, Boletín de la Sociedad Española de Cerámica y Vidrio,56(2), 83-89, 2017.

 [8]salman Ghasemi-Kahrizsangi, Hassan Gheisari Dehsheikh, Ebrahim Karamian, Mehdi Boroujerdnia, Khoshnaz Payandeh, “Effect of MgAl₂O₄ nanoparticles addition on the densification and properties of MgO-CaO refractories”, Ceramics International, 43, 6, 5014-5019, (2017).

[9] Salman Ghasemi-Kahrizsangi, Ebrahim Karamian, Hassan Gheisari Dehsheikh," The impact of ZrSiO₄ nanoparticles addition on the microstructure and properties of dolomite based refractories", Ceramics International,46, 15 13932-13937(2017).

[10] S. Gh. Kahrizsangi, A.Nemati, A. Shahraki and M. Farooghi “The effect of nano-additives on the hydration resistance of materials synthesized from the MgO-CaO system” International Journal of Engineering, 29 539-545(2016).

 [11] S. Ghasemi-kahrizsangi, M. Boroujerdnia, H. Gheisari-dehsheikhIranian, “the effect of nano meter size ZrO₂ particles addition on the densification and hydration resistance of magnesite– dolomite refractories”, Journal of Materials Science and Engineering, 13, 4, 33-40(2016).

 [12] S. Ghsemi Kahrizsangi, M .Barati, H. Gheisari, A. Shahraki, and M. Farooghi, “Densification and properties of ZrO₂ nanoparticles added magnesia–doloma refractories”,

 Ceramic International, 43, 14, 15658-15663(2016).