KAlSiO4-based Potassium Aluminosilicates for Alkali Corrosive Environments

Christos G. Aneziris, Nora Brachhold

Institute of Ceramics, Glass and Construction Materials, TU Bergakademie Freiberg, 09599 Freiberg/Germany

Revision 20.06.2014, 01.07.2014

Volume 6, Issue 3, Pages 93 - 98

Abstract

Alkali corrosion of refractory materials is a problem in high temperature aggregates. The problem has increased strongly during the last years due to secondary fuels used as energy carriers. This study presents potential new materials for alkali corrosive conditions. It investigated the synthesis of potassium aluminosilicates of the nominal composition of KAlSiO 4 . Two synthesizing procedures were applied: a pure thermal treatment at 1200 °C and a combined synthesizing procedure consisting of a hydrothermal treatment at 200 °C followed by a sintering step at 1200 °C. Furthermore, the study concentrated on the use of K 2 CO 3 as K 2 O source and compared the results to previous studies based on KOH as K 2 O source. The results showed that the use of K 2 CO 3 yielded the intended target phase, too. The reaction products based on K 2 CO 3 had a phase composition similar to thermally synthesized KOH­based material and were alkali corrosion resistant.

Keywords

alkali corrosion, alkali aluminosilicates, KAlSiO4

References

[1] Rigby, G.R.; Richardson, H.M: The Occurrence of artificial kalsilite and allied potassium aluminum silicates in blast­furnace linings. Min. Mag. 28 (1947) 75–88 [2] Farris, R.E.; Allen, J.E.: Aluminous refractories, alkali reactions. Iron Steel Eng. 50 (1973) [2] 67–74 [3] Schlegel, E.; Aneziris, C.G.; Fischer, U.: Alkali corrosion in cement rotary kilns. Interceram: International Ceramic Review (2009) [MANUAL 2009] 3–8 [4] Bartha, P.; Södje, J.: Degradation of refractories in cement rotary kilns fired with waste fuels. CN Refractories [Special Issue] 5 (2001) 62–71 [5] Vadasz, P.; et al.: Influence of alternative fuels on the corrosion of basic refractory lining. Inter­ Ceram 58 (2009) [2–3] 130–135 [6] Krasselt, V.: Wärmedämmende Werkstoffe, in: G. Routschka, H. Wuthnow (Eds.), Taschenbuch Feuerfeste Werkstoffe, 4 th Ed. Essen 2007, 353– 391 [7] Schulle, W.: Feuerfeste Werkstoffe, 1 st Ed. Leipzig 1990 [8] Brown, J.J.: The use of phase diagrams to predict alkali oxide corrosion of ceramics, in: A.M. Alper (Ed.), Phase diagrams in advanced ceramics. San Diego, CA, 1995, 43–83 [9] Schlegel, E.: Auswertung von Phasendiagrammen hinsichtlich der Alkalikorrosionsbeständigkeit feuerfester Baustoffe. Keram. Z. 61 (2009) [5] 266–271 [10] Schairer, J.F.; Bowen, N.L.: Melting relations In the systems Na 2 O–Al 2 O 3 –SiO 2 and K 2 O–Al 2 O 3 – SiO 2 . Am. J. Sci. 245 (1947) 193–204 [11] Salmang, H.; Scholze, H.; Telle; R.: Keramik. Berlin 2007, 494–586 [12] Richerson, D.W.: Modern ceramic engineering – properties, processing and use in design. 3 rd Ed. Boca Raton, FL, 2006, 386–394 [13] Schlegel E.: Grundlagen technischer hydrothermaler Prozesse. Freiberger Forschungshefte A655, Leipzig, 1982,12–17 [14] Brachhold, N.; Aneziris; C.G.: Synthesis of alkali aluminosilicates – materials for alkali contaminated environments at high temperatures. Int. J. Appl. Ceram. Technol. 10 (2013) [4] 707– 715 [15] Brachhold, N.; Aneziris; C.G.: Porous materials for alkali contaminated environments. J. Europ. Ceram. Soc. 33 (2013) [10] 2013–2021 [16] Aneziris, C.G.; Fischer, U.; Schlegel, E.: The use of secondary fuels (waste) and the corrosion problems of refractories. Keram. Z. 60 (2008) [5] 347–351 [17] EN 1094­2, Insulating refractory products – Part 2: Classification of shaped products (ISO 2245 : 1990, modified), 1998 [19] Dimitrijevic, R.; Dondur, V.: Synthesis and characterization of KAlSiO 4 polymorphs on the SiO 2 – KAlO 2 join. 2. The end­member of ana type of zeolite framework. J. Sol. St. Chem. 115 (1995) [1] 214–224

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