Rheology of High Performance Alumina and Spinel Castables

Jerry Dutton, Marion Schnabel, Andreas Buhr

Almatis GmbH, 60528 Frankfurt/Germany


Volume 4, Issue 2, Pages 95 - 100


The article provides a basic understanding of the impact of the matrix components on the rheology of castables with special focus on high performance alumina and spinel castables. A broad particle size distribution of the matrix fines helps to achieve optimised packing and therefore a high solids content with low viscosity of the suspension. As solids content increases the amount of water is consequently reduced. Additives are required to counterbalance agglomeration of the particles in a suspension.


alumina and spinel castables, workability, rheology


[1] Zschimmer & Schwarz GmbH & Co. KG: Informationsblatt „Wirkmechanismen von Verflüssigungsund Dispergiermitteln in keramischen Massen“


[2] Justnes, H.; Vikan, H.: Viscosity of cement slurries as a function of solids content. Ann. Transactions of the Nordic Rheology Soc. 13 (2005) 75–82


[3] Ferraris, C.F.: Measurement of the rheological properties of high performance concrete, state of the art report. J. of Res. of the National Inst. of Standards and Technol. 104 (1999)


[4] Hill, A.; Carrington, S.: Understanding the links between rheology and particle parameters. Technical paper (2006) www.americanlaboratory.com


[5] Seyerl, von J.: Chemical additives for castables. UNITECR 2011, Kyoto/JP; 1-D-11;


[6] Clavaud, B.; Kiehl, J.P.; Schmidt-Whitley, R.D.: 15 years of low cement castables in steelmaking. First Int. Conf. on Refractories, Tokyo/JP, (1983) 589–606


[7] Kriechbaum, G.; et al.: The matrix advantage System, a new approach to low moisture LC selfleveling alumina and alumina spinel cast-ables. 39th Int. Coll. on Refractories, Aachen/DE 1996, 211–218


[8] McConnell, R.W.; Fullington, A.: Responding to the refractory industry’s need for fully ground matrix aluminas. UNITECR 2001, Cancún/MX, 768–780


[9] Kockegey-Lorenz, R.; Schmidtmeier, D.; Buhr, A.; van Garsel, D.; Dutton, J.: E-SY aluminas for easy to use high performance castables. 53th Int. Coll. on Refractories, Aachen/DE 2009, 86–88


[10] Kockegey-Lorenz, R.; Buhr, A.; et al.: Review of Matrix aluminas for refractory formulations. UNITECR 2011, Kyoto/JP


[11] Myhre,B: The effect of particle-size distribution on flow of refractory castables. 30th Ann. Symposium of the Am. Ceram. Soc., St. Louis/USA 1994


[12] Eguchi, T.; et al.: Low-cement-bonded castable refractories. Taikabutsu Overseas 9 (1989) [1] 10–25


[13] Ceram Research Ltd.: Zeta potential. Technical article (2001), www.azom.com


[14] Myhre, B.: Hot strength and bond-phase reactions in low and ultralow-cement castables. UNITECR 1993, São Paulo/BR, 583–594


[15] Kriechbaum, G.; Gnauck, V.; Routschka, G.: The influence of SiO2 and spinel on the hot properties of high alumina low cement castables. 37th Int. Coll. on Refractories, Aachen/DE 1994, 150–159


[16] Kopanda, J.E.; MacZura, G.: Production processes, properties and applications for calcium Aluminate cements. Alumina Chemicals Handbook (1990) 171–183


[17] Braulio, M.A.L.; et al.: Microsilica effects on cement bonded alumia-magnesia refractory cast-ables. J. of the Tech. Ass. of Refractories Japan 28 (2008) [3] 180–184


[18] Buhr, A.: Tonerdereiche Feuerfestbetone für den Einsatz in der Stahlindustrie (High Alumina Refractory Castables for Use in the Steel Industry), Stahl und Eisen 116 (1996) [9] 59–66


[19] Schnabel, M.; Buhr, A.; Exenberger, R., Rampitsch, C.: Spinel: in-situ versus preformed – clearing the myth. refractories WORLDFORUM 2 (2010) [2] 87–93  


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