The Value of Additives in Refractory Castables – Part 2: Castables with Silica Fume

Dagmar Schmidtmeier1, Sebastian Klaus2, Jerry Dutton3, Andreas Buhr4, Zhongkai Tian5, Dale Zacherl6

1 Almatis GmbH, 67065 Ludwigshafen/Germany
2 GeoZentrum Nordbayern, Erlangen/DE
3 Stourbridge/GB
4 Almatis GmbH, 67065 Ludwigshafen/Germany
5 Qingdao Almatis Co. Ltd., Huangdao/CN
6 Almatis Inc., Leetsdale/US


Volume 6, Issue 4, Pages 51 - 60


Part 1 of this paper covered low cement refractory castables without silica fume. These included tabular alumina and spinel based materials for the highest temperature applications. However, silica fume is widely used as a fine filler in low cement castables for intermediate and high temperature applications. The use of fine matrix fillers requires the addition of additives for homogeneous dispersion of the fine particles during wet mixing (refractories WORLDFORUM 6 (2014) [3] 75). Part 2 of this paper compares the performance of traditional and modern additive concepts in silica fume castables with regard to additive dosage, storage stability of the dry mix, flow properties, working and setting time and also the strength development during curing.


additives, castables, dispersion


[1] Kockegey-Lorenz, et al.: The value of additives in refractory castables – part 1: Castables without silica fume, refractories WORLDFORUM 6 (2014) [3] 75–81 [2] Schnabel, M.; et al.: Castables for industrial applications – still room for improvement! 56. Int. Coll. on refractories, Aachen, Germany, 2013 [3] Gierisch, D.; et al.: Aging behaviour of alphabond and calcium aluminate cement bonded castables. 49. Int. Coll. on refractories, Aachen, Germany, 2006 [4] Kuzel, J.H.: An efficient conduction-type calorimeter TIZ 108 (1984) [50–51] 46–48 [5] Myhre, B.: Microsilica in refractory castables – how does microsilica quality influences performance? UNITECR 2005, Orlando, USA [6] Myhre, B.: Microsilica containing refractory castables – influence of additives on placing properties. 47. Annual symposium on Additives for Monolithics, St. Louis, USA, 2011 [7] Krebs, J.: Innovationen bei verflüssigten Feuerbetonen. Presentation at the refractory and chimney congress 2003 of GARC (German Association of Refractories and Chimneys) in Düsseldorf, Germany, June 16, 2003 [8] Alphabond 300 – Global Product Data, Almatis GP-RCP/015/ R04/0812, available under


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