Calderys developed new concept of refractory

Traditional Calcium Aluminate Cement (CAC) bonded castables require significant time to dry out and allow water to evaporate. This is due to the low gas permeability (i.e. capability of vapour to escape through the structure) of CAC castables and the high amount of water trapped in hydrates crystals, which can escape at elevated temperatures only. Would the dry-out schedule not be respected, then vapour pressure inside the lining would rise up to values exceeding the strength of the castable and the lining would explode.

Calderys has thus developed a new concept of refractory, called the Quick Dry No Cement Castables which is based on a unique bonding system. The bond forms due to surface interaction between ultra-fine pure mineral reactants when in contact with water, and the reaction does not build crystalline hydrates. As a result, this bond exhibits very high gas permeability. This, associated to the absence of bonded water, allows for fast water removal with low steam pressure. In terms of installation, QD NCC can be mixed using the same equipments as for traditional castables and can be installed the same way. Also and thanks to the quick strength development of the bond, QD NCC do not require curing, which saves additional installation time.

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