Towards Polymeric Fibers' Optimization as Refractory Castable Drying Agents - Insights From Direct Visualization

Permeability-enhancing additives are often applied to mitigate the risk of explosive spalling during refractory castables drying. The reasoning is that the easier percolation of water within the material reduces the likelihood of water vapor pressurization, enabling faster drying, increased end-user productivity and a substantial CO2 emissions reduction. Thanks to their advantageous features, polymer fibers are the predominant class of drying additives in the industry. The key challenge to unlocking optimized drying additives is understanding the detailed mechanisms of permeability enhancement provided by the polymeric fibers. Thus, neutron tomography was used to visualize the difference in the mass removal behavior of samples comprising polypropylene (PP), polyethylene (PE) and cellulose fibers. The PE and cellulose compositions initiated the drying process earlier, with the latter contributing to more extensive drying. Conversely, PP only accelerated the drying at later stages, however, it still achieved an efficiency comparable to cellulose.