Study on Drying Behavior of Hydratable Alumina-bonded High-Alumina Castables by Addition of Different Organic Fibers

• Published in: Journal of the Institution of Engineers (India): Series D Vol. 105; no. 1; pp. 183 - 189
• Main Authors: Rangdal, Pawan, Patil, Sharanabasappa B., Hiremath, Poornanand
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.04.2024; Springer Nature B.V
• Subjects: Alumina; Aluminum oxide; Castable refractories; Dehydration; Engineering; Mechanical properties; Organic fibers; Original Contribution; Phase transitions; Physical properties; Shock resistance; Spalling; Thermal resistance; Thermal shock; Weight loss; Rho alumina; Hydratable alumina (HA); Organic fibers; Drying behavior
• ISSN: 2250-2122; 2250-2130
• DOI: 10.1007/s40033-023-00468-9

The rho phase of alumina ( ρ -Al 2 O 3 ) commercially referred to as hydratable alumina (HA) is one of the popularly used no cement binders. The high surface area of HA when used as a binder in refractory castable creates a dense non-permeable structure. During firing of the castable, the water vapors get trapped in the impermeable structure and cause explosive spalling. In this study HA bonded high alumina castables were prepared by adding organic fibers. XRD analysis of ρ -Al 2 O 3 at different temperature showed formation of η and θ phase before forming the stable phase α -Al 2 O 3 . SEM and EXD analysis confirmed the purity of HA. Castable containing organic fibers showed poor physical and mechanical properties at 120–1200 °C compared to castable without organic fiber. After firing at 1650°, all the samples showed approximately same values of BD, AP and CCS. Addition of organic fibers did not affect the thermal shock resistance (TRS) of the castable as all the castables showed similar trend. TG-DSC analysis of castable containing organic fibers showed weight loss due to phase transformation and dehydration of HA, and that of castable without organic fibers showed weight loss due to phase transformation and dehydration of HA as well as burning of organic fibers.