Failure analyses of water-cooled smelt spouts

Rapid corrosion failures of water-cooled smelt spouts have affected several recovery boilers operated within North American pulp and paper mills. Spouts fabricated from alternative materials have been adopted as a solution, largely on an ad-hoc basis, and, in some cases without much success. To better understand the corrosion problem, a metallurgical assessment was performed on a set of degraded smelt spouts fabricated from a range of materials.