Bubbles implosion effect on cavitation wear of centrifugal pumps that transfer ammoniacal fluids

Abstract

This article exposes the effect bubbles implosion causes on buckets on the liquor from carbonate-ammonia leaching (mixture of water, ammonia and particles in suspension) of ferronickel lateritic ores. Based on the previous results that establish a relationship between the bubbles’ size and the ammonia concentration of the liquor, the microstructure of a Hastelloy C 276 steel blade affected by cavitation was analyzed. It was also obtained that affectations are smaller in the initial area of the bucket than the distal parts, where complete perforations can be produced in the metal, what is associated to the fact that bubbles develop a great size at a concentration of 34% of ammonia in the liquor and implode at the exit of the bucket producing more intense pressure waves than those generated by the bubbles formed at 27% and that implode in the initial zone. It is concluded that the microstructural changes in the bucket material are closely related to the concentration of ammonia in the liquor making pitting, cracks, and cavities larger when the concentration of ammonia is maximum (34%).

Keywords

• desgaste por cavitación
• bomba centrifuga
• implosión de burbujas
• licor amoniacal
• análisis microestructural
• Hastelloy C 276.