Proactive Maintenance at the South Grinding Mill

Employee alertness at Bauxite Wet Grinding (BWG) made it possible for production to be maintained despite what appeared to be a significant break on a south grinding mill pinion bearing, which is one of the parts involved in the rotation of the grinder.

During a weekly check, employees noticed an unusual noise coming from the pinion bearing at Hydrate East’s south mill. “The pinion bearing is a key part of the grinder. It keeps it rotating continuously,” explained Jean-Benoît Lamontagne, Manager at BWG. As the breakdown of this piece of equipment can potentially result in $500,000 worth of production losses, Pascal Morin, Vibration Analysis Specialist for Rio Tinto, was called to the site to monitor the part.

“The weekly vibration analysis confirmed that the part was in good condition and that it was not likely to cause an emergency shutdown,” Morin said. “However, rigorous monitoring had to continue so we could make sure that the situation was stable. We were lucky in a way, because the type of breakage detected on the ring does not get worse.”

Accurate information allows for informed decision-making, and it is through this analysis that BWG’s operations could be maintained at full capacity until the annual inspection shutdown. “Good shutdown planning is part of operational excellence. The know-how of the plant’s employees made it possible for us to make an informed decision about our operating mode,” said Jean-Philippe Jomphe, Technical Coordinator, Hydrate East Maintenance and Calcination Centre, Asset Management.

Thanks to everyone’s efforts, the bearing part was replaced at the time of the inspection, with minimal impact on production and, most importantly, without any HSE incidents.