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Belzona® Repairs Trunnion Ball Mill In Situ



Mining and Quarrying (MINQ)



Mechanical Power Transmission (MPT)


Customer Location:

Mine, MA, Brazil


Application Date:

February, 2011


Application Situation:

Sliding bearing area of the ball mill’s trunnion



Wear on the trunnion’s sealing edge due to ore’s abrasion between the rubber ring and the edge. In addition, localized wear on the trunnion’s seating area of the socket was present. Trunnion’s diameter: 1.200 mm. Operation is at room temperature.



Belzona 1131 (Bearing Metal)
Belzona 1311 (Ceramic R-Metal)
Belzona 1321 (Ceramic S-Metal)



Carbon Steel


Application Method:

After removal of oil and residual grease, the surfaces were prepared with electrical sander. The sealing edge was recovered with the application of Belzona 1311 and coated with Belzona 1321 to achieve a polished finishing resistant to abrasion. The seating area of the socket, was repaired with the application of Belzona 1131 (Bearing Metal) to rebuild thickness loss where there is metal to metal contact. The application and finishing were performed manually.


Belzona Facts:

Belzona technology offered the following advantages: quick return to service, elimination of hot work with electrical welding and low cost.


Photographs Description

Wear on the trunnion’s sealing edge Application of Belzona 1131 on the trunnion Application of Belzona 1311 on the trunnion’s edge Trunnion’s edge coated with Belzona 1321

Case study pic one


 Case study pic two


 Case study pic three


 Case study pic four


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