CI / HPRI / LTI Summary

CI / HPRI / LTI SummaryJoint Venture DivisionXstrata Copper1Category CIDescriptionCause analysisTwo mechanics were performing repairs on a Floway vertical pump PP-120 in the pump house of the Sulphides Plant removing the spacer between the pump and the motor. The objective was to remove material entrapped within the pump. The majority of the bolts were removed using a wrench and three bolts could not be removed in this way. Workers removed the bolts with a hand saw and while the fatally injured mechanic was cutting the third bolt, the axis of the impeller rotated and the spacer was ejected and impacted him in the face causing cranial fractures. He was transported to the hospital by ambulance where he later died from a heart attack. Direct CauseHydraulic lines were not blocked. Contributing Factors

Check valve failure.Material and debris routinely entered the pump circuit.Supervisor was not present during this task.Unclear reporting lines and formalized documentation for completion of this task.Common and accepted practice was to perform maintenance operations using the check valve as control for energy isolation.Key Corrective ActionsDue DateEmergency Response activated to transport worker for urgent medical attention.20-02-12Complete operational shutdown for 24 hours where safety reflections and reinforcement of energy isolation procedures all staff. 20-02-12Investigation Commission formed including direct participation by shareholders.21-02-12Lessons LearnedPendingCI / HPRI / LTI SummaryCollahuasi 20/02/12

Pump RoomPond 6

Vertical PumpEjected Spacer and one of the bolts