Kola MMC (MMC Norilsk Nickle subsidiary) has completed repairs of the electrical motor, which is integrated into the frame of the large MSh-300 ball mill. The repairs were conducted in brownfield conditions with two polar segments replaced, and drive elements partially disassembled and dismantled.
Preparations for the repairs took 18 months in conjunction with the manufacturer team from Siemens and the supplier company. The large ball mill has a service life of 20 plus years and constitutes approximately 40 % of the capacity of the concentration plant.
Since the mill went operational, some of its parts, in particular coils on polar segments went through substantial wear and tear around the insulation.
Replacement operations for polar segments are unique. There’re less than a dozen of such units in existence and no similar repairs have ever been undertaken. The repairs will improve reliability of machinery and cut down on emergency shutdown time. From this point onward Kola MMC team will handle similar repairs in-house to reach complete replacement of electrical motor polar segements in the large ball mill.