In accordance with the approved schedule of planned repairs, the drum of ball mill #121 was replaced at the ore beneficiation plant of Central Iron Ore, and routine repairs were carried out on the associated process equipment.

In total, 49 hours are allocated, in accordance with the regulations, for the repair crews and the process personnel of the ore beneficiation plant at Central Iron Ore to dismantle the worn drum and install a serviceable one. And although such work is familiar to specialists, each time it requires them to switch into a ‘pit‑stop mode’.

In total, 22 mills are in operation at the concentrate production site. When the replacement of one of them is scheduled, the production plan is adjusted to account for a two‑day shutdown of the respective unit of equipment. First, the maintenance personnel open the hatches and empty the drum of balls. Next, the equipment shall be dismantled and sent to the repair site.

The task of the process personnel of the ore beneficiation plant is to prepare the workplace for the drum replacement as quickly as possible. It is necessary to remove the balls from the pit and place them in a designated container, and to clean the drive, the discharge box and the shaft lining. Meanwhile, the repair crews of the service maintenance shop of Central Iron Ore proceed with the inspection and repair of the entire chain of equipment associated with the mill: conveyors, classifier spirals, hydrocyclones, etc.

“The latest mill replacement at the plant was carried out in a clear and well-coordinated manner, for which sincere thanks are due to all participants in the process. Separate teams of workers were engaged for each type of work,” said Eduard KOBITSKYI, Head of Production Section No. 1 for Maintenance of Process Equipment at the concentrate production section.

Within the timeframe specified by the regulations, the serviceable drum with new lining was installed in its place. The mine surveying service of the enterprise was involved in the final stage of the process. The specialists carried out the necessary measurements to ensure that the massive equipment was installed level and aligned, without any tilting or displacement. The MShTs  mill of the first crushing stage is operating in normal mode again. Its processing capacity can reach between 162 and 230 tonnes per hour, depending on the approved plans and the production requirements.