Minor overhauls are generally scheduled for one month (except in special circumstances where they can be performed at any time). The main overhaul items include the following:

(1) Inspect, clean, and change the oil pump, oil filter, and lubrication lines.

(2) Inspect, fill, and tighten the bolts on all parts of the grinding mill.

(3) Inspect the large and small transmission gears of the grinding mill, record the wear condition, and replace or repair worn small gears.

(4) Inspect the couplings and replace elastic gaskets or other types of parts.

(5) Inspect and repair the feed pipe and discharge pipe.

(6) Inspect and tighten the feeder, and replace the scoop head of the combined feeder.

(7) Inspect the motor bearings, oil rings, and brushes.

Intermediate overhauls are generally scheduled for 4-6 months. The main overhaul items are as follows:

(1) Includes the items from the minor overhaul.

(2) Inspect and replace the feed pipe, discharge pipe, and feeder. (3) Repair the transmission gear.

(4) Replace severely worn liners and grid plates.

The overhaul cycle is generally set at 2-4 years. The main overhaul items include the following:

(1) Items including minor and intermediate repairs.

(2) Replace the main bearing and gear.

(3) Inspect, repair, or replace the mill body.

(4) Repair or replace the mill’s inlet and outlet end covers.

(5) Repair the foundation, realign it, and perform secondary grouting.

The above requirements for minor, intermediate, and major repairs are only basic requirements. Actual repair content in production often differs from these requirements. The timing and content of minor, intermediate, and major repairs for the mill in the concentrator must be specifically arranged and formulated based on the specific condition of the equipment and production tasks of the plant. Repairs must be carried out according to the planned schedule and content. After repairs, equipment records must be properly stored, and repair files must be established.