The rod mill is decelerated and driven by the motor through the reducer and the surrounding large gear, or by the low-speed synchronous motor directly through the surrounding large gear to drive the cylinder to rotate. The cylinder body is equipped with appropriate grinding medium - steel rod. Under the action of centrifugal force and friction, the grinding medium is lifted to a certain height and falls in a throwing or discharging state. The ground material continuously enters the cylinder from the ore feeding port, is crushed by the moving grinding medium, and the product is discharged out of the machine through overflow and continuous ore feeding to carry out the next process [2]. When 80% of the product particle size is required to be less than 2.0% to 0.5mm, the rod mill is generally used. The product particle size of the rod mill is generally no more than 4.7MM and no less than 0.4mm. The ore feeding particle size of the rod mill is 80%, less than 20mm to 4mm, and the maximum ore feeding particle size can also be up to 50mm. Due to the material of the grinding rod and other reasons, the length of the grinding rod shall not exceed 6.1m, otherwise it will cause bad consequences such as disorderly rods. Therefore, the specification of the rod unloader has not exceeded specification 4.6 Ã?? 6.3m. When the ore is fed into the rod mill, the coarse particles are at the feeding end and the fine particles are at the discharge end: therefore, the rod group cannot be completely parallel and inclined during operation, which is also a reason why the grinding rod cannot be too long.