Working principle and maintenance of ball mill

Ball mill is the key equipment for crushing materials after crushing. It is widely used in the production of new building materials, refractory materials, fertilizers, black and non-ferrous metal beneficiation, etc., for dry or wet grinding of various ores and other grindable materials. There are many types, such as energy-saving ball mills, overflow ball mills, lattice ball mills and so on. According to the different ways of discharging, it can be divided into two types: grid type and overflow type. Its grinding mode consists of two types, one is wet type, and the other is dry type. Because it is an important part of industrial production, it is very necessary for the maintenance of the ball mill. This article starts with the actual industrial production and briefly analyzes the troubleshooting of the ball mill:

The working principle of the ball mill:

The ball mill is composed of a horizontal cylinder, a hollow shaft for feeding and discharging materials, and a grinding head. The cylinder is a long cylinder with a grinding body installed in the cylinder. The cylinder is made of steel plate and is fixed with a steel liner. , The grinding body is generally a steel ball, which is packed into the cylinder according to different diameters and proportions. The grinding body can also be made of steel. Choose according to the particle size of the grinding material. The material is loaded into the cylinder by the hollow shaft at the feed end of the ball mill. When the cylinder of the ball mill rotates, the grinding body is attached to the cylinder liner due to inertia, centrifugal force and friction. Carried away by the cylinder, when it is brought to the height, it will be thrown down due to its own gravity. The falling grinding body will crush the material in the cylinder like a projectile. The material is uniformly spiraled into the first bin of the mill through the feeding hollow shaft from the feeding device. The bin has a step liner or a corrugated liner, which is equipped with various specifications of steel balls. The rotation of the cylinder generates centrifugal force to bring the steel balls to a height. When it falls, it will have a heavy blow and grinding effect on the material. After the material reaches the rough grinding in the first warehouse, it enters the second warehouse through the single-layer partition board. The warehouse is lined with flat liners and steel balls to further grind the materials. The powder is discharged through the unloading grate to complete the grinding operation.

Common faults and maintenance of ball mill operation

1. The bearing of the ball mill is overheated and the motor is overloaded.

Reason: Inadequate lubrication, interruption of lubricating oil or insufficient amount of lubricating oil; incorrect rotation of bearings or couplings; too large or too small gap between journal and bearing shell, poor contact; damage to the oil groove prevents oil from flowing into the shaft Neck or bearing bush, etc.

Solution: Find out the cause of the shutdown, and solve the specific problems in detail. Check whether the lubrication is in place; install the bearing or coupling correctly; adjust the gap between the journal and the bearing bush, and check the oil groove in time.

2. The running sound of the ball mill is dull, the reading of the ammeter drops, and the output is small

Reason: Too much filling material and large particle size; material moisture is large, sticky ball is ground, grate is blocked; the grinding body is not properly filled, or the silo is out of adjustment due to the channeling, the length of each silo is unreasonable, etc.

Solution: reduce the filling material and reduce the particle size of the mill; reduce the moisture of the material and clean the grate; adjust the proportion of the grinding body and the length of each bin.

3. The reducer bearing heats up and the running sound is abnormal

Cause: The exhaust hole of the reducer is blocked; the balance wheel and the intermediate wheel of the reducer are not installed according to the specified meshing teeth.

Solution: Check the temperature of the reducer bearing and clear the exhaust hole; install the balance wheel and the intermediate wheel according to the specified meshing teeth.

4. Partial abrasion of the cylinder body

Reason: The liner is not installed in a wrong position; the liner continues to run after it falls off; there is material scouring between the liner and the cylinder.

Solution: stagger the liner; repair or replace the liner; make the liner closely fit the cylinder.

5. The oil pressure of the lubrication system is too high or too low

Cause: oil pipe is blocked or leaking; oil supply is insufficient; oil pump has problems.

Solution: Check whether the oil pipe is blocked or leaking, repair or replace the oil pipe in time; add oil regularly; check whether the oil pump enters air or leaks, and deal with it in time.

The ball mill is a key equipment for mineral processing. The faults in operation must be found and resolved in time to ensure the normal operation of the ball mill and create higher value. More questions about the working principle and maintenance of the ball mill are welcome