Causes and Solutions of excessive Wear of liner in Ball MillDate: 2019-07-10 Views:
Ball mill is an indispensable equipment in concentrator, and it is also a equipment with a large proportion of investment in the construction of concentrator, so it is very important to ensure the grinding efficiency and service life of ball mill. As an important part of the ball mill, the liner of the ball mill can not only effectively protect the cylinder of the ball mill, but also improve the impact and peeling between the medium and the material, so as to improve the grinding efficiency.
However, under the long-term operation of grinding medium, the liner wear of ball mill is too fast. So what is the problem, what are the reasons why the liner of the ball mill wears too fast? How to deal with or improve the application?
1. Wear and tear between liner and steel ball of ball mill
Both the ball mill liner and the steel ball are vulnerable parts. In the grinding process, the ball mill steel ball and the material drop line in the cylinder, when the ball mill liner and the steel ball, the material will collide with each other to produce friction. In continuous operation, the liner and steel ball of ball mill will appear serious wear phenomenon, which is directly related to the hardness of the material. The higher the hardness of the material, the faster the wear speed of the liner and steel ball of the ball mill, which may cause equipment damage and even safety accident.
In addition, it is also related to the ball mill steel ball, the size of the steel ball, the number of steel balls, will affect the service life of the ball mill liner. If the ball mill is in operation, increasing the amount of steel ball or filling the steel ball with large diameter will aggravate the wear of the liner of the ball mill.
Coping methods: reasonable selection of ball mill liner and steel ball is one of the main ways to reduce the overwear of liner.
First, the relevant staff need to understand the ratio of ball mill liner to steel ball, and select the corresponding steel ball size and quantity according to the ratio. In general, the hardness ratio of the liner of the conventional ball mill to the steel ball is about 1 ≤ 0.8.
Secondly, the ratio of the material to the steel ball needs to be controlled, and the material is twice as good as the steel ball.
Third, when selecting the ball mill, it is necessary to select the appropriate ball mill liner according to the mineral type, control the hardness of the ball mill liner and the steel ball, and do a good job of the reasonable collocation between the ball and the liner.
2. The material of the lining plate of the ball mill is not
The material of ball mill liner and its heat treatment process are the key to determine the mechanical properties of the liner. If the liner material is improperly selected, its fatigue strength and life will be greatly reduced, which will not only be unable to meet the requirements of the ball mill, but even plastic change or drum.
Coping methods: select the new wear-resistant liner material, the commonly used ball mill liner material is high manganese steel, high chromium steel, alloy steel and wear-resistant rubber and so on. Wear-resistant rubber is a new liner material in recent 10 years. Wear-resistant rubber and alloy steel can be used to form a composite liner, which not only improves the toughness of the liner, but also solves the contradiction between toughness and stiffness.
3. The heat treatment process of ball mill liner is unreasonable.
The unreasonable heat treatment of the liner of the ball mill will not only increase the wear phenomenon of the liner, but also affect the yield strength of the liner, resulting in the fracture of the bolt of the ball mill under the action of large shear force. In the practical operation, the staff lack the understanding of the liner material, and the heat treatment processing of the ball mill liner is insufficient, so the strengthening effect of the ball mill liner is not in place and the strength is low. When hit by the steel ball and material, the plastic deformation phenomenon often occurs.
Countermeasures: pretreatment of the liner of the ball mill can effectively reduce the wear degree of the liner of the ball mill, and the suitable pretreatment process can be selected according to the material of the liner.
4. the ball mill is not running properly
The ball mill is in an abnormal operation state, which will also bring adverse effects to the liner of the ball mill. When the ball mill is in normal operation, the steel ball is mixed with the material, and when the steel ball is thrown into the liner, it will form a barrier with the material, play a buffering role, and gradually grind the material. If the ball mill is in low load operation, the steel ball will directly impact on the liner, resulting in serious wear and even fracture of the liner of the ball mill.
Coping methods: the relevant staff should understand the running state of the ball mill and control the running state of the ball mill. When the ball mill is running under low load, it is necessary to adjust the ore intake of the ball mill in time to ensure the grindability of the material.
In addition to the four wear reasons described above, the design, manufacture and installation of ball mill liner are also one of the reasons that affect the wear of ball mill liner too fast. in order to improve the efficiency of ball mill liner, it is necessary to analyze the wear cause of ball mill liner in order to formulate a reasonable solution.