Ball mill: summer cooling method

The main bearing of the ball mill is one of the important components of the ball mill, which has an important influence on the operation efficiency of the ball mill.

Under the high temperature in summer, the main bearing of the ball mill is prone to high temperature of the bearing pad, and even a bearing accident in severe cases. In this article, we will discuss how to solve the problem of the high temperature of the bearing pad of the main bearing of the ball mill.

1. Replace the ball mill lubricating oil in time

During the operation of the ball mill, heat is generated due to the relative rotational friction between the hollow shaft and the bearing bush, which increases the temperature of the main bearing. Therefore, the friction can be reduced by replacing the lubricating oil, so that a uniform oil film can be formed on the bearing surface. Avoid increasing the temperature of the main bearing.

2. Adjust the cooling water and cooling device of the ball mill

The cooling of the ball mill is very important. The cooling water in the main bearing bush and the water in the main bearing oil tank cooler are the two main waters for the main bearing of the ball mill. The temperature of the cooling water has a great influence on the temperature of the main bearing of the ball mill, and the temperature of the cooling water is low. The cooling effect of the lubricating oil is fast and the cooling effect is good. Increasing the cooling water flow will also reduce the temperature of the main bearing bush.

3. Improve the environmental conditions of the ball mill

The temperature of the ball mill itself is greatly affected by the surrounding environment. In summer, the ambient temperature is high, and the temperature of the bearing bush of the ball mill is also high. The doors and windows of the factory building, the doors and windows of the oil pump room and the observation hole of the large tile should be opened to improve the ventilation conditions of the environment where the ball mill is located and reduce the temperature of the lubricating oil.

In addition, if conditions permit, an axial flow fan can be installed in the oil pump station to increase the circulating flow of air and reduce the temperature of the lubricating oil. The temperature can also be reduced by adding spray water to the oil return pipe and the oil outlet pipe.

4. Increase the cooling area of the oil pump

The cooler in the ball mill oil pump can be re-selected, or the cooling area of the ball mill lubricating oil can be increased by connecting the cooler in series, the heat exchange effect of the ball mill lubricating oil can be improved, and the temperature of the lubricating oil fed into the ball mill can be reduced. reduce bearing temperature

Below are the parameters of some of our ball mills for your reference

The "hidden rules" of ball milling

 Corresponding proportioning of the ball mill, so that it can crush minerals to the greatest extent, and meet the requirements of mineral crushing and grinding. The quality of mineral crushing can directly affect the efficiency of milling, and ultimately affect the overflow output of the ball mill. The level of ball loading can directly affect the crushing effect. These parameters are mainly affected by the specifications of the ball mill, the internal structure of the ball mill, and the fineness of the product.

The ball must have sufficient impact force so that the ball has sufficient crushing capacity to handle the material, which is directly related to the diameter of the steel ball.

The number of impacts of loading the ball must be enough so that the ball can crush the material. The average ball diameter and filling rate are the main influencing factors. The amount of filling is fixed. In order to ensure sufficient impact force, the diameter of the sphere can be reduced and the number of spheres can be increased to increase the number of impacts on the mineral and improve the crushing efficiency.

To ensure sufficient time for the material to grind in the mill, the ball must have the ability to control the flow rate to ensure that the material is fully crushed.

The law of two-level ball allocation

The use of two spheres of different specifications for grading is called two-stage grading, but there is a requirement that the diameters of the two spheres differ greatly. Its main function is to improve the impact capacity and the number of impacts of the mill. In addition, the higher bulk density allows the material to be fully ground.

In the two-stage ball distribution rule, the large balls are mainly used to crush materials, and the small balls are mainly used to fill the gaps of the large balls to increase the bulk density of the balls, thereby controlling the flow rate of the flow, thereby increasing the grinding The second is the transfer of energy; the last is to squeeze the coarse-grained materials in the gap into the impact area of ​​the big ball.

See details：https://www.pizzerie-u-pepy.cz

Failure analysis of ZGMn13 liner of ball mill

 Through the macro inspection and the onlooker inspection, it can be found that the liner of the ball mill will occasionally show loose casting, oxides, and a large number of massive unmelted carbides and needle-like carbides.

    The ideal microstructure of high manganese molten steel after treatment is a single austenite, but due to the metallographic examination of the liner, there are a large number of unmelted massive carbides and precipitated needle-like carbides in the microstructure. This is because the heating temperature is too low during the water toughening treatment, or the holding time is too short, so that the carbides are not fully integrated into the austenite. In the subsequent quenching and cooling process, a large amount of precipitation may be due to insufficient cooling speed. Needle carbide. From the field investigation, the heating temperature of the heat treatment furnace will be lower than the temperature required by the process due to long-term neglect and maintenance; when the water toughening treatment is cooled, because the water tank is too small, the treated tonnage is too heavy. The water temperature after cooling cannot be kept below 60 degrees Celsius, which reduces the cooling rate; if the workpiece stays in the water for too long from the furnace to the water, these will make the microstructure after the water toughening treatment appear abnormal.

    The chipping of the liner of the ball mill is mainly due to the improper longevity of the heat treatment process, the defective structure and casting shrinkage, as well as the existence of coarse non-metallic debris, which reduces the strength and toughness of the liner. Under the action of this, it will lead to the early failure of the liner.

Specific details can be consulted：https://clactononseaessex.uk/

Choose a ball mill or a rod mill?

Grinding operation is very important in the entire beneficiation process, the cost is also quite large, the investment is huge and the energy consumption is high, therefore, choosing a suitable mill is very important for the entire beneficiation plant.

At present, ball mills and rod mills are widely used in concentrators. However, the difference in appearance between ball mills and rod mills is not very large, and it is not easy to distinguish. However, a careful comparison shows that the difference between the two is still very large. First of all, from the point of view of the name, the grinding medium of the ball mill is a steel ball, generally less than 100 mm in diameter, and the grinding medium of the rod mill is a steel rod, generally greater than 500 mm in length. The discharge methods of the two are also very different. The ball mill has two types of discharge methods: grid type and overflow type. Both have advantages and disadvantages. The rod mill has no grid plate, and mainly has overflow type and opening. Two types. Secondly, the filling rate of the grinding media is also different, that is, the percentage of the equipment volume occupied by the grinding media is different. If the filling rate is too high or too low, the final effect will be affected. Usually, the ball mill is 40%-50%, and the rod mill is 35%. -45% is the most ideal. The performance of the two equipment is also quite different. Due to the different media, the rod mill grinding media is in linear contact with the ore, which has a certain selective grinding effect, the product size is more uniform, and there is less over-grinding. The ball mill media and the ore are in point contact, which has impact and grinding power, and the product size is finer, but the over-grinding phenomenon is more serious. Finally, the scope of application of the two is also different. When heavy separation or magnetic separation of tungsten tin ore and other rare metal ores, rod mills are often used to prevent excessive crushing; in the second-stage grinding process, rod mills are generally used As the first-stage grinding equipment, it has larger production capacity and higher efficiency. When processing soft or not too hard ores, rod mills can be used to replace short-head cone crushers for fine crushing, which is not only simple to configure, but also low in cost, and simplifies dust removal in the workshop.

Because of the fine grinding materials, the ball mill is prone to over-crushing. It is not suitable for the gravity separation production line in metal beneficiation, but is widely used in other beneficiation processes.

Due to the difference between ball mills and rod mills, users can choose according to their materials, grinding particle size, production methods, etc. In contrast, the products of ball mills are finer and the products of rod mills are rougher but more uniform.

Choosing the Right Ball Mill Feeders

Three types of ball mill feeding device configuration methods: drum feeder, combined feeder and feeding trolley.

1. Drum feeder

Drum feeder

(a) The materials are pushed into the feeding port through the spiral plate to realize compulsive feeding.

(b) The specially designed anti-spitting small cone effectively solves the problem of material leakage.

(c) It is suitable for use with a single spiral classifier or cyclone. It has a simple structure and is easy to use without maintenance.

2. Combined feeder

Combined feeder

(a) Keep feeding from a high position, no backflow and overflow, reduce labor intensity. Avoid pollution and improve efficiency.

(b) It is suitable for use with double spiral classifier.

3. Feeding trolley

Feeding trolley

(a) The trolley can move back and forth on the track, and the feed elbow can be directly inserted into the feed inlet.

(b) It connects the flange and the feeding device (silo or feeder).

(c) It has simple structure which is convenient to maintain. This device is suitable for large mills above 32.