# What are the methods of measuring ball mill load?

Date:2019-11-14 10:07 writer:cement editor Views:

Ball mill load is the sum of ball load, material load and water amount in the mill.**What are the methods of measuring ball mill load?**

## 1. The sound method

Industrial production practice shows that the sound of the ball mill has a certain relationship with the material load. The essence of this method is to determine the material load in the ball mill according to the difference in the noise produced by the ball mill.When the material load in the **ball mill** increases, the noise intensity of the ball mill decreases.On the contrary, the noise intensity of the ball mill increases, that is, there is a relationship between the noise intensity of the ball mill and the material load in the ball mill.Therefore, the noise intensity of the ball mill can be used to evaluate the material load in the ball mill.

## 2. Active power method

The working characteristics of a wet ball mill can be directly described by the useful power consumed.When the mill and its rotating speed are fixed, the theoretical calculation and actual test results show that there is a certain relationship between the active power of the ball mill motor and the load of the ball mill.With the increase of the ball mill load, the active power of the ball mill motor rises obviously at the beginning, and after reaching a certain extreme value, the active power decreases instead with the increase of the ball mill load. This extreme value can be considered as the optimal point of the ball mill load.Therefore, the useful power is directly related to the load of the ball mill.

## 3. The vibration method

When the **ball mill** is running, the grinding body and the material are on the side of the mill, and the grinding material and the rotating part of the mill are in a serious unbalance state, which causes the unbalance centrifugal force and makes the mill system vibrate.When the speed of the mill is unchanged, the vibration intensity of the mill is related to the amount of the grinded material.

## 4. Pressure sensor method

A load sensor is installed under the bearing of the feeding end and discharging end of the ball mill to continuously weigh the mill, so as to determine the total amount of ball medium, ore and water in the ball mill and determine the load of the mill.Its advantage is simple, the disadvantage is the detection accuracy is not high, can not accurately detect the ball mill medium, ore and water in the respective amount.In addition, the wear of ball mill lining plate, the change of ore property, the change of steel ball weight before and after adding will have a great impact on the test results.

## 5. Differential electromagnetic sensor method

It only measures the useful part of the vibration signal of the mill shell and eliminates the general interference signal.The sensor can be mounted at a distance of 71 ~ 80mm from the shell of the **ball mill**.The sensor has high reliability and sensitivity and low signal transmission delay.But this kind of detection system can't detect the concrete value of the ball mill's medium filling rate, material ball ratio and grinding concentration.

## 6.Hall power transmitter method

In the closed circuit grinding system of a ball mill with a double screw classifier, the load of the ball mill is indirectly reflected by measuring the amount of sand returned by the classifier.In the grinding production process, when the load of the ball mill exceeds the normal value, the coarse particle composition of the ball mill will increase, which will definitely increase the amount of returned sand; otherwise, the amount of returned sand will decrease.Therefore, it is feasible to measure the load of the **ball mill** indirectly by measuring the amount of returned sand. The hall power transmitter is used to measure the electric power of the classifier.At the same time, the absolute value of power is not required to be measured in this measurement, so only the single-phase power variation value of the three-phase motor with internal rotation of the double helix classifier is measured, so as to reflect the relative change of the returned sand amount and realize the automatic control of the ball mill load.

The single factor detection method introduced above is unable to judge the medium filling rate, material ball ratio and grinding concentration of the ball mill, so it is more important to choose the appropriate method according to the actual situation of the site.