# Ball mill operation tips

Date:2019-05-30 14:00 writer:admin Views:

**Ball mill **is a very common grinding equipment only in mineral processing applications.

The grinding principle is to make use of the friction between the material and the steel ball or column and the rotating form of the drum to promote the material to reach the ideal grain grade standard.

So, dressing equipment in the very important grinding equipment, the **ball mill** bears the burden of grinding, if a little mistake, the consequences will be very big, so as a central link of the **ball mill grinding** operation whether there must be emphasized the operation method?

Here in the noble machine that as long as the master of the "all mine, return to sand, high concentration" the nine words can achieve the most ideal grinding effect.

This is described in detail below.

What is "give mine"?

In fact, we can understand it this way, we also pay attention to the situation is "all mine".

Why do you say that?

In fact, there are two main aspects of the meaning: one is to give uniform ore size composition;

Second, the feeding speed (the amount of ore fed into the mill per unit time) is constant.

In order to improve grinding efficiency, the ore feed should be continuous, uniform and stable at a high level.

Time and time can make the mass fraction of the mill fluctuate frequently, which is not conducive to the grinding process.

Grinding feed in the bin often appear size segregation - fine in the middle, coarse around the material composition is not uniform, if not in accordance with the size of timely adjustment operation will appear "bulge belly".

Therefore, the bin should adopt multi-point discharge to ore as far as possible.

Then the meaning of "large return to sand" is also very simple, we require in the small ball mill grid plate operation process to achieve "large return to sand".

In order to explain the benefits of this, let's first look at what is the return of sand.

Returning sand refers to the coarse grain grade which is returned to the mill by the classifier after closed-circuit grinding.

The amount of ore returned is often several times the original amount.

The ratio between the amount of returned sand and the amount of raw ore is called the ratio of returned sand.

Practice has proved that the size of return sand ratio will directly affect the mill productivity.

Larger return sand ratio, because of the grinding mill to increase the amount of ore, so as to increase the mill discharge speed, material retention time in the mill is shortened, the cycle is accelerated.

In addition, although the return of sand is coarse ore, but after all than the original ore fine, so the mill to give the ore size composition of fine, comprehensive results are conducive to improve the productivity of **small ball mill**.

The relation between return sand ratio and relative productivity of mill is studied.

It can be known that, in a certain range (such as between 100% and 500%), with the increase of return sand ratio, the mill productivity increases with the increase, when reaching a certain value, the productivity increase range is very small, the mill full feed ore is close to the maximum capacity, easy to cause ball grinding bulge.

Therefore, the return sand ratio should be kept stable, close to a constant value.

The so-called "high concentration", the grinding mass fraction is an important factor affecting the mill productivity, it determines the friction between the grinding medium and the grinding material, slurry fluidity and the effective density of the medium (medium and slurry density difference).

At the same time, the amount of ore per unit volume is large, so the amount of ore is large.

However, if the pulp quality fraction is too high, as the pulp density increases, the effective density, activity ability and strike effect of dry ball mill steel ball loss will be weakened. Meanwhile, high mass fraction, high viscosity, poor fluidity and reduced total ore discharge will lead to reduced mill productivity and even "bulge belly".

Mainly refers to the mass fraction (pulp mass fraction) refers to the percentage of ore mass (dry weight) and pulp mass (ore + water) in the pulp, where the mass fraction refers to the pulp mass fraction (mill mass fraction) in the mill.

In the mill operation, a higher grinding mass fraction is generally used, so that a layer of pulp can be attached to the surface of the medium, thus enhancing the beneficial grinding effect on the grinding.

Therefore, "high concentration" refers to the appropriate increase of grinding mass fraction within a certain range, which is conducive to improving the grinding effect.

As long as you master the above **ball mill** operation specifications, or the predecessors through personal practice to experience and lessons, you can make the ball mill in the best working condition has been working.

The core problem revealed by this nine-word secret is the balance of input and output efficiency.