10 Ways to Improve Grinding Efficiency of Ball Mills

by Ivy Z. Mining Equipment Sales

Engineers from Fort Heavy Machinery share 10 ways to improve the grinding efficiency of  ball mills in the following part.

1. Change the grindability of raw ores

If the ore is easy to grind, the wear of the mill liner, the steel ball and the energy consumption will be smaller.

If the ore is difficult to grind or the ore requires fine grinding, a new treatment process can be considered to change the grindability of the ore:

• Add a certain chemical agent in the grinding process to improve the grinding effect and increase the grinding efficiency.

• Heat the ore to change the mechanical properties of the entire ore and reduce its hardness.

2. Reducing the feeding size

When the grain size is large, the workload of the ball mill is bound to increase, and its energy and power consumption will also increase.

To reduce the feeding particle size of grinding, it requires the size of crushed ores to be small, that is, to "crush more and grind less".

Moreover, the efficiency of crushed ore is obviously higher than that of grinding, and the energy consumption of crushed ore about 12%-25% of the energy consumption of grinding.

3. Reasonable filling rate

The greater the filling rate, the stronger the grinding effect, but the greater the power consumption.

In addition, too high filling rate can easily change the motion state of the steel ball and reduce the crushing force on large particles.

On the contrary, if the filling rate is too small, the grinding effect will be too weak.

At present, many mines set the filling rate at 45% to 50%. It may not be reasonable, because the actual conditions of each dressing plant are different, so it is not possible to achieve the ideal grinding effect by applying the data of others.

4. Reasonable size and the ratio of steel balls

Because steel balls in the ball mill are in point contact with ores, if the ball diameter is too large, the crushing force is also large, causing the ore to be crushed along the direction of the penetration force instead of the crystal interface of different minerals with weaker binding force, which cannot meet the purpose of grinding.

In addition, in the case of the same ball filling rate, too large ball diameter leads to too few steel balls, low crushing probability, more over-crushing and uneven product particle size.

If the steel ball is too small, the crushing force on the ore will be small and the grinding efficiency will be low.

5. Accurate adding ball

The grinding of steel balls on ores will cause the wear of steel balls, resulting in changes in the ratio of steel balls of various sizes, affecting the grinding process and causing changes in the fineness of the grinding products.

Therefore, a reasonable steel ball supply is required.

6. Proper grinding concentration

The grinding concentration affects the specific gravity of the pulp, the degree of adhesion of the ore particles around the ball and the fluidity of the pulp.

• If the grinding concentration is too low, the grinding efficiency cannot be exerted.

• If the grinding concentration is too high, it is easy to cause the material to be over crushed.

7. Optimize the grinding process

In actual production, the grinding process can be optimized according to the ore properties of the original ore, such as the distribution particle size of useful minerals, the degree of monomer dissociation, and the distribution particle size of gangue minerals.

Optimize the grinding system by pre-tailing, pre-enrichment, stage grinding and pre-classification can reduce the amount of grinding and recover useful minerals early.

8. Improve grading efficiency

High classification efficiency means that qualified particles can be discharged in time and efficiently.

Low classification efficiency means that most of the qualified particles are not discharged and return to the mill for regrinding, which is easy to cause over-grinding, thus affecting the sorting effect in the later period.

Two-stage classification or improved classification equipment can improve classification efficiency.

9. Appropriately improve the grading sand return ratio

Sand return ratio is the ratio between the sand return amount of the ball mill and the raw ore feed amount. Its size directly affects the productivity of the mill.

One way to improve the sand return ratio is to increase the original ore feed, and the other way is to reduce the shaft height of the spiral classifier.

10. Automatic control of grinding system

There are many variable parameters in the grinding operation, and a change will inevitably cause the successive changes of many factors.

The automatic control of the grinding operation can keep the grinding classification in a stable and suitable state, and can also improve the grinding efficiency.

Sponsor Ads

• Ad Space Available - Rent it Now!

Created on Mar 30th 2021 02:36. Viewed 271 times.

Comments