In grinding operation, the consumption of ball mill steel ball is very large, about 10 times more than that of ball mill liner. In order to make up for the loss of steel ball and keep the ball load particle size constant in the ball mill, it is necessary to add steel ball regularly according to a certain proportion.
The consumption of the steel balls of the ball mill mainly comes from mechanical wear and corrosion wear. They are the irreversible processes of "physical-mechanical" and "physical-chemical" occurring on the solid surface. How to effectively reduce the grinding quality of the ball mill What is the energy consumption of the ball mill ball? Fodamon engineers will share the analysis from 6 points.
1. Change ore grindability
The grindability of the materials fed into the ball mill is one of the reasons that affect the energy consumption of the ball mill's steel balls. Generally, the smaller the grindability of the feed material, the more the ore is easy to grind.
In actual production, if it is difficult to grind ore or ore requires fine grinding, it may be considered to add certain chemicals during the grinding process to improve the grinding effect and increase the grinding when economic and site conditions allow Mine efficiency; or heat treatment of ore to change the mechanical properties of the entire ore and reduce mineral hardness. Both methods can effectively reduce the energy consumption of the ball mill.
2. Reduce the feed particle size
The larger the particle size of the ball mill, the greater the work of the ball mill on the material. To achieve the specified grinding fineness, the workload of the ball mill is bound to increase, and the energy consumption of the steel ball will also increase.
To reduce the power consumption of the ball mill, the feed particle size of the grinding ore can be reduced. Therefore, the particle size of the crushed ore product is required to be small, that is, "more crushing and less grinding".
3. Control the filling rate of steel ball
When the rotation speed of the ball mill reaches a certain degree, the larger the filling rate is, the more times the ball strikes the material, the larger the grinding area and the faster the wear. In addition, if the filling rate is too high, the movement state of the ball mill will be changed, and the impact effect on the large particle material will be reduced. On the contrary, the filling rate is too small and the grinding effect is weak.
At present, the filling rate of steel balls in the grinding operation of the concentrator is generally: lattice grinder 45% -50%, overflow grinder 38% ~ 42%. If according to the actual situation of each dressing plant, it is not a reasonable filling rate, so it is necessary to determine the reasonable amount of ball loading through the beneficiation test.
4. Control ball size and proportion
Because the steel ball and the material in the ball mill are in point contact, if the diameter of the steel ball is too large and the crushing force is too large, it will cause excessive wear, and it is easy to cause the material to crush in the direction of the penetration force, which affects the grinding efficiency.
In addition, under the same conditions of steel ball filling rate, if the ball diameter is too large, the number of individual steel balls will be small, the probability of crushing is low, the phenomenon of over crushing will increase, and the product particle size will be uneven; if the steel ball is too small, the ore will be broken Low force and low grinding efficiency. Therefore, the reasonable steel ball size ratio will not only reduce the steel consumption of the ball mill, but also effectively improve the grinding efficiency.
5. Control grinding concentration
The size of the grinding concentration will affect the specific gravity of the slurry, the degree of adhesion of the material around the steel ball and the fluidity of the slurry. If the concentration of grinding ore is appropriate, the adhesion of the material around the steel ball is good, the impact and grinding effect of the steel ball on the material is also large, and the steel ball wears faster.
In actual production, the concentration of ore grinding can be controlled by controlling the amount of ore supplied, or the amount of water supplied, or adjusting the classification effect.
6. Control the speed of the ball mill
Under the premise of a reasonable ball mill steel ball ratio, the increase of the ball mill speed will cause the steel ball in the barrel to fall into a falling pile. When the rotation speed increases to a certain level, the useful power reaches the upper limit, and the grinding effect Better, the ball wear of the ball mill is more reasonable.
The theoretical critical speed of the ball mill is generally 78 to 85%. Due to the nature of the material and other factors, the speed of the ball mill needs to be determined according to the actual situation.
In addition, the quality of the steel ball affects both the size of the productivity and the ball consumption, which affects the grinding cost. When selecting the steel ball, first, the steel ball is not as hard as possible, but has its proper hardness If only the ball consumption is considered, the higher the hardness, the lower the consumption, but for the mill productivity, within a certain range, the productivity increases with the hardness of the steel ball, but when the hardness exceeds a certain range, the mill productivity Adverse effects reduce the productivity of the mill and the steel balls are brittle. Second, the density of the steel ball of the ball mill is also a problem that cannot be ignored.
In the grinding process, there are many factors that affect the energy consumption of the steel ball of the ball mill, and most of the factors are difficult to make quantitative analysis. Only the qualitative analysis and judgment can be made. The power of the ball mill steel ball must be reduced under the premise of ensuring a reasonable quality index. Consumption must be considered from multiple links, and each link must be well controlled to achieve technical and economic indicators and good product quality indicators.