Views:12 Author:Site Editor Publish Time: 2021-04-02 Origin:Site
Influence of grinding medium on hardness and density
The density and hardness of grinding medium play an important role in grinding efficiency: the higher the density of medium is, the higher the grinding efficiency is; the higher the hardness is, the smaller the wear is, the easier the purity of product is to be guaranteed; however, the density and hardness of grinding medium are not the higher the better when the specific gravity and viscosity of slurry are fixed.
Too high density of grinding media will cause uneven distribution of grinding media
in the barrel, and the greater the density difference, the more unreasonable the distribution, and the greater the probability of extrusion between grinding media. High hardness leads to poor toughness and impact resistance. When the grinding medium impacts (collides) the ground material at high speed, it is easy to break itself, increasing the possibility of breaking itself and other grinding media.
The influence of the shape and size of grinding medium on the grinding effect
The size of grinding medium ball directly affects the grinding effect and product fineness, which determines the number of contact points between grinding medium and material. The more contact points of grinding medium ball with small particle size in the same volume, the higher crushing efficiency in theory.
In industry, irregular media tend to be subject to greater wear and tear, which will cause obvious pollution. Therefore, spherical medium is widely used in practice, cylindrical medium is also used, and irregular medium is rarely used. The size of medium particle size depends on the particle size of material and required product. The finer the particle size of the product, the smaller the particle size of the medium. If the feed particle size is relatively large, the grinding medium needs to have a greater impact crushing effect, then the ball distribution should be larger.
Influence of production method of grinding medium ball on grinding effect
According to the research, due to the different production methods and control processes, the wear resistance of grinding balls of the same material is quite different. The most typical is the alumina ball. The forming methods of alumina ball include extrusion method, pellet method, hydraulic hard mold forming method and isostatic pressing forming method. The wear difference between isostatic pressing forming method and grouting forming method is more than ten times. The reason may be that the compactness and uniformity of the former is higher than that of the latter, and a solid whole can be formed after sintering.
In addition, the alumina raw materials used by the two may be different, and the differences in raw material purity, particle size, powder fluidity and other aspects will also have a great impact on the wear resistance of the grinding medium, and ultimately affect the grinding effect.
Influence of grinding medium gradation on grinding effect
When the total mass of grinding medium is the same, the influence of different grinding medium ratio on grinding effect is different. Generally speaking, in the process of continuous grinding, the size distribution of medium is a certain rule. In order to reduce the cost, the method of adding large balls is often used to restore the grinding capacity of the system, so it is difficult for the mill to maintain a fixed medium ratio in a long time. If the medium diameter difference is too large, it will aggravate the invalid grinding between the media, that is, the large medium grinds the small medium, which increases the cost of the grinding process.