The size of the ball diameter of the ball mill depends on many factors, such as the particle size, hardness, density of the material to be milled; the diameter and rotation speed of the ball mill; the density of the ball; the mass fraction of the pulp, but the actual production is mainly based on the material being ground in the mill. Depending on the particle size composition. The feed of the mill is composed of several particles of different sizes. Practice has proved that when dealing with large or coarse ore, it requires a large impact force, and balls of larger size should be added; when the ore is soft and the grinding grain size is small and finer grinding is required, it should be ground. Mainly, you can add balls of smaller size. Of course, the choice of the ball diameter is also related to the grinding machine diameter and speed, the diameter of the high speed of the mill; the ball diameter can be smaller.
In short, large ore needs big ball impact, and small ore needs small ball grinding. Although many people have proposed a relationship between the size of the nugget and the ball to be added, since the grinding process is a complicated process, each formula has its limitations and the deviation is large. The most basic formula is: Medium hardness ore, test to obtain i = 28, so in the formula D - should be added to the diameter of the ball, mm; d - the size of the material being milled, mm. After years of production practice, Lipu majority of mineral processing workers have summed up the empirical relationship formula between the ore size and the appropriate ball diameter: The symbol in the formula is the same as before. According to China's many years of production practice, the relevant personnel have summarized the corresponding relationship between the ball diameter and the ore size for medium or hard ore. See Table 18. Table 18 Relationship between ore size and suitable ball diameter (mm)
|Feeding granularity||12~18||10~12||8~10||6-8||4~6||2 to 4||1 to 2||0.3~1.0|