Ore mills in production to take a positive attitude towards greater hardness ore, such as through the test to find out the most suitable concentration of discharge, return the amount of sand and other operating conditions. The system requires crushing ore particle size as small as possible, the conditions under stable particle size, and find out the best ball match. Mineral hardness factor is unchangeable.

Milling mine procedure related to many factors. Summarized: grinding mechanism made​​, nature of the ore, the three major aspects of operating conditions. But in terms of the production site, the device is basically fixed, unchanging factors should be considered only ore properties and operating conditions over the quantity and quality of ore grinding operations product has a decisive influence. In order to ensure the quality of grinding minerals, workers must operate in accordance with the nature of the ore (particle size, hardness, etc.) changes, at any time to adjust to the amount of ore, while various operating conditions can change in a stable on the most appropriate level.
Ore mills directly determines the number of revolutions of the effect of the size of the cylinder body grinding media campaign status and grinding operations. When a low number of revolutions, the ball mill was promoted within the height of the smaller, the ball itself gravity load from the top of the ball rolling down the slide, was spilled off the state, this time the ball's impact is small, but very abrasive strong, mainly by grinding the ore stripping and grinding, high grinding effect department.

When the high number of revolutions, the height of the ball is lifted high. The ball rises to a certain height from the barrel, falling along a parabolic trajectory, in the falling operation. Point has a large impact on the falling action, mainly due to the impact crushing the ore, the maximum grinding efficiency. When the Ore mills exceeds a certain limit the number of revolutions (rpm high), the ball will not rotate with the cylinder whereabouts in centrifugal operation state. Then the ball ie no impact, abrasive grinding effect is also small so stop.
Structure dense, tiny crystals, a large hardness ore more difficult to grind. Therefore, such ore grinding process, grinding requires a longer time, in order to ensure the grinding fineness meet the requirements, but in general the main impact of the mill processing capabilities. The small hardness or easy to understand the development of ground ore, mill processing power per unit volume is high. Size of the ore hardness, which reflects the characteristics of the mineral composition of the ore itself is extremely physical and mechanical performance.