Overflow ball mills are the common mills in dressing plants. Here are the advantages and disadvantages of overflow ball mills.
Use the table of contents below to navigate through the guide:
01Advantages of overflow ball mills
Simple Structure. Overflow ball mills consist of feeding ends, shells, the discharge ends, main bearings and drive system. Hitherto, there is no complex grid plate at the discharge end, only helical blades with opposite rotary direction to mills, which makes overflow ball mills simpler structure than grid ball mills.
Cheaper Price. When it comes to the price of ball mills with the same specification, an overflow type is cheaper than a grid type.
Finer Grinding Fineness. The discharging principle of overflow ball mills is as follow. The ground ore fines overflow out of the mill because of their own gravity; while other ground ore particles and steel balls go back to the mill after their sedimentation to the helical blade with the opposite rotary direction with the mill in the feeding end because of gravity. Therefore, the grinding time ore particles stay in overflow ball mills is longer, making the grinding fineness higher than that of grid ball mills with the same specs, up to about 10%~15%. And such grinding fineness can perfectly fit customers requirement of a finer fineness.
02Disadvantages of overflow ball mills
Lower Capacity. The Overflow ball mills discharging speed is lower than that of grid ball mills. As a consequence, the capacity of the former is smaller than that of the latter, about 10% to 15%.
The tendency of Overgrinding. In overflow ball mills, the ores stay longer so it is easy to appear over-grinding phenomenon. However, grid ball mills do not.
The Possibility of "Sediment in Tank". The Overflow ball mills fine ores are overflowed outside because of their fineness. On the contrary, those ore particles with larger densities like reduced iron particles are inclined to settle into the tanks. Therefore, it is better not to choose overflow ball mills to grind ores with big densities.
Xinhai multiple types of wet overflow ball mills and cone overflow ball mills, with some huge share of domestic and foreign ball mills market. The reason why Xinhai overflow balls can be applied such widely in grinding process is that Xinhai is committed to innovate and develop, constantly optimizing the overflow ball mills. Therefore, Xinhai is the first choice when choosing overflow ball mills.