the surface area, size distribution and specific energy consumption for the material ground in the ball mill were used in conjunction with the single-particle data to provide an assessment of the energy efficiency of ball milling.
a survey of australian processing plants revealed a maximum ball mill diameter of 5.24 meters and length of 8.84 meters morrell, 1996 . autogenous mills range up to 12 meters in diameter. ball size distribution. as the mill starts, grinding action and throughput increases.
now we much select a ball mill that will d this power. the ball mill motor power requirement calculated above as 1400 hp is the power that must be applied at the mill drive in order to grind the tonnage of feed from one size distribution. the following shows how the size or select the matching mill required to d this power is calculated
a ball mill is a pulverizer that consists of a horizontal rotating cylinder, up to three diameters in length, containing a charge of tumbling or cascading steel balls, pebbles, or rods. these mills are usually found in utility plants. is capable of producing micrometer-fine pulverized coal with a narrow particle size distribution. in
the ball mill motor power requirement calculated above as 1400 hp is the power that must be applied at the mill drive in order to grind the tonnage of feed from one size distribution. the
this is important as if you have not seen if yourself, you can not trust it is really 10mm. there should be no scats at 10 mm unless you are using much too small a grinding ball or the mill charge is much too low. for example, i was told by a client his ball mill feed was p80 = 9mm but when i went to look at the feed belt, i saw this below.
the steady state ball size distribution in the mill depends on the top-up policy. the effect of the ball size distribution on the milling rate of coal has been measured as a function of ball size distribution. the change in ball size distribution as affected by wear and ball top-up policy has been modelled.
for ball mills, ball charge level, lining and diaphragm condition must be monitored and maintained in near-optimum condition. mill stops, defined as mill motor off, and measured by mean time between failures mtbf , are frequently poorly recorded and the resolution of underlying issues is frequently not addressed.