when the rocks are about 3/8-inch or smaller, they are fed as a slurry into the two ball mills. each ball mill is turned by a single 3,000 horsepower electric motor. these mills contain literally hundreds of thousands of three-inch diameter steel balls that pulverize the ore until it is like fine sand or face powder.
grinding of materials in a tumbling mill with the presence of metallic balls or other media main features of pebble/ball mills: size range from 5 ft. x 8 ft. with
copper ore, in concentrations ranging from 0.29 percent to ten times that amount, is mined from open pit or underground mines the crushed mine ore is ground in rod and ball mills and then sent to flotation machines where the copper mineral rises to the top in a froth, making a copper concentrate of approximately 30 percent, 27 percent iron and 33 percent sulfur.
each primary grinding line is supported by two secondary ball mills at 5.03 metres in diameter. each ag mill at 10.36 metres in diameter by 4.57 metre long is supported by one 2.13 metre cone crusher for pebble crushing and each is followed by one 5.03 metre diameter and 8.83 metre long secondary mill..
in this section, ball abrasion was calculated via manufacture`s ball charge program. at the time of this research, mill ball charged, feed rate, and average moisture were 7 tons ball size was 100 mm per week, 720 t/h and 5%, respectively. then, ball abrasion rate was calculated by equations 4, 5 and 6.
copper mountains concentrator was commissioned in may 2011. the circuit consists of a 34 x 20 egl sag mill, a raptor 900 pebble crusher and two 24 x 396 ball mills. each mill is equipped with a 2 x 8500hp dual pinion drive system. the plant was designed to process 1585 h mtpof sag feed.
estimates of electricity requirements for the recovery of mineral commodities, with examples large electrically -driven ball mills used for grinding ore to a size suitable as feedstock to the a photograph of the cripple creek and victor mining companys open-pit gold operation in cripple creek, colorado, showing a fairly typical heap
obviously, the longer the copper ball mill runs, the smaller the powder will be. ultimate particle size depends entirely on how hard the ground material is, and how long the copper ball mill runs. ourcopper ball mills have been being used to grind glass, make ceramic glaze, powder various chemicals, and make black powder.
grinding - ball mills. ball mills are generally used to grind material 1/4 inch and finer, down to the particle size of 20 to 75 microns. to achieve a reasonable efficiency with ball mills, they must be operated in a closed system, with oversize material continuously being recirculated back into the mill to be reduced.
investigations were carried out in a laboratory ball mill having the size of dxl = 160x200 mm with a ribbed inside surface of the drum. the mill ball loading was 40% by volume, the rotation rate was equal to 85% of the critical speed. balls were made from steel: s4146, extra high quality, having hardness 62 ± 2 hrc according to rockwell.
small 30 ball mill. the shell is cast in one piece with a flange for bolting to the head. in converting the mill from a 30x 18 to a 30x 36 unit with double the capacity, it is only necessary to secure a second cast shell a duplicate of the first and bolt it to the original section.
the copper mountain ball mills are 7315 mm 24 feet in diameter and 12040 mm 39.5 feet long. they are overflow discharge ball mills with inside diameters of 7315 mm 24 feet and grinding lengths of 11887 mm 39 feet . each ball mill is also driven by two 8,500 horsepower abb motors. figure 3 - the 24 x 39.5 ball mill