Concentrating Copper Ores 37 Table 3.1 Industrial crushing and grinding data for three copper concentrators, 2001 They all treat ore from large open-pit mines Flotation details are given in Table 3.3 Concentrator Candaleria, Chile Mexicana de Bagdad Copper, Cobre, Mexico Arizona Ore treated per year, 25 000 000 27 360 000 31 000 000 tonnes 0.4 0.522 Ore grade, %Cu 0.9 - 1.0 Crushing primary gyratory one one crusher 1.5 x 2.25 1.52 x 2.26 diameter x height, m 1.52 x 2.26 375 at -600 450 522 power rating, kW R' FM product size, m energy consumption, kWh per tonne of ore secondary crushers First stage grinding mill type number of mills diameter x length, m power rating each mill, kWh rotation speed, RF'M vol % 'steel' in mill ball size, initial ball consumption feed product size oversize treatment energy consumption, kWh per tonne of ore Second stage grinding mill type number of mills diameter x length, m power rating each mill, kW rotation speed, RPM vol % 'steel' in mill feed product size energy consumption, kWh per tonne of ore Hydrocyclones 0.15 0.2 no no semi-autogenous 11 x 4.6 ball mills 12 x 7.3 autogenous 12 000 4000 4500 9.4-9.8 -13.8 32 10 0.1-0.13 0.3 (estimate) 12-15 12.5 cm 0.3 kghonne ore 70% ore, 30%H20 80% < 140 pm 22% ore recycle through two 525 kW crushers 80%