Tham khảo tài liệu 'extractive metallurgy of copper 4th ed. - w. davenport_ et. al. (2002) ww part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Concentrating Copper Ores 37 Table . 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 . Concentrator Candaleria Chile Mexicana de Cobre Mexico Bagdad Copper Arizona Ore treated per year tonnes 25 000 000 27 360 000 31 000 000 Ore grade Cu Crushing primary gyratory crusher one 2 one diameter X height m X X X power rating kw 522 375 at -600 450 RPM product size m energy consumption kWh per tonne of ore estimate secondary crushers First stage grinding no 6 no mill type semi-autogenous ball mills autogenous number of mills 2 12 5 diameter X length m 11 X 5 X 10 X 4 power rating each mill kWh 12 000 4000 4500 rotation speed RPM 10 vol. steel in mill 12-15 32 0 ball size initial cm ball consumption kg tonne ore feed 70 ore 83 ore 30 H2O 17 H2O product size 80 140 pm 80 215 im 4 cm oversize treatment 22 ore recycle screened and through two 525 recycled through kw crushers cone crushers energy consumption kWh per tonne of ore 8 Second stage grinding mill type ball mills ball mills ball mills number of mills 4 4 5 diameter X length m 6x9 X X power rating each 5600 2200 mill kw rotation speed RPM 13 vol. steel in mill -15 40 feed 85 ore 15 H2O product size 80 58 pm 80 130 pm energy consumption kWh per tonne of ore 7 estimate 6 Hydrocyclones 14 Krebs m 6 2 to 3 diameter m diameter Particle size monitor yes no 38 Extractive Metallurgy of Copper cyclones send correct-size material on to flotation and oversize back to the ball mill for further grinding. Flotation Feed Particle Size A critical step in grinding is ensuring that the final particles from grinding are fine enough for efficient flotation. Coarser particles must be isolated and returned for further grinding. Size control is universally done by hydrocyclones Fig. Krebs .
