W Total = WSAG + W Ball Mill (2) Where W is the grinding mill work input in kWh/t. For the above reason, the Starkey SAG mill was built in 1991 to measure the energy required to grind ore to a size of 80% passing 10-mesh or 0.17 mm (T80) by grinding small drill core samples to precisely that size.

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SAG mills grinding media includes some large and hard rocks, filled rate of 9% – 20%. SAG mill grind ores through impact, attrition, abrasion forces. In practice, for a given ore and equal processing conditions, the AG milling has a finer grind than SAG mills. How does a …

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Crushing Theory • The amount of power required for crushing is a major consideration in selecting crushing equipment. • The greatest problems lies is the fact that most of the energy input to a crushing and grinding is absorbed by the machine itself, and only a small fraction of the total energy is available for breaking the material.

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In semi-autogenous grinding (SAG), the grinding mill inventory, (i.e. volume of total charge, volume of ball charge, etc.) is important in determining the optimum operating condition for maximum production (tph), minimum specific energy (kwh/t) or lowest cost ($/t). A two-dimensional graphical method is presented for determining the actual ball charge within the …

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Figure 2 – Single-stage SAG Mill Grinding Circuit Flowsheet . The circuit feedrate of 125 tph to 150 tph was primary crushed to an F80 size of between 105 mm and 120 mm and the SAG mill slowed down and charged with a 7% (by volume, v/v) load of 125 mm balls. The smaller diameter CAVEX 400 cyclones produced an overflow P80 size of 90 µm to ...

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Grinding (AG), Semi-Autogenous Grinding (SAG), rod, and ball mill circuits operating within the normal range of appli-cation. This guideline does not directly address analysis of crushing plants and fine grinding circuits, but it is a useful reference for such endeavors. Applying power-based analysis techniques requires suf-

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Control of -SemiAutogenous Grinding(SAG) mill weight is an example of an important process that exhibits many of these aspects. Maintaining the SAG mill weight at the optimum value is critical for achieving maximum grind rate efficiency and mill production (Powell, M.S., van der Westhuizen, A.P., & Mainza, A.N. 2009).

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in the semi-autogenous grinding process by dynamically modeling the SAG mill-pebble crusher loop to improve the SAG mill throughput. Cleary [8–10] studied the e ect of rock particle shape on the dynamic filling and energy utilization in a SAG mill and analyzed the operation status of a SAG mill under di erent collision conditions through the ...

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SAG mill liner development draws primarily on practical experience from SAG milling operations supported by computer-based modeling of charge motion in SAG mills and on established good design practice. Liner design needs to respond to the process aspects of mill liner action that are critical to good SAG mill performance, i.e., the impact of shell liners on the …

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supported grinding mills up to the largest sizes. SAG/ball mill circuit incorporating pebble crushers and a POLYCOM® high-pressure grinding roll. SAG and ball mill for gold ore grinding. One of three SAG mills with 9.75 m diameter and 2 x 4000 kW drive power. These mills operate in conjunction with ball mills for iron ore grinding in Iran.

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2 THEORY 2.1 SAG mill modeling In MODSIM, one of the simulation models used for a SAG mill unit is SAGT (Semi-Autogenous Grinding with Trommel) model. In this model, a SAG mill with a trommel screen at mill discharge is modeled using the full population balance including particle attrition and wear (King 2001b). In this

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Rely on our proven track record of AG and SAG Mill superiority. Since the early 1980s, we have been designing and manufacturing Semi Autogenous Mill (SAG Mill) and Autogenous Mill (AG Mill) under the Fuller-Traylor brand. Semi-autogenous grinding uses a minimal ball charge in the range of 6-15% while autogenous grinding uses ore only.

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1 CONGA: THE WORLD'S FIRST 42 FOOT DIAMETER 28 MW GEARLESS SAG MILL T. Orser1, V. Svalbonas 2 and *M. Van de Vijfeijken 3 1Newmont Mining Corporation 10101 East Dry Creek Road Englewood, CO 80112, USA 2Metso Corp. 2715 Pleasant Valley Rd.

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viable SAG grinding circuit, using principles of theory, measurement and empirical interpretation. Considering all of the tests and SAG design methods currently in use, none are so good or so inexpensive that further improvements are not possible. The SAG Power Index (SPI) and Bond Ball Mill Work Index

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product grind if the AG/SAG is producing at ... For SAG mills the equation becomes Power=(5.6115+%balls*0.1438)*D24. 6* L Mill Critical speed Crit Crit D = 42.3 n - revs per min nC= s*Crit Cs is the fraction of the critical speed Slurry S.G ...

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The circuit comprises a SAG mill, 12 m diameter by 6.1 m length (belly inside liners, the effective grinding volume), two pebble crushers, and two ball mills in parallel closed with cyclones. The SAG mill is fitted with a 20 MW gearless drive motor with bi-directional rotational capacity. (Reversing direction evens out wear on liners with ...

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Pulp density has a large influence on the grinding efficiency. In this case, the optimum is in the region of 73.4% or 1.989 kg/l. If one goes below that, the higher dilution will 'flush' the fines out of the mill and reduce the overall residence time in the mill. This will result in a coarser grind with a slightly

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LG A mill power equation for SAG mills. Minerals and Metallurgical Processing. Feb 1990 pp57-62. Gross power No load power Net power drawn by the charge (8.13) The net power is calculated from Net power KD2.5L e! c./ Watts (8.14) In equation 8.14, D is the diameter inside the mill liners and Le is the effective length of the mill including the ...

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Originally commissioned as a Fully Autogenous Grinding (FAG) circuit in 1997, preparations to convert the Katinniq Concentrator Mill to SAG had in fact commenced as early as 1999, but were halted owing to alternative process improvements which achieved up …

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Energy efficient solutions to maximize grinding productivity and profitability. With over a century of experience, Outotec designs and manufactures the most comprehensive line of grinding mills and entire grinding systems for mining companies around the world. The comprehensive offering provides reliable and energy efficient technology ...

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SAG milling extends itself to many applications due to the range of mill sizes available. They can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill and some or all of the work done by a ball mill. SAG mills are also an optimum solution for wet grinding since crushing and screening in these ...

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Grinding in ball mills is an important technological process applied to reduce the. size of particles which may have different nature and a wide diversity of physical, mechanical and chemical ...

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Last year, we affected one rather interesting topic – use of the energy indices in the grinding process design. We had planned to consider three calculation methods. Having studied this issue in more detail, we've decided to cover this topic in more detail. We will try to briefly, but as informative as possible, describe the methodology for providing the fifteen generally …

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Attrition mill is a type of grinding mill by kinds of media to crush lump to powder-like substances. The impact can be rock on rock such as in an Autogenous Grinding (AG) mill, rock and a small ball charge (~10%), used in Semi Autogenous Grinding (SAG) mills, balls of various sizes in Ball Mills and less commonly these days, steel rods in Rod Mills.

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The accurate control of feeders in semiautogenous grinding(SAG) mills plays an important role for obtaining good operational results. This brief presents the design of a Smith predictor for multi ...

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