4.4 SYSTEM CURVE The system curve is a plot of the Total Head vs. the flow for a given system. The higher the flow, the greater the head required (see Figure 4-9). The shape of the system curve depends on the type of system being considered. The system curve equation for a typical single outlet system such as in Figure 2-10 is:
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When mill diameter and mill power became again increased, only the Gearless Mill Drive (GMD) could be envisaged to cover this requirement above 10 MW. The GMD is by its nature a variable speed drive system. Process operators, once having the facility of adjustable speed, could not live anymore without it for SAG mills.
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Clarabelle Mill SAG, Rod & Ball Mill Pinion Gear Thermal Acceptance Criteria General Industry Acceptance Guidelines for this size and gearset is as follows:* A. 25 degree Celsius differential across the teeth of the pinion face will most likely result in premature wear and pitting. (serious, shutdown and inspect).
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Elastic mill sag by weight of mill balls and materia! to grind A: After temporary alignment of the teeth of pinion and girth gear with the mill empty, Fig. 8a, re-alignment should be undertaken with the mill filled with mill balls, i. e. with reference to the elastic sag in cold con- dition, Fig. 8b.
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The primary function of the Hot Strip Mill is to reheat semi-finished steel slabs of steel nearly to their melting point, then roll them thinner and longer through 12 successive rolling mill stands driven by motors totaling 77,000 hp, and finally coiling up the lengthened steel sheet for transport to the next process.
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the final drive train is designed, recheck for power loss at actual output speeds to ensure that the output torque of the inching system is equal to or greater than the output torque of the main drive system. The key issue to keep track of is the amount of output torque generated by the main drive in main drive mode and
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Industrial Buildings—Guidelines and Criteria DR. JAMES M. FISHER The purpose of this paper is to provide the designer of industrial buildings with guidelines and design criteria for the design of buildings without cranes, or buildings with light-to-medium cranes. It would seem a simple task to design a good industrial building. The basic ele
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Errath, R., 2006, "The Gearless Mill Drive, the Work Horse for SAG and Ball Mills", SME Conference, St. Louis. Protection and Supervision Systems for Gearless Mill Drives M Ahrens
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3 SAG mill (8 – 15% ball charge) Variable competency ore 4 High ball charge SAG mill (15 to 25% ball charge) Incompetent ore 5 Low ball charge SAG mill, high mill speed. (4% ball charge, 90% Nc) A cross between AG and SAG for competent, abrasive ores. As typically operated in RSA. 6 SAG mill (configurations 3, and 5 ) with recycle crusher
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2.1 SAG mill model The particles fed to the mill are ground in the milling chamber and subsequently downloaded into the discharge zone, where, according to a classification probability, they are either returned to the milling chamber for further grinding or …
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The crushed pebbles fall directly onto the SAG mill feed belt and return to the SAG mill. SAG mill product feeds two parallel ball mills of 6.6 m×11.1 m (internal diameter×length), each with a 9.7 MW twin pinion drive. The ball mills are operated at a ball charge volume of 30–32% and 78.5% critical speed.
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mill work index 11.4 kWh/t and an average RQD of 44%. RQD values of 25% resulted in a SAG mill feed size (F80) between 55 and 60 mm and throughputs of 6200 t/h. RQD values of 55% resulted in SAG mill feed size (F80) of over 70 mm and a SAG mill throughput of 5200 t/h. The Batu Hijau SAG mill specific energy was a function of point load test and ...
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Similar to the COMBIFLEX® drive system, the direct drive also integrates the girth gear, drive pinion, and sliding shoe bearing with slide ring into a single housing. The three-stage gear unit with integral auxiliary drive is installed separately. l. to r. Principle of the direct drive. Tube mill with direct drive. SAG mill with COMBIFLEX ...
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With more than 100 years of experience in developing this technology. Metso Outotec has designed, manufactured and installed over 8,000 ball and pebble mills all over the world for a wide range of applications. Some of those applications are grate discharge, peripheral discharge, dry grinding, special length to diameter ratio, high temperature ...
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criteria for short term grinding circuit optimisation and future expansions. ... Common understanding of the factors that drive throughput has been embedded into daily Management Operating and Business Planning (BP) systems. ... SAG throughput is influenced by both mill feed size and ore hardness/breakage rates. Work from
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stresses in large SAG mills helped to drive the development of greatly improved liner materials. However, this cost engineering approach ignored the mill performance and overlooked the other key function of mill liners. The second primary function of a liner is to transfer rotary motion of the mill to the grinding media and charge.
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Matching Mill Drive Description to Mill Requirements Once the power level for the primary (SAG) mill has been set, i.e., design tonnes per hour (tph) x design E total kWh/t from the "geo-comminution" sample profile, serious thought can be applied to sizing the required grinding equipment. Space here does not permit a detailed discus-
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produce a sag to electricity users downstream of that location, and depending on the system topology, users upstream or even on connected distribution circuits can be affected as well. Depending on the ride through capability of a variable frequency drive, a …
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Investigation Report SAG Mill 20110414 An investigation into the SAG Mill's peak on the – power versus loading curve. Investigation Report Conveyor 20110428 – Discovery of under-designed pebble crusher discharge conveyor, and other conveyors and feeders under-designed when considering process design criteria surplus factors.
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TMEIC2 installed its first AC adjustable-speed motor drive system for a rolling mill main stand in 1980; by January 2004 TMEIC had installed AC adjustable-speed motor drive systems on more than 700 main mill stands, coilers and reels, constituting more than 2,400 MW of installed main drive power. 2. TMEIC: includes equipment supplied by Toshiba
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The twin dc motor drive system with each motor connected to a pinion and each fed from a static thyristor power supply has been successfully installed and operated at the Lornex Mine in British Columbia on a 10.4 m (34 ft) mill rated at 9,325 kW (12,500 hp).
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We can supply Ball Mills, SAG Mills and other milling systems to your specific requirements given your particular technical specifications. The selection and type of mill you require, FAG, SAG, SABC, rod or ball, is at best ... 5500, 8500, China, 2. ... Sag Mill, Sag Mill Suppliers and Manufacturers at Alibaba.
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Ball mill/SAG mill drive lubrication system. Abstract: This paper describes the function and operation of lubrication systems for Ball Mill and SAG Mill Drives. Provided within this paper are hydraulic schematics, functional description and a general overview of system layout as well as some of the important features and factors relevant to ...
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Selection Criteria for Sag Mill Drive Systems. October 1990 · IEEE Transactions on Industry Applications. S.A. Greer; The various options available …
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New Human Machine Interface - RMD Cockpit. With the RMD plus solution, operations and maintenance activities are fully optimized with the newly developed Human Machine Interface "RMDcockpit".. Based on ABB's 800xA platform, the RMDcockpit is a specific mill application tool comprised of a touch screen panel allowing full access to the main parameters of the drive …
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Table 1). SAG mill drive systems used on the same size grinding mill: Cupitul cost fixed speed ac synchronous drive In calculating the NPC, the capital complete with ring and pinion gears; cost in US dollars for each SAG mill variable speed dc drive complete system was determined. Although the with ring and pinion gears; ringmotor gearless drive.
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SAG mill ball charge determination and its influence on mill drive requirements Abstract: In semiautogenous grinding (SAG), the grinding mill inventory, ( 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 ...
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The main requirements for con verter-fed synchronous motors used to move the mills are as follows: 1) starting with at least 120% rated torque without af fecting the voltage profile of the...
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The SAG mill drive is normally designed … the mill manufacturer and civil Gearless Mill Drive Sales Rev Up to Meet Demand … to drive large SAG and ball mills. … a separate inching drive to position the mill for liner … always been a concern with gearless drive suppliers, …
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Selection criteria for SAG mill drive systems The main difference in this bearing system and others that have been supplied in SAG mills is the addition of hydraulic jacks to maintain properly the air gap in the motor and to assist the bearing and race to remain circular.
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Single stage SAG Mills are very beneficial in reducing CAPEX for plants with a staged throughput approach. When future tonnage is to be increased, the SAG Mill can feed downstream ball milling to boost capacity. Fuller-Traylor SAG/AG Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW.
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The various options available for large-horsepower semiautogenous grinding (SAG) mill drive systems are examined, together with their impacts on mill design and relative capital and operational costs. A brief history of large-mill drive systems is given. State-of-the-art mill design and mechanical design considerations are also discussed. A design for fixed-speed or variable …
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A high abrasion index, for example > 0.6, would suggest a preference for a single stage crusher-SAG mill circuit to avoid multiple stages of crushing and costly liner replacement operating costs. For A i values > 0.15 non-autogenous impact crushers are considered uneconomic and for A i values > 0.7 double toggle jaw crushers are preferred to ...
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• 28 MW GMD for a 40' SAG mill • 28 MW GMD for 42' SAG mill Whether it is size or an installation at the highest altitude (4600 m.a.s.l.), ABB's GMDs are well positioned to contribute to the building of larger and ever more powerful mills. — Leading the gearless mill drive evolution The ABB gearless mill drive (GMD) is the most powerful ...
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An induction motor fed by GE's MV7000 Medium Voltage drive is one of the latest solutions designed and offered by GE for all rolling mill applications. As the induction motor provides more availability, reliability, lower maintenance and reduced electrical distribution equipment, this solution can contribute to significant savings for our ...
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crushers to SAG circuits, on both greenfield and retrofit projects, to increase feed rate to the SAG mill. In other words, crushing plants, from primary to quaternary circuits, are here to stay. There are three main steps in designing a good crushing …
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