mills and sag mill problem

mills and sag mill problem

SAG Mill Grinding Circuit Design - 911metallurgist

Jun 06, 2016 · As a result, under-sizing an SAG mill has disastrous results on throughput— across the industry, there are numerous examples of the SAG mill

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What's the Difference Between SAG Mill and Ball Mill ...

Nov 26, 2019 · 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

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Minding the Grind: Maintenance Options to Keep SAG Mills ...

Component wear, regardless of whether it involves bearings, lifters or other parts of the machine, is a constant concern for SAG mill operators. Industry suppliers have developed a wide variety of liner shapes, composite-material combinations and

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Mill drives: the desire for increased power and the ...

SAG mill drives (as GMDs) by some operators and principal motor designers/manufacturers until the reasons for known problems in design or manufacturing were better understood and resolved. Accordingly, the latest 40 ft dia. SAG mill is rated at 29 MW and 78% C.S., with a 42 ft dia. mill built but not yet operational. The more recent option

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How grinding mill design changed over the last 30 years ...

Jun 03, 2020 · When the first 42 foot SAG mill was designed and manufactured around 2010-11, there were a lot of issues with getting such big equipment pieces fabricated and machined. The costs go up exponentially as we try to push the envelope. That challenge falls on the engineers to optimize mill design using creative ways.

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Literature Review: Gearless Motor Failures – A Mill ...

Sep 10, 2014 · The SAG mill cracked through the flange and into the shell and this threatened the integrity of the mill. The crack repair required removal of balls and liners and half the head to enable access to the the crack. This was as substantial an undertaking as the repairs to the Cadia rotor poles and required more time to complete.

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TECHNICAL NOTES 8 GRINDING R. P. King

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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Mining Industry: What is a grinding mill? How does it work ...

Answer (1 of 6): A grinding mill is an instrument that is intended to break a strong material into more modest pieces. There are various kinds of crushing factories and numerous sorts of materials prepared in them. Little mills can be fueled by hand, like a mortar and pestle or a pepper processor...

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Need help with Hitachi mill + 6M control

Nov 25, 2011 · If the control comes on (gets a Machine Ready signal), that shows that it has been in an E-stop condition. The typical things that will cause E-stop are hard overtravel on any axis, a thermal overload or a circuit breaker tripped. Also, check for additional E-stop buttons, like near the magazine or chip conveyor.

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Ball Mills and Sag Mill problem | AMP Maintenance Forums

Nov 21, 2007 · Ball Mills and Sag Mill problem. Registered Member 10/16/072:46 AM 2 replies. RM. Registered Member. Follow. Hello all, I work in an industrial copper company as vibration analysis supervisor. This company started to work about 2 years ago. We have two Ball Mills and one Sag Mill. We had some visual inspection on pinion and ring gears, during ...

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How an issue with SAG mill dischargers become a nine-year ...

Jan 03, 2021 · How an issue with SAG mill dischargers become a nine-year-and-counting collaboration. 3 January 2021. With its two SAG mills suffering a range of performance issues, a polymetallic mine in Mexico invited us in to assess the situation. Nine years later and our partnership with the mine had yielded a range of solutions that have significantly ...

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Solito, Inc. | Sag Mills

Sag Mill Problem: Far too frequent lube oil filter changes were eating into the mill’s productivity due to far too frequent oil and filter changes. Eleven unscheduled changes each year were causing complete shut downs. Solution: $247,500 of lost production was returned to operations.

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Item Conduit and SAG Mill (pull problem) : feedthebeast

The problem comes when i want to add multiple mill-smelter assemblies. My cobble generation is quick enough that I can keep 3 sag mills fed, and I'm a huge fan of conduits over pipe. so here's the problem, and it only applies to the feed side, not the exit:

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SAG Mill | Autogenous and Semi-Autogenous Mills | FLSmidth

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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AG & SAG Mill for Mineral Processing Wet & Aerofall SAG ...

The SAG mill (AG mill) has both crushing and grinding two functions. The grinding mode can be divided into dry type and wet type, also known as aerofall type SAG mill and dump type SAG mill. The SAG mill (AG mill) needs less auxiliary equipment, is easy to realize production automation, and the product granularity is relatively stable.

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Literature Review: Gearless Motor Failures – A Mill ...

Sep 10, 2014 · The Collahuasi motor was for a 40 ft SAG mill. The Antamina 38 ft SAG mill was also driven by an ABB motor and the hanger plates had not failed on that machine after several years of operation. Similarly, the Sossego motor for the 38 ft SAG mill had not failed. It too had an ABB motor and it had operated longer than the Collahuasi motor.

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TECHNICAL NOTES 8 GRINDING R. P. King

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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Optimization and Performance of Grinding Circuits: The ...

Semi-Autogenous Grinding (SAG) mill and a ball mill. The SAG mill circuit also includes ... This implies that, there could be no problem with the efficiency of the gravity circuit for the BGM operation, where the gold contained in pyrite-pyrrhotite could be easily concentrated. However, the efficiency of flotation and ... 3.2 Tumbling Mills ...

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Studies Show Snags to Mill Optimization | E & MJ

Studies Show Snags to Mill Optimization. More than 100 virtual operators have been deployed over the course of three years at Los Bronces mine. Above, the Los Bronces mine milling control room in Chile. (Photo: Anglo American) Two studies identify obstacles to SDGs, while a major miner announces the windfall from deploying automation.

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Mill (grinding) - Wikipedia

SAG mill. SAG is an acronym for semi-autogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.

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Semi Autogenous Grinding Mill - an overview ...

In a SAG mill the dimensions of the mill were 9.75. m × 3.5 m and the specific gravities of the mineral and that of the balls charged were 4.1 and 7.9 respectively.. The mill was rotated at 75% of its critical speed when 8 % of the mill volume was charged with grinding balls.Estimate:1. The mill power drawn, 2. The maximum mill filling possible.

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Grinding Mills and Their Types – IspatGuru

Apr 09, 2015 · Grinding Mills and Their Types. satyendra; April 9, 2015; 0 Comments ; autogenous grinding, ball mill, grinding mills, hammer mill, rod mill, roller mill, SAG,; Grinding Mills and Their Types In various fields of the process industry, reduction of size of different materials is a basic unit operation.

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Alphatec Egnineering SL - SAG mill complete foundation ...

SAG mill complete foundation repair service Mining "The grinding mill is at the heart of a mining operation, but a poorly designed, constructed, or deteriorated foundation will not only affect grinding mill performance but potentially render the mill out of action, costing millions of dollars in lost production."

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How an issue with SAG mill dischargers become a nine-year ...

Jan 03, 2021 · How an issue with SAG mill dischargers become a nine-year-and-counting collaboration. 3 January 2021. With its two SAG mills suffering a range of performance issues, a polymetallic mine in Mexico invited us in to

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LARGE DIAMETER SAG MILLS NEED LARGE DIAMETER BALL MILLS ...

In an attempt to address this problem a new AG/SAG mill model has been developed which incorporates the capability to respond to changes in most design and operational variables.

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Optimizing your SAG mill operation - International Mining

Mar 21, 2007 · The amount of pebbles passing through the grate increases with the angle of the grate. It is imperative to ensure the efficient removal of both slurry and coarse pebbles (critical size) in order to ensure the efficient operation of AG/SAG mills. Elimination of the above mentioned material transport problems will allow the mill to respond truly ...

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Grindin' at the Mill - investigating bottleneck in ...

The SAG mill feed is controlled by the mill weight, measured by 4 load cells on the mill bearing system. Therefore if the ore does not grind quickly enough in the SAG mills, the mill weight increases and the control system reduces feed to the mill to maintain the desired mill weight.

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Mill (grinding) - Wikipedia

SAG mill. SAG is an acronym for semi-autogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.

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Grinding mills. - Free Online Library

Sep 01, 1991 · The standard line of mills includes autogenous ( AG ) and semiautogenous ( SAG ) mills, beginning with a 6 ft x 2 ft ( 1.83 m x 0.61 m ) 25 hp ( 18.7 kW ) laboratory mill and is followed by 12 ft to 36 ft ( 3.7 m to 11 m ) diameter mills ranging in power from 150 to 20,000 hp ( 112 to 14,900 kW ).

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US8453956B2 - Slurry return system for grinding mills ...

The grinding mill may be any one of a Sag, Ag, Ball or Rod mill. US8453956B2 - Slurry return system for grinding mills - Google Patents ... which in turn enters the actual trunnion of the mill, creating several problems. The first and most severe problem is the contamination of lubrication systems, however other problems also occur, such as ...

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Gearless mill drives - ABB

• 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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Grinding Mill Foundations

Sep 23, 2014 · Most of our work since 2000 has been in developing grinding mill foundations to avoid vibration and unacceptable deflections. On a recent project for a plant in Peru, the client was told by the mill vendor that there was no need to do a systems (dynamic) analysis on the mill foundations because the mills on that project were gear driven rather than being driven by

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Industrial Solutions polysius ball mills

Air-swept mill and single-compartment mill These mills are used to grind very moist materials that need to be dried using low-temperature air. If the relevant explosion-protection equipment is used, air-swept mills are optimally suited for grinding solid fuels, such as coal or petcoke. Single-compartment mills are of a similar design to air-swept

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TECHNICAL AND COMMERCIAL BENEFITS OF GEARLESS MILL

general, the bigger the mill diameter, the lower are the mill operating and critical speeds. Thus, for larger mills the number of poles will increase. As a result, the number of poles can vary from 48 to 72 poles (Fig. 3.) with typical mill speed requirements of about 10 rpm for larger SAG mills and about 15 rpm for smaller ball mills. Figure 3.

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A Method of C alculating Autogenous/ Semi-Autogenous ...

Rod mills are limited in size to 2000 kW because the longest commercial grinding rod available is 6 m long. For this reason rod mills are rarely selected in the present day environment of large AG/SAG mills and large ball mills. However, it is necessary to discuss their operation because a Rod mill product has a similar slope to AG/SAG mills.

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Composite Linner for SAG Mill - topmie

Composite Linner for SAG Mill. Download. Solved Problem. Composite liners are a new product developed by TOMINE to address cracks on alloy liners in SAG mills and leaks due to insufficient torque of liner bolts, as well as overgrinding of ore, resulting in an improved liner service life and mill working efficiency. The configuations are such as ...

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Outotec offers a complete Poly-Met solution mill linings

SAG mills, AG mills, ball mills, FGD mills, rod mills, scrubbers and washing drum Mill lining solutions Poly-Met mill linings Skega Poly-Met™ mill linings from Outotec are carefully designed to maximize the availability of your mill and keep your costs to a minimum. Targeting increased uptime Mining operations aim to reduce downtime

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