sag mill optimum charge size

(PDF) Influence of feed size on AG / SAG mill performance

When the feed size of a SAG mill becomes coarser, i.e. α r increases, the energy required to break the ore increases, i.e. φ r and φ f increases (Morrell et al., 1996; Morrell and Valery, 2001 ...

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Optimum SAG Mill Discharge Density - Grinding ...

To participate in the 911Metallurgist Forums, be sure to JOIN & LOGIN Use Add New Topic to ask a New Question/Discussion about Grinding. OR Select a Topic that Interests you. Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent). Using Add Reply allows you to Attach Images or PDF files and provide a more complete input. Use Add Comment = to comment on someone else’s ...

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SAG Mill Ball Sizing - Grinding & Classification Circuits ...

To participate in the 911Metallurgist Forums, be sure to JOIN & LOGIN Use Add New Topic to ask a New Question/Discussion about Grinding. OR Select a Topic that Interests you. Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent). Using Add Reply allows you to Attach Images or PDF files and provide a more complete input. Use Add Comment = to comment on someone else’s ...

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Autogenous and Semi-Autogenous Mills - ScienceDirect

Jan 01, 2016 · The SAG mill had a 6–8% ball charge and the power consumption was 8 kWh/t, which agreed well with the expected value. 9.6. Problems. 9.1. In an SAG mill the dimensions of the mill were 9.75 m × 3.5 m and the specific gravities of the mineral and

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Difference Between Sag Mill vs Ball Mill - mech4study

Oct 12, 2017 · SAG mill make use of steel balls included with some large and hard rocks for grinding. These mills utilize the balls in making the large fragments of materials broken into pieces. The ball charge of a SAG mill is about 9% to 20%.This process takes place inside the large rotating drum of SAG mill which is filled with balls partially.

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Calculate and Select Ball Mill Ball Size for Optimum Grinding

In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a Mineral Processing Engineer AKA Metallurgist to do. Often, the ball used in ball mills is oversize “just in case”. Well, this safety factor can cost you much in recovery and/or mill liner wear and ...

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Ball Mills - an overview | ScienceDirect Topics

Optimum ratio between length L and diameter D, L:D is, usually, accepted in the range 1.56–1.64. The mill productivity also depends on many other factors: physical-chemical properties of feed material, filling of the mill by balls and their sizes, armor surface shape, speed of rotation, milling fineness and timely moving off of ground product.

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Optimizing your SAG mill operation - International Mining

The optimal performance of AG/SAG mills is the key to successful plant operation. All AG/SAG mills using radial or curved pulp lifters suffer from inherent material transport problems such as slurry and pebble pooling, which decrease throughput and increase energy consumption.

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SAG/AG SCU - Millwatch

CHARGE LEVEL. Maintaining an optimum charge in a SAG mill remains one of the fundamentals for efficient mill processing. If the charge level or the ball to charge ratio is incorrect, breaking liners and/or increasing power consumption is inevitable and can only result in degraded mill efficiency.

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Optimizing your SAG mill operation - International Mining

The optimal performance of AG/SAG mills is the key to successful plant operation. All AG/SAG mills using radial or curved pulp lifters suffer from inherent material transport problems such as slurry and pebble pooling, which decrease throughput and increase energy consumption.

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Ball Mills - an overview | ScienceDirect Topics

Optimum ratio between length L and diameter D, L:D is, usually, accepted in the range 1.56–1.64. The mill productivity also depends on many other factors: physical-chemical properties of feed material, filling of the mill by balls and their sizes, armor surface shape, speed of rotation, milling fineness and timely moving off of ground product.

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Optimization of the Design of SAG Mill Internals Using ...

Ball Size Evaluation The selection of an optimum top ball size for a large SAG mill is determined by several factors: wear rate, particle breakage effectiveness and liner damage. This example shows how 3D DEM can be used to provide quantitative input on each of these factors. In this case the performance

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SAG/AG SCU - Millwatch

CHARGE LEVEL. Maintaining an optimum charge in a SAG mill remains one of the fundamentals for efficient mill processing. If the charge level or the ball to charge ratio is incorrect, breaking liners and/or increasing power consumption is inevitable and can only result in degraded mill efficiency.

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AMIT 135: Lesson 6 Grinding Circuit – Mining Mill Operator ...

The mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills 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 of a ball mill. Because of the range of ...

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sag mill ball size - kettenreime.de

SAG Mill Ball Sizing Grinding Classification Circuits. With high aspect ratio SAG mills total charge to ball charge ratio should be greater than 2 up to 25 for a coarse mill feed say F80 110 mm If the mill feed size is fine say 50 mm or 30 mm then you are looking at a total charge to ball charge ratio of about 1516

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OUTOTEC GRINDING TECHNOLOGIES

Outotec ® MillSense Mill Charge Sensor System ... mill size, intended duty, and environmental conditions at the installation site. ... SAG and AG mills typically have grate discharge arrangements which can be either with or without trommel screens. SAG and AG mills with open-

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(PDF) Maximising SAG mill throughput at Porgera gold mine ...

Summary of Mill Survey Results 80 survey 1, SAG 2 70 Survey 1 2 2 3 60 Blast # 340-319 320-314 320-314 310-316 SAG 1 Muck Load, vol % 26.3 22.8 - 26.9 50 Ball Load, vol % 11.0 13.8 13.8 13.2 40 Ball Size, mm 150 125 125 125 30 Power, KW 4550 4650 3970 4310 20 Bearing Pressure, 3900 3740 3720 3927 10 kpa 0 Mill Speed, rpm 11.42 11.42 10.79 11.50 ...

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Mill (grinding) - Wikipedia

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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(PDF) Milling curves as a tool for characterising SAG mill ...

The effect of increasing the feed size was found to be dependent upon the mode of mill operation ie AG or SAG, with AG mill throughput increasing as the feed F80 was increased.

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Taking Control of the Mill Feed R2 - Orway Mineral

to the SAG mill feed conveyor. A 736 Allis Chalmers pebble crusher (110 kW) performed this duty. A Process Flow Diagram is presented in Figure 2. The 8.53 m Ø x 3.92 m EGL (28 x 12.8-ft) SAG mill is fitted with two 1850 kW motors. An operating ball charge in the range of 4 to 10% is used. The mill currently operates at a fixed speed

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Optimize SAG milling with customised grinding ball design ...

The sheer size and scale of new ore processing operations, with their associated desire to substantially increase product throughput, means that primary SAG mills have grown to larger capacities. Paul Peng, CEO and chief metallurgist at Sino Grinding Industries (SGI), emphasizes it is critical that grinding media is designed and manufactured to cope with this []

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CONGA: THE WORLD’S FIRST 42 FOOT DIAMETER 28 MW

sizes. The results of these studies showed that a single line 40 ft SAG mill circuit gave the best project economics. Further work was followed up to optimize the 40 ft SAG mill size with the results showing that a slightly more expensive 42 ft SAG mill with equivalent power to the 40 ft SAG mill enhanced the project economics.

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EFFECT OF BALL SIZE DISTRIBUTION ON MILLING PARAMETERS

A.2 Results of size analysis for + 9500 – 6700 microns coal using 30.6 mm balls 82 A.3 Results of size analysis for + 2360 – 1700 microns coal using 30.6 mm balls 83 A.4 Results of size analysis for + 26500 – 22400 microns coal using 38.8 mm balls 83 A.5 Results of size analysis for + 16000 – 13200 microns coal using 38.8 mm balls 84

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What’s the difference of Ball mill, SAG mill, AG mill?

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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Measuring SAG Mill Charge and the Increased Benefits of ...

Jul 08, 2019 · Measuring SAG Mill Charge and the Increased Benefits of Utilizing Accelerometers for Positioning Published on July 8, 2019 July 8, 2019 • 64 Likes • 1 Comments

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sag mill ball size - kettenreime.de

SAG Mill Ball Sizing Grinding Classification Circuits. With high aspect ratio SAG mills total charge to ball charge ratio should be greater than 2 up to 25 for a coarse mill feed say F80 110 mm If the mill feed size is fine say 50 mm or 30 mm then you are looking at a total charge to ball charge ratio of about 1516

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Optimizing Performance of SABC Comminution Circuit of

circuit included an increase in the SAG mill ball charge from 8% to 10% v/v; an increase in the mill ball ... all ores will have an optimum particle size which maximizes the economic ... This causes a higher variation in the feed rate and particle size distribution in the feed to the SAG mill, which results in a greater variation in the SAG ...

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(PDF) Maximising SAG mill throughput at Porgera gold mine ...

Summary of Mill Survey Results 80 survey 1, SAG 2 70 Survey 1 2 2 3 60 Blast # 340-319 320-314 320-314 310-316 SAG 1 Muck Load, vol % 26.3 22.8 - 26.9 50 Ball Load, vol % 11.0 13.8 13.8 13.2 40 Ball Size, mm 150 125 125 125 30 Power, KW 4550 4650 3970 4310 20 Bearing Pressure, 3900 3740 3720 3927 10 kpa 0 Mill Speed, rpm 11.42 11.42 10.79 11.50 ...

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EFFECT OF BALL SIZE DISTRIBUTION ON MILLING PARAMETERS

A.2 Results of size analysis for + 9500 – 6700 microns coal using 30.6 mm balls 82 A.3 Results of size analysis for + 2360 – 1700 microns coal using 30.6 mm balls 83 A.4 Results of size analysis for + 26500 – 22400 microns coal using 38.8 mm balls 83 A.5 Results of size analysis for + 16000 – 13200 microns coal using 38.8 mm balls 84

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(PDF) Milling curves as a tool for characterising SAG mill ...

The effect of increasing the feed size was found to be dependent upon the mode of mill operation ie AG or SAG, with AG mill throughput increasing as the feed F80 was increased.

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how to calculate ball charge in sag mills

The SAG mills make use of a minimal ball charge of 6 to 15 It provides a large diameter and short length primary ball mill efficiency calculations Primary mill circuits types is very diffi cult to accurately predict or calculate A SAG mill ball charge level of 14 percent was targeted.

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Understanding Size Effects of Semi-autogenous Grinding ...

Oct 10, 2016 · Understanding Size Effects of Semi-autogenous Grinding (SAG) Mill Operation as a Pathway to Solving Feed Disturbances - Case Study using the MMG Century SAG Mill, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 321–330 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

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Ball Size effect analysis in SAG Grinding - CEEC ...

The analysis of the influence of ball sizes in SAG grinding hasn't been developed in detail by considering the effect on process parameters inside the mill, grinding efficiency or internal classification. Historically a conventional grinding reference has been made on the empirical

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Taking Control of the Mill Feed R2 - Orway Mineral

to the SAG mill feed conveyor. A 736 Allis Chalmers pebble crusher (110 kW) performed this duty. A Process Flow Diagram is presented in Figure 2. The 8.53 m Ø x 3.92 m EGL (28 x 12.8-ft) SAG mill is fitted with two 1850 kW motors. An operating ball charge in the range of 4 to 10% is used. The mill currently operates at a fixed speed

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Expert mill control at AngloGold Ashanti

The ROM SAG mill circuit—a brief description The typical ROM SAG mill circuit is depicted in Figure 1. The circuit is usually closed with either a screen or, more commonly, a cyclone for product size classification. The focus of control can be divided into two parts, viz. the mill and the cyclone. The importance of cyclone performance should ...

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Minerals | Free Full-Text | Optimizing Performance of SABC ...

The final plan was to increase the ball charge in the SAG and ball mill to 10% v / v and 27% v / v, respectively; set the upper limit of the operating power in the ball mill to 5800 kW; use a TRIO TC Series crusher (without a power-/feed rate–controlling device, but with a feed bin) to crush pebbles for recirculation back to the SAG mill feed ...

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Optimize SAG milling with customised grinding ball design ...

The sheer size and scale of new ore processing operations, with their associated desire to substantially increase product throughput, means that primary SAG mills have grown to larger capacities. Paul Peng, CEO and chief metallurgist at Sino Grinding Industries (SGI), emphasizes it is critical that grinding media is designed and manufactured to cope with this []

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