SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to

If the SAG mill is not intended to be the rate-limiting step in a process plant, then it is best to adjust the SAG load (and power) to hold a constant tonnage to satisfy another constraint elsewhere. Underground mines are an example: the hoisting capacity of the mine shaft is the rate-limiting step in the process, and the SAG mill must adapt to ...

John Starkey, P. Eng. has worked in SAG mill hardness testing since 1964 where he worked as pilot plant engineer for A. MacPherson’s projects. He invented the SPI and SAGDesign tests. The latter is now acknowledged by our clients to be a world-class method for grinding circuit design, and is accepted by our peers as a standard for ore ...

was commissioned in March 2008 with a 32’ x 32’ EGL, 16.5MW single stage SAG mill, to process 5 ... SAG MILL Availability (%) 92 Design throughput (t/h) 620 Circuit P80 (um) 75

operating SAG mills (it is not intended for design, but could help with it). Even if the mill total load is a key variable and can be indi-rectly measured with bearing pressure measurements, it was decided to discard it as an input variable. The main reason is that

the mill speed as a fraction of the critical speed, ϕC, can be observed by plotting the process power and torque draw superimposed on the relevant motor capability curve. Such plots for an example mill, the SAG mill at Cadia (described by Dunne et al., 2001) is shown in Figure 3.

The paper specifically describes SAG mills, but the equa-tions and principles apply equally to any conventional tumbling mill, such as AG, ball or rod mills. The engineering and process effects of choosing a motor design speed. 3 Motor electro-mechnical characteristics The cost of a motor of a Gearless Mill Drive depends mainly on two ...

was commissioned in March 2008 with a 32’ x 32’ EGL, 16.5MW single stage SAG mill, to process 5 ... SAG MILL Availability (%) 92 Design throughput (t/h) 620 Circuit P80 (um) 75

operating SAG mills (it is not intended for design, but could help with it). Even if the mill total load is a key variable and can be indi-rectly measured with bearing pressure measurements, it was decided to discard it as an input variable. The main reason is that

the mill speed as a fraction of the critical speed, ϕC, can be observed by plotting the process power and torque draw superimposed on the relevant motor capability curve. Such plots for an example mill, the SAG mill at Cadia (described by Dunne et al., 2001) is shown in Figure 3.

SAG Mill Circuit Example — Gold Processing SAG mill circuit example for gold processing [image: (135-6-3)] AG/SAG Mill. AG/SAG mills are normally used to grind run-off-mine ore or primary crusher product. Wet grinding in an AG/SAG mill is accomplished in a slurry of 50 to 80 percent solids. 2D and 3D simulations of particles in a SAG Mill

The paper specifically describes SAG mills, but the equa-tions and principles apply equally to any conventional tumbling mill, such as AG, ball or rod mills. The engineering and process effects of choosing a motor design speed. 3 Motor electro-mechnical characteristics The cost of a motor of a Gearless Mill Drive depends mainly on two ...

The designs of autogenous and semi-autogenous (SAG) grindings mills are described followed by the description of their methods of operation in grinding circuits involving crushers and ball mills. Methods of estimating SAG mill volumes, mill charges, feed size and power consumptions and optimum speeds of rotation during operation are described.

Sag mill design pdf Computer-based modeling of charge motion in SAG mills and on established good design practice. sag mill design pdf Liner design needs to respond to the process aspects of mill.The test and study work showed that a single line 42 ft SAG mill circuit gave the.

• the selection of two 15 MW SAG mills and two 13 MW ball mills for the grinding circuit, and • detailed modelling of the pyrite concentrate carbonin-leach (CIL)/sulphidisation acidification recovery - thickening (SART)/acidification volatilisation recovery (AVR) process to optimise design for copper and cyanide recovery from leach liquors.

Dec 06, 2018 In the mining sector, these losses can be quite substantial. For example, a trained professional crew may require up to 120 hours to replace the worn liner of a SAG mill with each hour costing tens or even hundreds of thousands of dollars, depending on the size of the mill and the plant in which it operates.

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 ...

grade materials are trucked close to the mill, in anticipation of possible future treatment. The concentrator is designed to treat 40,000 metric tons per day of ore to produce 400,000 metric tons per year of copper in concentrate product. It includes two 28’ x 14’ SAG mills and four 18’ x 24’ ball mills in closed circuit,

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.

The current practice of exploratory design of ore pre-treatment process increasingly uses laboratory testing of ore strength, which allows simple and inexpensive but reliable ranging of crushing and milling machines [2]. Three methods of lab testing are best suitable for sizing SAG mills and accu-rate determination of parameters of the mill drives:

Sep 07, 2017 However, the SAG route is more power-intensive and, for very hard ores, comes with some process risk in predicting performance. More recently, a hybrid solution has become available in the form of high pressure grinding rolls (HPGRs), which can replace the third stage of crushing and also the SAG mill.

operating SAG mills (it is not intended for design, but could help with it). Even if the mill total load is a key variable and can be indi-rectly measured with bearing pressure measurements, it was decided to discard it as an input variable. The main reason is that

was commissioned in March 2008 with a 32’ x 32’ EGL, 16.5MW single stage SAG mill, to process 5 ... SAG MILL Availability (%) 92 Design throughput (t/h) 620 Circuit P80 (um) 75

AG/SAG mill test methodology which allows mill performance to be evaluated would lower costs, reduce material and time to gather the data required. Previous work using pilot scale AG/SAG mill tests with mills between 0.6 and 1.8m in diameter have shown that pilot scale tests can be used to successfully predict aspects of

DESIGN OF THE AGNICO-EAGLE LARONDE DIVISION SAG MILL by John Starkey, Jean Robitaille, Paul Cousin, James Jordan and Glenn Kosick. Presented at SAG 2001 in Vancouver, October 2001. 8. A CRITICAL REVIEW OF SAG DESIGN PROCEDURES FOR THE 21 ST CENTURY by John Starkey. Presented at Comminution 01 in Brisbane, Australia, March 2001.

Dec 06, 2018 In the mining sector, these losses can be quite substantial. For example, a trained professional crew may require up to 120 hours to replace the worn liner of a SAG mill with each hour costing tens or even hundreds of thousands of dollars, depending on the size of the mill and the plant in which it operates.

• the selection of two 15 MW SAG mills and two 13 MW ball mills for the grinding circuit, and • detailed modelling of the pyrite concentrate carbonin-leach (CIL)/sulphidisation acidification recovery - thickening (SART)/acidification volatilisation recovery (AVR) process to optimise design for copper and cyanide recovery from leach liquors.

Jun 02, 2017 Autogenous grinding (AG) and semi-autogenous grinding (SAG) mills use the material to be ground as the grinding media. Autogenous grinding mills use larger rocks to impact and break smaller rocks as the mill rotates. Semi-autogenous mills are basically the same autogenous mills, but with the addition of balls, similar to those in ball mills.

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.

grade materials are trucked close to the mill, in anticipation of possible future treatment. The concentrator is designed to treat 40,000 metric tons per day of ore to produce 400,000 metric tons per year of copper in concentrate product. It includes two 28’ x 14’ SAG mills and four 18’ x 24’ ball mills in closed circuit,

Sep 07, 2017 However, the SAG route is more power-intensive and, for very hard ores, comes with some process risk in predicting performance. More recently, a hybrid solution has become available in the form of high pressure grinding rolls (HPGRs), which can replace the third stage of crushing and also the SAG mill.

“Many SAG mill liner designs perform very well in their objective to achieve the desired particle size and protect the mill structure. However, no matter how well a mill is operated, and no matter how well a liner design performs, a mill is only as good as its ability to discharge the slurry out of the mill.

SGS's comminution experts use the SAG Mill Comminution (SMC) test to characterize ore samples, an important first step to grinding circuit design, optimization and production forecasting. Read more The SMC test is an abbreviated, less expensive version of the JK Drop-weight test.

Nov 03, 2016 The relining of mills is a necessary process and it is very often the critical maintenance path of a concentrator shut down. Generally speaking, and depending on current ore prices, the production of a large SAG mill usually equates to between US$30,000 and US$200,000 per hour.

The mill power draw, throughput and product size distribution are used to compute a specific energy input and the MacPherson autogenous work index (AWI). Although the importance to achieve steady-state in a grinding test is widely accepted (Bond tests), the MacPherson test remains the only small-scale AG/SAG mill test that offers this option.