The Ball Charge in SAG and Ball Mills, in other words, the fraction of the mill volume constituted by balls, has a significant impact on the performance of a mill and the greater Grinding circuit. Running at the wrong Ball Charge adversely impacts not only throughput but the consistency of the product particle size (P80) as well.

SAG Balls. MILL LINER BOLT. Twist Lock Pin. Easy Out Bolt. The Molycop range of SAG grinding balls is prepared for impact. Through an innovative manufacturing process we've produced a ball with greater impact resistance and reduced spalling compared to the standard SAG ball, ready to perform in the highest impact SAG milling environments.

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. SAG and AG Mills operate by lifting ore/grinding media and dropping it on ...

SAG mills of comparable size but containing say 10% ball charge (in addition to the rocks), normally, operate between 70 and 75% of the critical speed. Dry Aerofall mills are run at about 85% of the critical speed. The breakage of particles depends on the speed of rotation.

The starting point for ball mill media and solids charging generally starts as follows: 50% media charge. Assuming 26% void space between spherical balls (non-spherical, irregularly shaped and mixed-size media will increase or decrease the free space) 50% x 26% = 13% free space.

CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Discrete Element Method simulation of charge motion in ball, SAG and autogenous mills has become a standard for lifter design, power draft evaluation, etc. Both two-dimensional and three-dimensional codes are being used. The two-dimensional code dominates the user market since the code …

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. Interior of the drum uses the lifting plates. These plates inside the drum are responsible for picking the grinding material up to fall down again throughout the rotations.

Even the SAG ball charge needs to be adjusted based on the size and hardness of ore it's working on. Too many grinding balls can prematurely wear out the grinding balls themselves. Operating a mine mill requires balancing a dynamic set of tradeoffs.

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).

the ball charge is a function of the bulk fraction of the sag mill volume ( jb) occupied by balls; the ore retained in the mill is the result of the volumetric filling which depends on the ore size distribution (specially the % +6″ and the % −6″ +1″), on the rotational speed ( n / nc) and on the solid concentration by weight fraction inside the …

mill charge and speed. SAG Mill product P80 values are typically in the range of … OPTIMIZING SAG MILL PRODUCT SIZE IN SAG MILL _ BALL MILL GRINDING CIRCUITS

The ball charge is a function of the bulk fraction of the SAG mill volume (Jb) occupied by balls; the ore retained in the mill is the result of the volumetric filling which depends on the ore size distribution (specially the % +6″ and the % −6″ +1″), on the rotational speed (N/Nc) and on the solid concentration by weight fraction inside ...

Stamp mill,Crusher, AG mill, SAG mill, Pebble m ill, Ball mill, Rod mill. ... SAG m ills use a ball charge of 8 to 21%. The largest SAG mill is . 42' in diameter, powered by a 28 MW ...

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. SAG and AG Mills operate by lifting ore/grinding media and dropping it on ...

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 Competent ores, better suited to coarse grind sizes as circulating loads can be high 7 SAG mills treating ...

ball chargers Storage hoppers and trays for steel ball grinding media Transmin specialises in a range of systems available to safely store and feed (charge) steel balls into mills or conveyors – from simple kibbles, through to complex handling systems comprising storage hoppers connected to ball feeders of the cassette or 'star feeder ...

The value T80 is the "synthetic" transfer size between the SAG mill and ball mill – a fines-corrected 80% passing size 2 of the SAG mill product (or the combined SAG mill product and crushed pebbles if the circuit is sending crushed pebbles to …

Mill application features. Frozen charge protection – Detects frozen charge in the mill, minimizing equipment wear and liner replacements.; Coupling supervision – Detects if a failure or slippage occurs in the couplings and stops the system in case, preventing major damages.; Stand-still detection – Prevents the motors from re-starting if the mill is still rocking or moving …

The SAG mill was designed to treat 2,065 t h −1 of ore at a ball charge of 8% volume, total filling of 25% volume, and an operating mill speed of 74% of critical. The mill is fitted with 80 mm grates with total grate open area of 7.66 m 2 ( Hart et al., 2001 ).

Grinding media is grinding feed plus 4-12% ball charge (ball dia.100- 125 mm) High capacity (short retention time) Less sensitive to feed composition (critical size material) Semi-Autogenous Mill Note the size of the mill: Why does the diameter need to be so big? [image: (135-6-2)] SAG Mill Circuit Example — Gold Processing

mill speed and shell liner/lifter simulations and, particularly, ball charge volume and ball top size, both of which are dependent upon the contingency applied to the transfer size in the SAG circuit product. Iterations of these para-meters can be performed in some models (e.g., DJB's "Reduced Recovery" and "Millpower2000") to determine

The grind-out condition cannot decline below the ball charge level of the SAG mill; if this happens, another warning message is displayed saying the SAG mill speed must be reduced to achieve the target power draw. The model assumes all SAG mills are variable-speed; if a fixed-speed mill encounters this condition, it will completely grind out ...

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.

For SAG milling applications, the diameter of the balls, mill and throw action of the charge provide for a high impact environment - therefore a balance must be achieved between abrasion resistance and impact resistance in SAG balls to avoid excessive breakage.

and optimal grinding charge trajectory for the SAG, Ball and Rod Mills. • Identified potential benefits could be obtained with an ideal grinding media charge, mill speed as well as optimisation of lifter profile (specialty lifter face 20 angle) which is directly related with mill power draw, internal motion of mill charge,

SAG mills (semi-autogenous milling) is a type of grinding carried out with a small amount of ball charge and with the help of bigger parts crumbling the smaller parts of ore. In addition to being preferred in gold, copper, platinum and silver mines, SAG MILLS are preferred in mines such as lead, zinc, alumina and nickel.

model to ball mill grinding. However, the same models could not be extended to semi autogenous grinding. Simply carrying out pilot scale SAG grinding is a very tedious task. At this time, the discrete element method appeared on the scene. DEM helps in simulating a number of features of SAG mills and AG mills, not to mention balls mill as well.

• Mill type: SAG, FAG, Rod mill, primary ball mill, secondary ball mill, regrind, …) • Ore feed size (F80,F100) and required product size (P80) determining the grinding mechanism to be favoured • Mill size (diameter, length) • Maximum ball top-up size • Mill rotational speed (rpm, variable or fixed speed, single or dual rotation)

The contribution of the work reported here is to present further examples of state estimation for SAG mills and novel models of the SAG mill discharge, SAG mill ball charge and shell protective lining. State estimation of mill rock charge, ball charge (J b), water charge and thus total charge (J t) is demonstrated. An assessment of structural ...

SAG Mill Ball Charge The SAG mill was simulated to require a 10-12% ball charge with a top size of 125mm. During the commissioning phase no balls were required to be added to the SAG mill to achieve the target throughput of 575tph. This allows for great flexibility in the future and significant security for the future.