grate open area in sag mills

sag mill design

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

COMMINUTION - sgs.ca

SAG mill feed, grate size, open area, classification size, ball diameter or ball charge, total mill load, mill speed, etc. can be investigated at pilot plant scale. All tests are evaluated based on: • Feed rate • Power consumption • Product size analysis Unless single-stage autogenous grinding is considered, we recommend that the

(PDF) Slurry flow in mills with TCPL — An efficient pulp ...

Extensive test work carried out on slurry removal mechanism in grate discharge mills (ag/sag) has shown that the conventional pulp lifters (radial and curved) have inherent drawbacks. They allow short-circuiting of the slurry from pulp lifters into …

effect of grate discharge area of sag mill

Optimization of the single stage SAG mill circuit at the . single stage SAG mill at Minera Yanacocha 39s Gold Mill facility loed in northern Peru The Gold Mill was commissioned in March Figure 9 shows some design variations of the rubber discharge grates Table 3 Rubber discharge grates design changes Grate total area m2 Slots Slot dimension mm x mm Passing single …

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that are believed to take place in AG/SAG mills. Transport of slurry through the mill is described by a function which relates the hold-up of slurry, grate design, grate open area and mill speed to the volumetric discharge rate through the grate. The model ret1ects feed size changes by

Demo | Minerality | Minerals processing Software, Training ...

Pegging of the discharge grates in SAG mills often occurs and this will result in a drop in throughput. The effect of new grates can be simulated in terms of new open area, size of apertures or new pebble ports. Exercise 6 in Demo: Flow Sheet Configuration. Change, Diverting crusher product.

Comminution Services - SGS

grate open area, etc.) or to integrate into a CEET®-based design. • The MacPherson Autogenous Grindability Test determines the MacPherson Autogenous Work Index. This can be used in conjunction with the Bond Rod and Ball Mill Work Indices to determine power requirements and to suggest circuit configurations for AG/SAG circuits.

New SAG Mill Model for Better Mine-to-Plant Planning

constant as an empirical function of the open area, grate design, mill speed, charge volume and pulp lifter specifications. Menacho and Chávez (2008) reported a slurry transport model in SAG mills by using the porous media fluid transport theory. Tupper, Govender, Mainza and Neville Plint (2013) reported a mechanistic

SAG Mill Liner Design - Mineral Processing & Metallurgy

To a more significant degree than in other comminution devices, SAG Mill Liner Design and Configuration can have a substantial effect mill …

(PDF) The Influence of Liner Wear on Milling Efficiency

grate open area fraction was equal for all three surveys at 0.059. Thus the discharge rates stayed relatively . constant during the three surveys, as expected. ... (9.75 m) SAG mill, it …

t10 (%) Weighted Fit 63 x 53 - SMC Testing

o grate open area of 7%. 3 o apertures in the grate are 100 % pebble ports with a nominal aperture of 56 mm Trommel ... AG and SAG Mill Circuit Selection and Design by Simulation, in . Proceedings Autogenous and Semi-Autogenous Grinding, pp 769 – 790 (University of British

Optimizing your SAG Mill | Mining Surplus

As a result, mines have shifted their emphasis in optimization from ball mills to SAG mills. The rock load in the mill essentially depends on ore characteristics and the discharge rate of broken particles through the discharge end. The discharge rate depends on how efficiently the discharge pump (grate and pulp lifters) operates.

Drainage Grate Flow Calculators - EJ

A = Open area of grate (ft 2 ) g = Acceleration due to gravity (32.2ft/sec 2 ) d = Depth of water over grate (in feet) Using an Orifice coefficient of 0.67 and correcting open area from square feet to square inches and depth of water from feet to inches, this equation simplifies to: …

(PDF) Slurry flow in mills with TCPL — An efficient pulp ...

Process. 79 (2006) 174–187 179 In ag/sag mills the volume of the grinding media It has been a usual practice to increase the grate open (balls and coarse ore) tends to change with the type of area to obtain an increased discharge rate.

and FL Semi-Autogenous Grinding Mill Liner ...

As a casting foundry, HG Casting also has own SAG Semi-Autogenous Grinding Mill Liner and AG Autogenous Grinding Mill Liner design. In general terms, lifter spacing and angle, grate open area and aperture size, and pulp lifter design and capacity must be considered.

Improved Relationships for Discharge in SAG/AG Mills

(SAG) mills. In order to optimize this section, the skills to accurately model and understand its underlying mechanisms are required. The literature exposed a clear lack of previous research on the influence and performance of grate/pulp lifter design in AG/SAG mill discharge. The current understanding from

Typical data gathering for plant optimization studies ...

c. SAG & AG Mill sizes i. Diameter, inside shell ii. EGL or Flange to flange width iii. Grate design, open area, aperture of grates, or pebble ports iv. Overflow or grate discharge v. Pinion motor installed power vi. liner thickness vii. Cone end flat or 15 degrees. c. Mill trommel and/or screen OR dedicated HPGR circuit discharge screens i ...

(PDF) Slurry flow in mills: Grate-pulp lifter discharge ...

RPL, 30% charge volume, 7.05% grate open area) Inf lu en ce of charg e vol u me on p erf orman ce of pu l p l ift ers Figu re 10 sh o ws th e infl ue nc e …

Optimizing your SAG mill operation - International Mining

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 ...

Modelling and Simulation Techniques Applied for ...

believed to take place in AG/SAG mills. Transport of slurry through the mill is described by a function which relates the hold-up of slurry, grate design, grate open area and mill speed to the volumetric discharge rate through the grate. The model reflects feed size changes by changing the load size distribution and hence rock grinding media size.

Open Ended Discharge Grinding Mill - Outotec

Furthermore, the spider and discharge cone are segmented and removable. Together these solutions minimize the time and cost associated with mill relining and discharge-end servicing. Optimized discharge-end serviceability is particularly important for an open-ended mill as the grate design is the primary mechanism to control the slurry pool level.

Pebble Crushing in SAG Mill Circuit - 911 Metallurgist

The initial pebble port grates had 448 each 76 mm by 76 mm (3 in. x 3 in.) square openings for a total open area of 2.6 square meters (4032 sq. in.).

Modelling of the Performance of AG/SAG Mills

Transport of slurry through the mill is described by a function which relates the hold-up of slurry, grate design, grate open area and mill speed to the volumetric discharge rate through the grate (Morrell and Stephenson, 1996): Jp = k Q0.5 g-1.25 A-0.5 f0.67 D-0.25 (7) where. Jp = fractional slurry hold-up. D = mill diameter (m)

Automated condition monitoring of mill ball size ...

Many grates in operation are pegged by grinding media to varying degrees of severity. This paper introduces a comprehensive, accurate and rapid method to measure and track the size and pegging status of each and all grate holes in situ, and therefore provides tracking information on the Open Area of a SAG mill.

Mill Liners - The Group

® discharge grates have flexibility in size, shape and location of apertures. Options range from small multiple apertures per grate to large AG/SAG mill applications, with integrated reinforcement for structural integrity and open pebble ports for maximum open area.

Free Full-Text - MDPI - Publisher of Open Access Journals

The discharge grates of the SAG mill were identified as a key component in the SABC circuit, and their design is a crucial factor in the mill's performance [17,18,19,20,21]. The initial design of the grate section caused a serious accumulation of pebbles within the SAG mill which contributed to a decreased grinding efficiency.

Grate liners | Magotteaux

Designed for discharge efficiency The role of the grate is to allow the discharge of the material ground in the mill via the slots. With our range of alloys and design experience we can offer the longest possible lifetime with the optimal grinding efficiency. The design of the grates will depend on: Drilling pattern Mill speed (rpm)

SAG MILLS OPTIMIZATION: IMPLEMENTATION AND …

• Antamina´sSAG mill has the worst condition of slurry evacuation in trommel: α = 222 m 3/h/m 2 • Esperanza and ndida´sSAG mills have high values of α, but they have a screen • Trommel of 40 feet SAG mill of Collahuasi has an high value of α = 172 m 3/h/m 2. Open Pulp Free Flow by Free SAG 1011 Area, % Flow, m 3/h Area, m 2 Area ...

SAG Mill Trommel Screens | Multotec

The SAG mill trommel screen provides a simple mechanism to classify large volumes of mill product.. Many designers and mill operators believe that the benefits of simplicity and the ability to handle throughputs in excess of 5 000 tph of solids make trommels the preferred equipment for this application.

SAG MILL DISCHARGE SCREENS-TROMMEL vs. …

SAG MILL DISCHARGE SCREENS-TROMMEL vs. VIBRATING ... the mill from the grates in the slot between the grates and the head. The oversize falls into a bucket wheel on the discharge end of the trommel, gets picked up as the trommel ... The size is also dictated by the open area of the urethane panels which is only