Here I try to explain how ground slurry is discharged from a grate ball mill (or SAG). How it works is, the slurry flows across the grate as it would a screen panel. On the other side of the grate/screens are veins like a pump impeller. As the mill …
to the discharge grate will be obtained. The discharge function can then be more realistic and scaleable, as it will not have to accommodate the ... the SAG mill and the key testwork data is given ...
A detailed investigation by Latchireddi (2002), Latchireddi and Morrell (1997, 2003a and 2003b) on impact of the discharge grate and pulp lifters on slurry transport in SAG mills revealed the ...
Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding capacity) of these mills is strongly influenced by the discharge grate design––open area and position of apertures, as well as the performance of the pulp lifters.
The best way to eliminate material problems is to use a grate, peripheral discharge trunnion supported mill or use a grate, open-ended discharge shell …
SAG mill liner development draws primarily on practical experience from SAG milling operations supported by computer-based modeling of charge motion in SAG mills and on established good design practice. Liner design needs to respond to the process aspects of mill liner action that are critical to good SAG mill performance, i.e., …
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)
The slurry transportation in AG/SAG mills is a two-stage process consisting of flow through the grate and the discharge of slurry by pulp lifters into the discharge trunnion. The grate-only discharge condition provides the ideal relation between slurry hold-up and flowrate.
Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding …
Grate discharge Diameter 38′ Length 25'5″ flange-to-flange EGL 22′ Components / Inclusions Feed chutes Discharge grates Steel pulp lifters SAG mill trommel Mill braking system Hydraulic jacking system Portable hydraulic power unit. Motor and Drive 26,000 HP (19.4 MW) Siemens wrap-around drive motor
The results of study on material flow through a grate discharge tumbling mill verses an overflow tumbling mill are presented to emphasize the effect of discharge flow mechanism. The experimental results are analyzed to study the influence of operating variables on specific energy, product size, hold-up and residence time distribution in ...
Generally, the discharge from AG/SAG mills consists of one or both of the following components: slurry (water and finer particles) and pebbles (20-100mm). ... The commercially viable and industry accepted alternate is a grate discharge trunnion supported mill or a grate discharge shell supported mill using pulp lifters.
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.
AG & SAG Mill Grinding Compared – Which is Best. ... In North America, with wet primary mills, the practice has been to use low or high level grate discharge or peripheral discharge and a nominal ratio …
(AG), semi-autogenous (SAG) and grate discharge ball mills. The flow capacity (grinding capacity) of these mills is strongly influenced by the discharge grate design - open area and position of apertures, as well as the performance of the pulp lifters. As mill sizes have progressively increased and closed-circuiting has become more popular
Converting a ball mill from overflow to grate discharge involves installing a grate inside the mill at the discharge end. The grate holds the balls inside the mill but allows the slurry to pass through, and it …
Pulp lifters, also known, as pan lifters are an integral part of the majority of autogenous (AG), semi-autogenous (SAG) and grate discharge ball mills. The performance of the pulp lifters in conjunction with grate design determines the ultimate flow capacity of these mills. Although the function of the pulp lifters is simply to transport the slurry passed through …
Semantic Scholar extracted view of "Slurry flow in mills: grate-only discharge mechanism (Part-1)" by S. Latchireddi et al. Skip to search form Skip to main content Skip ... (DEM) study of load movement within a SAG mill 12,192 × 7620 (40′ × 25′) in normal operating conditions is performed. The purpose is to determine how the geometry ...
First, the ore that enters the mill (with a size distribution of fi) is subject to the size reduction process in the grinding chamber. The product of this stage (represented by the fictitious flow P*, t/h) undergoes internal classification stages and transport towards discharge, determined by the grate – pulp lifters – discharge cone - discharge …
Discharge grate slot analysis is carried across all grate designs to optimize open area, recycle size and product passing. ... (AG) and semi-autogenous (SAG) grinding mills, having a significant impact on the throughput, efficiency and performance of mills. Underestimating the importance of an optimised liner design in a mill can lead to back ...
Generally, the discharge from AG/SAG mills consists of one or both of the following components: slurry (water and finer particles) and pebbles (20-100 mm). ... The commercially viable and industry accepted alternate is a grate discharge trunnion supported mill or a grate discharge shell supported mill using pulp lifters. The only way …
The GDM include autogenous (ag), semiautogenous (sag) and grate discharge ball mills. The purpose of the pulp lifters is simply to transport the slurry passing through the grate holes into the discharge trunnion. …
The data from the full scale mills were obtained during research programmes of the JKMRC and include the Warrego ag mill (Stanley, 1974), the Alcoa sag mill at Pinjarra (Morrell, 1989) and the Red Dome sag Table 1 Mill details Mill Operation Diameter Length % Critical Mill Mill discharge inside inside speed product % solids (v/v) liners (m ...
SAG mill A SAG mill is almost always a high-impact application. Hence, it is wise to use tough, impact-resistant materials that are somewhat softer but less brittle to avoid cracking, chipping, or breaking. Rubber/steel composite liners are often a good choice as is the range of more impact-resistant cast alloys. Rod mill As there should be very
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
Grate Inside A SAG Mill Inner grate plate Shell lifter Charge Lifter ... > Good for discharge grates > Mineral Processing > RESOURCE PROJECTS > TECHNOLOGY > INTEGR > Engineering Design > Training > Specialist ServicesATED SERVICES High Carbon Chrome Moly Steel > 325 to 380 BHN > Chromium and molybdenum both individually increase …
The slurry transportation in AG/SAG mills is a two-stage process consisting of flow through the grate and the discharge of slurry by pulp lifters into the discharge …
Highlights One-way coupled SPH–DEM models can predict the flow of solids and fluid charge in SAG mills. End walls and worn shell liners create significant axial flow and recirculation in a SAG mill charge. Slurry flow through the grate and along the pulp lifters and discharge from the mill can be predicted. End wall lifters are critical to grate …
SAG 1 SAG 2 Unutilised space Figure 4 Los Bronces SAG mill 2 discharge grate As illustrated in Figure 4, the mill has classic massive pebble porting, typical of the operations aiming for maximum pebble discharge rate. The open area is successful at achieving this, but at an associated cost that is generally not appreciated. ...
OPTIMISATION OF THE SOSSEGO SAG MILL Homero Delboni1, ... Accordingly, the 32 grate discharge plates originally installed in the SAG mill operated from March to December 2004. Since this period a
As secondary ball mills are usually fed a relatively (compared to SAG mills) fine F80 and have high re-circulating loads and produce product fineness of the P80 - 100 to 160 micron range, fitting a grate discharge needs to be carefully considered. ... In simple words, grate discharge mills give higher tonnage, but produce coarser grinding, that ...
Most mills can be converted from metal liners to composite rubber liners. These liners combine the best characteristics of metal alloys and rubber to obtain a superior design for use in AG/SAG, grate discharge, overflow ball mills and grinding ball mills. By using special alloy steel segments moulded into rubber, composite plates
Bullnose® discharge cone system reduces the relining times by 50% to maximise mill availability. Discharge grate slot analysis is carried out across all grate designs to …
A Discrete Elements Method (DEM) study of load movement within a SAG mill 12,192 × 7620 (40′ × 25′) in normal operating conditions is performed. ... The number of linings in the whole interior was kept fixed, the discharge grate area and the volume of the pulp lifters were retained; regardless of the study case, the cross section or the ...
operation of SAG mills. SAG mills are currently the technology of choice in hard rock milling operations for reducing primary-crushed ore to ball mill feed. In recent years, the trend has been towards larger-sized SAG mills with diameters of 10.4 m (34 ft) and above, with the largest being 12.2 m (40 ft) in
The slurry transport from the AG/SAG mill through grate holes into the discharge trunnion is the main function of the pulp lifter. This process develops complex flow behaviour in the region of the ...
