SAG Mill | Autogenous and Semi-Autogenous Mills
Fuller-Traylor SAG/AG Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW. Our team of product engineers continually improves SAG/AG Mill designs in order to provide the most robust, safe, and efficient grinding mills …
Unlock SAG mill capacity with process control optimisation
The instrumentation installed on a SAG mill is integral to control. For example, the mill load and noise sensors are instruments that provide essential information for an optimized SAG mill operation. Insufficient understanding of the ore characteristics and feed composition can result in an ineffective SAG mill operation.
SAG Mill Liner Design
Based on experience, mill-liner designs have moved toward more open-shell lifter spacing, increased pulp lifter volumetric capacity, and a grate design to facilitate maximizing both pebble-crushing circuit utilization and SAG mill capacity. As a guideline, mill throughput is maximized with shell lifters between ratios of 2.5:1 and 5.0:1.
A Comprehensive Guide to SAG Mill Operation
SAG mills are typically operated at a constant speed, with the feed rate controlled by the mill weight. The mill weight is measured by load cells or a strain gauge, and the controller adjusts the feed rate accordingly. SAG mills can be operated in open or closed circuit, depending on the downstream process requirements. Maintenance of a SAG Mill
A Hybrid Intelligent Framework for Maximising SAG Mill …
purposes, SAG mills utilise a combination of steel balls and coarse ore to achieve the desired discharge particle size [2]. An essential performance metric for a SAG mill is its throughput, which measures the volume of processed ore ... including mill weight, power draw, turning speed, inlet water, feeder ratios, pebble crusher working status ...
SAG Mill Process Control
Treatment capacity is the result of operating mill in a healthy weight range that will ensure the optimum total level filling and utilization of full power which is the energy that is …
SAG Mills Archives
SAG Mill Grinding Circuit Design. AG and SAG mills are now the primary unit operation for the majority of large grinding circuits, and form the basis for a variety of circuit configurations. SAG circuits are common in the …
Feed hardness and acoustic emissions of autogenous/semi …
Abstract. In this study, the relationship between acoustic emissions and hardness of different rock types (model quartz, model calcite, and real iron ore) coupled with binary mix ratios of model quartz and iron ore (1:3, 1:1 and 3:1) was investigated in a laboratory-based AG/SAG mill. The acoustic emission response and sensitivity of the …
Relationship between SAG mill power draw, bearing
The process variables that are linked to the SAG mill are used in clustering, such as weight or bearing pressure, power draw, feed size, feed rate, percent solids, acoustic noise, and water addition.
A comparison of SAG mill power models
Gross power = 265 + 1.26 × (2,233 + 215) = 3,349 kW. The conversion between motor input (gross) power and mill shell power, described earlier, is 0.931. Therefore, the predicted power at the mill shell is 3,119 kW, which is 71 kW less than the measured shell power (3,190 kW), a difference of 2%.
Charge segregation and slurry transport in long SAG …
the SAG mill and the key testwork data is given in Table 1. The total weight of the emptied out charge was 62.2 tons making up a total mill (slurry) filling
Three factors that determine the wear life and …
weight, method of installation, and user preferences. 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
SAG Mill Testing
Bond Rod Mill 0.305 12.7 Any 1.18 15 10 Locked-cycle Y Y Bond Ball Mill 0.305 3.35 Any 0.149 10 5 Locked-cycle Y Y Mod Bond 0.305 3.35 Any N/A 2 1.2 Batch N Y Table 1 – Summary of Grindability Test Procedures 1Weight requested for the test, for typical ores (S.G. = 2.8g/cm3). Denser samples require more weight, proportional to the S.G.
Comparison of Ore Hardness Measurements for …
was surprising that the Bond Rod Mill Wi average was 11.3 kWh/t. Since the ore is unusually soft, the Rod Mill Wi is probably irrelevant in determining required power for the SAG mill. Drop Weight Tests Drop Weight tests were done at Hazen and analyzed by Contract Support Services, Inc. Table 4: Summary of 6 JKTech Drop Weight Tests
SAG Mill Control: It Shouldn't be that Hard | E & MJ
SAG mill control fundamentally means managing the load in the mill by adjusting the feed rate of ore to the mill and/or manipulating the rotational speed of the mill. The best way to measure load is to mount the mill on load cells. ... but not the weight of the mill itself. While many mills today are mounted on load cells, others employ bearing ...
BrainWave: Control solutions for SAG mills
control the weight in the SAG mill to promote optimum grinding. This strategy has been demonstrated to improve mill throughput by as much as 3%. When copper prices are …
Improved mill control at Lihir Gold Mine in Papua New Guinea
The SAG mill weight measurement combines mill shell mass, charge mass and liner mass. Powell (2006; 2009), via a series of mill charge inspections at various operating mill weights, confirmed that strong relationships can be developed between volumetric mill filling and mill weight. These relationships will only hold in the short term …
Model Predictive Control of Sag Mills and Flotation Circuits
MPC was used to stabilize the weight or bearing pressure for SAG mills leading to demonstrated throughput increases greater than 1.5% at three separate mine sites. These performance improvements are relative to the expert systems already in use at these sites. One mine site reported secondary benefits of over 50% variability reductions in mill ...
Machine Learning and Deep Learning Methods in Mining
For SAG mill 1, the information is split into 179, 71, and 90 days (8600, 3400, 4340 data points), while for SAG mill 2 the information is split into 166, 66, and 99 days (7953, 3181, 4771 data points) for the train, validation, and testing datasets, respectively. ... the bearing pressure BPr is associated to the mill weight, considering the ...
Influence of feed size on AG / SAG mill performance
The process variables that are linked to the SAG mill are used in clustering, such as weight or bearing pressure, power draw, feed size, feed rate, percent solids, acoustic noise, and water addition.
Understanding the SAG Mill in Copper Ore Mining Process
Unlike traditional mills that rely on steel balls or other media to break down materials, SAG mills use their own weight and the force of material being fed into them to grind ores. This makes them more energy-efficient than other types of machines. SAG mills are typically large cylinders made from steel with a rotating drum inside.
Choosing a SAG Mill To Achieve Design Performance
Choosing a SAG Mill To Achieve Design Performance. John Starkey1, Principal Consulting Engineer Sami Hindstrom2, Manager, Grinding Travis Orser2, …
AG – Autogenous & SAG Semi-Autogenous Mill …
AG mills (or SAG mills with low ball charges) are often used in single-stage grinding applications. Based on their higher throughput and coarser grind relative to AG …
Autogenous and Semi-Autogenous Mills
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. ... the tumbler test is recommended. The drop weight test has been described in Chapter 3. The tumbling test is as follows. Test conditions: 1. mill size: 305 × 305 mm with four lifter bars 6. ...
Increase throughput and capacity in SAG mills
SAG mills are the main workhorses in the majority of comminution circuits globally. They need to be fed and kept working round the clock. ... mill weight and bearing pressure. It can then automatically take corrective action if needed and adjust parameters such as the mill ore feed rate, mill speed or slurry density. Where an operator might ...
Quantifying variability of ore breakage by impact
Later, the JK drop weight tester (JKDWT) was developed at JKMRC by Doug Brown and Steve Morrell (Brown, 1992) for characterising impact breakage of ores for the purpose of AG/SAG mill and crusher modelling (Fig. 1).
Inferential measurement of SAG mill parameters III
SAG mill fractional total filling (J t) and ball filling (J b) are determined by solving the powerdraw or mill weight equations given mill power draw or weight process measurements as inputs. 4. SAG mill total feed (SMTF) is then calculated by mill model inversion after making assumptions about the ball charge size distribution. 5.
Semi-autogenous grinding (SAG) mill liner design and …
Semi-autogenous grinding mills (SAG mills) are tumbling mills that most commonly have a shell diameter-to-length ratio of around two. With this high aspect ratio, SAG mills generate both thrown and cascading ball-milling actions with shell linings shaped to lift and to throw alloy steel grinding balls of up to 150 mm (6 in.) in diameter. These
(PDF) Real-Time Estimation of SAG Mill Charge
However, when combined with an accurate SAG mill power-draw model, total charge volume and ball load can be estimated with reasonable accuracy. ... Mill Weight (t) Mill Power (kW / 10) Mill Speed ...
Autogenous Grinding & Semi Autogenous …
Autogenous grinding is favored when the ore is quite competent and a fine grind is required. Semi-autogenous grinding is applied when fine crushing could cause severe problems or when ore is …