RECENT DEVELOPMENTS IN AG/SAG MILLING IN …
• Control • Mill Design . 3.1 Circuit Design . Ag/sag milling has now been accepted to the point where it is the favoured choice in nearly all new projects. For many years, however, the ...
Манай Ag Sag Milling Control
(PDF) The collection and analysis of single sensor surface …
Improved measurement tools for monitoring and control of AG/SAG mill p erformance have a . high level of interest in industr y. Historically, acoustic emission monitoring has been widely used .
AG
Product Size: All passing 6 mesh with 80% passing 20 mesh. Net power from pilot plant: 16.5 KWH/ST. Mill, gear and pinion friction multiplier: 1.025. Mill Power required at pinionshaft = (240 x 16.5 …
AG/SAG mill acoustic emissions characterisation under …
Abstract. Towards the development of an improved and more efficient online monitoring system in an industrial AG/SAG grinding mill, the present study employs a laboratory-based AG/SAG mill and acoustic sensor to investigate the acoustic characteristics of different mill operating conditions. Specifically, mill operating …
How to Control a SAG Grinding Mill Circuit
Another control the grinding operator can often employ is the number of cyclones in the circuit. By increasing or decreasing the number of cyclones in the circuit the operator can influence the pressure drop across the cyclone. This will influence the size separation in the cyclone, the sharpness of the separation and, most probably the …
BrainWave: Control solutions for SAG mills
SAG mill #1 load control Plant staff, after extended testing and rigourous data analysis, determined that BrainWave reduced load variability by 14% while increasing production by 1.5%. This was a great success for everyone involved. Assuming a copper price of 4 USD/lb, ANDRITZ AUTOMATION estimates that BrainWave SAG mill led to an extra …
Optimal Speed Control for a Semi-Autogenous Mill Based …
However, adjusting the mill speed to the optimal state presents a very challenging problem. In a SAG mill, the speed control system is a nonlinear and strongly coupled multivariable system. The proportional integral (PI) vector control method is used in the mill control system . The PI vector control method cannot meet the requirements …
SAG Mill Response to Changes in Feed Size as …
The internal workings of an AG/SAG mill are difficult to visualise and capture in real time because the shell of the mill is opaque, and the grinding environment is aggressive [11][12][13][14].
Power-based modelling of single-stage AG and SAG mill …
comminution models are calibrated to two-stage AG/SAG mill and ball mill circuits -- this work compares the performance of several commonly used power-based models to …
The future of SAG mills
Pilot scale testing is essential for designing AG milling circuits. Photo: . Alternatives to SAG mills: Going fully autogenous SAG mill-based flowsheets typically have high greenhouse emissions (GHG) associated with two stages of grinding. This makes alternative flowsheets that include autogenous mills or single-stage grinding more …
Model predictive control of semiautogenous mills (sag)
MIMO control system design based on the MPC strategy for a SAG mill. • Control action exhibit an additional effort in the water as manipulated variable. ... Among the different grinding processes, Autogenous (AG) and Semi-Autogenous (SAG) mills are widely used for ore size reduction. The main difference between these two mills is the …
(PDF) Real-Time Estimation of SAG Mill Charge
The Morrell C-model is generally regarded as one of the most accurate tumbling mill power-draw models and is ideally suited for this application of estimating fill levels of the SAG mill in real time.
Applying grindcurves to mill operation and optimisation
The operation of AG/SAG mills is sensitive to mill filling, therefore developing grindcurves to relate mill filling to performance indicators such as throughput, power draw, and product size can assist in achieving optimal mill operations. The throughput, power draw, and product size have been shown to peak at different mill filling levels.
SAG vs. AG Mills: Understanding the Key Differences
For example, if the application requires a high degree of control over the grinding process, a SAG mill may be more suitable due to its ability to handle larger volumes of ore and larger grinding media. On the other hand, if the process requires a finer product size and lower operating costs, an AG mill may be the better choice. Cost and ...
SAG Mill Grinding Circuit Design
Kidston Gold Mines is a 14 000 tonnes per day rated operation located 280 kilometers west of Townsvilie in Queensland. The principle shareholder is Placer Development Limited. Kidston's orebody consists of 44.2 million tonnes graded at 1.79 g/t gold and 2.22 g/t silver. …
A Comprehensive Guide to SAG Mill Operation
Working Principle of a SAG Mill. The rock and grinding media are placed in the mill and rotated, causing the grinding media to tumble and crush the rock into smaller pieces. The mill operates in a closed circuit with screens that size the ore and send it back to the mill for further grinding. The product from the mill is then sent to a cyclone ...
THE FUTURE OF SAG MILLS
Alternatives to SAG mills: Going fully autogenous SAG mill-based flowsheets typically have high greenhouse emissions (GHG) associated with two stages of grinding. …
Autogenous and Semi-autogenous Grinding Circuits
AG and SAG mills are very efficient at making angular particles round. Crushers are very efficient at making round particles angular. So there is a potential synergy from passing …
Expert mill control at AngloGold Ashanti
and the broader holistic approach to mill control are discussed. The ROM SAG mill circuit—a brief description The typical ROM SAG mill circuit is depicted in Figure 1. The circuit is usually closed with either a screen or, more commonly, a cyclone for product size classification. The focus of control can be divided into two parts, viz. the
SAG Mill Optimization using Model Predictive Control …
MODEL PREDICTIVE CONTROL OF SAG WEIGHT. The MPC controller was installed to control the SAG mill weight, the belt weight in the ore feed system, and the SAG mill sound emissions. A diagram of the control strategy is shown in Figure 3. Figure 3 – SAG mill MPC control strategy The MPC SAG weight controller includes measured …
Acoustic Sensing of Fresh Feed Disturbances in a Locked …
Accordingly, mill operators may lose control of the mill during the transient periods when there is a change in the feed ore characteristics [4], displaying notable effects in downstream processes (e.g., flotation and leaching) [3,7–10]. The traditional method that ... To mimic an AG/SAG mill's continuous mode of operations and demonstrate the
Feed hardness and acoustic emissions of autogenous/semi-autogenous (AG
Different feed rock hardness can be classified with mill acoustic responses. AG/SAG mill acoustic emission response changes as mill feed disintegrate with time. AG/SAG mill acoustic response is affected by binary ratios of different rock types. The key features of the mill acoustic emission signal were ascertained with RMS, DWT, and …
SAG milling & grinding pilot plants
The larger units can also be matched with the SAG mill in SAB/SABC configuration. Stirred mills (Regrinding). Finer regrinding or ultra-fine grinding is a frequent requirement in pilot plants and ALS has a range of units that can run continuously in pilot applications. The following mills are located at Balcatta: ISAMill tm, Deswik, and ...
Acoustic Sensing of Fresh Feed Disturbances in a Locked …
In a large-scale operation, feed ores are introduced into the AG/SAG mill in a continuous mode at a given flow rate to replace the discharging slurry. Nonetheless, the variations in the feed characteristics, typically hardness and size distribution, could cause sudden disruption to the mill operation. This would be challenging to detect in practice, …
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, Project Manager, Grinding. Starkey & Associates Grinding Design and Process Engineering 336 – 268 Lakeshore Rd. E. Oakville, Ontario L6J 7S4 PH: (905) 465-7512 Fax (905) 844-5297.
Autogenous and Semi-Autogenous Mills
Austin considered the mill power as the sum of the power required by the central cylindrical portion and that required by the two end cones. The mill power for either AG or SAG mill can be computed from the equation (9.9) P M = K D 2.5 L ϕ C 1 − 0.1 2 9 − 10 ϕ ρ C J C (1 − A J C) (1 + F) where K = a constant
Feed hardness and acoustic emissions of autogenous/semi …
AG/SAG mill acoustic emission response changes as mill feed disintegrate with time. AG/SAG mill acoustic response is affected by binary ratios of different rock …
SAG Mill Grinding Circuit Design
Single stage AG/SAG milling; AG/SAG mills as a primary grinding stage in a circuit with or without additional stages of comminution; ... The original SAG mill control loop, a mill motor power draw set point of 5200 Amperes controlling the coarse ore feeder speeds, was soon found to give excessive variation in the mill ore charge volume and ...
The performance improvement of a full-scale autogenous mill by setting
Tracking the mill performance showed that the mill power consumption decreased from 9.49 to 6.63 kWh/t (a nearly 30% reduction), P 80 of the mill product decreased from 611 to 355 μm, and the mill fresh feed flow rate increased from 511 to 521 t/h by decreasing the feed ore hardness from 112 min to 58 min based on SAG power …
THE FUTURE OF SAG MILLS
Alternatives to SAG mills: Going fully autogenous SAG mill-based flowsheets typically have high greenhouse emissions (GHG) associated with two stages of grinding. This makes alternative flowsheets that include autogenous mills or single-stage grinding more attractive. "Fully autogenous milling requires similar energy inputs as
Feed hardness and acoustic emissions of autogenous/semi-autogenous (AG
Experimental set-up of laboratory AG/SAG mill with mill control PC, signal monitoring PC, and acoustic system. Mill charge consisting of 2 kg of ore sample, 860 ml water (∼70 wt% solid loading), and 5 kg of 23 steel balls [(size = ∼ 4 cm), fractional volumetric ball filling J b = 10.2 vol%] were used for the study ( Amelunxen et al., 2014 ).
Applying grindcurves to mill operation and optimisation
Fig. 1. The interactive drivers of SAG mill operation. low aspect SAG mill operated with a very high ball load in closed circuit, the power response is generic. Fig. 3 illustrates the expected throughput response of a generic SAG mill based on simulations conducted by Morrell (Powell et al., 2001) for a range of ore hardness, AG/SAG operation ...
Materials | Free Full-Text | Optimization of the SAG Grinding …
Additional applications of machine learning to SAG modeling put the focus on the control of SAG grinding mill circuits, predicting power consumption [90,91], ... Morrel, S.; Valery, W. Influence of Feed Size on AG/SAG Mill Performance. In Proceedings of the SAG 2001, Vancouver, BC, Canada, 30 September–3 October 2001; pp. …
AG & SAG Mill Grinding Circuit Automatic Control
The objective is to develop preliminary cause and effect relationships that provide the foundation for a computer based control strategy for maximizing, or …
SAG Ball Mill Monitoring | Emerson US
SAG / Ball Mill Monitoring Condition Monitoring to Ensure Reliability for Critical Grinding Equipment in Mining Today's mining operations must keep crucial milling assets online and running optimally, but variations in ore particle size, feed rate and moisture content, can lead to plugging, high vibration and machine bearing wear, and ...
SAG Conference 2023
08:45 09:00 Paper 3 AG mill design for low competence ores (T. Beyl) 08:45 09:00 Paper 3 Low-cost SAG milling opportunities (M. Powell) 08:45 09:00 Paper 3 ... SAG Mill Advanced Process Control and Optimization Using BrainWave MPC (A. Kheradmand) 11:30 11:45 Paper 11 Optimizing Energy and Throughput for HPGR: A Case Study
Dynamic modeling and simulation of a SAG mill-pebble …
SAG mill model. The dynamic model of an AG/SAG mill includes several interlinked sub-process modules, and these modules can be updated individually. As shown in Fig. 1, the mill is divided into n sections, where m is the section number and q is the transported material. All sections have the same length, and each section contains a …
Demystifying The Sag Mill: What Is It And How Does It Work?
The SAG mill is a type of mill used in the mining industry for grinding and crushing ores. The acronym SAG stands for Semi-Autogenous Grinding, which means …