SAG Mill Control: It Shouldn't be that Hard | E & MJ. The first successfully implemented multivariable process control (MPC) is described for a SAG mill circuit in a bauxite processing refinery at Wagerup, Australia (Refs: Gopinath, Mathur et al, 1995 and Le Page, Freeman et al 1996, Luse, Mathur et al 1997).
The paper is illustrated by trend plots taken from a SAG mill in a major gold mine. The paper goes on to explain the practical causes of the instability ranging from inappropriate type 2 control strategies to poor control loop tuning and to inappropriate operator intervention caused by lack of operator training.
SAG Mill Control It Shouldnt be that Hard. Know More . In this case mill speed is the primary manipulated variable used to control mill load While there is no generic control strategy for SAG milling there is a considerable amount of reusable engineering In contrast to an expert or black box system the control loop approach was built using ...
Constrained: Further improvements can be achieved on SAG mill control though or model predictive control (MPC) control strategy which increases the target setpoints closer to the maximum limit. Optimized: Once the process is working within a tight operational control, realtime insights can be gathered from the instrumentation allowing for further dynamic response.
SAG (semi-autogenous) milling circuit is described with the emphasis on the process control systems employed. The history of the circuit (process) controller is then discussed briefly to illustrate the differences between historical and new techniques. The evolutions of the control philosophy, as well as the financial benefits, are described. Global
Single stage SAG Mills are very beneficial in reducing CAPEX for plants with a staged throughput approach. When future tonnage is to be increased, the SAG Mill can feed downstream ball milling to boost capacity. Fuller-Traylor SAG/AG Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW.
Robust control of a SAG millScienceDirect. Apr 29 2002 · SAG mill control. In general terms the benefits sought from improved primary grinding circuit control include increasing throughput at the desired grind size reduction of grinding ball consumption and minimisation of the SAG mill …
This is excellent for good SAG mill control. There are three major sources of disturbances that produce instability in the grinding circuit. These are, 1. Coarse ore stock pile feeder trips 2. Large variability in ore competency in the mill feed 3. Recycle Crusher Operation Controlling a SAG mill utilising older control techniques will give
If the SAG mill is not intended to be the rate-limiting step in a process plant, then it is best to adjust the SAG load (and power) to hold a constant tonnage to satisfy another constraint elsewhere. Underground mines are an example: the hoisting capacity of the mine shaft is the rate-limiting step in the process, and the SAG mill must adapt to what the shaft can supply.
SAG Mill Control: It Shouldn't be that Hard E MJ. 2020-4-8 A control strategy recently implemented on a large variable-speed SAG mill at MMG's Century Zinc operation in Australia is shown in the chart (found on pg. 32). In this case, mill speed is the primary manipulated variable used to control mill load.
Ag Sag Milling Control. 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 15 This was a great success for everyone involved Assuming a copper price of 4 USDlb ANDRITZ AUTOMATION estimates that BrainWave SAG mill led to an extra 12M USD
Control stabilization for SAG millsBrainWave is ideally suited to stabilize the operation of SAG mills. Effective grinding in a SAG mill depends largely on how it is loaded. A mill containing too much material does not allow for adequate movement of the ore and balls
Download Citation | SAG Mill Control: It Shouldn't be that Hard | The use of advanced control in the plant control systems (PCS) such as programmable logic controllers (PLC) or distributed control ...
06-06-2016· By combining with SAG discharge and screening on the SAG discharge screens, top size control to the ball-mill circuit feed is maintained while still unloading the SAG circuit (Mosher et al, 2006). A variant of this method is to direct pebble-crushing circuit product to the ball-mill sump for secondary milling: while convenient, this has the disadvantage of not controlling the top size of feed ...
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. The load cells are calibrated to measure the total weight of water, grinding media (balls) and ore in the mill ...
SAG and AG Mills operate by lifting ore/grinding media and dropping it on the operating bed of the mill charge. High impacts from lifting ore and media promote impact breakage which is the primary mechanism for size reduction in the mill.
OPTIMAL SAG MILL CONTROL USING VIBRATION & DIGITAL SIGNAL PROCESSING TECHNIQUES ABSTRACT Recent developments in low power wireless and Digital Signal Processing (DSP) technologies have given rise to a new system that can monitor vibrations in real-time on the rotating surface of SAG, AG, and Ball mills.
Effective SAG mill control will maximise throughput, minimise damage to mill internals (liners and lifters) and contribute significantly to achieving maximum recovery in flotation. Well designed and implemented SAG control will payback in weeks not years. SAG mill control is essentially the stabilisation of mill load (and/or power) and density
Model Predictive Control for SAG Milling in Minerals ... 2 | Model Predictive Control for SAG Milling in Minerals Processing Ore from primary crushers is combined with water in the mill where rotation causes the grinding media and the ore to be drawn upwards with the mill liners and tumble, causing fracturing in the first instance, followed by further grinding.
SAG Mill Control: it shouldn't be that hard An economically appealing method for improving operations is available without the capital expense — get more out of a mill by applying the advanced control capabilities in the existing plant control system.
control in processing plants. Objects from the MET/G2/GDA libraries are used to represent the SAG milling environment schematically. This approach results in a straightforward and flexible system with fast and simple connection to data sources. The attributes of the Ok Tedi SAG mills . that are used by the expert system
For SAG mill control, expert systems are often used as they are able to detect the rapid increase in mill weight and anticipate an imminent overload using combinations of rules. However they often reduce the feed rate more than necessary in some situations, and require time to return the feed rate to maximum
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.
29-04-2002· SAG mill controlIn general terms, the benefits sought from improved primary grinding circuit control include increasing throughput at the desired grind size, reduction of grinding ball consumption and minimisation of the SAG mill power requirement.
Evolution of SAG Mill Process Control at the Xstrata Nickel Raglan Operation Erik Bartsch1, Chief Engineer Guy Comeau2, Senior Metallurgist Colin Hardie3, Former Chief Metallurgist 1 Process Control Group, Xstrata Process Support 6 Edison Rd, Falconbridge, Ontario P0M 1S0 PH: (705) 693 2761 X 3438 E-mail: [email protected]
The control loops and sensors for a SAG-mill and the levels of control are illustrated in Fig. 18.22. According to Elber [10,17], the levels are: Fig. 18.22. Three levels of control of a AG/SAG mill. Level 1. The operation at Level 1 mainly consists of controlling the feed rate and the water inputs.
Ag Sag Milling Control. Agsag mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill.Because of the range of mill sizes available, agsag milling can often be accomplished grinding circuit design agsag milling can be accomplished with a variety of flowsheets.
Sag Mill Example To illustrate the power of fuzzy logic we will next look at its application in controlling a typical sag mill circuit as is shown in Figure 2. Figure 2. Typical Sag Mill Configuration as Defined in KnowledgeScape. An example of controlling SAG mill speed will be …