over high speed and high bearing pressure, signalling a good mill filling. All process points showing high critical impact rate are shown on the same plot. Most points are situated outside the field of high tonnage conditions. Only at the zone of high speed and medium bearing pressure is Figure 10.
SAG is an acronym for Semi-Autogenous Grinding. SAG mills are autogenous mills but use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.
decided to make SAG control one of its priorities in order to further increase throughput and improve stability. The original primary mill control logic delivered by the Optimisation Project in 2005 consisted of a simple PID loop controlling the mill charge (bearing pressure) through feed rate changes.
Within the scope set for both controllers are: · · Adjust SAG mill tonnage set point and speed, so as to meet the goals, primarily by reducing the variability of the bearing pressure and maximize the tonnage fed to the SAG mill. Check the power consumed by the SAG mill…
• MILL SPEED CONTROL - Automatic speed control using the Liner Damage Level signal. • MILL FILL LEVEL CONTROL - Use the Mill Feed Rate to control the Mill Fill Level (rather than bearing pressure). The Mill Fill Level setpoint can be pushed to a safe maximum to optimise the throughput.
SAG Mill Control at Northparkes Page: 1 SAG Mill Control at Northparkes Mines (Not So Hard After All) ... Bearing oil pressure suffers from inaccuracy. Load cells are expensive to retrofit to existing mills and, if they stop working, are difficult to repair.
Model Predictive Control on a SAG Mill and Ball Mills The solution for the SAG Mill is an adaptive controller which controls mill load using direct mill weight measurement or indirectly from bearing oil pressure. The solution automatically controls ore master feed rate and water addition to increase
bearing. Pressure [bar] Slide shoe bearing Depending on the size of mill, its shell is supported at the periphery by two, four or six slide shoes. The self-aligning support of the slide shoes compensates any slide ring wobbling and eccentricity caused by mill sag, thermal distortion and manufacturing tolerances. Hydrodynamic or hydrostatic ...
Reduce downtime, save on energy costs and increase throughput and capacity in your SAG mill. ... Within seconds, SAGwise can analyse audio frequencies as well as on board power usage, 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 ...
Optimized Asset Monitoring For More Efficient Mill Operation Today's mining operations must keep crucial milling assets online and running optimally, but variations in ore variations particle size, feed rate and moisture content, can lead to plugging, high vibration and machine bearing wear, and ultimately unscheduled stoppages and labor-intensive restarts.
Figure 4 – Bearing pressure and power response following SAG mill grind out (inverse relationship) Figure 3 and Figure 4 show real-life examples of the Bell Creek SAG mill being ground-out following mill overloads. In Figure 3, both bearing pressure and mill power can be seen to be increasing up until the mill feed is stopped.
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, but not the weight of the mill itself. While many mills today are mounted on load cells, others employ bearing oil pressure as a proxy measurement of mill load.
Initially, six inputs (SAG density, bearing pressure, revolutions per minute, noise, recycle, and feed rate) were used to model power draw. Model predictions had a high R 2 (0.87), with 90% of the ...
• Maintain SAG mill bearing pressure below limits • Maintain ball mill power draw below limits • Maintain pebble recycle flow below limits • Maintain SAG mill power draw below limits Grinding circuit MPC Manipulated Variable Disturbance Variable Controlled Variable Constraint Variable Maximize Upper Constraint Lower
1 Vancouver 2015 RNMC - Expert System Control Using Bearing Pressure Signal Definitions: Bright Blue - Mill Feed Olive - Mill RPM Pink - Mill Pressure Green - Inlet Sensor Blue - Outlet Sensor Yellow - Shell Sensor - Shell signal is at least 5-6 min. in advance of bearing pressure.
The model output variables are: power-draw, load level, ball load, mineral discharge rate and size distribution, water discharge rate, ball throughput, bearing pressure, pebble throughput, and toe and shoulder angles of the internal load. 2.1. SAG mill model
At the Lihir Gold Mine, the plant was utilizing mill's bearing pressure to calculate load measurement for the SAG mill in HGO1. The use of SAG mill weight for process control is additionally complicated at Lihir by compromised and suddenly drifting load cell and bearing pressure measurements on two of the process plant's three SAG mills.
sag mill bearing pressure . lift pumps in sag and ball mill lubri ion systems. Ball Mill Trunnion Bearing Lube System 911 The ball mill's low pressure oil system pumps oil from the SAG Mill ...
is the SAG Mill 1 Bearing pressure (described later in Figure 3). These fuzzy belief values are used as inputs to 80 rules, which describe the knowledge of the mill's control strategy. In addition to the attributes used by the expert system, the neural network also uses real …
BrainWave Control solutions for SAG mills. 02 The solution: Measure. Control. And profit. BrainWave SAG mill is a unique control package using patented model-based predictive adaptive control technology. It is well known within the mining industry ... ing feed rate to keep bearing pressure at set point. Testing and analysis by plant staff
Ball Mill Trunnion Bearing Lube System View Larger Image On a 11'-6" x 22'-0" Ball Mill, the trunnion bearing lubrication system provides continuous low pressure flood oil for cooling and lubrication of the bearings, and high pressure oil for hydrostatic lift of the feed and discharge trunnions during start-up of the mill.
Outotec Grinding technologies 005 Robust design Outotec mills are designed to produce optimal results, even in harsh environments. Outotec offers both trunnion and shell supported mill design, complemented by a drive solution tailored for optimum performance in any environment. Mill bearings The type of support bearing is selected on the basis of
adjust mill speed. • New rules for the expert system speed control: High LDL signal and low bearing pressure, reduce speed and prevent "metal on metal" operation. • Two vibration systems installed and in operation at Gold Corp Peñasquito on their two 2265 TPH SAG mils.
But the FL SAGwise™ system takes this digital audio data and uses techniques such as model predictive control and fuzzy logic rules to assess the mill process parameters." "Within seconds it has analysed the audio frequencies as well as taking on board power usage, mill weight and bearing pressure.
SAG Mill process control classically maintains the SAG mill volumetric filling within a set operating range. Typically a SAG mill weight measurement, by either bearing pressure transducers or load cells, is used as an inferred measurement of volumetric filling. To maintain volumetric filling within a set operating range the SAG weight setpoint ...
Typically, SAG mill control is performed with respect to bearing pressure and other process variables which are used to estimate volumetric loading in order to optimize the mill throughput. While these methods are typically effective, they can also have several shortcomings when changes in mill liners, lifter profiles (wear), ore density ...
Jan 13, 2014· Parts of SAG Mill to be lubricated: Trunion Bearing (feed end) Motor Bearings Gearbox Pinion Bearings Fig.1 : SAG mill Diagram Trunion Bearing (dis. end) 7. Lubricant Data: Masbate Gold Project's SAG mill uses Compounded Gear Oil as their main lubricant. But a different class of Gear oil is use in every operating system of the SAG mill.
©Copyright © 2019.Company HOR All rights reserved.sitemap