Optimization of the Design of SAG Mill Internals Using,
of SAG mill performance through 1. Changes in liner/lifter design to maximize throughput while maintaining acceptable wear levels. 2. Changes in ball size to maximize particle breakage without producing exceptionally high impact forces. 3. Changes in grate and pan lifter designs to decrease internal mill recycle and increase throughput.Steady-state and dynamic simulation of a grinding mill,,Jun 15, 2020· Grind curves assist in finding the set points of the economic controlled variables that optimize the economic performance of the mill (Le Roux and Craig, 2019). By way of example, Craig et al. (1992) developed a throughput-optimizer based on the grind curves of an industrial single-stage closed semi-autogenous grinding (SAG) mill circuit.Optimizing your SAG mill operation - International Mining,Mar 21, 2007· The optimal performance of AG/SAG mills is the key to successful plant operation. All AG/SAG mills using radial or curved pulp lifters suffer from inherent material transport problems such as slurry and pebble pooling, which decrease throughput and increase energy consumption.IMPROVING ENERGY EFFICIENCY IN BARRICK GRINDING,Figure 3 - Cone crusher performance curves . Following the upgrades in the SAG mill circuit, sampling and modeling of the ball mill circuit, The SAG mill and ball mill original design was reviewed and a change resulted in the application of a gearless drive wrap-around motors on both machines. This immediately delivered energy savings asCrushing SAG Mill Critical Size Material - 911 Metallurgist,Apr 18, 2018· This method has proven to accurately predict the performance of the secondary ball mill circuit at the plant, under normal operating conditions (Figure 1)., in which the shape of the feed and products size distribution curves are similar. Ultrafines Production and Size Reduction Mechanisms in Autogenous Grinding, which relates the SAG,(PDF) Maximising SAG mill throughput at Porgera gold mine,,Summary of Mill Survey Results 80 survey 1, SAG 2 70 Survey 1 2 2 3 60 Blast # 340-319 320-314 320-314 310-316 SAG 1 Muck Load, vol % 26.3 22.8 - 26.9 50 Ball Load, vol % 11.0 13.8 13.8 13.2 40 Ball Size, mm 150 125 125 125 30 Power, KW 4550 4650 3970 4310 20 Bearing Pressure, 3900 3740 3720 3927 10 kpa 0 Mill Speed, rpm 11.42 11.42 10.79 11.50,
SAG Mill Control: It Shouldn’t be that Hard | E & MJ
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.Autogenous and Semi-Autogenous Mills | FLSmidth,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.Performance enhancement tools for grinding mills,the mill load, audible as a continuous stochastic noise. An example of the waveform of this noise may be found in Figure 6, obtained on a 36’ diameter mill running at 8 rpm and well filled with mineral. When the minerals hold-up in the mill decreases, the mill noise intensity grows inversely, as shown in Figure 7.BHP Billiton Copper,Dec 01, 2015· performance during a period of significant project activity December 2015 BHP Billiton Investor Briefing, Copper Overview 7 1. Total Recordable Injury Frequency (TRIF) for Escondida, Pampa Norte and Olympic Dam. 2. Incidents with uncontrolled release of energy for Escondida, Pampa Norte and Olympic Dam. BHP Billiton Copper safety performancePerformance characterisation of AG/SAG mill pulp lifters,,The pulp lifter is an integral component of autogenous (AG) and semi-autogenous (SAG) grinding mills as it controls the throughput, performance and efficiency of mills. The slurry transport from the AG/SAG mill through grate holes into the discharge trunnion is the main function of the pulp lifter.Optimization of the Design of SAG Mill Internals Using,,of SAG mill performance through 1. Changes in liner/lifter design to maximize throughput while maintaining acceptable wear levels. 2. Changes in ball size to maximize particle breakage without producing exceptionally high impact forces. 3. Changes in grate and pan lifter designs to decrease internal mill recycle and increase throughput.
FREDA REBECCA SAGMILLING CIRCUIT OPTIMIZATION
The qualitative effect of changes in particle size distributions (PSD) on the SAG mill performance can be addressed by using the grind curves. The operation of SAG mills is extremely sensitive to mill filling; from a qualitative point of view, for a given fill level and constant feed rate and speed, if the PSD becomes slightly coarser, then,Optimizing your SAG mill operation - International Mining,Mar 21, 2007· The optimal performance of AG/SAG mills is the key to successful plant operation. All AG/SAG mills using radial or curved pulp lifters suffer from inherent material transport problems such as slurry and pebble pooling, which decrease throughput and increase energy consumption.BENCHMARKING COMMINUTION CIRCUIT PERFORMANCE,However, the SAG mill specific energy is calculated using proprietary models and the specific ball milling specific energy is the differential between the SAG mill and total specific energy requirements. This method acknowledges the limitations of using the P 80 of the transfer size between the SAG mill and the ball mill.AG - Autogenous & SAG Semi-Autogenous Mill Design Calculations,Apr 17, 2018· Obviously, the SAG mill is consuming more and the ball mill less power than was predicted by the empirical method, but the overall total is 99.5% of the predicted total. Examples The Hemlo gold project of Teck-Corona (1000 mtpd) provides an example of mill sizing using the empirical calculation method alone.(PDF) Exploring the effect of blast design on SAG mill,,100 80 % passing 60 Design1 40 Design2 20 Design3 0 0.001 0.01 0.1 1 Size m Figure 8 – Predicted Crusher Product Size Distributions Having simulated the gyratory crusher the product was then simulated through the sag mill. Mill performance is usually evaluated in terms of throughput, specific energy (kWh/t) and final grind size.SAG Mill Control: It Shouldn’t be that Hard | E & MJ,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.
Downstream Effects Of Cave Fragmentation - Cave Mining Forum
To simulate the effect on SAG mill performance, these fragmentation curves were passed through a primary crusher model. As shown in the figure, the variation in mill feed (80% passing size, in mm) is evident as the cave propagates upward and the secondary fragmentation generates more fines and aPerformance enhancement tools for grinding mills,the mill load, audible as a continuous stochastic noise. An example of the waveform of this noise may be found in Figure 6, obtained on a 36’ diameter mill running at 8 rpm and well filled with mineral. When the minerals hold-up in the mill decreases, the mill noise intensity grows inversely, as shown in Figure 7.Application of Operating Work Indices in Autogenous,,circuit or the overall performance of an autogenous-semiautogenous (AG-SAG)/ball mill circuit, but they are of, curve with the same T 80 that is parallel to the product size distribution). In, work indices for the AG/SAG mill and ball mill can be re-organised as [7] and [8], where B’Wio and A’Wio are the,Development of an Innovative Copper Flowsheet at Phu Kham,CRUSHER SAG MILL No.1 BALL MILL TAILINGS DAM CONCENTRATE THICKENER CONCENTRATE TANK CONCENTRATE FILTER CONCENTRATE STOCKPILE MILL CYCLONES ROUGHER CONCENTRATE CYCLONES. Layout of IsaMill and Jameson Cell., Grade-Recovery Curve Performance 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 28.00Methods to Estimate AG/SAG Mill Power Requirements,Oct 20, 2015· By repeating tests at different volumetric ball loads but the same initial total charge load one could develop a comprehensive SAG model.The big challenge is to reconcile Malcolm Powell’s Grind Curves for a continuously fed mill controlled to maintain a constant total load volume at values above those giving the maximum throughput or power,Understanding the Effects of Liner Wear on Semi-autogenous,,It is commonly observed that the three key performance criteria of SAG milling; throughput, power and product size all improve as the liner wears. The increase in throughput is generally ascribed to the increase in the grate apertures and the increase in mill volume due to the wear of these components.
Performance Characteristics and Optimisation of the,
by the installation of a 12MW SAG mill with a diameter of 10.97m (36ft). The mill, when built, was the largest SAG mill operating at any existing Australian mine. To aid in commissioning and optimising the mill, the Julius Krutt- schnitt Mineral Research Centre (JKMRC) and plant staff con- ducted extensive surveys of the grinding circuit.Steady-state and dynamic simulation of a grinding mill,,(SAG) mill by means of a step-wise procedure. Grind curves give the steady-state values of the performance variables throughput, power draw, and grind in terms of the mill lling and critical mill speed. The grind curves indicate the operable region of the grinding mill. An analysis and dynamic simulation of the modelØ Effect of SAG Mill Feed Size Distribution and Ore,,The relationship demonstrated improved mill performance as the SAG mill shell liners wore (the SAG mill load dropped), as well as an overall improvement in operating performance at the lower filling level. From the start of the first cycle (right hand side of the curve) mill throughput gradually increased to a maximum, at around 900 tonnes.Application of Operating Work Indices in Autogenous,,circuit or the overall performance of an autogenous-semiautogenous (AG-SAG)/ball mill circuit, but they are of, curve with the same T 80 that is parallel to the product size distribution). In, work indices for the AG/SAG mill and ball mill can be re-organised as [7] and [8], where B’Wio and A’Wio are the,BENCHMARKING COMMINUTION CIRCUIT PERFORMANCE,However, the SAG mill specific energy is calculated using proprietary models and the specific ball milling specific energy is the differential between the SAG mill and total specific energy requirements. This method acknowledges the limitations of using the P 80 of the transfer size between the SAG mill and the ball mill.Downstream Effects Of Cave Fragmentation - Cave Mining Forum,To simulate the effect on SAG mill performance, these fragmentation curves were passed through a primary crusher model. As shown in the figure, the variation in mill feed (80% passing size, in mm) is evident as the cave propagates upward and the secondary fragmentation generates more fines and a
MILLING CONTROL & OPTIMISATION - MINTEK
These dynamics degrade the performance of PID controllers, making feed optimisation more challenging., • Estimates the power load curve and optimum load., Figures 8 and 9 on the right show results from a gold plant’s SAG mill achieved with MillStar’s Segregated Ore Feed ControllerSAG Mill Control: It Shouldn’t be that Hard | E & MJ,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.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. But challenges can arise when capacity is not optimised causing unnecessary downtime and liner wear leading to the one sound operators do not want to hear - the sound of the mills standing still.Simulation of Material Transport in a SAG Mill with,,Sep 20, 2018· 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 purpose is to determine how the geometry of the lifters affects the kinetics of the load inside the mill. Specifically, the changes produced by the incorporation of inclined lifters and spiral or helicoidal pulp lifters to the kinetics are,Characterization and Modeling of Semi-Autogenous Mill,,MODELING OF SAG PERFORMANCE UNDER OSD DISTURBANCES 4.1 Qualitative analysis The qualitative e ect of changes in ore size distribution (OSD) on the performance of the mill can be addressed using the grindcurves (Powell and Mainza, 2006) of the SAG mill under analysis. The operation of SAG mills is extremely sensitive to mill lling; from a,Overflow Versus Grate Discharge Ball Mills: An,,Hence there is a possibility for much quicker transport of material through the mill, which is being accomplished in overflow mills by higher circulating load. Recent developments in understanding the importance of material transport in performance improvement of AG/SAG mills and the limited research work on comparing discharge mechanisms in,
Optimization of mill performance by using
Optimization of mill performance by using online ball and pulp measurements Soon after a stop, a mill is a dangerous place to enter for the personnel tasked with taking measurements or samples. Crash stops are difficult to handle. The mill and all feed streams should be stopped simultaneously but, often, they are stopped around about the same time.Development of an Innovative Copper Flowsheet at Phu Kham,CRUSHER SAG MILL No.1 BALL MILL TAILINGS DAM CONCENTRATE THICKENER CONCENTRATE TANK CONCENTRATE FILTER CONCENTRATE STOCKPILE MILL CYCLONES ROUGHER CONCENTRATE CYCLONES. Layout of IsaMill and Jameson Cell., Grade-Recovery Curve Performance 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 28.00,,,,
