To maximize the capacity of these circuits, the general practice is to use grates with pebble ports (reaching 100 mm) instead of normal grate openings to increase the pebble removal. In addition, operating mills at relatively higher speeds has become an option to increase mill capacity.

SAG mill liners, which protect the equipment's shell, must be replaced when they wear out, impacting the operation's budget and unscheduled downtime. As a result, the industry is continually exploring new ways to produce more failure-resistant, longer-lasting liners.

SAG, AG, Mill, Vibration, Process, Control, Optimization INTRODUCTION The vibration sensor based signals are more responsive and have a greater dynamic range than traditional control signals such as electronic ears, bearing pressure and mill power. The increased response

the SAG mill critical speed; Pc = SAG mill power consumption (kW); % 600 +100 = % of the fresh feed in the size range 152 +25 mm. M. Silva, A. Casali/Minerals Engineering 70 (2015) 156–161 157 In fact the later can be modelled as a function of the others.

• Ball Mill Limited: the overall grinding circuit is constrained by the Ball Mill capacity and the SAG mill and Pebble Crusher circuits have spare capacity. This limitation is commonly experienced during the processing of the low grade ores (less than 0.4%Cu). This also confirms theBWi ore hardness – grade correlation.

@article{osti_895022, title = {ONLINE SAG MILL PULSE MEASUREMENT AND OPTIMIZATION}, author = {Rajamani, Raj and Delgadillo, Jose and Duriseti, Vishal}, abstractNote = {The grinding efficiency of semi autogenous milling or ball milling depends on the tumbling motion of the total charge within the mill. Utilization of this tumbling motion for efficient …

An optimization is carried out to minimize the yearly cost of energy for the operation of the SAG mill. This cost includes the energy consumption cost in $/kWh and the capital cost for the PV-BESS infrastructure, prorated over the life of the battery system, accounting for the discount rate through an annuity factor (Pamparana et al. 2019a, b).The …

Mill filling is an important operational parameter in a SAG mill circuit and by its control and optimisation it can produce significant improvements in production capacity and energy efficiency. However, it is industry practice to report mill load as the total output given by load cells, or kPa for systems based on lubrication bearing back pressure, rather than the actual percent total mill ...

the mill is used primarily to lift the load (medium and charge). Additional power is required to keep the mill rotating. 8.1.3 Power drawn by ball, semi-autogenous and autogenous mills A simplified picture of the mill load is shown in Figure 8.3 Ad this can be used to establish the essential features of a model for mill power.

How to improve sag mill tonnage grinding amp classification circuits metallurgist amp mineral processing engineer. to participate in the 911metallurgist forums, be sure to join amp login. use add new topic to ask a new questiondiscussion about grinding. or select a.

In a SAG mill the dimensions of the mill were 9.75. m × 3.5 m and the specific gravities of the mineral and that of the balls charged were 4.1 and 7.9 respectively.. The mill was rotated at 75% of its critical speed when 8 % of the mill volume was charged with grinding balls.Estimate:1. The mill power drawn, 2. The maximum mill filling possible.

ABSTRACT Mill filling is an important operational parameter in a SAG mill circuit and by its control and optimisation it can produce significant improvements in production capacity and energy efficiency However it is industry practice to report mill load as the total output given by load cells or kPa for systems based on ... an understanding of ...

Optimize underperforming assets and remove the need for capital expenditure: Optimal control of the SAG mill can be achieved by using existing DCS or PLC. It is commonly assumed SAG mill control can only be successfully implemented using "black-box" solutions; this is just not true.

However, open circuiting the SAG mill by feeding crushed pebbles directly to a ball-mill circuit is often considered as a technique to increase SAG throughput.

• Uses the changes in the mill load and power to automatically detect whether the mill is overloaded or underloaded. • Uses . safety controllers. to change the solids feed rate and feed water to prevent mill overloads. • Estimates the power load curve and optimum load. By optimising the mill power usage and preventing mill overloads,

2006). The laboratory bench-scale SAG mill reproduces operating conditions of a commercial SAG mill, in a closed circuit dry grinding environment. The ground product for the laboratory SAG mill is then submitted to the Bond ball mill work index test. The number of SAG mill revolutions required to grind the material to a P

SAG Mill Power. SAG milling can be optimised to achieve maximum breakage and throughput (or any other number of objectives). The relationships between the key variables are highly non-linear and shift as the ore hardness, steel load and liner conditions change. Traditional and basic control and modelling techniques are therefore not veryfective.

An increase in mill throughput of a nominal 5%. • A nominal 8% reduction in mill power consumption. • More efficient grinding resulting in a nominal 10% reduction in the mill work index. Magnetic separation has also been recently applied to the SAG mill discharge.

AG/SAG mill and crusher circuit simulations through the use of JKSimMet. Independent of this it can be used in power-based calculations, which in conjunction with the Bond ball work index test, enable the prediction of the specific energy of comminution circuits where such circuits include combinations of any of the following equipment:

The discovery of excess mill pooling in the SAG mill prompted a review of the "pumping" capacity of the SAG mill. The excess slurry pool inhibited grinding and caused unnecessary power draw on the mill with the internally recirculating slurry. Crash stop …

SAG Mill power draw models are used in mill design and grinding circuit modelling to predict how much power will be consumed by a particular mill geometry and operating configuration. This paper will compare SAG mill models by Morrell, Loveday (using "Power Numbers" published by Barratt) and Austin against several published mill surveys.

the primary crusher performance and proper control of the ratios for the SAG mill feeders drawing the ore from the stockpile. The ball mill grinding efficiency was poor and could be indicated by the fraction < 125 µm of only 5-9 % or x. P, 80: >400 µm in the mill discharge. This was deemed due

The Effect of the Mill Power on the Throughput 8200 8300 8400 8500 8600 8700 8800 Mill Power, kW The Effect of the Mill Power on the Throughput 19 1320 1340 1360 1380 1400 1420 1440 Throughput, mt/h Lifter Face Angle (°) Mill Power (kW) Throughput (mt/h) Throughput Difference (%) 30 8250 1340 0.00 25 8310 1349 0.67 15 8730 1418 5.82 10 8746 ...

SAG Mill Circuit Example — Gold Processing SAG mill circuit example for gold processing [image: (135-6-3)] AG/SAG Mill. AG/SAG mills are normally used to grind run-off-mine ore or primary crusher product. Wet grinding in an AG/SAG mill is accomplished in a slurry of 50 to 80 percent solids. 2D and 3D simulations of particles in a SAG Mill

precision for optimization of mine production schedules and utilization of mine equipment • Selection of a "design ratio" of primary mill power to secondary mill power that permits the range of vari- ability samples to be processed according to whether a "SAG Mill limiting" condition, i.e., harder ore, or a

Mill power Usually, plant operators use mill power readings as an indicator of ball filling degree and, often, try to keep it at the maximum level. It is well known that the mill absorbed power depends on operating parameters other than ball level, such as pulp density and liner configuration. Figure 2 shows that there is no linear relation between

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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.

The best use of that asset is to try to maximize the power draw. Try to hold the mill speed high and vary the feed rate to hold the weight (or bearing pressure), but watch out for "cycling" or "surging" that indicates instability in the charge. It is not easy, but is the best use of the capital cost of the mill. Victor Bergman 6 years ago Like

Studies Show Snags to Mill Optimization. More than 100 virtual operators have been deployed over the course of three years at Los Bronces mine. Above, the Los Bronces mine milling control room in Chile. (Photo: Anglo American) Two studies identify obstacles to SDGs, while a major miner announces the windfall from deploying automation.

Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of …

The milling circuit include two identical lines of single stage SAG milling. Each low aspect ratio (D/L) SAG mill has a diameter of 16 ft, length of 24 ft, installed power of 2 MW and operate in ...

Automated SAG Mill Speed Control Using ... Mill power transmission loss, estimated, [%] 5% Feed slurry percent solids, [%] 65% ... being to bring in some new information both for the expert system and operator to use to optimize the mill speed and further understand the real-time operating conditions inside the mill.