sag mills weight

SAG mills of comparable size but containing say 10% ball charge (in addition to the rocks), normally, operate between 70 and 75% of the critical speed. ... the tumbler test is recommended. The drop weight test has been described in Chapter 3. The tumbling test is as follows. Test conditions: 1. mill size: 305 × 305 mm with four lifter bars 6. ...

AG mills (or SAG mills with low ball charges) are often used in single-stage grinding applications. Based on their higher throughput and coarser grind relative to AG …

24 x 8 Boliden Allis (Allis Chalmers) Sag Mill for Sale Boliden Allis (Allis Chalmers) SAG semi-autogenous grinding mill. Size: 24 ft. dia. x 8 ft. long (7.3m x 2.74m). Steel liners 3000 hp s ID: 50186 Quote + 17 Foot dia. X …

SAG Mill Comminution (SMC) Test®. The SMC Test® is conducted on a single size range which is typically -31.5 mm +26.5 mm, hence the sample requirements are less than drop weight test. The test generates the Drop Weight Index (DWI) which is expressed in KWh/m 3, which strongly correlates to values generated from a Drop Weight Test.

At this stage the weight and volume of the liner could be easily determined. The complete mill model which is consisted of 120 liners placed in their proper positions is shown in Fig. 3. Download : Download full-size image; …

Semi-autogenous grinding mills (SAG mills) are tumbling mills that most commonly have a shell diameter-to-length ratio of around two. With this high aspect ratio, SAG mills generate both thrown and cascading ball-milling actions with shell linings shaped to lift and to throw alloy steel grinding balls of up to 150 mm (6 in.) in diameter. These

control the weight in the SAG mill to promote optimum grinding. This strategy has been demonstrated to improve mill throughput by as much as 3%. When copper prices are …

Unlike traditional mills that rely on steel balls or other media to break down materials, SAG mills use their own weight and the force of material being fed into them to grind ores. This makes them more energy-efficient than other types of machines. SAG mills are typically large cylinders made from steel with a rotating drum inside.

Control of Semi-Autogenous Grinding (SAG) mill weight is an example of an important process that exhibits many of these aspects. Maintaining the SAG mill weight at the …

The instrumentation installed on a SAG mill is integral to control. For example, the mill load and noise sensors are instruments that provide essential information for an optimized SAG mill operation. Insufficient understanding of the ore characteristics and feed composition can result in an ineffective SAG mill operation.

Based on experience, mill-liner designs have moved toward more open-shell lifter spacing, increased pulp lifter volumetric capacity, and a grate design to facilitate maximizing both pebble-crushing circuit utilization and SAG mill capacity. As a guideline, mill throughput is maximized with shell lifters between ratios of 2.5:1 and 5.0:1.

The load is measured by using load cells, which 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. In many SAG mills, oil pressure is also used to provide an indirect measurement of the mill load.

The process variables that are linked to the SAG mill are used in clustering, such as weight or bearing pressure, power draw, feed size, feed rate, percent solids, acoustic noise, and water addition.

SAG mills are the main workhorses in the majority of comminution circuits globally. They need to be fed and kept working round the clock. ... 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 slurry density. Where an operator might ...

The process variables that are linked to the SAG mill are used in clustering, such as weight or bearing pressure, power draw, feed size, feed rate, percent solids, acoustic noise, and water addition.

purposes, SAG mills utilise a combination of steel balls and coarse ore to achieve the desired discharge particle size [2]. An essential performance metric for a SAG mill is its throughput, which measures the volume of processed ore ... including mill weight, power draw, turning speed, inlet water, feeder ratios, pebble crusher working status ...

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 use for …

was surprising that the Bond Rod Mill Wi average was 11.3 kWh/t. Since the ore is unusually soft, the Rod Mill Wi is probably irrelevant in determining required power for the SAG mill. Drop Weight Tests Drop Weight tests were done at Hazen and analyzed by Contract Support Services, Inc. Table 4: Summary of 6 JKTech Drop Weight Tests

Choosing a SAG Mill To Achieve Design Performance. John Starkey1, Principal Consulting Engineer Sami Hindstrom2, Manager, Grinding Travis Orser2, …

Power Index (SPI®), Bond ball mill grindability and JK drop weight tests are used to characterize ore samples. For subsequent design simulations, SGS' IGS and JKSimMet are used. For ... to the 6'x2' SAG mill, in order to lower aspect ratio mills of 6'x3' or 6'x5'. A typical test program involves

(EGL) SAG mill driven by a 24,000 kW gearless drive. The SAG mill feeds two FL ball mills each 26 ft. in diameter × 40 ft. long (EGL), each driven by a 16,400 kW drive. ... SAG mill weight stability and preventing of over filling of the mill Reduction of undesirable critical impacts, trough the integration with the impactmeter ...

1Weight requested for the test, for typical ores (S.G. = 2.8g/cm3). Denser samples require more weight, proportional to the S.G. 2Approximate weight consumed in the test for …

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. ... but not the weight of the mill itself. While many mills today are mounted on load cells, others employ bearing ...

However, when combined with an accurate SAG mill power-draw model, total charge volume and ball load can be estimated with reasonable accuracy. ... Mill Weight (t) Mill Power (kW / 10) Mill Speed ...

Treatment capacity is the result of operating mill in a healthy weight range that will ensure the optimum total level filling and utilization of full power which is the energy that is …

SAG mill fractional total filling (J t) and ball filling (J b) are determined by solving the powerdraw or mill weight equations given mill power draw or weight process measurements as inputs. 4. SAG mill total feed (SMTF) is then calculated by mill model inversion after making assumptions about the ball charge size distribution. 5.

MPC was used to stabilize the weight or bearing pressure for SAG mills leading to demonstrated throughput increases greater than 1.5% at three separate mine sites. These performance improvements are relative to the expert systems already in use at these sites. One mine site reported secondary benefits of over 50% variability reductions in mill ...

Autogenous grinding is favored when the ore is quite competent and a fine grind is required. Semi-autogenous grinding is applied when fine crushing could cause severe problems or when ore is …

For example for SAG mill you can use SMC,SAG mill test, JK Drop weight test or SAG power index. U. Unterstarm. 8 years ago. Unterstarm 8 years ago. Like. It depends on a number of factors but the old 10-12% rule not the optimum in many cases. With less competent ores and fine feed Freeport uses up to 21% balls. Cadia around 16% for more ...

parameters from the drop weight test indicate that the UG2 platinum ore is softer than the other two ore types. ... SAG mills SAG mills are normally operated with ball loads ranges from 5 – 18 % ...

Bond Rod Mill 0.305 12.7 Any 1.18 15 10 Locked-cycle Y Y Bond Ball Mill 0.305 3.35 Any 0.149 10 5 Locked-cycle Y Y Mod Bond 0.305 3.35 Any N/A 2 1.2 Batch N Y Table 1 – Summary of Grindability Test Procedures 1Weight requested for the test, for typical ores (S.G. = 2.8g/cm3). Denser samples require more weight, proportional to the S.G.

Fuller-Traylor SAG/AG Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW. Our team of product engineers continually improves SAG/AG Mill designs in order to provide the most robust, safe, and efficient grinding mills …

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, …

SAG mills are typically operated at a constant speed, with the feed rate controlled by the mill weight. The mill weight is measured by load cells or a strain gauge, and the controller adjusts the feed rate accordingly. SAG mills can be operated in open or closed circuit, depending on the downstream process requirements. Maintenance of a SAG Mill

Ball mill： Ball mills are the most widely used one. Rod mill： The rod mill has the highest efficiency when the feed size is <30mm and the discharge size is about 3mm with uniform particle size and light overcrushing phenomenon. SAG mill: When the weight of the SAG mill is more than 75%, the output is high and the energy …

SAG mills, the mill weight is tightly controlled around the required set . Page 15 . point. Again the control system works the mill harder by operating at a . higher speed range.

chrome–molybdenum steel with a Brinnell hardness S. Banisi, M. Hadizadeh / Minerals Engineering 20 (2007) 132–139 135 Table 1 Some characteristics of the Sarcheshmeh SAG mill liners Volume Weight Length Cross No. of lifters No. of lifters (m3) (kg) (mm) section in each series along mill (cm2) length 0.1407 1130 2084 672 60 2 between 325 and ...

SAG mills contain balls of up to 150mm in diameter that occupy 5%-18% of mill chamber volume. Ball mills, conversely, contain grinding media up to 50mm in diameter, occupying between 25% - 40% of mill chamber volume. To effectively reduce material size, each type of mill needs to generate different charge load actions, or the type of motion ...

SAG mills use a combination of steel balls and rock particles as grinding media, while AG mills use only the ore itself. Both types of mills are used for grinding ore in mineral processing operations, but SAG mills are larger in size and can grind larger quantities of ore. AG mills, on the other hand, are smaller and are typically used for ...

weight, method of installation, and user preferences. SAG mill A SAG mill is almost always a high-impact application. Hence, it is wise to use tough, impact-resistant materials that are somewhat softer but less brittle to avoid cracking, chipping, or breaking. Rubber/steel composite liners are often a good choice as is the range of