sag mill power index

Methods to Estimate AG/SAG Mill Power Requirements

 · A linkedin group was recently discussing this by asking: I''ve tried to estimate AG/SAG Mill power requirements using several different methods: (1) Using the results of SMC data. (2) Using SAG Power Index (SPI) data. (3) Using the 1989 Barratt method updated on Alex Doll''s Web site (February 16, 2015)

SAG Power Index (SPI) Test | SGS Chile

Conducted in a bench-scale comminution mill, the SPI test measures the energy needed to perform a standard size reduction and is expressed as an index. It is a measure of the hardness of the ore from a SAG or AG milling perspective. The test is a batch test, run with 2 kg of ore in a standard 10 cm diameter by 30 cm long mill, and it measures ...

TECHNICAL NOTES 8 GRINDING R. P. King

mill is the energy consumption. The power supplied to 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 ...

Bond Work Index

Ball mill design requires a Bond work index, BWi, for ball mills at the correct passing size; SAG mill design requires an appropriate SAG test, for example, SPI (Chapter 5). Flotation design needs a valid measure of kinetics for each sample, including the maximum attainable recovery and rate constants for each mineral ( Chapter 12 ).

Power-based comminution calculations using Ausgrind

• The SAG Power Index (SPI) test was developed by Starkey and Dobby (Starkey and Dobby, 1996) as the AG/SAG equivalent to the work index test. A SAG mill is operated in closed circuit

Single Stage SAG AG Milling Design

If determined to be reasonably power-efficient, single stage SAG milling is likely to be a comparatively profitable grinding circuit design. xMedium Grind – 80% passing size between 106 and 75 µm. To mill in single stage SAG configuration, the feed must be consistent and the downstream process reasonably capable of handling some fluctuations ...

Optimizing Performance of SABC Comminution Circuit of the ...

 · operating at 90% of its maximum power. The combined power draw of the SAG mill and ball mill was 8658 kW, which caused partial over-grinding. From experience in processing plants outside of China, the power rating of the ball mill should be higher than that of the SAG mill [5]. The pebble crusher had an over-powered configuration.

SAG Mill

SAG-mill Power Index® (SPI) Test. The SPI® test is carried out in a standardised mill under set conditions, with the output being the time to reach a given size, which can be converted to a SAG mill specific energy input (in kWh/t). The SPI® index provides a profile of the hardness of the ore type and can be used for geometallurgical models.

Advances in Discrete Element Method Application to ...

power draft in a slice of the mill is computed and is then converted to power draft of the full mill length. The author has successfully computed SAG and ball mill power in hundreds of case studies besides verifying power prediction in laboratory size mills as shown in Figure 1 (Rajamani et al. 2000). The capability of 2D DEM for power ...

AMIT 135: Lesson 6 Grinding Circuit – Mining Mill Operator ...

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

SAGMILLING .:. Home

Sagmilling is home to a collection of both free and subscription-based calculation tools to aid metallurgical process engineers perform comminution calculations. Grinding circuit design tools, including for SAG mill-ball mill circuits, and geometallurgy energy models are available to subscribers. The online library of technical articles ...

Minerals | Free Full-Text | Optimizing Performance of SABC ...

The final plan was to increase the ball charge in the SAG and ball mill to 10% v / v and 27% v / v, respectively; set the upper limit of the operating power in the ball mill to 5800 kW; use a TRIO TC Series crusher (without a power-/feed rate–controlling device, but with a feed bin) to crush pebbles for recirculation back to the SAG mill feed ...

power ag sag mill iron ore

Power Ag Sag Mill Iron Ore. Difference between sag mill and ball mill - iron ore miningct 22, 2012 before the esperanza order, fls largest sag mill measured 38 and its ball mills, 26o the average person, the difference between a 38 and a 40 sag autogenous mills, semi-autogenous mills and ball mills for wet sag and ball mill for gold ore grinding.

Comminution testing

 · The Bond BMWI has no correlation with the throughput or power requirements of a SAG Mill. ... An improved method using less mass compared to the Bond Ball Mill Work Index test. The JK Bond Ball Mill (JKBBM) test, is a locked cycle grindability test conducted using a standard laboratory Bond Ball Mill with the same steel ball charge and material ...

power calculation formula of sag mill

A comparison of SAG mill power models - SAGMILLING . ... published his method of energy calculation with an index called Bond work index (Bond 1961). In ... SAG mills and AG mills, not to mention balls mill as well. ... ture was the advancement of Bond''s formula (Bond 1961) for mill power …

Energy Use of Fine Grinding in Mineral Processing

 · compared to the power used by a semi-autogenous mill and a ball mill in a primary grinding circuit; a ball mill can have an installed power of up to 15 MW, while installed power for a SAG mill can go up to 25 MW. However, the energy used for fine grinding is still significant. Moreover, as this paper seeks to demon-

Performance enhancement tools for grinding mills

consequence has been that as long as the mill is consuming the expected power, there is little concern about the class of bodies using the supplied energy1. Sensing load movement: the Impactmeter* (patent pending) In recognition of ore variability, many current SAG mills …

Taking Control of the Mill Feed R2

also reveals that the circuit is limited at the SAG mill, with spare power in the ball mill. Table 2: Power analysis of survey data Power Utilisation Units Survey 1 Survey 2 SAG Mill Specific Energy kWh/t 12.4 14.5 Ball Mill Specific Energy kWh/t 9.7 11.2 Operating Work Index …

Testwork: SAG grindability index

 · The main grinding circuit at Les Mines Selbaie consists of two mills, one SAG mill in closed circuit with an 8'' x 20'' vibrating screen with 700 micron deck, and one ball mill. The SAG mill is 8.23m (27'') diameter x 3.75m (12.3'') long. The Holt-McDermott grinding circuit uses a large primary SAG mill which is 5.03m (16.5'') diameter x

The SAG Power index also known as the Starkey SAG Test ...

The SAG Power index also known as the Starkey SAG Test, also known as the SAG Grindability Index Test Procemin 2013 In this paper, the authors undertake a critical review of the Starkey test and the publicly available infor- mation related to the test equipment, procedures, and scale-up methodology.

Mineral Processing

 · SAG mills are primarily used at gold, copper and platinum mines with applications also in the lead, zinc, silver, alumina and nickel industries. The largest SAG mill is 42'' in diameter, powered by a 28 MW (38,000 HP) motor AUTOGENOUS GRINDING MILL SAG . They are so-called due to the self-grinding of the ore.

PACIFIC BOOKER MINERALS INC

Index SPI (minutes) BWi (kWh/t) Samples Average 13.7 105.2 16.4 The results show the ore has an average a Crusher Index of 13.7, SAG Power Index (SPI) of 105 minutes and Ball Bond Work Index (BWi) of 16.4. Results from the testwork indicate that the material sample has a medium hardness from the perspective of semi-autogenous milling.

SAG MILLS CHOOSING METHODS. II. The working index of F ...

 · Wi – Bond''s working index; P_80 – the mill feed size, 80% passes the control sieve; F_80 – the product size at the output, 80% passes the control sieve. What does the term "F. Bond''s Working Index" mean? The "F. Bond''s Working Index" is a grinding parameter expressing the material resistance to crushing or grinding.

Optimization of a SAG Mill Energy System: Integrating Rock ...

 · 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 energy requirements are defined by the SAG ...

Autogenous and Semi-Autogenous Mills | FL

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.

Sag Mill Power Index

Power calculation formula of sag mill. The S Power Index SPI test Starkey Dobby, 1996 uses a benchscale S mill test to determine the specific energy of an industrial S mill. The test is operated in closed circuit and the time required to grind the material to a P 80 of mm is used to predict S Get Price.

SAG Power Index (SPI) Test | SGS Algeria

At least 2 kg of passing 3⁄4" ore for the SPI mill feed (with no more than 80% passing 1⁄2"). 10 kg is required for the Crusher Index (Ci) determination. * Dobby G, Kosick G, and Starkey J, "Application of the Minnovex SAG Power Index Test at Five Canadian SAG Plants", in International Autogenous and Semiautogenous Grinding ...

Mill (grinding)

SAG mills are autogenous mills that also 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. A SAG mill with a 44'' (13.4m) diameter and a power of 35 MW (47,000 HP) has been ...

Mill power draw models

Mill Power Draw Models. The mill power draw models are used to predict how much power will be consumed by a particular type of mill, mill geometry and set of mill operating conditions. This power is transferred to the ore and used to predict the throughput when combined with the specific energy consumption models.

Magnetic Separation Techniques to Improve Grinding …

However, the total mill power consumption dropped 8% from an average of 7600 kW to 7000 kW. The mill work index dropped 10 percent from an average of 5.5 kW-hr/T to 5.0 kW-hr/T. Conclusions This represents a current view of the effects of grinding ball fragments in the milling circuit and the impact on the crushing and grinding circuit.

Geometallurgy

Geometallurgy relates to the practice of combining geology or geostatistics with metallurgy, or, more specifically, extractive metallurgy, to create a spatially or geologically based predictive model for mineral processing plants. It is used in the hard rock mining industry for risk management and mitigation during mineral processing plant design. It is also used, to a lesser extent, for ...

(PDF) Power-based comminution calculations using Ausgrind

In contrast Ausgrind uses a Bond-style power model to estimate total specific energy and an empirical model to estimate the SAG mill Ecs as a function of DWI (or other comminution parameters), as ...

Throughput optimisation in milling circuits

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.

Boost the performance of your SAG Mill

Optimise your SAG Mill with SAGwise. There is no doubt that operating an SAG Mill is a costly exercise. Not only do they consume huge amounts of power, they require expensive mill liners that need to be replaced, potentially resulting in hundreds of thousands of dollars in downtime costs.

Operating work index is not the specific energy consumption

 · To calculate the operating work index of a circuit, you must measure four things: P: The power draw of the mill. This is usually calculated from the input leads to the motor, then multiplied by ...

SAG Calculator | Edmund Optics

Sag (mm): --. SAG= R−√R2 −(D 2)2 SAG = R − R 2 − ( D 2) 2. R. Radius of Curvature.