The results showed that the HPGR-ball mill circuit achieved a 21% reduction in energy consumption over the existing SAG-ball mill circuit at the same P80 grind size of 160 mircons (μm). At a grind of 80% passing 75 μm, the HPGR-stirred mill circuit showed a 34% reduction in energy compared to the base case.
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AG/SAG SE values to enable the additional power required for AG/SAG milling to be determined. AG/SAG inef ciency varies according to the transfer size fi (T80), whereby the ner sizes have less ineffi ciency than the fi coarser sizes. This means a closed circuit single stage AG/ SAG mill can operate at a reasonable ef ciency if the fi nal fi
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plots taken from a copper mine SAG mill. In the plot, the mill is shown to be rotating in a clock-wise direction with energy plotted increasing towards the center of the plot. The top of the mill/plot corresponds to 0 degrees and the bottom of the plot corresponds to 180 degrees.
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circuit or the overall performance of an autogenous-semiautogenous (AG-SAG)/ball mill circuit, but they are of limited value in evaluating AG-SAG and ball mill sections separately. This problem arises due to the difficulty of describing particle size distributions with different shapes by one number, the eighty percent passing size. This
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This flowsheet is typical of many mills that have been built throughout the world. Figure 3 shows a typical semi-autogenous (SAG) circuit with feed coming directly from a primary crusher, and the semi-autogenous mill product going to the separation process.
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in a SAG and Ball mill circuit where there is no scope for storage capacity between milling stages and throughput is normally limited by a bottleneck at one stage or the other. In this case any ore with a high BWi value will have reduced . throughput due to the ball mill despite the capability of the SAG mill to handle
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It includes single stage jaw crushing with reclaim from a live stockpile and open circuit SAG mill, feeding cyclones that in turn operate in a closed circuit with a ball mill.. A pebble crusher will receive scats from the SAG mill, crush them and return them to the SAG for further grinding.. The process will include a conventional single-line SAG mill circuit (Semi-Autogenous Ball Mill ...
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in the SAG mill extremely hard in the ball mill. The but significance of this waste sample in determining SAG throughput is that the waste will not impede SAG throughput but will cause a larger circulating load and a slightly coarser final cyclone product in the ball mill circuit.
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SAG mills are also an optimum solution for wet grinding since crushing and screening in these cases can be difficult, if not impossible. Efficiency through automatic operation Metso Outotec's process engineers will assist you in creating an efficient software-driven process, from circuit design to start-up and optimization, to ensure you get ...
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It is commonly referred to as a SABC circuit, for Semi-Autogenous Ball mill Crusher (SABC). This circuit shows a semi-autogenous grinding (SAG)/ball mill circuit where both grinding mills are in closed circuit, with the SAG mill closed with a crusher to control the amount of 'critical size' material in the circuit.
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AG/SAG mills as a primary grinding stage in a circuit with or without additional stages of comminution Inclusion of pebble-crushing circuits in the AG/SAG circuit Circuits above, but with feed preparation including two stages of …
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considered, such as a primary SAG and secondary ball mill circuit where the individual stages would be ESAG and Eball, and the combined total circuit CEE would be Etotal. In all cases, the specific energy consumption is defined as the motor power consumed relative to …
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and Graham Bonn, Dynamic modelling of a SAG mill – pebble crusher circuit by data-driven methods, presented in proceedings of SAG conference 2019, Vancouver, September 2019. Paper D. Li, Haijie, Magnus Evertsson, Mats Lindqvist and Gauti Asbjörnsson, A data-driven method to isolate the effect of pebble recycling on AG/SAG mill circuit. To
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circuit is shown in Figure1. It is commonly referred to as a SABC circuit, for Semi-Autogenous Ball mill Crusher (SABC). This circuit shows a semi-autogenous grinding (SAG)/ball mill circuit where both grinding mills are in closed circuit, with the SAG mill closed with a crusher to control the amount of 'critical size' material in the circuit.
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The mills can be operated in open circuit, feeding downstream secondary grinding, or operated in closed circuit as single stage mills generating a finer product size. 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 ...
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The mills can be operated in open circuit, feeding downstream secondary grinding, or operated in closed circuit as single stage mills generating a finer product size. Single stage SAG Mills are very beneficial in reducing CAPEX for …
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AG/SAG and ball mill circuit data is also very poor. Use of equation 2 shows a very different picture, the results being illustrated in Figure 7. This shows that on average the "M" operating work indices of AG/SAG and ball mill circuits are very similar and hence energy utilisation efficiencies are similar. Also the AG/SAG and ball mill ...
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SAG mill. SAG is an acronym for semi-autogenous 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.
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The behavior of the SAG mill circuit is multivariable i.e. exhibit complex interactions and nonlinear behavior between the process variables. It is also dynamic i.e. delay times between variables within the process need to be considered before control actions are executed. Given these challenges, the objectives for acceptable SAG mill operation ...
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In multi-stage ABC/SABC circuits, the AG or SAG mills are in closed circuit with screens and pebble crushers. The mill discharge from these mills consists of slurry, which goes to the ball mills for further grinding, and coarse pebbles/rocks, which …
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Simulation models were developed at the Julius kruttschnitt Mineral Research Centre to provide accurate estimates of power consumption for a wide range of equipment. With the models, a range of circuits and operating conditions can be compared by simulation for a particular ore type. Accurate models of classification allow for the interaction between classifier …
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SAG mill in closed circuit with hydro cyclones at Freda Rebecca Gold Mine would affect through put and specific energy consumption using an Excel based milling process simulator developed by Hinde, a comminution specialist who has worked for Mintek for …
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single SAG mill, a two stage grinding circuit is recommended. 4 SELECTION OF AN APPROPRIATE SINGLE STAGE CONFIGURATION The first step in designing a single stage circuit is the selection of the optimum circuit configuration. Single Stage AG and SAG circuits can be sub-divided into a number of
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John Starkey, P. Eng. has worked in SAG mill hardness testing since 1964 where he worked as pilot plant engineer for A. MacPherson's projects. He invented the SPI and SAGDesign tests. The latter is now acknowledged by our clients to be a world-class method for grinding circuit design, and is accepted by our peers as a standard for ore ...
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order to test the developed method, the SAG mill circuit dynamic model has to be able to handle changes in the feed ore characteristics. The SAG circuit consists of a SAG mill and a screen as shown in the schematic diagram of Fig. 1. The dynamic model for the SAG mill is based on the constant ore model given in Amestica et al. (1993) and
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The results of these studies showed that a single line 40 ft SAG mill circuit gave the best project economics. Further work was followed up to optimize the 40 ft SAG mill size with the results showing that a slightly more expensive 42 ft SAG mill …
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Circuit surveys reported a SAG specific energy of 8.6 kWh/t and ball mill specific energy at 8.0 kWh/t (Dunne et al, 1999 Hart et al, 2001). The T 80 was not given so …
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(MPC) is described for a SAG mill circuit in a bauxite processing refinery at Wagerup, Australia (Refs: Gopinath, Mathur et al, 1995 and Le Page, Freeman et al 1996, Luse, Mathur et al 1997). The MPC controller presented in this paper is perhaps the first successful implementation of MPC for ball mills described in the literature.
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Based on experience, mill liner designs have moved toward more open shell lifter volumetric capacity and a grate design to facilitate maximizing both pebble-crushing circuit utilization and SAG mill capacity. Mill throughput is maximized with shell lifters between ratios of …
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considered, such as a primary SAG and secondary ball mill circuit where the individual stages would be ESAG and Eball, and the combined total circuit CEE would be Etotal. In all cases, the specific energy consumption is defined as the motor power consumed relative to …
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The circuit consists of a 34' x 20' EGL SAG mill, a Raptor 900 pebble crusher and two 24' x 39'6" ball mills. Each mill is equipped with a 2 x 8500HP dual pinion drive system. The plant was designed to process 1585 h mtpof SAG feed. From startup, the mill struggled to meet the required production rates.
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approach the total specific energy of the entire AG/SAG circuit is firstly predicted using the SAG mill feed F80 and the ball mill cyclone overflow P80. Morrell's model (Morrell, 2011) relates the feed, mill geometry and operating conditions to the specific energy of the circuit. However, the F80 is not enough to represent properly
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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 contain several papers on metallurgical topics including comminution modelling, mass balance calculations and laboratory comminution testwork program information.
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Each milling circuit is unique, and as such the goals and most optimal control strategy might differ for individual cases. Process IQ is an expert in implementing control systems for SAG and Ball milling circuits, making use of advanced stabilisation …
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The biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mill's ...
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AG & SAG Mill Grinding Circuit Automatic Control. It is obviously well understood that autogenous AG and semi-autogenous SAG mills operate quite differently from conventional rod mill or ball mills. Since these mills are of a grate discharge type, they operate with varying loads, with the power drawn by the mill being dependent upon the ...
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