This is of particular relevance to RoM and other SAG/AG mills operating in closed circuit. Improvements in mill efficiency from the installation of the TCPL design is only likely to occur if a slurry pooling problem exists in the first instance. The presence of slurry pooling can be detected online in a couple of ways.
Slurry viscosity has been observed to range from 0.025 Pa s for primary ball mill discharge and SAG mills up to 0.1 Pa s for AG mills which have much higher concentrations of very fine (−37 μm) particles (Shi and Napier-Munn, 1996).In this work, we will therefore explore the effects of viscosity with in the range of 0.03–0.30. Pa s.. In …
Slurry viscosity has been observed to range from 0.025 Pa s for primary ball mill discharge and SAG mills up to 0.1 Pa s for AG mills which have much higher …
Sag Slurry Pooling - Free download as PDF File (.pdf), Text File (.txt) or view presentation slides online. This document discusses issues related to slurry pooling and transport in sag mills. It defines key terms like slurry pooling, crash stop, aspect ratio, discharge grate, and pulp lifter. Slurry pooling occurs when excess slurry accumulates in the mill, …
manuel villon. 2011, SAG 2001. Fluctuations in feed size distribution are second only to ore competence variation in their influence on autogenous and semi-autogenous mill performance. For some operations where feed size is not well controlled this creates significant problems with mill stability and is understandably seen as a major problem …
Alloys used for SAG mill liners should have impact and abrasion resistance [5,11,17]. Highcarbon Cr-Mo and low-carbon Cr-Mo steels are common alloys to produce SAG mill shell liners [17][18] [19]. ...
The coarse particulate flow in the 36′ SAG mill. Fig. 1 shows a snapshot of the steady state particle distribution of charge motion in the 10.86 m SAG mill as predicted by the DEM simulation. The particles are coloured by their speed. Balls and rocks near the liner are dragged clockwise around the mill from the toe to the shoulder position.
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This is particularly the case with so-called slurry pooling in AG/SAG mills which can result in significant lowering of power draw. From a predictive viewpoint there are currently no published models that explicitly describe the influence of slurry level on power draw and the relationship between slurry level, slurry flow and pulp lifter design.
The 36′ SAG mill considered is a geometrically scaled-up version of the 1.8 m Hardinge pilot scale mill but with a longer belly …
Improvements in mill efficiency from the installation of the TCPL design is only likely to occur if a slurry pooling problem exists in the first instance. The presence of slurry pooling can be detected online in a couple of ways. ... ss Fig. 10 Power increase arising from mi Id slurry pooling on Union SAG mill. Based on the sensitivity of the ...
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. The TPL completely eliminates slurry pooling and pebble pooling problems and ensures the best grinding conditions, thus allowing …
A SAG mill, or semi-autogenous grinding mill, operates on the principle of autogenous or self-grinding. It uses a combination of ore and grinding media to break down larger rocks into smaller pieces. Understanding the working principles of a SAG mill is crucial for anyone involved in the mining industry. In this section, we will delve deeper ...
All AG/SAG mills using radial or curved pulp lifters suffer from inherent material transport problems such as slurry and pebble pooling, which decrease …
I've got to explain this a little bit. This flowsheet is typical of lines 1 and 3. The SAG mill has a trommel on the discharge end of it. Oversize is returned to the mill by a bucket wheel and water jet. Trommel undersize was pumped to a vibrating screen where the screen oversize was sent back to the mill and the undersize was pumped to the ...
SAG mills are a key asset for mineral processing operations as one of the critical stages of extracting mineral out of ore, and their continued stable operation is central to productivity. ... "The operator can be alerted when undesirable conditions such as slurry pooling are imminent, reducing the risk of the mill being overloaded.
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. ... Powell, M.S., Valery, W., 2006. Slurry pooling and transport issues in SAG mills. In: International Autogenous and Semiautogenous Grinding Technology 2006, …
I-133 SLURRY POOLING AND TRANSPO RT ISSUES IN SAG MILLS Malcolm Powell1 and Walter Valery2 1Head Comminution Group, Mineral Processing Research Unit, University of Cape Town, Rondebosch, 7700 ...
Pulp lifters, also known as pan lifters, are an important component of grate discharge mills (GDM). The GDM include autogenous (ag), semiautogenous (sag) and grate discharge ball mills. The purpose of the pulp lifters is simply to transport the slurry passing through the grate holes into the discharge trunnion.
The slurry level in AG/SAG and ball mills has an influence on their power draw, which in some instances can be profound. This is particularly the case with so-called slurry pooling in AG/SAG mills ...
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 mills, it is more common for SAG mills to he used as the primary stage of grinding, followed by a second stage of milling. AG/SAG circuits producing a fine grind …
The findings from emptying out and sizing 62 tons of charge, from a 4.7 m by 3.5 m diameter South African style SAG mill, into four axial segments are presented.
SAG mill power consumption (Pc) in kW, in 4 grinding circuits (GC1 to GC4) at different % of the fresh feed in the size range −6″ +1″ ... Slurry pooling and transport issues in sag mills. SAG 2006, Vancouver, Canada (2006), pp. I133-I152. Google Scholar. Simkus and Dance, 1998.
SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to
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.
Slurry pooling, excessive accumulation of slurry in the mill, and the associated loss of throughput and grind, are well recognised on lowaspect, single-stage SAG mills. However, it is becoming apparent that a wide range of the high-aspect mills also suffer from pooling …
Batch experiments in a 0.6 m diameter mill have shown that improvements of about 13 per cent in the efficiency of energy utilisation can be realised in ball mills by replacing 25 per cent of the ...
are well recognised on low-. aspect which decrease throughput and increase …Slurry pooling the mill throughput has increased from 390 (with RPL) to 470 tph on average by ensuring the best grinding environment inside the mill without slurry pool.Citic SMCC has 9 SAG mill data sets from mills which were found to be operating with varying degrees of …
the SAG mill and the key testwork data is given in Table 1. The total weight of the emptied out charge was 62.2 tons making up a total mill (slurry) filling of 43 % and a ball load of …
Ausgrind program improvements include: Mill liner wear and life prediction for any liner/lifter design. SAG mill slurry pooling model to predict the onset and effect of slurry pooling for varying operating conditions. Grinding mill trajectory model to determine safe operating speed ranges based on liner/lifter design.
The pooling causes a dilution of the slurry leading to a lowered viscosity, and the well know associated drop in milling efficiency. Additionally, the …
This paper uses a 1-way coupled DEM–SPH method in three dimensions to analyse the full slurry flow for a 1.8 m diameter by 0.6 m long AG/SAG pilot mill. This provides detailed information on the internal flow of slurry within a SAG mill, including the prediction of dry regions and of slurry pooling.
Obviously this creates its own set of separate issues. S. Sturmbann. 8 years ago. Sturmbann 8 years ago. Like. ... Do not confuse with a AG/SAG mill where pooling can be detrimental. In ball mills all the media is balls with a high SG so the impact of pooling is not as large. Additionally, in ball mills grinding is primarily through cascading ...
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A simplified form of the model was used to predict the performance of an 8 m diameter SAG mill with LID = 0.5 grinding a copper ore, and predicted maximum capacity and minimum kWh/ton at about ...
the SAG mill and the key testwork data is given in Table 1. The total weight of the emptied out charge was 62.2 tons making up a total mill (slurry) filling of 43 % and a ball load of 22 %. The ...
Slurry pooling, excessive accumulation of slurry in the mill, and the associated loss of throughput and grind, are well recognised on low-aspect, single-stage SAG mills. …
UNIVERSITY OF BRITISH COLUMBIA Vancouver, B. C., Canada SLURRY POOLING AND TRANSPORT ISSUES IN SAG MILLS Malcolm Powell1 and Walter Valery2 Slurry pooling The development of a pool along the length of a mill, arising from slurry in excess of what can be held within the grinding charge.
View of the inside of a SAG mill with a slurry pool problem. Download : Download high-res image (139KB) Download : Download full-size image; Fig. 9. Measured vs predicted power draws of mills SAG mills with slurry pools – assumption in model (Eq. (1)) is that there is no slurry pooling and θ tp = θ tm. Download : Download high-res …
