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Pebble removal decreases the abrasive overgrinding as reflected in the mill discharge size distributions (Table 4). Total grinding power consumption decreases and SAG mill capacity increases significantly. Later tests, with other types of ore, have shown lesser differences between those size distributions.
grinding, to single stage crushing and semiautogenous grinding (SAG) and ball mill (SAB) circuits. This progression has, not necessarily, been accompanied by an improvement in the efficiency of power utilisation in achieving the target grind size, but has seen an improvement in the overall efficiency of mineral processing as
the SAG mill or Ball mill in the range of SAG product size adjustments from mm to mm. The SAG mill transfer size T80 can be adjusted using the Bond Work Index, for product sizes coarser or finer than the basic SAG product (T80) of mm. More specifically, in the T80 range of to mm,
Obviously, the SAG mill is consuming more and the ball mill less power than was predicted by the empirical method, but the overall total is % of the predicted total. Examples. The Hemlo gold project of TeckCorona (1000 mtpd) provides an example of mill sizing .
Sag mill feed size distribution Henan Mining Machinery . A Nral Network Model for SAG Mill Control. SAG specific power range of about 3 to 9 kWht for this site The design of the ore stockpiling and conveying system contributes to fluctuating size distribution with significant shortterm segregation occurring under certain operating situations Depending on ore type and feed size distribution ...
The mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill. Because of the range of ...
In SAG mill operation, the grinding rate passes through a minimum at a "critical size" (Chapter 5), which represents material too large to be broken by the steel grinding media, but has a low selfbreakage rate. If the critical size material, typically 25–50 mm, is accumulated the mill energy efficiency will deteriorate, and the mill feed ...
Jan 01, 2016· The SAG mill had a 6–8% ball charge and the power consumption was 8 kWh/t, which agreed well with the expected value. Problems. In an SAG mill the dimensions of the mill were m × m and the specific gravities of the mineral and .
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. FullerTraylor SAG/AG Mills range in size from through in diameter with powers as high as 28,000 kW.
= SAG mill feed sample mass, grams The ball mill pinion energy is determined from the Bond the Third Theory of Comminution : S dBWI = * / (P cs G pb ) / (10 / P 80 1/2 – 10 / F 80 1/2) where : S dBWI = Bond ball mill work index on SAG ground ore, kWh/ton ground F 80 = 80% passing of SAG ground of the test feed size ...
SAG Mill Grinding Circuit Design. The following are factors that have been investigated and applied in conventional ball milling in order to maximize grinding efficiency: a) Mill Geometry and Speed – Bond (1954) observed grinding efficiency to be a function of ball mill diameter, and established empirical relationships for recommended media size and mill speed that take this factor into account.
PDF | On Jan 1, 2001, S. Morrell and others published Influence of feed size on AG / SAG mill performance | Find, read and cite all the research you need on ResearchGate
SAG milling extends itself to many applications due to the range of mill sizes available. They can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill and some or all of the work done by a ball mill. SAG mills are also an optimum solution for wet grinding since crushing and screening in these
Changes to the ore hardness, feed size or ore specific gravity require an alert operator to adjust the variables while keeping up with all the other demands in the plant. With the operator''s attention frequently drawn away from the SAG mill, the actual mill load would vary around the target, resulting in large corrections to the manipulated ...
Transfer Size, T80: Is the 80% passing size of ore as it passes from the SAG mill to the ball mill. It is typically about 1/3 the size of the screen opening but can be coarser than 1/3, especially when a pebble crusher is used. Screening at 5 mm ensures that the T80 will be about 10
Every mining operation has a unique grinding process. has experience of over 8,000 grinding mills globally, including manufacturing and delivering the largest SAG/AG mills in the world. Our experts welcome the opportunity to assist you with circuit and circuit control design as well as startup, operation, and optimization of your mill.
Jan 01, 2015· In Fig. 3, Fig. 4 the data is presented in order to show the effect of the fresh feed size, particularly the % −6″ +1″ (−152 +25 mm), on the SAG mill power consumption (Pc) in kW and on the SAG mill specific energy consumption (Ecs) in kW h/t, obtained by dividing the power consumed (kW) by the fresh feed rate (t/h).
The number of SAG mill revolutions required to grind the material to a P 80 of mm is used to predict AG/SAG specific energy using quation 4. Correction E factors for feed size and pebble ing are applied to the AG/SAG specific energy, as well as specific crush energy adjustment from mm to the mill transfer size T
AG/SAG is short for autogenous mill and semiautogenous mill, it combines with two functions of crushing and grinding, uses the ground material itself as the grinding media, through the mutual impact and grinding action to gradually reduce the material size. SAG mill is usually used to grind large pieces into small pieces, especially for the ...
xG is the mill feed d80, not the circuit feed. For SAG mill, the xG value has to be determined by scalping of the full size distribution. The particles larger than the minimum pebble size (given by the pebble extraction grate opening) has to be excluded from the distribution to calculate the top ball size!
Even though production was dramatically improved, the product size of the secondary ball milling was reduced and recovery increased. The results in SAGMill line 2 are even more dramatic. Because of segregation on the coarse feed stockpile, SAGmill 2 receives a higher percentage of coarse material.
size reduction in a comminution device. Because grinding theories are imperfect and ore hardness can vary with size, grindability tests are designed to best represent the size reduction of the industrial equipment analysed. For that reason, it is preferable to design a primary ball mill from a rod mill work index rather than a ball mill
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 in the grind size.
The company said it has supplied trommel screens for almost four decades and has the capability to size SAG mill trommel screens with diameters up to m. It designs the trommel screens to suit each customer''s unique requirements, with capacities ranging up to more than 3,500 tons per hour (t/h) solids.
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