Sag Mill Feed Size

SAG mills mimic the same shortcoming. It follows that in order to obtain the specifi c energy (SE) to achieve a certain transfer size, based on the 80 per cent passing value, an ineffi ciency factor must be applied to the SE of single stage ball mills, rod mills or AG/SAG mills when calculating power according to the Bond Third Theory method.

efficient, single stage SAG milling is likely to be the most profitable grinding circuit design. 2. Medium Grind – 80% passing size between 106 and 75 µm. To mill in single stage SAG configuration, the feed must be consistent, not too coarse or too fine. The downstream process must be able to handle fluctuations in the grind size. If these

102. Circulating load calculation in grinding circuits. 1. I ntroduction. The mass ba lances in m ineral pro - c essing circ uits are based on t he equation of mass conservation, given by: F = C ...

Amelunxen SGI Model. This is a model that estimates the specific energy consumption of a SAG or AG mill plus ball mill circuit using the equation by Amelunxen (2014) for E SAG and the classical Bond work index equation for E ball substituting CF ball in the place of the Rowland efficiency factors.. The model requires manual calibration factors for both equations (CF SAG and CF ball ...

Optimization of mill performance by using online ball and pulp measurements Soon after a stop, a mill is a dangerous place to enter for the personnel tasked with taking measurements or samples. Crash stops are difficult to handle. The mill and all feed streams should be stopped simultaneously but, often, they are stopped around about the same time.

P80 is the SAG hydrocyclone overflow 80% passing size, µm F80 is the milling circuit feed 80% passing size, µm, fSAG is a calibration parameter for pebble crushing and/or fine feed (typically 1.0 for 80% passing six inch mill feed and when no pebble crusher is present). WiBM is …

The software uses the particular power model (Bond/Barratt, Morrell Mi, etc.) to determine what is the transfer size where the ratio of E SAG to E ball matches the ratio of mill power (1:1.5 in this example). This is the 'maximum efficiency' transfer size where the mills will both operate at full power.

Fo - Optimum Feed Size for rod mills F o W r =16 000 ... size and power relationships For SAG mills the equation becomes Power=(5.6115+%balls*0.1438)*D24. 6* L Mill Critical speed Crit Crit D = 42.3 n - revs per min nC= s*Crit Cs is the fraction of the critical speed

In this presentation an historical perspective of the origins of Mine-to-Mill is described and is followed by a discussion of how AG/SAG feed size affects throughput and specific energy and the factors that in turn influence AG/SAG feed size, such as ore hardness, Run of Mine (RoM) size distribution and crusher operation (both primary and secondary).

3.5.2.2 Ball Mills. The ball mill accepts the SAG or AG mill product. Ball mills give a controlled final grind and produce flotation feed of a uniform size. Ball mills tumble iron or steel balls with the ore. The balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds.

Developments in SAG Mill Design and Operation Over the last few years, SAG mill manufacturing technology has advanced rapidly. The bounds of mill size have been pushed from two directions. Firstly, the advent of ring motors has removed the constraint applied by the power that a …

The crushed pebbles fall directly onto the SAG mill feed belt and return to the SAG mill. SAG mill product feeds two parallel ball mills of 6.6 m×11.1 m (internal diameter×length), each with a 9.7 MW twin pinion drive. The ball mills are operated at a ball charge volume of 30–32% and 78.5% critical speed.

The capacity of the SAG mill is related to lots of factors such as feed size, size distribution, discharge size and grindability, etc., and it should be confirmed according to the actual situation. SM40*14'——means it is a dry mill.

Other variables which can be manipulated to have an impact on mill throughput include: Mill feed and discharge water flow Use of different cyclone configurations, pressures or densities to manipulate the particle size leaving the SAG mill Varying the speed of the feeders to preferentially feed finer or coarser material from the stockpile ...

Influence Of Feed Size On AG/SAG Mill Performance Mapping Orebody Hardness Variability For Ag-SAG Crushing And HPGR Circuits Modelling And Simulation Techniques Applied For Optimisation Of Mine To Mill Operations And Case Studies Modelling The Influence On Power Draw Of The Slurry Phase In Autogenous (AG), Semi-Autogenous (SAG) And Ball Mills

respect with SAG mills being increasingly less sensitive as the ball charge is increased (Morrel S and Valery W, 2001). 2.2. EFFECT OF FEED SIZE DISTRIBUTION ON SAG MILLING The qualitative effect of changes in particle size distributions (PSD) on the SAG mill performance can be addressed by using the grind curves.

ball-mill sized feed. Feed ore with a top size of up to 200 mm (8 in.) and water enter the feed end of a SAG mill through a feed chute; the ore is milled in the shell and milled product exits through grates and pulp lifters at the discharge end (Fig. 1). The discharge is screened and the undersize, typically less than 12 mm (0.5 in.), provides ball

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!

As all ex- primary crusher ag/sag mill feed size distributions are the result of how in-situ rock has been blasted and subsequently treated by the primary crusher, it is reasonable to expect that by changing how blasting is carried out and how the primary crusher is operated …

A number of samples were taken from the SAG mill feed belt and subjected to SMC Tests and Bond ball mill work index tests. Note that the Bond tests were conducted using 150 microns as the closing screen size so that the final product size from the tests was similar …

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 …

When the feed size of a SAG mill becomes coarser, i.e. α r increases, the energy required to break the ore increases, i.e. φ r and φ f increases (Morrell et al., 1996; …

The system adopted for feeding the AG/SAG mill consisted initially in screening the ROM feed size distributions, separating into five individual size fractions: −203 + 152 mm; −152 + 76.2 mm; −76.2 + 25.4 mm; −25.4 + 12.7 mm and −12.7 mm.

The feed size is usually between 20-30mm and the product size is 0-3mm. Feed. Both the autogenous grinding mill and the ball mill feed parts are welded with groove and embedded inner wear-resistant lining plate. As the sag mill does not contain grinding medium, the abrasion and impact on the equipment are relatively small.

The crushed pebbles fall directly onto the SAG mill feed belt and return to the SAG mill. SAG mill product feeds two parallel ball mills of 6.6 m×11.1 m (internal diameter×length), each with a 9.7 MW twin pinion drive. The ball mills are operated at a ball charge volume of 30–32% and 78.5% critical speed.

After closed-circuit secondary crushing, the SAG mill feed 80% passing (F80) size was 25 mm to 30 mm. Installed grinding power is split equally between the two mills with the SAG mill fitted with a variable speed drive (VSD). SAG discharge screen oversize ('pebbles' or 'scats') was …

the ball mill is less energy efficient than a crusher and has to input more energy to do the same amount of size reduction). Hence from equation 7, to crush to the ball mill circuit feed size (x. 2) in open circuit requires specific energy equivalent to: f x f x 2. 1 W c ic. 1.19* 4 …

By combining with SAG discharge and screening on the SAG discharge screens, top size control to the ball-mill circuit feed is maintained while still unloading the SAG circuit (Mosher et al, 2006). A variant of this method is to direct pebble-crushing circuit product to the ball-mill sump for secondary milling: while convenient, this has the ...

size depending on the required mill feed rate and ore hardness. Figure 3 – Meadowbank milling flowsheet . Crushed ore is conveyed to a covered stockpile with an 8,500 t live capacity. Two variable frequency drive pron feeders reclaima the stockpiled material to a conveyer belt feeding the SAG mill in the primary grinding circuit.

Size analysis diagram of underscreen stream along with SAG mill feed is showed in Figure 6. Characteristics of the third sample and its comparison with plant design numbers (targets) could be ...

January 2007, two complete grinding circuit surveys were performed followed by a SAG mill crash stop and grind-out. After stopping the mill, a SAG mill feed sample was also collected from Conveyor 1.

The SAG mill pinion energy, W SDT (kWh/t) and SAG discharge Bond ball mill work index, S d-BWI (kWh/t), are then used to calculate the total energy to grind the ore from 80% passing 152 mm to 80% passing the client specified final product size P 80.This information, along with the ore specific gravity, is used to calculate necessary mill sizes and motor power in industrial applications.

P80 is the SAG hydrocyclone overflow 80% passing size, µm F80 is the milling circuit feed 80% passing size, µm, fSAG is a calibration parameter for pebble crushing and/or fine feed (typically 1.0 for 80% passing six inch mill feed and when no pebble crusher is present). WiBM is …