Modern, large SAG mills are major capital- cost items with price tags reaching well into the eight-figure dollar range. They stand at the entry point to a variety of comminution circuit setups and when they stop for whatever reason, the revenue losses per circuit mount quickly.
pressure on mill sizing has resulted in non-flexibility in new SAG mill circuit designs. In order to defend the mill size selected, the owner's engineers need to be able to quantify the loss in productivity that will occur if the SAG mill is downsized. Power based methods allow this calculation to be executed rapidly with good accuracy.
Alternatively, if you are designing a new circuit then choose a different combination of SAG and ball mills that operates in a more reasonable transfer size range. The optimum feed size for the rod mill oversize feed factor (EF 4 RM) in the Barratt E SAG equation is calculated using the greater of the sample's rod mill or crushing work index.
AG/SAG mills, circuit design, plant performance, optimization INTRODUCTION AG or SAG mills have been in use in comminution circuits since the 1950's and are considered a mature technology in most countries. However, a reasonable number of recent SAG mill based projects
Next step is to add mills to the circuit: Create a new SAG mill by clicking the "+ primary mill" button. Further instructions. Continue adding mills (and pebble crushers) to the new circuit. The mills assigned to this new circuit are listed and can be edited (if necessary) by clicking the looking glass icons. Choosing the right model
Rather than design the SAG circuit with an arbitrary fraction of total circuit power, it is more useful to base the required SAG mill size on the product of the unit power requirement for the ore and the desired throughput, and then size the …
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.com 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 ...
into AG/SAG mill circuits to break the critical size particles that accumulate in the mill and to increase the performance of the primary grinding circuits. Many studies have been carried out, mainly focusing on optimizing of SAG mills and cone crushers, respectively, but only a few have investigated the dynamic interactions between a ...
been implemented on the Fimiston SAG mill which have increased the. Fimist on plant throughput from 11.0 million tpa to 12.5 million tpa. With. an increase in the plant throughput, the overall ...
The ball mills were the bottleneck of the circuit and therefore returning a part of the cyclone underflow to the SAG mill would increase circuit capacity by higher utilisation of SAG mill power. Simulation with 10% of underflow returning to the SAG mill indicated that P80 could be reduced from 140 to 132µm.
and Closed Circuit AG/SAG Mills S Morrell1 ABSTRACT The aspect ratio (mill diameter/mill length) of autogenous and semi autogenous mills varies widely and can be as high as three or as low as 0.5. The literature on the subject of what effect aspect ratio has on grinding mill performance or energy efficiency is almost non-existent.
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 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 ...
MODEL PREDICTIVE CONTROL OF SAG MILLS AND FLOTATION CIRCUITS *Michael G. Forbes and Bill Gough . ANDRITZ AUTOMATION Ltd. 100 – 13700 International Place Richmond, BC V6V 2X8 Canada (*Corresponding author: [email protected]) ABSTRACT . Precise control of SAG mill loading and flotation cell level is critical to maximize production and
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. 'Critical size' …
crushed ore is fed into a SAG/Ball mill circuit with a median size of approximately 12,000 microns. Most SAG Mills are operated in closed circuit with a screen. The screen fi lters undersized ore, normally minus ½ inch, to a ball mill discharge sump. The combined mill discharg-es are pumped to undergo classifi cation, normally via hydrocyclones.
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 many years. Other initiatives to increase
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 ...
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.
PDF | On Sep 1, 2001, S. Strohmayr and others published SAG mill circuit optimisation at Ernest Henry Mining | Find, read and cite all the research …
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 …
Where the SAG mill/ball mill circuit is the bottleneck in the processing plant the pebble circuit can be a significant factor in limiting overall plant capacity. The pebble circuit recirculating load can be very significant (depending on the ore …
single-stage mill is finished material suitable for flotation or leaching, usually in the size range of 80% passing 200 µm to 100 µm. The design of such circuits is complicated by the typical power-based models used for conceptual design being calibrated to a two-stage circuit with AG or SAG mill product being passed to a
Grinding Circuit Modelling Documentation. This documentation describes the operating and underlying mathematics of the SAGMILLING.COM grinding circuit modelling program. It is intended to be used by the model users who want to operate and understand the functioning of grinding models.
The standard method for sizing secondary ball mills (usually the overflow type) in AG/SAG circuits follows published mill supplier information with aspect ratios in the range 1:1.5 to 1:2.0, depending upon product sizing and pulp flow, i.e., the highest expected circulating loads (Morrell, 2001). The applied net power, calculated from testwork
SAG mills in closed circuit with pebble fraction are more complicated than the single stage SAG mill operation, because the coarse pebbles behave significantly different to that of slurry in pulp lifters. In addition, operation of mills at higher speed, to …