Abbs gearless mill drive system is the most powerful mill drive system in the market to power semiautogenous sag, ball and autogenous ag mills. Optimization and control of a primary sag mill using real. Because of segregation on the coarse feed stockpile, sag mill 2 receives a higher percentage of coarse material. In recent years, the trend has been towards largersized sag mills with diameters of 10. Karl gugel, digital control lab started its life in 1998 as an electronics consulting firm known as dicon labs. The performance of tumbling mills is sensitive to the volumetric mill filling which influences grinding media wear rates, throughput, power draw, and product grind size from the circuit. This video was made for the sag conference, in which a company wanted to show a visual walkthrough of the sag mill, from the beginning of its processes to. A ball mill is a type of grinder used to grind, blend and sometimes for mixing of materials for use. Miduk copper concentrator is located in kerman province, iran, and its size reduction stage includes one gyratory crusher which feeds one sag mill 9. Put another way, the sag mill energy required according to this statement, is 2.
Sep 10, 2012 what large 120,000 tpd grinding circuit in operation is. Another very important point to consider is that the load distribution on ball mills fed by a sag mill is not equally distributed. The operation principle of softswitching dcac converter was analyzed and the. A wet grinding ball mill in closed circuit is to be fed 100 tph of a material with a work. Outotec grinding mills optimize grinding mill performance, efficiency, and availability to ensure you meet your plants operational targets. The bounds of mill size have been pushed from two directions. Pdf optimisation of the cadia hill sag mill circuit. In the 2009 database, sag pinion energies to grind from f80 152 mm to t80 1. Introduction this tutorial describes how to setup and analyze a sag semiautogenous grinding mill simulation. Posted by matrix on 21st march 2007 sanjeev latchireddi, chief process engineer grinding americas, outokumpu technology, looks at the shift from ball mills to sag mills. The converters output voltage consists of parts of the line voltage.
The mill is lined with wear resistant steel liners which are fitted with lifters to assist with raising the load. Continuous monitoring of mineral processes with special. Sag mill breaks the raw material into pieces for the further grinding. Rocky dem the most powerful particle simulation software. The cyclone overflow gravitated to the first leach tank via a trash screen. These equations are used by smcc pty ltd to estimate the specific energy of ag sag mills under all normal operating conditions, eg ball load, mill speed, feed size and ore hardness and for all. Morrell and others published ag and sag mill circuit.
Sag mill feed is conveyed from the coarse ore stockpile. Whether youre talking about sag or a ball mill, space is. Refining cupellation parkes process bottomblown oxygen converter poling isakidd process. It too had an abb motor and it had operated longer than the collahuasi motor. Mechanical installation of a sag mill christof industries. The discharge grates of the sag mill were identified as a key component in the sabc circuit, and their design is a crucial factor in the mill s performance 171819 20 21. These machines are typically electrically powered, but have been modified from a variety of powering systems over the years. Download limit exceeded you have exceeded your daily download allowance. The liners are replaced as they wear and the lifting action has degraded. Then define the behavior to be rigid or flexible, sticky or dry. A method of c alculating autogenous semiautogenous. Composed of a twelve pulse cycloconverter together with a synchronous ringmotor. The rom sag mill circuita brief description the typical rom sag mill circuit is depicted in figure 1. The electric current of the motor is the main creator of.
The ability to mill a broad range of ore types in various circuit configurations, with reduced numbers of unit operations and a. Gearless mill drive protection improvements and its. It is similar in operation to a sag mill as described below but does not use steel balls in. Sep 10, 2014 the collahuasi motor was for a 40 ft sag mill.
Ball milling pdf crusher mills, cone crusher, jaw crushers. The knowledgescape strategys ability to maintain smooth and stable operation of the mill was more apparent when contrasted to the dcs control on the difficult line. Each of these performance parameters peaks at different filling values. Dec 12, 2016 if p is less than 80% passing 70 microns, power consumption will be. At the constant size of the cycle feed and discharge, sec is a prime characteristic of material grindability in a certain ore pretreatment. It rotates, tumbling its contents violently, causing a breaking action. The circuit is usually closed with either a screen or, more commonly, a cyclone for product size. Ball mill is used to grind the pieces of raw material into.
Sag mill liner development draws primarily on practical experience from sag milling operations supported by computerbased modeling of charge motion in sag mills and on established good design. I expect that this type of drive would be the most common large mill variable speed mill drive in the worlds minerals. Supplying resources, processing machines and power generation of redstone flux to automate the production of diverse and interesting items, such as armor, tools, lighting. There are 12 short steps that will guide you throughout the tutorial. Nowadays, the more successful plants are those that have adopted effective and efficient strategies to optimize their plant operation. Outotec highperformance grinding mills use advanced simulation tools for the best possible process efficiency, mechanical reliability, and maintainability. Modifying the sag mill feed size distribution,secondary secondary crushing of sag mill feed has also been used by plant designers to minimise but the bond rod mill work index is high at 23 kwht.
The generators are still outputting correctly to cells. The function of the frequencyconverter, control system drive and lubrication systems are described. High fidelity simulation of sag milling is a technique, which uses dem, cfd and. Sag mill is an investment that can produce handsome returns if extra production is needed or simply to give the mine the option to mill the hardest ores at design throughput rates. A variant of this method is to direct pebblecrushing circuit product to the ball mill sump for secondary milling. My alloy smelter or sag mill is not takeing any charge from. By counting the number of lifters showing during a mill shutdown and comparing to the total number of lifters including those buried in the charge the fraction of the mill under the charge is determined. Simine gearless mill drives digital asset management siemens. Two silos containing merensky and ug2 ore respectively feed the mill that operates at a fixed 75% of the critical speed. Similar to the impeller design affecting pump capacity, the pulp lifter design affects the discharge capacity or mill throughput of ag and sag grinding mills.
The word genesis comes from the first word in the hebrew bible, in the beginning. Typically operated in rsa on witwatersrand gold ore driefontein underground, kloof, jacobina 6 sag mill with recycle crusher 8 15% ball charge competent ores, better suited to coarse grind sizes. Whether youre talking about sag or a ball mill, space is a delicate issue, especially in the. Ag and sag mills are now the primary unit operation for the majority of large grinding circuits, and form the basis for a variety of circuit configurations. Just say what youd like to make, what you already have, it will do the rest, giving you a list of raw materials and instructions of which items to make in the proper order. The mill filling should be measured at a minimum of 3 points along the mill. The antamina 38 ft sag mill was also driven by an abb motor and the hanger plates had not failed on that machine after several years of. It shouldnt be that hard an economically appealing method for improving operations is available without the capital expense get more out of a mill by applying the advanced control capabilities in the existing plant control system by andrew thornton. Liner design needs to respond to the process aspects of mill liner action that are critical to good sag mill performance, i. The sag mill is usually part of the primary stage in the grinding process.
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. Generally, the discharge from ag sag mills consists of one or both of the following components. Comparative study of alnimo alloys obtained by mechanical alloying in different ball mills pdf. The synchronous machine is fed by a cycloconverter ccv. Jan 11, 2015 i dont know what has happened it was working a few days ago, and i havnot been on since. Sag mills are autogenous mills that also use grinding balls like a ball mill. Particle breakage will not take place during this simulation.
Each module at waterval concentrator wvalc employs a. Ball mill is a secondary, and it is used after the sag mill. What large 120,000 tpd grinding circuit in operation is. A method to determine the ball filling, in miduk copper. The circuit is closed with a 600 m aperture classification screen with. It accepts energy in the form of redstone flux or minecraft joule, with an internal buffer of 100,000 rf and consumption of 20 rf per tick. The results in sagmill line 2 are even more dramatic. Sag mill 4% ball charge, 90% nc a cross between ag and sag for average competency, abrasive ores.
Ag and sag mill circuit selection and design by simulation. Sag mill crash stops after the project was approved baseline data collection was required in the form of sag mill crash stops. In order to continuously optimize mill operation, it is vital to. Modify a default shape, scan a real 3d object, or custom design your own shape and import it. Because of segregation on the coarse feed stockpile, sagmill 2 receives a higher percentage of coarse material.
Commissioning variable speed sag mill gearless drive. A wet grinding ball mill in closed circuit is to be fed 100 tph of a material with a. My alloy smelter or sag mill is not takeing any charge. Online monitoring of rheological effects in grinding mills using lifter deflection measurements. It uses micro infinity i to grind or mill items into their crushed variants, like ores into dusts. The test and study work showed that a single line 42 ft sag mill circuit gave the. The results in sag mill line 2 are even more dramatic. A positive set point change will be applied if all of the following conditions are true. The wet grinding plant for gold ore consists of an sag mill and a ball mill.
Sag mill liner development draws primarily on practical experience from sag milling operations supported by computerbased modeling of charge motion in sag mills and on established good design practice. The sag test reproduces commercial sag mill grinding conditions on 4. Pdf a silverleadzinc mine in queensland, australia was originally designed to treat 1. Sag mills are currently the technology of choice in hard rock milling operations for reducing primarycrushed ore to ball mill feed.
Two silos containing merensky and ug2 ore respectively feed the. These equations are used by smcc pty ltd to estimate the specific energy of agsag mills under all normal operating conditions, eg ball load, mill speed, feed size and ore hardness and for all. The sag semiautogenous grinding mill is a machine designed to to grind smaller particles and break larger rocks. Autogenous and semiautogenous mills wet grinding plants. The antamina 38 ft sag mill was also driven by an abb motor and the hanger plates had not failed on that machine after several years of operation.
Each decision cycle the expert system calculates a change in the sag mill water set point. I dont know what has happened it was working a few days ago, and i havnot been on since. A pendulum driven generator placed on the mill end produces the power to the transceiver, or. Rocky dems highperformance computing hpc abilities can simulate a large number of realsized and realshaped particles faster and with less memory usage. How does a sag mill work crusher mills, cone crusher, jaw. Many grinding mill owners choose a variable speed drive. You could do that by measuring the material flowrate qtonsh through the mill as well as the quantity mtons of material that. The worlds first 42foot diameter 28 mw gearless sag mill.
It can be seen from this set of operational data that the mill weight varies over a wide range and this is consistent with normal operator control of a sag mill. The performance of train 1 sag mill before the new manta cube. Sufficient time is required to obtain all the important measurements correctly during the crash stop. Sag mill optimization using model predictive control. Im trying to set up item automation and im running into an issue where i have an input for sag mill on the top face set to the pull setting and a retriever with what. Semiautogenous grinding sag mill liner design and development. Sag mill feed is at its maximum and mill sound is high. Tested using a sag mill surrounded by 2 survivalist generators, as detailed in the dw20 lets play. Similarly, the sossego motor for the 38 ft sag mill had not failed. Difference between sag mill vs ball mill mech4study. Pieces of raw or fairly reduced materials are ground into smaller pieces for further processing or sorting. Ball mill discharge combined with sag mill discharge to form the feed to the screen see figure 1. The ore passes through a gyratory crusher where it is reduced to 8 inch diameter before being dumped on the pile. The sag mill product is then crushed to 100% passing 3.
Firstly, the advent of ring motors has removed the constraint applied by the power that a single pinion gear was able to transmit. In a crash stop the sag mill is operated under steadystate conditions and then stopped as if the power plug was pulled. Crafting guide gives stepbystep instructions for making anything in minecraft or its many mods. Typical tests required to define a hardness variability function, are given below in figure 1. Developments in sag mill design and operation over the last few years, sag mill manufacturing technology has advanced rapidly. Taking control of the mill feed r2 orway mineral consultants. During the early years, dicon lab was contacted by a leading cement. A sag mill is usually a primary or first stage grinder. Optimizing your sag mill operation international mining. The engineering and process effects of choosing a motor.
Evolution of liner design from current to future operations julius stieger1, process superintendent dave plummer2, process maintenance planner sanjeeva. The enderio mod implements compact transportation for power, items, liquids and me network data, making it possible to run different types of conduits in a single block space. Mechanical installation of a 28 x 15,5 sag mill including lubrication and cooling system, mill wear liner as well as commissioning assistance and surveying after trail run. A method of c alculating autogenous semiautogenous grinding. Posted by matrix on 21st march 2007 sanjeev latchireddi, chief process engineer grinding americas, outokumpu technology, looks at the shift from ball mills to. If p is less than 80% passing 70 microns, power consumption will be. The gearless motor is fed by a cyclo converter, which is an extremely compact. Estimates the charge volume of a grinding mill based on the number of exposed lifters. Optimization of the design of sag mill internals using high fidelity. Pdf ag and sag mill circuit selection and design by simulation. Modeling and evaluation of cycloconverterfed twostatorwinding.
745 518 341 17 1385 1157 687 779 1488 738 206 14 605 1120 703 149 759 888 1034 22 992 687 291 1535 1230 477 1110 1160 286 77 27 1158 1497 1355 1392 537 1097