based on semiautogenous (SAG) milling and involve as a rule primary wet autogenous mill (WAM) and a series of ball mills. WAM is customary chosen either based on examination of analogous equipment specifications, or from the evidence of very expensive commercial and semicommercial testing that requires large sampling, much time and high investment
WhatsApp: +86 18203695377
Figure 5. Highlow wave ball mill liner Materials The selection of the material of construction is a function of the application, abrasivity of ore, size of mill, corrosion environment, size of balls, mill speed, etc. liner design and material of construction are integral and cannot be chosen in isolation.
WhatsApp: +86 18203695377
SAG MILL TESTING AN OVERVIEW OF THE TEST PROCEDURES AVAILABLE TO CHARACTERIZE ORE GRINDABILITY AUTHOR: VERRET, G. CHIASSON AND A. MCKEN SGS KEYWORDS ... Bond Ball Mill Any 10 5 Lockedcycle Y Y Mod Bond Any N/A 2 Batch N Y Table 1 Summary of Grindability Test Procedures ...
WhatsApp: +86 18203695377
Ball Mill SAG Mill Figure 2 Core pressing system with spring plate/washer and retightening statistics in a typical installation Access to the inside of the motor and the cooling system The easier the access to the inside of the motor is, the more convenient and efficient is the work on the motor.
WhatsApp: +86 18203695377
SAG Mill vs Ball Mill. ... Design Drive Power. C. Total Feed Conditions, including total mill volumetric flow rate; ... First evidence of grate failure occurred at 678 000 tonnes throughput, and at 850 000 tonnes, after three grates had been replaced on separate occasions, the remaining 25 were renewed. ...
WhatsApp: +86 18203695377
Ignoring mechanical losses in this drive train, the power transmission at each stage, defined as torque x speed, is constant. The typical mechanical inching drive motor speed is around 1500 to 1800 RPM while the mill inching speed is in the order of to RPM. Thus, the gear reduction ratio between the inching drive motor and the mill is ...
WhatsApp: +86 18203695377
For economy of scale, new projects consider grinding circuits with SAG and ball mills with 36′ or larger mill diameters with cycloconverterfed drives with powers in the range near 20. MW.. For the huge volume of slurry flows, big pumps with lowspeed gearless drives fed by medium voltage converters in the range of 12 MW are being considered.. Due to the high mechanical torque involved ...
WhatsApp: +86 18203695377
Siemens' gearless drive technology of to % as confirmed by real operational data from the Antapaccay mine in Peru. It was the first plant worldwide to use gearless drives for both applications. KEYWORDS Gearless Mill Drives, Gearless Conveyor Drives, Availability, SAG Mill, Ball Mill, Overland Conveyor, Antapaccay 15
WhatsApp: +86 18203695377
Most of our work since 2000 has been in developing grinding mill foundations to avoid vibration and unacceptable deflections. On a recent project for a plant in Peru, the client was told by the mill vendor that there was no need to do a systems (dynamic) analysis on the mill foundations because the mills on that project were gear driven rather than being driven by ring motors (gearless drives).
WhatsApp: +86 18203695377
• 22 MW GMD for 28' ball mill • 28 MW GMD for a 40' SAG mill • 28 MW GMD for 42' SAG mill Whether it is size or an installation at the highest altitude (4600 ), ABB's GMDs are well positioned to contribute to the building of larger and ever more powerful mills. — Leading the gearless mill drive evolution
WhatsApp: +86 18203695377
The plus ore will be handled separately and the two will be stored in separate stockpiles. The feed to their SAG mills will be a mix of the two, the plus as media rock and the minus as rock to be ground. The ultimate product from their SAG mill will be about 6 Mesh ( mm). Further grinding will be by ball mill after magnetic separation at ...
WhatsApp: +86 18203695377
At present, the removal of the bolts which fasten the liners should be carried out manually as part of the maintenance procedure SAG mills should be subjected to. The disadvantage of this procedure is the fact it should be carried out manually which makes the system to lose efficiency due to the high maintenance periods. Due to the above, a robot system and method have been developed to carry ...
WhatsApp: +86 18203695377
For economy of scale, new projects consider grinding circuits with SAG and ball mills with 36′ or larger mill diameters with cycloconverterfed drives with powers in the range near 20 MW.
WhatsApp: +86 18203695377
This lack of movement towards larger mills is somewhat surprising since in the same period the drive rating of ball mills for similar duties such as ore grinding has shown an increase in drive ...
WhatsApp: +86 18203695377
Effective preassembly. There are two things to consider for effective preassembly: the speed at which operators can work and the weight of the tool. Of course, the power of the tool is essential to enabling operators to complete tasks at a faster rate, thus reducing downtime. For example, the use of an impact wrench for pretightening bolted ...
WhatsApp: +86 18203695377
The use of VSDs makes it very easy to set the mill speed by just modifying this value on a touchscreen. But this is not only an option for new installations. In installations where SAG and Ball mills have been working for several years at fixed speed, but the speed regulation has been observed to be necessary VSDs can also be integrated very ...
WhatsApp: +86 18203695377
Larger ball and SAG mills, with higher installed power ratings relative to the mill diameter, offer higher efficiency and throughput, roundtheclock reliability and the opportunity to mine in remote areas. ... Two 28 MW gearless mill drive systems (GMDs) are operating in the mine's 40 foot SAG mills and four MW GMDS are employed in 26 ...
WhatsApp: +86 18203695377
For economy of scale, new projects consider grinding circuits with SAG and ball mills with 36′ or larger mill diameters with cycloconverterfed drives with powers in the range near 20 MW.
WhatsApp: +86 18203695377
Grade control during ore haulage delivery to die mill 28 Coordination with mill 29 Metallurgical balance 30 References 30 PART II. PROCESSING TECHNOLOGY 33 CHAPTER 3. PROCESSING CONCEPTS 35 References 37 . CHAPTER 4. ORE PREPARATION 39 Introduction 39 Crushing and grinding 39 Introduction 39
WhatsApp: +86 18203695377
This paper describes the function and operation of lubrication systems for Ball Mill and SAG Mill Drives. Provided within this paper are hydraulic schematics, functional description and a general overview of system layout as well as some of the important features and factors relevant to improving the reliability of this very critical part of the grinding mill drive system. Also discussed are ...
WhatsApp: +86 18203695377
As well as ever larger SAG mills, ball mills are also expanding in size. In the late 1990s the trend moved towards using GMDs to power these larger ball mills, as well as using the drive to vary the speed. GMDs quickly moved from 20' ball mills, expanding to 24, 25 and then 26' mills. In early 2010 ABB commissioned the first GMDs for two 27 ...
WhatsApp: +86 18203695377
This option comprises an open circuit SAG mill followed by a closedcircuit ball mill. Due to the high throughputs associated with this circuit, the ball mill is most often closed with a hydrocyclone classifier. The course material is returned to the ball mill feed and the fine overflow product reports to the downstream process.
WhatsApp: +86 18203695377
According to Figure 1, the dynamic model of the ball mill is where is the rotation resistance coefficient of the drive motor, is the friction torque, and the rotation direction of the ball mill is determined by the sign function sign().. When the rotational speeds of the clutch are synchronised,, =, the clutch no longer slips. The dynamic model can be written as follows:
WhatsApp: +86 18203695377
mills in the older plants that had many mills in parallel. In fact this is generally still the case in the multistream plants, where mill liner design and selection is only tackled on a cost consumables basis. However, the gains to be had through good liner design and selection are just as great as on the large SAG mills.
WhatsApp: +86 18203695377
Over the past seven years, there have been approximately 40 projects globally working on installations of energyefficient SER drives. With our SAG mill running at % critical speed (mill ...
WhatsApp: +86 18203695377
The method of powering mills such as AG, SAG and Ball has a long and technically interesting history. It can be said; almost every decade in the last half century had its own trend. ... When mill diameter and mill power became again increased, only the Gearless Mill Drive (GMD) could be envisaged to cover this requirement above 10 MW. The GMD ...
WhatsApp: +86 18203695377
Ball Mill Wi test on SAG ground ore from the first or SAG stage of the test. The SAG stage therefore had to use enough material to do the Bond Wi test. To ensure this, the SAGDesign SAG mill was designed to be 488 mm (") in diameter and 163 mm (") long (EGL). Other design parameters for the SAGDesign SAG mill were selected to
WhatsApp: +86 18203695377
the AG/SAG mill (because there is no recycle), but loads the ball mills instead. Often an existing plant that observes their SAG mill is limiting throughput, but the ball mills are underloaded can opencircuit the primary mill to better balance the grinding load with the secondary mill. The coarse transfer size to the ball mill makes this circuit
WhatsApp: +86 18203695377
CERAMIC LINED BALL MILL. Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15″ x 21″ to 8′ x 12′. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume.
WhatsApp: +86 18203695377
Fig. 1 shows the grinding circuit of a modern copper concentrator with rated capacity of 110 000 tonnes per day (MTPD) with four gearless mill drives (GMD), comprising one SAG mill of HP and three ball mills of HP each one. Slurry pumps with a rating near 2000 HP with gearless lowspeed motors fed by frequency converters are applied (Bergholz et al., 2003, Rotella et al., 2003).
WhatsApp: +86 18203695377
A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
Copyright © 2023 GMC Co., Ltd. SiteMap
