In a largescale operation, feed ores are introduced into the AG/SAG mill in a continuous mode at a given flow rate to replace the discharging slurry. Nonetheless, the variations in the feed characteristics, typically hardness and size distribution, could cause sudden disruption to the mill operation. This would be challenging to detect in practice, owing to the hostile environment of the mill.
WhatsApp: +86 18838072829varying it as the mill water addition rate changes. Loveday/Barratt Model Brian Loveday published a simple SAG mill model (Loveday, 1978) of the form in Equation 2. The equation uses mill dimensions (inside the liners), the density of the mill charge and an empirical "power number" that encapsulates the mill speed and volumetric filling.
WhatsApp: +86 18838072829I try to size and select two ball mills, which the first is in open circuit with feed rate of 125 t/h and its discharge goes to the sump of hydrocyclone and together with discharge of second ball mill, enters to the cyclone for classification. the se... SmartDog. Simple answer: yes 125 x =
WhatsApp: +86 18838072829Resource Type: Technical Report Country of Publication: United States Language: ... The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between and kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes ...
WhatsApp: +86 18838072829Due to its strong lifting capacity and excellent grinding performance, the trapezoidal liner is widely used in the SAG mill. The structure of the trapezoidal liner is shown in Fig. 1, the main dimensions are: dip angle (tau), length of the top edge (L) and height (h).Dip angle (tau) determines the trajectory of the mediums in the SAG mill, which directly affects the impact speed and ...
WhatsApp: +86 18838072829Based on experience, millliner designs have moved toward more openshell lifter spacing, increased pulp lifter volumetric capacity, and a grate design to facilitate maximizing both pebblecrushing circuit utilization and SAG mill capacity. As a guideline, mill throughput is maximized with shell lifters between ratios of :1 and :1.
WhatsApp: +86 18838072829Mines (WA) 36ft SAG mill the number of Outer Head Liners was reduced from 36 to 18 pieces and in doing so reduced the time to replace them by 9 hours at a cost downtime saving of about U25,000 per hour. In this case the liners sections are t each. For smaller mills the liners have to be handled and installed manually, so smaller blocks with
WhatsApp: +86 18838072829Type of milling process and operational parameters. SAG and ball mills grind material through different actions and are usually applied in different stages of the process. SAG mills usually have a larger diameter than length and are used to reduce large feed size ore (typically ~300mm) down to ~3mm, often for further grinding in a secondary ...
WhatsApp: +86 18838072829supported grinding mills up to the largest sizes. SAG/ball mill circuit incorporating pebble crushers and a POLYCOM® highpressure grinding roll. SAG and ball mill for gold ore grinding. One of three SAG mills with m diameter and 2 x 4000 kW drive power. These mills operate in conjunction with ball mills for iron ore grinding in Iran.
WhatsApp: +86 18838072829HPGR test results published by Grier (1992) on gold ores from the Mt. Todd project showed significant energy savings for a HPGR/Ball Mill circuit as compared to a SAG/Ball Mill plant. By adding a Polycom highpressure grinding roll, the throughput of existing plants can be increased by as much as 150% while simultaneously reducing the power ...
WhatsApp: +86 18838072829The purpose of the primary crusher is to reduce the ROM ore to a size amenable for feeding the secondary crusher or the SAG mill grinding circuit. The ratio of reduction through a primary crusher can be up to about 8:1. Feed: ROM up to m. Product: 300mm (for transport) to 200mm (for SAG mill) Feed Rate:
WhatsApp: +86 18838072829> Mill throughput and efficiency gains are iterative over time > Mill trajectory modelling based on bar heights, angles, spacing and speed is very predictive > Field trials are the acid test operator, designer and vendor > Optimisation strategy: Maximise impact grinding AG/SAG mills Avoid impact on the shell rather the toe of the charge
WhatsApp: +86 18838072829With the AK type starter series, GINOAKA provides a costeffective, reliable solution for the cement and industrial sector. ... For larger machines, typically used in mining applications, such as Ball and SAG Mills we offer the MAK series with additional features to reach higher performance levels. Starter Type AKEP MAK Tank volume 1000 to ...
WhatsApp: +86 18838072829The purpose of a grinding mill is to convert electrical energy into rock breakage. The best use of that asset is to try to maximize the power draw. Try to hold the mill speed high and vary the feed rate to hold the weight (or bearing pressure), but watch out for "cycling" or "surging" that indicates instability in the charge.
WhatsApp: +86 18838072829Early SAG mill designs using gear drives were limited in the amount of power that could be applied to the pinions, MPa (5000 hp). The exception to this design was the Hibbing taconite operation. It used MPa (6000 hp) motors to drive a 1Imdiam x long (36ftdiam x 15 ft) autogenous mill. However, recent SAG mill designs now ...
WhatsApp: +86 18838072829Figure 3 Grinding area detail showing SAG Mill of x and 3 ball mills of x 5 Figure 4 explains the changes in production throughput from each type of material, clearly outlining the changes made with each type of material.
WhatsApp: +86 18838072829Furthermore, the SAG mill circuit indicated varying feed sizes ( xF,80 =102 to 185 mm) which could be rectified by closer monitoring and control of ratios for the SAG mill feeders drawing the ...
WhatsApp: +86 18838072829CERAMIC 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 18838072829raising the availability to > 94% to match those of SAG mills. The large scale test currently being conducted on a hard abrasive gold ore will prove that this technology is now ready to challenge conventional circuit design. Maximum feed size vs roll diameter 0 10 20 30 40 50 60 70 80 Roll diameter [ m ]] mdot = 200 225 250
WhatsApp: +86 18838072829These include semiautogenous (SAG) .mills, rod mills, conventional ball mills, and tower mills. The different types ofgrinding media available for these grinding applications include heattreated and asrolled grinding rods, forged steel balls, cast steel balls, cast high chrome iron balls, and cast slugs (or cypebs). Some media types are best ...
WhatsApp: +86 18838072829> Mill throughput and efficiency gains are iterative over time > Mill trajectory modelling based on bar heights, angles, spacing and speed is very predictive > Field trials are the acid test operator, designer and vendor > Optimisation strategy: Maximise impact grinding AG/SAG mills Avoid impact on the shell rather the toe of the charge
WhatsApp: +86 18838072829m length (190) single SAG mill equipped with a 20 MW electric motor. The SAG mill product flows to two m (120) by m (240) horizontal screens, whose combined oversize (pebbles) is diverted to two MP 800 cone crushers. The crushed product returns to the SAG mill feed, closing the primary grinding circuit. The horizontal screen ...
WhatsApp: +86 18838072829Mill, gear and pinion friction multiplier: Mill Power required at pinionshaft = (240 x x ) ÷ = 5440 Hp. Speed reducer efficiency: 98%. 5440 Hp ÷ = 5550 HP (required minimum motor output power). Therefore select a mill to draw at least 5440 Hp at the pinionshaft.
WhatsApp: +86 18838072829Ball mill: Ball mills are the most widely used one. Rod mill: The rod mill has the highest efficiency when the feed size is <30mm and the discharge size is about 3mm with uniform particle size and light overcrushing phenomenon. SAG mill: When the weight of the SAG mill is more than 75%, the output is high and the energy consumption is low ...
WhatsApp: +86 18838072829Closed circuit single stage SAG mills. The advantage of the SAG mill is that it can handle very course primary crusher feed and achieve very high reduction ratios. As such secondary crushing is not required in this option and the SAG mill can produce final product in a single stage. High throughputs are also achievable in single line plants.
WhatsApp: +86 18838072829As semiautogenous (SAG) mills become increasingly larger in size, the design of SAG mill liners has been more and more important, and the appropriate liners would enhance mill efficiency and performance. The replaceable liners are mounted inside the mill and exposed to media and/or the material being ground.
WhatsApp: +86 18838072829as the mill rotates, providing a combined crushing and grinding effect on the ore. One of the main reasons for the use of SAG mills is the elimination of the secondary and tertiary crusher stages, and the substantial reduction in consumed power over conventional milling. A typical SAG mill with a smaller conventional ball mill shown in the
WhatsApp: +86 18838072829GRINDABILITY TEST MILL DIA. TOP SIZE CLOSING SIZE SAMPLE REQUESTED1 SAMPLE CONSUMED2 TYPE STEADYSTATE DATABASE (M) (MM) (CORE)3 (MM) (KG) (KG) (Y/N) (Y/N) Bond Lowenergy Impact N/A PQ/HQ N/A 25 10 Single Particle N Y Media Competency 165 N/A 750 300 Batch N Y MacPherson Autogenous 32 NQ 175 100 Continuous Y Y
WhatsApp: +86 18838072829SAG Mill Circuit Example — Gold Processing SAG mill circuit example for gold processing [image: (13563)] AG/SAG Mill. AG/SAG mills are normally used to grind runoffmine 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
WhatsApp: +86 18838072829factor in the grinding mill selection, other factors, such as reliabil ity of mill drives and power source, are important elements in the decision making process. This article examines how the NPC calculation, plus reliabil ity and power source, influence SAG mill selection. SAG mill drives There are two types of SAG mill drives.
WhatsApp: +86 18838072829voltage sag. When a linetoground fault occurs, there will be voltage sag until the protective switch gear operates. Some accidents in power lines such as lightning or falling an object can be a cause of linetoground fault and voltage sag as a result. Sudden load changes or excessive loads can cause voltage sag.
WhatsApp: +86 18838072829This paper discusses, and is centered on the Appendix of this paper that compiles all Autogenous and SemiAutogenous mill installations worldwide, through the end of March 2015. Updates have been ...
WhatsApp: +86 18838072829The grinding circuit consists of a conventional SAB circuit with a x m 3,356 kW SAG mill and a m x m 4,474 kW ball mill in closed circuit with 6 hydrocyclones (4 operating and 2 on standby). SAG mill throughput typically ranges from 473 515 tph depending on the ore type being processed.
WhatsApp: +86 18838072829SAG 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. Liner design needs to respond to the process aspects of mill liner action that are critical to good SAG mill performance,, the impact of shell liners on the grinding action and of grates ...
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