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Gearless Mill Drives ABB

Capacity: SAG Mill 1000 t/h Ball Mills 1000 t/h Consultant: Bechtel, USA Mill Builder: FFE Minerals, USA Mill Size: SAG Mill 38 feet/11,58 m Ball Mills 24 feet/7,32 m Ore processed: Copper/Zinc Drive Rating: SAG Mill 20,1 MW, 9,23 rpm Ball Mills 11,2 MW, 11,38 rpm Award of Contract: March 1999 Start of Operation: June 2001 ABB’s scope of supply: Four complete Gearless Mill Drive Systems

Evolution of SAG Mill Process Control at the Xstrata

In addition to the new process equipment, the SAG mill was commissioned with all controls implemented on the new PLC software platform. This removed the control strategy limitations previously described. Additional mill control loops and measurements now included: Mill feed tonnage (automatic PI control operator or remote set-point from mill

Autogenous and Semi-Autogenous Mills ScienceDirect

01/01/2016 Such replacements lead to savings in capital expenditure in a plant design. The SAG mills have been mostly used for milling hard gold and copper ores with quartz, ultramafic or green stone as host rocks. The Bond work index of these ores ranges between 12 and 14 kWh/t. Subsequently, SAG mill application has been extended to softer ores, such as bauxite and clayey hard-capped gold ores.

SAGMILLING.COM .:. Mill Critical Speed Determination

The "Critical Speed" for a grinding mill is defined as the rotational speed where centrifugal forces equal gravitational forces at the mill shell's inside surface. This is the rotational speed where balls will not fall away from the mill's shell. Result #1: This mill would need to spin at RPM to be at 100% critical speed.

Choosing vibration monitoring methods Applications

A SAG mill is generally used as a primary or first-stage grinding solution. Attrition between grinding balls and ore particles causes grinding of finer particles.SAG mills are primarily used at gold, copper and platinum mines with applications also in the lead, zinc, silver, alumina and nickel industries. These mills are characterized by their large diameter and short length, as compared to ball mills. The inside of the

What's the Difference Between SAG Mill and Ball Mill

In addition, these mills also play an important role in cold welding, alloy production, and thermal power plant power production. SAG mill vs Ball mill Crushing ratio. The biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1

(PDF) OPTIMIZATION OF THE SAG MILL CIRCUIT AT

RPM has two processing plants, an old o ne constit uted of five ball mill lines and a new S AB circuit (a SAG mill followed by two Ball m ill lines). The Run of Mine (ROM) ore s ent o the SAG

Autogenous and Semi-Autogenous Mills ScienceDirect

01/01/2016 Such replacements lead to savings in capital expenditure in a plant design. The SAG mills have been mostly used for milling hard gold and copper ores with quartz, ultramafic or green stone as host rocks. The Bond work index of these ores ranges between 12 and 14 kWh/t. Subsequently, SAG mill application has been extended to softer ores, such as bauxite and clayey hard-capped gold ores.

(PDF) Acoustic emissions monitoring of SAG mill

The PSD from multiple revolutions of AG/SAG mill surface vibration data has been shown to be a good bulk spectroscopic inferential measure (particularly in terms of frequency band power) of what

THE ENGINEERING AND PROCESS EFFECTS OF CHOOSING A

the mill speed as a fraction of the critical speed, ϕC, can be observed by plotting the process power and torque draw superimposed on the relevant motor capability curve. Such plots for an example mill, the SAG mill at Cadia (described by Dunne et al., 2001) is shown in Figure 3.

Improving Energy Efficiency Via Optimized Charge

Depending on the mill size the SAG mills draws between 2 MW and 17 MW. 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 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding

Evolution of AG mill shell liner design at Gol-E-Gohar

Liner design is becoming an increasingly more important tool for the AG/SAG mill performance optimization. The Gol-E-Gohar iron ore concentration plant uses three 9 m × 2.05 m autogenous mills (AG) in parallel in a dry operation. Due to large variations in feed characteristics and inadequate blending, the performance of AG mills has been lower than the target value. In order to increase the

Autogenous AG & SAG Mills for Sale 911Metallurgist

A 13′ x 6′ SAG Mill has a reasonable range of: 20 to 30 TPH for gold ore SAG & Ball Mill duty; 25 to 40 t/h for copper porphyry SAG & Ball Mill duty ; In Single Stage SAG duty, the approximate capacity reduces to only 8 to 13 TPH for gold ore duty. The autogenous mill itself is a coarse-grinding device, consisting of tumbling drum with a 25% to 40% volume filling of ore. Metallic or

Performance enhancement tools for grinding mills

SAG and ball mills have grown in size and there are now many operational mills in the range of 28–40 feet in diameter with installed powers ranging between 8–20 MW. The very high capacity of these mills and the common use of variable speed drives often result in operational problems. These problems are associated with high-energy impacts striking mill liners resulting in poor energy

Morgardshammar 5.2m X 6.6m (17' X 21.8') Egl Sag Mill

Buy Morgardshammar 5.2m X 6.6m (17' X 21.8') Egl Sag Mill With 1,800 Kw (2413 Hp) Motor, 4160 Volts, 1190 Rpm from A.M. King Industries. Request a quote online today.

The influence of mill speed and pulp density on the

•Mill outlet water (l/min) • Speed (rpm) •Mill torque on the driving shaft (Nm) •Electric power (kW) •Mill weight (kg) • Throughput (kg/h). The absorbed power is calculated by multiplying the torque on the driving shaft with the shaft speed (rad/sec) and hence excludes any losses associated with the gearbox and motor. The pulp weight in the mill is obtained by subtracting the mill

A comparison of SAG mill power models

SAG Mill power draw models are used in mill design and grinding circuit modelling to predict how much power will be consumed by a particular mill geometry and operating configuration. This paper will compare SAG mill models by Morrell, Loveday (using "Power Numbers" published by Barratt) and Austin against several published mill surveys. The purpose of the comparison is to identify the

THE ENGINEERING AND PROCESS EFFECTS OF CHOOSING A

the mill speed as a fraction of the critical speed, ϕC, can be observed by plotting the process power and torque draw superimposed on the relevant motor capability curve. Such plots for an example mill, the SAG mill at Cadia (described by Dunne et al., 2001) is shown in Figure 3.

(PDF) Acoustic emissions monitoring of SAG mill

The PSD from multiple revolutions of AG/SAG mill surface vibration data has been shown to be a good bulk spectroscopic inferential measure (particularly in terms of frequency band power) of what

Converting AG to SAG mills: The Gol-E-Gohar Iron Ore

01/02/2012 The Gol-E-Gohar iron ore concentration plant located in southeast Iran. Three 9 m × 2.05 m AG mills are used in parallel in a dry operation to grind a feed nominally passing 32 cm, which is the product of a gyratory crusher.The SAG mills is driven by a 4023 hp motor and runs at a constant (12 rpm rotational) speed (i.e., 85% of critical speed) in one direction.

Evolution of AG mill shell liner design at Gol-E-Gohar

Liner design is becoming an increasingly more important tool for the AG/SAG mill performance optimization. The Gol-E-Gohar iron ore concentration plant uses three 9 m × 2.05 m autogenous mills (AG) in parallel in a dry operation. Due to large variations in feed characteristics and inadequate blending, the performance of AG mills has been lower than the target value. In order to increase the

The engineering and process effects of choosing a motor

RPM is the mill rotational speed, revolutions per minute ⌽ C is the mill rotational speed, fraction of critical speed (eg. 0.72 for 72%) D is the mill nominal diameter inside the shell, m d is the mill liner nominal thickness, m Figure 4: „Tent“ diagram for the Cadia SAG mill described in Figure 3

Case Study: Tooth cracking observation from monthly

34′ X 20′ SAG Mill Nameplate Mill Power (HP) 17,000 Motor Power (HP) Max 8,985 Face Width [mm] 1,016 Mill Speed (RPM) Nominal 10.3 Gear Ratio 20.2 Mesh Per Revolution 2.0 Operating Hours at First Detection 35,345 Gear tooth load cycles 43,686,420 March 2016: Detecting Cracks with ASTM E 2905 A complete cleaning and girth

Performance enhancement tools for grinding mills

SAG and ball mills have grown in size and there are now many operational mills in the range of 28–40 feet in diameter with installed powers ranging between 8–20 MW. The very high capacity of these mills and the common use of variable speed drives often result in operational problems. These problems are associated with high-energy impacts striking mill liners resulting in poor energy

Major Mines & Projects Casposo Mine

The SAG mill is a 4.9 m diameter by 7.0 m long Allis grate discharge mill, driven by a 1,870 kW motor. The mill speed range is varies between 12.8 rpm and 15.5 rpm using a variable speed drive (VSD). The mill generally runs at 76% of the critical speed. The nominal throughput of the SAG mill is 50 dry t/h. The SAG mill operates with a ball charge up to 16% by volume. The ball charge is

Used Ball Mills for sale. Allis-Chalmers and Cyclone

30 x 7 ft (9.1 x 2.1 m) Allis Chalmers ( TON) SAG Mill components with 4079 HP motor, 200 RPM. Allis Chalmers 30 x 7 ft SAG Westinghouse AC brushless synchronous motor with spare stator: 4079 HP (3000 kW) 200 RPM 3300 V 50 Hz Mill includes: Bull gear Pinions Lube units