Higher capacity than AG mill grinding; Primary, coarse grinding (up to 400 mm feed size) ... Larger than Ball mills at same power draw . Special Tumbling Mill Special tumbling mills [image: (135614)] ... normally expressed in kWh/ short ton). Other established methods, for instance Hardgrove Index, population balance. ...
Cytec Handbook. Why have a large circulation load:. If a product all finer than a certain critical size is required, the capacity of the ball mill is increased considerably by using it in closed circuit with a classifier and this increase is made still greater by increasing the circulating load in between the ball mill and the classifier (Fig. 70).
Few problems • A certain crusher accepts a feed of rock having diameter of in and discharge a product of diameter in. the power required to crush 12 tons per hr is hp. What should be the power required if the capacity is reduced to 10 ton per hr and as a consequence of which the diameter of product become in?
Kick's law (1885) the energy required to reduce a material in size is directly proportional to the size reduction ratio dL/L, that is the ratio of the initial particle size to the finial particle size This implies that P equal to 1. If P = 1 then 2 1 ln L L CE putting C = KKfc gives: 2 1 ln L L fKE cK KK is not dimensionless.
Very large tonnages can be ground with these ball mills because they are very effective material handling devices. Ball mills are rated by power rather than capacity. Today the largest ball mill in operation is m diameter and m long with a corresponding motor power of 22 MW (Toromocho, private communications).
0 5 10 15 20 25 30 35 40 45 50 55 60 65 Specific grinding energy w from Denver slide rule (kwh/) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Specific grinding energy w from the proposed model (kwh/) Comparison line y=x Medium ore ... (kWh/short ton) and T is the required mill capacity ... Ball mill power draw predicted from the Denver slide ...
The basic parameters used in ball roller structure (power calculations), rod mill otherwise any tumbling mill sizing live; material to must ground, characteristics, Bond Work Index, bulk specific, specific density, desired mill tonnage capacity DTPH, operating % solids or pulp gas, feed size as F80 and maximum 'chunk size', product size as P80 and maximum and finally the type off circuit ...
The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5′ x 5′ Ball Mill has a working diameter of 5′ inside the liners and has 20 per cent more capacity than all other ball mills designated as 5′ x ...
Chemical Engineering questions and answers. QUESTION FOUR (a) What is the power required to crush 100 tons/hr of limestone if 80% of the feed passes 2" screen and 80% of the product passes 1/8" screen? The work Index for limestone may be taken as kWh/short ton. 5 Points (b) If a ball mill requires 3 kWh per ton of feed to reduce a feed of ...
Furthermore, it should be observed that a grate discharge ball mill converts about 20% more energy than an overflow discharge mill with the same shell dimensions. ... particles pass a screen with 25 x 25 mm apertures shall be ground to approx. 95% passing mm in a x m ball mill of 35 ton charge weight. In ... the power required to ...
At present, the average level of unit energy consumption of Cement Manufacturing Plants is at 33 kWh, in some Cement Manufacturing Plants, it could be 40 kWh higher than the average number. Through technology improvement, equipment update, and new type abrasion materials, the Cement Manufacturing Plant could reduce the unit energy consumption ...
The mill used for this comparison is a diameter by meter long ball mill with a 5000 HP drive motor. It is designed for approximately 90 per hour. This type twocompartment mill is a state oftheart shell supported cement finish mill. The torque and time requirements of the mill with the ball
The motor power draw required to turn a mill from rest to the operating speed includes the energy required for the initial starting torque and mechanical arrangements to rotate the mill. It is generally accepted that practical mill power (PM ) is a function of mill capacity and diameter,,P M = Mill Constant * (Mill Diameter ) n
If the capacity of the mill is 150 t/h, what would be the power consumption in the mill? (20 points) Mill Feed Wt, Size fractions (μm) (%) +500 500+400 ... 1 Calculate the power required for ball mill grinding. 2 Calculate the percent critical velocity (φ) of the mill if a grinding ball of size m is to be used and the ...
The capacity of the ball mill is usually considered to vary as the power of the diameter and directly as the length. As the effective diameter of the ball mill is measured inside the liners, it is important to know exactly whether the diameter of the ball mill in question is measured inside the shell or inside the liners when calculating ...
The calculated power input or horsepower in the above example is 316. Therefore, a 350hp motor is required and this in turn indicates that an 812 (8′ x 12′) Rod Mill is required. In the same way Fig. 3 indicates that an 800hp motor and a 101/214 or ′ by 14′ Ball Mill is required. Following is a condensed tabulation of the above ...
Abstract: In determining the proper mill size required to meet a targeted production rate, many factors are evaluated including: length to diameter (L/D) ratio, individual compartment lengths, rotational velocity, liner type, ball gradation and percent filling degree. This paper examines the effects of changing mill filling degree with respect to specific power consumption (kWh/ton) and ...
a. ball mill c. fluid energy mill b. rod mill d. jaw crusher. 4. Maximum size reduction in a ball mill is done by ... What is the power required to crush 100 ton/hr of limestone if 80 percent of the feed passes a 2in screen and 80 percent of the product a 1/8 ... What would be the power consumption of the capacity is reduced to 100kg/h and the ...
I'm interested to know when sizing a new ball mill, as to why recirculating load has no effect on the power calculation, although it will have effect on volumetric capacity naturally. For instance a mill of 300tph with a 300% recirculating load would have 1200 tph going through effectively, but if we reduce the recirculating load to 200% at ...
The raw vertical roller mill has four rollers, 3000 KW main drive, m table diameter, m roller diameter with 330 t/h capacity (made by LOESCHE Company from Germany).
Problem Calculate the operating speed of a ball mill from the following data: (i) Diameter of ball mill=500 mm (ii) Diameter of ball= 50mm Operating speed of ball mill is 35 % of critical speed. Problem Calculate the power required in horsepower to crush 150000 kg of feed, if 80 % of feed passes through 2 inch screen and 80% of product ...
The Ball Mill. Ball mills or tubular mills are built with diameters up to meters and lengths up to 20 meters; the drive ratings today are as high as 10,000 kW with stable operation, and maintenance of a ball mill is relatively simple . The maintenance cost and the capital cost are relatively low compared to other technologies.
However, a rough estimate suggests that a ball mill with a 30tonperhour output capacity could range from 200,000 to million USD. It is advisable to consult with manufacturers or suppliers ...
Estimates of the increases in power draw possible with grate discharge ball mills range from 10% to 20%, according to mill size and other operating parameters. The figures from pilot tests and some operating sites are even higher, up to 25% more power draw.
WI= Work Index= specific energy per ton, kwh/metric ton (characterizes the ore) F80 = 80% passing size of the circuit feed, in microns. P80 = 80% passing size of the circuit product, in microns. Example. The dry feed of a ball mill circuit is 300 t/h. The power at the pinion of the ball mill is 1800 kW.
Gyratory crusher: feed diameter to ; reduction ratio 5:1 to 10:1, usually 8:1; capacity 140 to 1000 kg/s; Mohs hardness <9. More suitable for slabby feeds than jaw crusher. [reduction by compression]. Roll crusher: feed diameter 1 cm: reduction ratio 5:1 to 10:1; capacity to 20 kg/s: Mohs hardness <
Ball Mill, Wet Ball Mill Lubrication system, Mill circuit tank with an agitator, Mill circuit Pump, Mill Hydro ... Design Capacity of mill TPH ... other components/ module shall be fully equipped to provide all signal requirements. All the 420 mA output signals from transmitters/other control system shall be able to drive minimum
In test 3, in which the grid was used to segregate the different sizes of balls, a further advantage of about 4 percent in efficiency is shown. The conical mill in test 4 increased the efficiency to 58 percent more than in test 1. The efficiency with the long (6foot) conical mill was about the same as with the short (3foot) one.
Do you need a quick estimation of a ball mill's capacity or a simple method to estimate how much can a ball mill of a given size (diameter/lenght) grind for tonnage a product P80 size? Use these 2 tables to get you close. No BWi Bond Work Index required here BUT be aware it is only a crude approximation for "most soft ores" from F80 1 cm ...
The operational controls are also reviewed for optimized mill operation. Every element of a closed circuit ball mill system is evaluated independently to assess its influence on the system. Figure 1 below is a typical example of inefficient grinding indicated by analysis of the longitudinal samples taken after a crash stop of the mill.
19. A certain crusher takes rock whose average particle diameter is m and crusher is to give a product whose average particle diameter is m at the rate of 20,000 kg/hr. At this rate, the mill takes 684 kgf m/sec of power and 35 kgfm/sec power is required to run it empty. (1) What would be the power consumption in terms of HP for same capacity if the average particle diameter in ...
Rule 1: Always use a jaw crusher if you can due to lower costs. Rule 2: For low capacity applications, use jaw crusher and hydraulic hammer for oversize. Rule 3: For high capacities, use jaw crusher with big intake openings. Rule 4: For very high capacities, use gyratory crusher.
The following four gridtype ball mill models are recommended to meet the daily production demand of 1500 tons: MQGg2740: Diameter: Length: 4m. Motor Power: 380kW. Processing Capacity: ...
Grate Discharge Ball Mills have shown 25% to 45% more tonnage ground and a substantial reduction in power consumed per ton of material compared size for size with overflow mills. To illustrate the characteristics of various type mills we have shown the types of discharge for rod mills and ball mills. There are essentially four types of rod mill ...
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