The main differentiation factor between tube mill and ball mill is the (A) Length to diameter ratio (B) Size of the grinding media (C) Final product size (D) Operating speed

The main differentiation factor between tube mill and ball mill is the
(A) Length to diameter ratio
(B) Size of the grinding media
(C) Final product size
(D) Operating speed
by

1 Answer

Answer :

(A) Length to diameter ratio
by

Related questions

A tube mill as compared to a ball mill (A) Employs smaller balls (B) Gives finer size reduction but consumes more power (C) Has larger length/diameter ratio (>2 as compared to 1 for ball mill) (D) All (A), (B) and (C)

Description : A tube mill as compared to a ball mill (A) Employs smaller balls (B) Gives finer size reduction but consumes more power (C) Has larger length/diameter ratio (>2 as compared to 1 for ball mill) (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

A tube mill compared to a ball mill (A) Has a higher length/diameter ratio(B) Produces a coarser product(C) Has a higher diameter/length ratio(D) Uses much larger balls

Description : A tube mill compared to a ball mill (A) Has a higher length/diameter ratio (B) Produces a coarser product (C) Has a higher diameter/length ratio (D) Uses much larger balls

Last Answer : (A) Has a higher length/diameter ratio

Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) Wet grinding in low viscous suspension (B) Wet grinding in high viscous suspension (C) Dry grinding of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills

Description : Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) ... of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills

Last Answer : (D) Dry grinding of large particles in un-baffed mills

Rod mills employed for grinding (A) Employ a steel shell having L/D ratio of 1.5 to 3.0 (B) Is useful for handling sticky materials (C) Employ steel rods of 2-12 cms diameter extending over full length of the mill (D) All 'a', 'b' & 'c'

Description : Rod mills employed for grinding (A) Employ a steel shell having L/D ratio of 1.5 to 3.0 (B) Is useful for handling sticky materials (C) Employ steel rods of 2-12 cms diameter extending over full length of the mill (D) All 'a', 'b' & 'c'

Last Answer : (D) All 'a', 'b' & 'c'

In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)

Description : In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

A pebble mill (A) Is a ball mill (B) Employs flints or ceramic pebbles as the grinding medium (C) Is a tube mill lined with ceramic or other non-metallic liner (D) Both (B) and (C)

Description : A pebble mill (A) Is a ball mill (B) Employs flints or ceramic pebbles as the grinding medium (C) Is a tube mill lined with ceramic or other non-metallic liner (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a(A) Buhrstone mill(B) Ball mill(C) Crushing rolls(D) Hammer mill

Description : For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a (A) Buhrstone mill (B) Ball mill (C) Crushing rolls (D) Hammer mill

Last Answer : (A) Buhrstone mill

__________ balls capable of grinding the feed in a ball mill gives the maximum efficiency. (A) Cast iron (B) Minimum size (C) Maximum size (D) Elliptical

Description : __________ balls capable of grinding the feed in a ball mill gives the maximum efficiency. (A) Cast iron (B) Minimum size (C) Maximum size (D) Elliptical

Last Answer : (B) Minimum size

Length/diameter ratio of a ball mill is (A) 1.5 (B) 1 (C) < 1 (D) > 1

Description : Length/diameter ratio of a ball mill is (A) 1.5 (B) 1 (C) < 1 (D) > 1

Last Answer : (C) < 1

Tube mill compared to ball mill (A) Produces finer products (B) Is long in comparison with its diameter (C) Uses smaller balls (D) All (A), (B) & (C)

Description : Tube mill compared to ball mill (A) Produces finer products (B) Is long in comparison with its diameter (C) Uses smaller balls (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

In case of a hammer crusher, the final product size depends on the (A) Feed rate (B) Rotor speed(C) Clearance between hammer & grinding plates(D) All (A), (B) and (C

Description : In case of a hammer crusher, the final product size depends on the (A) Feed rate (B) Rotor speed (C) Clearance between hammer & grinding plates (D) All (A), (B) and (C

Last Answer : (D) All (A), (B) and (C

Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Description : Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Last Answer : (C) Fine grinding

Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Grinding efficiency of a ball mill is of the order of __________ percent. (A) 1-5 (B) 40-50 (C) 75-80 (D) 90-95

Description : Grinding efficiency of a ball mill is of the order of __________ percent. (A) 1-5 (B) 40-50 (C) 75-80 (D) 90-95

Last Answer : (A) 1-5

3. __________ mill is normally used for grinding of talc. (A) Tube (B) Compartment (C) Ring-roll (D) Pebble

Description : 3. __________ mill is normally used for grinding of talc. (A) Tube (B) Compartment (C) Ring-roll (D) Pebble

Last Answer : (A) Tube

A __________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end. (A) Compartment (B) Tube (C) Rod (D) Pebble

Description : A __________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end. (A) Compartment (B) Tube (C) Rod (D) Pebble

Last Answer : (A) Compartmen

Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines? (A) Compartment mill (B) Rod mill (C) Pebble mill (D) Tube mill

Description : Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines? (A) Compartment mill (B) Rod mill (C) Pebble mill (D) Tube mill

Last Answer : (B) Rod mill

Out of the following size reduction equipments, the maximum feed size can be accepted by the (A) Tube mill (B) Ball mill (C) Jaw crusher (D) Jet pulveriser

Description : Out of the following size reduction equipments, the maximum feed size can be accepted by the (A) Tube mill (B) Ball mill (C) Jaw crusher (D) Jet pulveriser

Last Answer : (C) Jaw crusher

Cement clinker is reduced to fine size by a (A) Roll crusher (B) Ball mill (C) Tube mill (D) Hammer mill

Description : Cement clinker is reduced to fine size by a (A) Roll crusher (B) Ball mill (C) Tube mill (D) Hammer mill

Last Answer : (C) Tube mill

In ball mill operation, the feed size (Df in meters) and the ball diameter (Db in metres) are related as (where, K = grindability constant (varying from 0.9 to 1.4 in increasing order of hardness)) (A) Db 2 = K.Df (B) Db = K.Df (C) Db 3 = K.Df (D) Db 2 = K.Df

Description : In ball mill operation, the feed size (Df in meters) and the ball diameter (Db in metres) are related as (where, K = grindability constant (varying from 0.9 to 1.4 in increasing order of hardness)) (A) Db 2 = K.Df (B) Db = K.Df (C) Db 3 = K.Df (D) Db 2 = K.Df

Last Answer : (A) Db 2 = K.Df

What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls? (A) 0.5 (B) 1.0 (C) 2.76 (D) 0.66

Description : What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls? (A) 0.5 (B) 1.0 (C) 2.76 (D) 0.66

Last Answer : (D) 0.66

The operating speed of a ball mill should be __________ the critical speed. (A) Less than (B) Much more than (C) At least equal to (D) Slightly more than

Description : The operating speed of a ball mill should be __________ the critical speed. (A) Less than (B) Much more than (C) At least equal to (D) Slightly more than

Last Answer : (A) Less than

In case of a ball mill, (A) Coarse feed requires a larger ball (B) Fine feed requires a larger ball (C) Operating speed should be more than the critical speed (D) None of these

Description : In case of a ball mill, (A) Coarse feed requires a larger ball (B) Fine feed requires a larger ball (C) Operating speed should be more than the critical speed (D) None of these

Last Answer : (A) Coarse feed requires a larger ball

The mechanism of size reduction by a hammer mill is by impact and attrition between the (A) Grinding element & the housing (B) Feed particles (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : The mechanism of size reduction by a hammer mill is by impact and attrition between the (A) Grinding element & the housing (B) Feed particles (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Which of the following size reduction equipments employs mainly attrition for ultrafine grinding? (A) Jet mills (B) Fluid energy mill (C) Micronizer (D) All (A), (B) and (C)

Description : Which of the following size reduction equipments employs mainly attrition for ultrafine grinding? (A) Jet mills (B) Fluid energy mill (C) Micronizer (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Wet grinding in a revolving mill __________ as compared to dry grinding. (A) Gives less wear on chamber walls (B) Requires more energy (C) Increases capacity (D) Complicates handling of the product

Description : Wet grinding in a revolving mill __________ as compared to dry grinding. (A) Gives less wear on chamber walls (B) Requires more energy (C) Increases capacity (D) Complicates handling of the product

Last Answer : (C) Increases capacity

Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of (A) Bronze (B) Stainless steel (C) Flint or porcelain (D) Concrete

Description : Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of (A) Bronze (B) Stainless steel (C) Flint or porcelain (D) Concrete

Last Answer : (C) Flint or porcelain

In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these

Description : In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these

Last Answer : (D) None of these

Run of mine (ROM) coal is crushed by a __________ for use in domestic ovens. (A) Jaw crusher (B) Hammer crusher (C) Ball mill (D) Tube mil

Description : Run of mine (ROM) coal is crushed by a __________ for use in domestic ovens. (A) Jaw crusher (B) Hammer crusher (C) Ball mill (D) Tube mil

Last Answer : (B) Hammer crusher

For the preliminary breaking of hard rock, we use a (A) Gyratory crusher(B) Ball mill(C) Tube mill(D) Squirrel-cage disintegrator

Description : For the preliminary breaking of hard rock, we use a (A) Gyratory crusher (B) Ball mill (C) Tube mill (D) Squirrel-cage disintegrator

Last Answer : (A) Gyratory crusher

Limestone is normally crushed in a (A) Roll crusher (B) Hammer crusher (C) Ball mill (D) Tube mill

Description : Limestone is normally crushed in a (A) Roll crusher (B) Hammer crusher (C) Ball mill (D) Tube mill

Last Answer : (B) Hammer crusher

Fibrous material is broken by a (A) Roll-crusher (B) Squirrel-cage disintegrator (C) Ball mill (D) Tube mill

Description : Fibrous material is broken by a (A) Roll-crusher (B) Squirrel-cage disintegrator (C) Ball mill (D) Tube mill

Last Answer : (B) Squirrel-cage disintegrator

Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) (A) D (B) 1/D (C) D2.5 (D) 1/D2.5

Description : Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) (A) D (B) 1/D (C) D2.5 (D) 1/D2.5

Last Answer : (C) D2.5 (D) 1/D2

For efficient grinding, ball mills must be operated (A) At a speed less than the critical speed (B) At a speed more than the critical speed (C) At a speed equal to the critical speed (D) With minimum possible small balls

Description : For efficient grinding, ball mills must be operated (A) At a speed less than the critical speed (B) At a speed more than the critical speed (C) At a speed equal to the critical speed (D) With minimum possible small balls

Last Answer : (A) At a speed less than the critical speed

__________ mill is not used for grinding wheat into flour and for milling of cereals & other vegetable products. (A) Buhrstone (B) Roller (C) Attrition (D) Pebble

Description : __________ mill is not used for grinding wheat into flour and for milling of cereals & other vegetable products. (A) Buhrstone (B) Roller (C) Attrition (D) Pebble

Last Answer : (D) Pebble

A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra-grinding (D) Crushing

Description : A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra-grinding (D) Crushing

Last Answer : (C) Ultra-grinding

A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra grinding (D) Crushing

Description : A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra grinding (D) Crushing

Last Answer : (C) Ultra grinding

Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent

Description : Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent

Last Answer : (D) Highly turbulent

Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately? (A) Rittinger's law (B) Kick's law (C) Bond's law (D) None of these

Description : Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately? (A) Rittinger's law (B) Kick's law (C) Bond's law (D) None of these

Last Answer : (A) Rittinger's law

Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them. (A) Jaw crusher, Ball mill, Fluid energy mill(B) Ball mill, Jaw crusher, Fluid energy mill(C) Fluid energy mill, Jaw crusher, Ball mill(D) Fluid energy mill, Ball mill, Jaw crusher

Description : Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them. (A) Jaw crusher, Ball mill, Fluid energy mill (B) Ball mill, Jaw crusher, Fluid ... C) Fluid energy mill, Jaw crusher, Ball mill (D) Fluid energy mill, Ball mill, Jaw crusher

Last Answer : (A) Jaw crusher, Ball mill, Fluid energy mill

Coal is finally pulverised to 200 mesh size for burning in boilers by a (A) Hammer crusher(B) Ball mill(C) Roll crusher(D) Gyratory crusher

Description : Coal is finally pulverised to 200 mesh size for burning in boilers by a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory crusher

Last Answer : (B) Ball mill

Feed size of ≥ 25 cms can be accepted by (A) Ball mill (B) Rod mill (C) Fluid energy mill (D) Jaw crusherFeed size of ≥ 25 cms can be accepted by(A) Ball mill(B) Rod mill(C) Fluid energy mill(D) Jaw crusher

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Last Answer : (D) Jaw crusher

Maximum size reduction in a ball mill is done by the, __________ action. (A) Attrition (B) Compression (C) Impact (D) Cutting

Description : Maximum size reduction in a ball mill is done by the, __________ action. (A) Attrition (B) Compression (C) Impact (D) Cutting

Last Answer : (C) Impact

The energy consumed by a ball mill depends on (A) Its speed (B) Its ball load (C) The density of the material being ground (D) All (A), (B) and (C)

Description : The energy consumed by a ball mill depends on (A) Its speed (B) Its ball load (C) The density of the material being ground (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Critical Speed (Nc ) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively). (A) Nc = (1/4π). √(g/R1 - R2 ) (B) Nc = (1/2π). √(g/R1 - R2 ) (C) Nc = (1/π). √(g/R1 - R2 ) (D) Nc = (1/2π). √(R1 - R2 /g)

Description : Critical Speed (Nc ) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively). (A) Nc = (1/4π). √(g/R1 - R2 ) (B) Nc = (1/2π). √(g/R1 - R2 ) (C) Nc = (1/π). √(g/R1 - R2 ) (D) Nc = (1/2π). √(R1 - R2 /g)

Last Answer : (B) Nc = (1/2π). √(g/R1 - R2 )

In which of the following cases, kinetic energy is being used in performing work? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Description : In which of the following cases, kinetic energy is being used in performing work? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Last Answer : (2) Driving a car to cover a distance Explanation: The work done on any object goes into changing the kinetic energy of that object. Since the work done by the car engine is equal to the change in ... defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

In which of the following cases, kinetic energy is being used in performing work ? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Description : In which of the following cases, kinetic energy is being used in performing work ? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Last Answer : Driving a car to cover a distance

In closed circuit grinding as compared to open circuit grinding, the (A) Specific surface of product is more (B) Product has lesser size uniformity (C) Production rate at a given limiting size is lower (D) Operation is economical

Description : In closed circuit grinding as compared to open circuit grinding, the (A) Specific surface of product is more (B) Product has lesser size uniformity (C) Production rate at a given limiting size is lower (D) Operation is economical

Last Answer : (D) Operation is economical

Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with __________ to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Description : Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should ... to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Last Answer : (C) 1.34

For constructing a terrazzo floor, Pick up the incorrect statement from the following: (A) A base course is prepared as in cement concrete flooring (B) A 32 mm thick layer of cement concrete (1 : 2 : 4) is laid on the base course and the surface is made smooth by trowelling (C) Glass strips are driven into the layer according to the pattern required (D) After final grinding is over, oxalic acid mixed with water is spread over and rubbed hard with soft material

Description : For constructing a terrazzo floor, Pick up the incorrect statement from the following: (A) A base course is prepared as in cement concrete flooring (B) A 32 mm thick layer of cement concrete ... final grinding is over, oxalic acid mixed with water is spread over and rubbed hard with soft material

Last Answer : Answer: Option B