Size reduction of asbestos and mica is done by (A) Hammer mills (B) Rod mills (C) Gyratory crushers (D) Crushing rolls

Size reduction of asbestos and mica is done by
(A) Hammer mills
(B) Rod mills
(C) Gyratory crushers
(D) Crushing rolls
by

1 Answer

Answer :

(A) Hammer mills
by

Related questions

Size reduction of the __________ can be suitably done by ball mills, crushing rolls and rod mills. (A) Metalliferous ores (B) Non-metallic ores (C) Basic slags (D) Asbestos & mica

Description : Size reduction of the __________ can be suitably done by ball mills, crushing rolls and rod mills. (A) Metalliferous ores (B) Non-metallic ores (C) Basic slags (D) Asbestos & mica

Last Answer : (A) Metalliferous ores

Size reduction does not occur due to compression in case of (A) Rod mills (B) Gyratory crushers (C) Jaw crushers (D) Smooth roll crushers

Description : Size reduction does not occur due to compression in case of (A) Rod mills (B) Gyratory crushers (C) Jaw crushers (D) Smooth roll crushers

Last Answer : (A) Rod mills

Pick out the wrong statement pertaining to the roll crushers. (A) Maximum feed size determines the required roll diameter (B) For hard material's crushing, the reduction ratio should not exceed 4 (C) Both the rolls run necessarily at the same speed (D) Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced

Description : Pick out the wrong statement pertaining to the roll crushers. (A) Maximum feed size determines the required roll diameter (B) For hard material's crushing, the reduction ratio should not ... ratio and differential roll speed affect production rate & energy consumed per unit of surface produced

Last Answer : (C) Both the rolls run necessarily at the same speed

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

Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher? (A) Rod mill (B) Fluid energy mill (C) Gyratory crusher (D) Ball mill

Description : Which of the following crushers can be considered as a combination of a jaw crusher and a roller crusher? (A) Rod mill (B) Fluid energy mill (C) Gyratory crusher (D) Ball mill

Last Answer : (C) Gyratory crusher

Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size (C) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types

Description : Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed ... ) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types

Last Answer : (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size

Size reduction of fibrous materials like wood, asbestos, mica etc. is done by a disintegrator exemplified by the(A) Blake jaw crusher(B) Cage mill(C) Stamp mill(D) Bradford's breaker

Description : Size reduction of fibrous materials like wood, asbestos, mica etc. is done by a disintegrator exemplified by the (A) Blake jaw crusher (B) Cage mill (C) Stamp mill (D) Bradford's breaker

Last Answer : (B) Cage mill

In case of a hammer crusher, (A) Crushing takes place by impact breaking (B) Maximum acceptable feed size is 30 cms (C) Reduction ratio can be varied by adjusting the distance from cage to hammers (D) All (A), (B) and (C)

Description : In case of a hammer crusher, (A) Crushing takes place by impact breaking (B) Maximum acceptable feed size is 30 cms (C) Reduction ratio can be varied by adjusting the distance from cage to hammers (D) All (A), (B) and (C)

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

Ball mills and tube mills with flint or porcelain balls are used for size reduction of (A) Asbestos (B) Rubber (C) Non-metallic ores (D) Limestone

Description : Ball mills and tube mills with flint or porcelain balls are used for size reduction of (A) Asbestos (B) Rubber (C) Non-metallic ores (D) Limestone

Last Answer : (C) Non-metallic ores

Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers (C) States that the work required to form particle of any size from very large feed is proportional to the square root of the volume to surface ratio of the product (D) States that the work required for the crushing is proportional to the new surface created

Description : Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers ( ... (D) States that the work required for the crushing is proportional to the new surface created

Last Answer : (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law

The term 'angle of nip' is concerned with the operation of the __________ crushers. (A) Jaw (B) Roll (C) Gyratory (D) None of these

Description : The term 'angle of nip' is concerned with the operation of the __________ crushers. (A) Jaw (B) Roll (C) Gyratory (D) None of these

Last Answer : (B) Roll

Gyratory crushers compared to the reciprocating jaw crushers (A) Have greater capacity per unit of discharge area (B) Crush intermittently (C) Are less suitable for coarse materials (D) Have less steady power consumption

Description : Gyratory crushers compared to the reciprocating jaw crushers (A) Have greater capacity per unit of discharge area (B) Crush intermittently (C) Are less suitable for coarse materials (D) Have less steady power consumption

Last Answer : (A) Have greater capacity per unit of discharge area

As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms). (A) LS (B) 93 LS (C) 250 LS (D) √(LS)

Description : As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms). (A) LS (B) 93 LS (C) 250 LS (D) √(LS)

Last Answer : (B) 93 LS

Pick out the wrong statement. (A) For the compressible cake, voidage & the specific resistance of the cake can be assumed to be constant (B) Cake resistance is independent of the pressure drop (C) Crushing of explosive materials are done by employing dry-grinding (D) Gyratory crusher is a coarse crusher

Description : Pick out the wrong statement. (A) For the compressible cake, voidage & the specific resistance of the cake can be assumed to be constant (B) Cake resistance is independent of the pressure ... Crushing of explosive materials are done by employing dry-grinding (D) Gyratory crusher is a coarse crusher

Last Answer : (B) Cake resistance is independent of the pressure drop

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

Basic slag is not ground in (A) Jaw crushers (B) Ball mills

Description : Basic slag is not ground in (A) Jaw crushers (B) Ball mills

Last Answer : (A) Jaw crushers

Angle of nip of the crushing rolls does not depend upon the (A) Diameter of the rolls (B) Speed of the rolls (C) Product size (D) Feed size

Description : Angle of nip of the crushing rolls does not depend upon the (A) Diameter of the rolls (B) Speed of the rolls (C) Product size (D) Feed size

Last Answer : (B) Speed of the rolls

Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Description : Pick out the wrong statement. (A) Hammer crushers operate by impact action (B) Standard screens have circular opening (C) With increase in mesh number of screens, their diameter in microns decreases (D) 200 mesh screen has 200 openings per linear cm

Last Answer : (D) 200 mesh screen has 200 openings per linear cm

Which of the following is used for primary crushing of very hard lumpy materials? (A) Toothed roll crusher (B) Gyratory crusher

Description : Which of the following is used for primary crushing of very hard lumpy materials? (A) Toothed roll crusher (B) Gyratory crusher

Last Answer : (B) Gyratory crusher

Size reduction of __________ is accomplished in steam heated rollers and roll crushers. (A) Resins (B) Gums (C) Hard rubber (D) Waxes

Description : Size reduction of __________ is accomplished in steam heated rollers and roll crushers. (A) Resins (B) Gums (C) Hard rubber (D) Waxes

Last Answer : (C) Hard rubber

Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression

Description : Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression

Last Answer : (B) Compression

Pick out the wrong statement. (A) More commonly used jaw crusher between Dodge jaw crusher and Blake jaw crusher is the later one(B) There are only four methods namely compression, impact, attrition andcutting, which the size reduction equipments employ(C) Cutting machines mainly employ 'attrition' for size reduction of solids(D) Operating principles of Dodge and Blake jaw crushers are combined inthe working of universal jaw crushers

Description : Pick out the wrong statement. (A) More commonly used jaw crusher between Dodge jaw crusher and Blake jaw crusher is the later one (B) There are only four methods namely compression, impact ... Operating principles of Dodge and Blake jaw crushers are combined in the working of universal jaw crushers

Last Answer : (C) Cutting machines mainly employ 'attrition' for size reduction of solids

Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Toothed roll crushers achieve size reduction by (A) Tearing (shear) and compression (B) Impact and attrition (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Carbon black is pulverised in a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory crusher

Description : Carbon black is pulverised in a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory crusher

Last Answer : (B) Ball mill

Size reduction of ice and gypsum can be accomplished suitably by a __________ crusher. (A) Blake jaw (B) Toothed roll (C) Gyratory (D) None of these

Description : Size reduction of ice and gypsum can be accomplished suitably by a __________ crusher. (A) Blake jaw (B) Toothed roll (C) Gyratory (D) None of these

Last Answer : (B) Toothed roll

Which of the following achieves the least reduction ratio for a given feed size? (A) Jaw crusher (B) Roll crusher (C) Cone crusher (D) Gyratory crusher

Description : Which of the following achieves the least reduction ratio for a given feed size? (A) Jaw crusher (B) Roll crusher (C) Cone crusher (D) Gyratory crusher

Last Answer : (B) Roll crusher

Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. (A) Cage (B) Hammer (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill. (A) Cage (B) Hammer (C) Both (A) & (B) (D) Neither (A) nor (B)

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

What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls? (A) 16° (B) 32° (C) 40° (D) 46°

Description : What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls? (A) 16° (B) 32° (C) 40° (D) 46°

Last Answer : (B) 32°

Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively). (A) cos α = (dr + dp)/(dr + df) (B) cos α = (dr + df)/(dr + dp) (C) tan α = (dr + dp)/(dr + df) (D) sin α = (dr + dp)/(dr + df)

Description : Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively). (A) cos α = (dr + dp)/(dr + df) (B) cos α = (dr + df)/(dr + dp) (C) tan α = (dr + dp)/(dr + df) (D) sin α = (dr + dp)/(dr + df)

Last Answer : (A) cos α = (dr + dp)/(dr + df)

Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m). (A) 3.6 V.W.Dr.ρ (B) 3.6 V.W. ρ (C) 3.6 W.Dr.ρ (D) 3.6 V.W.Dr/ρ

Description : Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls ... V.W.Dr.ρ (B) 3.6 V.W. ρ (C) 3.6 W.Dr.ρ (D) 3.6 V.W.Dr/ρ

Last Answer : (A) 3.6 V.W.Dr.ρ

Stamp mills are generally used for crushing (A) Iron ores (B) Gold ores (C) Talc (D) Diamond

Description : Stamp mills are generally used for crushing (A) Iron ores (B) Gold ores (C) Talc (D) Diamond

Last Answer : (B) Gold ores

Reduction ratio of crushers is the (A) Ratio of feed opening to discharge opening (B) Ratio of discharge opening to feed opening (C) Determining factor for minimum dia of the feed and the product (D) None of these

Description : Reduction ratio of crushers is the (A) Ratio of feed opening to discharge opening (B) Ratio of discharge opening to feed opening (C) Determining factor for minimum dia of the feed and the product (D) None of these

Last Answer : (A) Ratio of feed opening to discharge opening

Which of the following is not an ultrafine grinder (colloid mill)?(A) Micronizers (B) Agitated mills and fluid energy mills (C) Toothed roll crusher (D) Hammer mills with internal classification

Description : Which of the following is not an ultrafine grinder (colloid mill)? (A) Micronizers (B) Agitated mills and fluid energy mills (C) Toothed roll crusher (D) Hammer mills with internal classification

Last Answer : (C) Toothed roll crusher

__________ mills are termed as impactors. (A) Hammer (B) Cage (C) Rolling-compression (D) None of these

Description : __________ mills are termed as impactors. (A) Hammer (B) Cage (C) Rolling-compression (D) None of these

Last Answer : (A) Hammer

Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials

Description : Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials

Last Answer : Option C

Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of materials (C) Size enlargement (opposite of size reduction) is not a mechanical operation (D) A 'dust catcher' is simply an enlargement in a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas

Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas

Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation

Pick out the wrong statement. (A) Gape is the greatest distance between the crushing surfaces or the jaws (B) The angle of nip (2α) is the angle between roll faces at the level where they will just take hold of a particle and draw it in the crushing zone (C) Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing (D) Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product

Description : Pick out the wrong statement. (A) Gape is the greatest distance between the crushing surfaces or the jaws (B) The angle of nip (2α) is the angle between roll faces at the level where they will ... Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product

Last Answer : (C) Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing

Energy consumption in a crusher decreases with increase in the (A) Size of the product (at constant feed size) (B) Capacity of the crushing machine (C) Size of feed (at constant reduction ratio) (D) All (A), (B) & (C)

Description : Energy consumption in a crusher decreases with increase in the (A) Size of the product (at constant feed size) (B) Capacity of the crushing machine (C) Size of feed (at constant reduction ratio) (D) All (A), (B) & (C)

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

For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to(A) The new surface created(B) The size reduction ratio(C) The change in volume due to crushing(D) None of these

Description : For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to (A) The new surface created (B) The size reduction ratio (C) The change in volume due to crushing (D) None of these

Last Answer : (A) The new surface created

In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing. (A) Primary (B) Secondary (C) Fine

Description : In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing. (A) Primary (B) Secondary (C) Fine

Last Answer : (C) Fine

In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing. (A) Primary (B) Secondary (C) Fine (D) Ultrafine

Description : In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing. (A) Primary (B) Secondary (C) Fine (D) Ultrafine

Last Answer : (B) Secondary

In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. (A) Secondary (B) Fine (C) Primary (D) Ultrafine

Description : In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. (A) Secondary (B) Fine (C) Primary (D) Ultrafine

Last Answer : (C) Primary

Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression

Description : Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression

Last Answer : (B) Attrition

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)

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)

__________ mills fall in the category of tumbling mills, (A) Ball and pebble (B) Rod and tube (C) Compartment (D) All (A), (B) & (C

Description : __________ mills fall in the category of tumbling mills, (A) Ball and pebble (B) Rod and tube (C) Compartment (D) All (A), (B) & (C

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

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'

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

"Fire-fighting clothes" are made from (1) Mica (2) Asbestos (3) Talc (4) Steatite

Description : "Fire-fighting clothes" are made from (1) Mica (2) Asbestos (3) Talc (4) Steatite

Last Answer : (2) Asbestos Explanation: Bunker Gear or "Turnout Gear" are terms used by many firefighters to refer to their system of outer protective clothing. Fire fighter used to be made of asbestos in ... firemen, rescuers and industrials made of materials FR cotton, Nomex, Modacryl, FR viscose and others.

Which of the following is a good conductor of heat but bad conductor of electricity? (1) mica (2) asbestos (3) celluloid (4) paraffin wax

Description : Which of the following is a good conductor of heat but bad conductor of electricity? (1) mica (2) asbestos (3) celluloid (4) paraffin wax

Last Answer : (1) mica Explanation: Mica is a good conductor of heat but bad conductor of electricity.