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

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

1 Answer

Answer :

(B) Gyratory crusher
by

Related questions

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Description : Which of the following is a coarse crusher? (A) Smooth roll crusher (B) Toothed roll crusher (C) Gyratory crusher (D) Tube mill

Last Answer : (C) Gyratory crusher

Which of the following is a fine crusher? (A) Blake jaw crusher (B) Gyratory crusher (C) Toothed roll crusher (D) Dodge jaw crusher

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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

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Last Answer : (B) Toothed roll

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

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

Which is a secondary crusher for a hard & tough stone? (A) Jaw crusher(B) Cone crusher(C) Impact crusher(D) Toothed roll crushe

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

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

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Last Answer : (C) Toothed roll crusher

Pick out the correct statement: (A) Removal of iron from ceramic material is necessitated (by magnetic separation method) so as to avoid discolouration of ceramic products (B) The operating cost of shaking screen is more than that of a vibrating screen (C) Screen capacity does not depend upon the specific gravity of the minerals (D) Asphalt is best crushed using toothed roll crusher

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Last Answer : (A) Jaw crusher

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Last Answer : (B) Ball mill

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Last Answer : (B) Ball mill

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

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Last Answer : (B) Roll crusher

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)

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

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

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Last Answer : (A) Gyratory crusher

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

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

The material is crushed in a gyratory crusher by the action of (A) Impact (B) Compression (C) Attrition (D) Cutting

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Last Answer : (B) Compression

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

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Last Answer : (C) Gyratory crusher

According to Taggart's rule for selecting between a gyratory crusher and a jaw crusher; the later should be used, if the hourly tonnage to be crushed divided by the square of the gape expressed in cm is less than (A) 0.00184 (B) 0.0184 (C) 0.184 (D) 1.84

Description : According to Taggart's rule for selecting between a gyratory crusher and a jaw crusher; the later should be used, if the hourly tonnage to be crushed divided by the square of the gape expressed in cm is less than (A) 0.00184 (B) 0.0184 (C) 0.184 (D) 1.84

Last Answer : (B) 0.0184

The capacity of a gyratory crusher is __________ that of a jaw crusher with the same gape, handling the same feed & for the same product size range. (A) Same as (B) 2.5 times (C) 5 times (D) 10 times

Description : The capacity of a gyratory crusher is __________ that of a jaw crusher with the same gape, handling the same feed & for the same product size range. (A) Same as (B) 2.5 times (C) 5 times (D) 10 times

Last Answer : (B) 2.5 times

Capacity (in tons/hr) of jaw/gyratory crusher is equal to (where, L = length of the receiving opening, cm S = greater width of the discharge opening, cm). (A) 0.01 L.S (B) 0.087 L.S (C) L.S (D) L.S/0.087

Description : Capacity (in tons/hr) of jaw/gyratory crusher is equal to (where, L = length of the receiving opening, cm S = greater width of the discharge opening, cm). (A) 0.01 L.S (B) 0.087 L.S (C) L.S (D) L.S/0.087

Last Answer : (B) 0.087 L.S

To get a fine talc powder from its granules, the equipment used is (A) Roller crusher (B) Ball mill (C) Jaw crusher (D) Gyratory crusher

Description : To get a fine talc powder from its granules, the equipment used is (A) Roller crusher (B) Ball mill (C) Jaw crusher (D) Gyratory crusher

Last Answer : (B) Ball mill

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

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

Last Answer : (A) Hammer mills

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)

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)

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)

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

Choke crushing (in case of a Jaw crusher) compared to free crushing (A) Results in increased capacity (B) Consumes less power (C) Consumes more power (D) Both (A) and (C)

Description : Choke crushing (in case of a Jaw crusher) compared to free crushing (A) Results in increased capacity (B) Consumes less power (C) Consumes more power (D) Both (A) and (C)

Last Answer : (C) Consumes more power

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

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

What is the purpose of the pet bottle crusher? Where can I buy the best plastic crushing machine?

Description : What is the purpose of the pet bottle crusher? Where can I buy the best plastic crushing machine?

Last Answer : May I ask why you wish to buy the best crushing machine if you don't even know the purpose behind it? The purpose would be to save space when throwing away or recycling plastic bottles. Since 2 ... lift back up with the handle. Repeat for each plastic bottle. BONUS. Works for aluminum cans as well.

Hot, lumpy & abrasive materials are best transported by using a/an __________ conveyor. (A) Apron (B) Belt

Description : Hot, lumpy & abrasive materials are best transported by using a/an __________ conveyor. (A) Apron (B) Belt

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Bucket elevators are not suitable for the vertical lifting of __________ materials. (A) Fine (e.g. - 200 mesh size coal) (B) Sticky (e.g. clay paste) (C) Small lumpy (e.g. grains and sand) (D) Free flowing

Description : Bucket elevators are not suitable for the vertical lifting of __________ materials. (A) Fine (e.g. - 200 mesh size coal) (B) Sticky (e.g. clay paste) (C) Small lumpy (e.g. grains and sand) (D) Free flowing

Last Answer : (B) Sticky (e.g. clay paste

Horsepower required for a roll crusher is directly proportional to its (A) Reduction ratio (B) Capacity(C) Both (A) & (B)(D) Neither (A) nor (B)

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

In a roll crusher, the specific power consumption and the production rate is affected by the (A) Reduction ratio (B) Differential roll speed (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : In a roll crusher, the specific power consumption and the production rate is affected by the (A) Reduction ratio (B) Differential roll speed (C) Both (A) and (B) (D) Neither (A) nor (B)

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In a roll crusher, both the rolls (A) Have the same diameter (B) Are rotated towards each other (C) Run either at the same or different speeds (D) All (A), (B) and (C

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

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

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

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Last Answer : (C) Heavy tonnages of rocks or gravel

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

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Crushing of mineral particles is accomplished in a 'cage mill', when one or more alloy steel bars are revolved in opposite directions. It is a type of __________ mill. (A) Impact (B) Roll (C) Vibratory (D) None of these

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

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

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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

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

Which of the following crushing laws is most accurately applicable to the fine grinding of materials? (A) Bond's crushing law (B) Kick's law (C) Rittinger's law (D) None of these

Description : Which of the following crushing laws is most accurately applicable to the fine grinding of materials? (A) Bond's crushing law (B) Kick's law (C) Rittinger's law (D) None of these

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__________ are mixed using ribbon blenders. (A) Lumpy solids and low viscosity liquids (B) Dry powders (C) High viscosity liquids (D) Thick pastes

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Overall thermal efficiency of a lumpy coal fired suitably designed heating furnace, if operated & maintained properly may be about __________ percent. (A) 10-15 (B) 25-30 (C) 45-50 (D) 65-70

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The function of secondary combustion air is to (A) Pneumatically convey the pulverised coal (B) Completely burn the volatile matter (C) Burn the lumpy coal (D) None of these

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Combustion of pulverised coal compared to the lumpy coal (A) Provides better control of furnace temperature (B) Facilitates combustion with lower excess air (C) Provides higher thermal efficiency & flame temperature (D) All (A), (B) & (C)

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

Gravity stamp mill is meant for the __________ crushing. (A) Primary (B) Intermediate (C) Fine (D) Ultrafine

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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

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Last Answer : (C) Fine