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
Description : Ultrafine grinders operate principally by (A) Slow compression (B) Impact (C) Attrition (D) Cutting action
Last Answer : (C) Attrition
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
Description : General mechanism of size reduction in intermediate and fine grinder is by (A) Cutting action (B) Compression (C) Compression and tearing (D) Impact and attrition
Last Answer : (D) Impact and attrition
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
Description : The main size reduction operation in ultrafine grinders is (A) Cutting (B) Attrition (C) Compression (D) Impact
Last Answer : (B) Attrition
Description : Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression
Description : Maximum size reduction in a fluid energy mill is achieved by (A) Compression (B) Interparticle attrition (C) Cutting (D) Impact
Last Answer : (B) Interparticle attrition
Description : For coarse reduction of hard solids, use (A) Impact (B) Attrition (C) Compression (D) Cutting
Last Answer : (C) Compression
Description : The grinding in a hammer crusher takes place due to the (A) Attrition (B) Impact (C) Both (A) & (B) (D) Neither (A) nor (B
Last Answer : (C) Both (A) & (B)
Description : Energy requirement (per unit mass of material crushed/ground) is highest for (A) Jaw crusher (B) Rod mill (C) Ball mill (D) Fluid energy mil
Last Answer : (D) Fluid energy mil
Description : 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 ... upon the specific gravity of the minerals (D) Asphalt is best crushed using toothed roll crusher
Last Answer : (A) Removal of iron from ceramic material is necessitated (by magnetic separation method) so as to avoid discolouration of ceramic products
Description : Soft & non-abrasive materials can be made into fines by (A) Attrition (B) Compression (C) Cutting (D) None of these
Last Answer : (A) Attrition
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)
Description : Which of the following comes in the category of primary crusher for hard and tough stone? (A) Jaw crusher (B) Cone crusher (C) Gyratory crusher (D) None of these
Last Answer : (A) Jaw crusher
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
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
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
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
Description : Which of the following is a coarse crusher? (A) Smooth roll crusher (B) Toothed roll crusher (C) Gyratory crusher (D) Tube mill
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
Description : Which of the following is a fine crusher? (A) Blake jaw crusher (B) Gyratory crusher (C) Toothed roll crusher (D) Dodge jaw crusher
Last Answer : (C) Toothed roll crusher
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
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
Description : Carbon black is pulverised in a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory 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
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
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
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
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
Description : Limestone is normally crushed in a (A) Roll crusher (B) Hammer crusher (C) Ball mill (D) Tube mill
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
Description : Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression
Last Answer : (B) Compression
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)
Description : Los Angeles testing machine is used to conduct (A) Abrasion test (B) Impact test (C) Attrition test (D) Crushing strength test
Last Answer : Answer: Option A
Description : Explain the working, advantages and disadvantages of any one mill based on the principle of combined impact and attrition?
Last Answer : which of the following mill works on the principle of combined impact and attrition
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)
Description : Which is a secondary crusher for a hard & tough stone? (A) Jaw crusher (B) Cone crusher (C) Impact crusher (D) Toothed roll crushe
Last Answer : (B) Cone crusher
Description : Wheat is ground into flour in a (A) Hammer crusher (B) Roller crusher (C) Impact mill (D) Fluid energy mill
Last Answer : (B) Roller crusher
Description : The crushed material received for separation is called feed or (A) Tailing (B) Heading (C) Concentrate (D) Middling
Last Answer : (B) Heading
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
Description : Rittinger's number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger's number of a material indicates its (A) Easier grindability (B) Poor grindability (C) High power consumption in grinding (D) None of these
Last Answer : (A) Easier grindability
Description : Rittinger number which designates the new surface produced per unit of mechanical energy absorbed by the material being crushed, depends on the (A) State or manner of application of the crushing force (B) Ultimate strength of the material (C) Elastic constant of the material (D) All (A), (B) and (C)
Description : What is the process that tends to build up the land surface by deposition of solid material in its lower areas, known as? a. Abrasion b. Agglomeration c. Aggradation d. Attrition
Last Answer : c. Aggradation
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
Description : Cement pressure grouting is suitable for a) Very fine crack b) weathered concrete c) Active crack where cause of crack is known and remedial action has been taken* d) Crushed masonry
Last Answer : c) Active crack where cause of crack is known and remedial action has been taken
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
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
Description : Reciprocating screens are normally inclined at an angle of 5° with the horizontal and employ gyratory motion at feed end & reciprocating motion at the discharge end. They are not suitable for the ... Dry chemicals (C) Heavy tonnages of rocks or gravel (D) Powdered food & granular materials
Last Answer : (C) Heavy tonnages of rocks or gravel
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