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 : 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 : 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 : 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 : For coarse reduction of hard solids, use (A) Impact (B) Attrition (C) Compression (D) Cutting
Last Answer : (C) 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 : The material is crushed in a gyratory crusher by the action of (A) Impact (B) Compression (C) Attrition (D) Cutting
Last Answer : (B) Compression
Description : Ultrafine grinders operate principally by (A) Slow compression (B) Impact (C) Attrition (D) Cutting action
Last Answer : (C) 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)
Last Answer : (C) Both (A) & (B)
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)
Description : Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression
Description : Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition
Last Answer : (C) Fine grinding
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
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 : 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 : __________ 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
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)
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
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)
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
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
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
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
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
Description : A patient has improperly formed DEJ, reduction in size of pulp chamber, chipping and attrition of enamel that would MOSTLY be: A. Fluorosis B. Amelogenesis imperfecta C. Dentinogenesis imperfecta
Last Answer : C. Dentinogenesis imperfecta
Description : For achieving maximum capacity of the ball mill, the ball charge should be equal to about __________ percent of the ball mill volume. (A) 10 (B) 25 (C) 50 (D) 75
Last Answer : (C) 50
Description : Alloy powder manufactured by the following process have spherical shapes. (A) Electrochemical deposition (B) Gaseous reduction (C) Atomisation (D) Mechanical attrition
Last Answer : (C) Atomisation
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
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)
Description : Mixing of light fine powder such as insecticides is done by (A) Banbury mixer (B) Pug mill (C) Impact wheels (D) Kneader
Last Answer : (C) Impact wheels
Description : Which of the following is not a revolving/tumbling mill used for size reduction? (A) Compartment mill (B) Pebble mill (C) Cage mill (D) Rod mill
Last Answer : (C) Cage mill
Description : __________ test is done to find out the softening point of bitumen. (A) Impact (B) Ball and ring (C) Flame (D) Viscosity
Last Answer : (B) Ball and ring
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)
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
Description : 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
Last Answer : (A) Length to diameter ratio
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 : Feed size of ≥ 25 cms can be accepted by (A) Ball mill (B) Rod mill (C) Fluid energy mill (D) Jaw crusher
Last Answer : (D) Jaw crusher
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
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 : 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
Description : 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
Last Answer : (A) Impact
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 : 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
Description : A __________ mixer resembles a ball mill without balls. (A) Banbury (B) Pug mill (C) Tumbling (D) Pan
Last Answer : (C) Tumbling
Description : In a ball mill, the volume occupied by the balls (when the mill is stopped) is about __________ percent of the volume of the mill. (A) 35 (B) 50 (C) 70 (D) 85
Last Answer : (B) 50
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
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 : Which of the following terminology is not used for size reduction of materials to fine sizes or powders? (A) Comminution (B) Dispersion (C) Pulverisation (D) Compression
Last Answer : (D) Compression
Description : A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra-grinding (D) Crushing
Last Answer : (C) Ultra-grinding