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 : 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 : 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 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 : 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 : Size reduction mechanism used in Jaw crushers is (A) Attrition (B) Compression
Last Answer : (B) 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 : 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 : 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
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
Description : Basic slag is not ground in (A) Jaw crushers (B) Ball mills
Last Answer : (A) Jaw crushers
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
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
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 : Which of the following is a coarse crusher? (A) Smooth roll crusher (B) Toothed roll crusher (C) Gyratory crusher (D) Tube 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 : 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 : Colloid mills achieve size reduction mainly by (A) Impact (B) Attrition (C) Cutting (D) Compression
Last Answer : (B) Attrition
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 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 : 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 : 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 : 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 : 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 : 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 : 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 : Carbon black is pulverised in a (A) Hammer crusher (B) Ball mill (C) Roll crusher (D) Gyratory crusher
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
Description : The material is crushed in a gyratory crusher by the action of (A) Impact (B) Compression (C) Attrition (D) Cutting
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
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 : During size reduction by a jaw crusher, the energy consumed decreases with the (A) Decreasing size of product at constant size of feed (B) Decreasing machine capacity (C) Increasing size of feed at constant reduction ratio (D) None of these
Last Answer : (C) Increasing size of feed at constant reduction ratio
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 : 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 : 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 : __________ 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
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'
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
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 : 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 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 : What is the cause of reduction of jaw flesh in the mouth i.e. size of jaw hole and what is the solution ?
Last Answer : There may be different reasons for this: 1. You are suffering from malnutrition. 2. Not eating food on time. 3. You are not sleeping as much as you need to sleep . 4. Thinks unnecessarily. 5. Excessive masturbation. If the above causes occur, avoid them.
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 : 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
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
Description : __________ mills are termed as impactors. (A) Hammer (B) Cage (C) Rolling-compression (D) None of these
Last Answer : (A) Hammer
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 : The main size reduction operation in ultrafine grinders is (A) Cutting (B) Attrition (C) Compression (D) Impact
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 : 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