In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these

In case of a revolving mill, wet grinding compared to dry grinding
(A) Requires more energy
(B) Has less capacity
(C) Complicates handling & classification of the product
(D) None of these
by

1 Answer

Answer :

(D) None of these
by

Related questions

Wet grinding in a revolving mill __________ as compared to dry grinding. (A) Gives less wear on chamber walls (B) Requires more energy (C) Increases capacity (D) Complicates handling of the product

Description : Wet grinding in a revolving mill __________ as compared to dry grinding. (A) Gives less wear on chamber walls (B) Requires more energy (C) Increases capacity (D) Complicates handling of the product

Last Answer : (C) Increases capacity

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 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)

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

A __________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end. (A) Compartment (B) Tube (C) Rod (D) Pebble

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Last Answer : (A) Compartmen

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) Wet grinding in low viscous suspension (B) Wet grinding in high viscous suspension (C) Dry grinding of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills

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

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'

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Last Answer : (D) All 'a', 'b' & 'c'

Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with __________ to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Description : Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should ... to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34

Last Answer : (C) 1.34

Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of (A) Bronze (B) Stainless steel (C) Flint or porcelain (D) Concrete

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Last Answer : (C) Flint or porcelain

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

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Last Answer : (A) Length to diameter ratio

Use of 'grinding aids' is done in __________ grinding. (A) Dry (B) Wet (C) Ultrafine (D) Intermediate

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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)

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

Close circuit grinding by a ball mill with air sweeping employs a (A) Classifier (B) Cyclone separator between mill & classifier (C) Both (A) & (B) (D) Neither (A) nor (B)

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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

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To remove all the moisture from a wet solid it requires exposure to __________ air. (A) Perfectly dry (B) Highly humid (C) High temperature (D) None of these

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A tube mill compared to a ball mill (A) Has a higher length/diameter ratio(B) Produces a coarser product(C) Has a higher diameter/length ratio(D) Uses much larger balls

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

Natural gas recovered along with crude oil from oil wells is called wet natural gas which has a higher __________ compared to the dry natural gas. (A) Unsaturated hydrocarbon content (B) Calorific value (C) Quantity of propane (D) Quantity of butane

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Tube mill compared to ball mill (A) Produces finer products (B) Is long in comparison with its diameter (C) Uses smaller balls (D) All (A), (B) & (C)

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

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

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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

When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the (A) Partial pressure of water vapour is less than the total pressure (B) Humidity is < 100% & dew point temperature of air has not reached (C) Dew point temperature of air has not reached & air is not saturated fully (D) Air is fully saturated

Description : When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the (A) Partial pressure of water vapour is less than the total pressure (B) Humidity is < 100% & dew ... Dew point temperature of air has not reached & air is not saturated fully (D) Air is fully saturated

Last Answer : (D) Air is fully saturated

Sweet orange requires a. Dry and semi arid conditions b. Dry and sub humid conditions c. Wet and sub humid conditions b. Non of these

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Last Answer : Dry and sub humid conditions

Efficient burning of anthracite coal requires (A) Low preheat of air (B) Fine grinding (C) High excess air (D) All (A), (B) and (C)

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Last Answer : (B) Fine grinding

Pick out the correct statement. (A) The capacity and the effectiveness of a screen are the same (B) The capacity and the effectiveness of screen are opposing factors (C) The screening surface of a 'reel' (a revolving screen used in flour mills) is made of silk bolting cloth supported by wire mesh (D) Both (B) and (C)

Description : Pick out the correct statement. (A) The capacity and the effectiveness of a screen are the same (B) The capacity and the effectiveness of screen are opposing factors (C) The screening surface of a 'reel' (a ... flour mills) is made of silk bolting cloth supported by wire mesh (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C

Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be (A) More (B) Less (C) Same (D) Either more or less; depends on the climatic conditions

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Last Answer : (B) Less

A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case, the pump (A) Develops a lower head (B) Capacity is reduced (C) Requires more power (D) All (A), (B) and (C)

Description : A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case, the pump (A) Develops a lower head (B) Capacity is reduced (C) Requires more power (D) All (A), (B) and (C)

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

Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb temperature c) equal to the wet bulb temperature divided by the dry bulb temperature d) the ratio of the mass of water vapour divided by the mass of dry air e) the ratio of the mass of water vapour divided by the mass of wet air

Description : Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb ... of dry air e) the ratio of the mass of water vapour divided by the mass of wet air

Last Answer : ANSWER : A