A pebble mill (A) Is a ball mill (B) Employs flints or ceramic pebbles as the grinding medium (C) Is a tube mill lined with ceramic or other non-metallic liner (D) Both (B) and (C)

A pebble mill
(A) Is a ball mill
(B) Employs flints or ceramic pebbles as the grinding medium
(C) Is a tube mill lined with ceramic or other non-metallic liner
(D) Both (B) and (C)
by

1 Answer

Answer :

(D) Both (B) and (C)
by

Related questions

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

Description : 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

Last Answer : (C) Flint or porcelain

3. __________ mill is normally used for grinding of talc. (A) Tube (B) Compartment (C) Ring-roll (D) Pebble

Description : 3. __________ mill is normally used for grinding of talc. (A) Tube (B) Compartment (C) Ring-roll (D) Pebble

Last Answer : (A) Tube

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

Description : 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

Last Answer : (A) Compartmen

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

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

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)

Description : 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)

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

__________ 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

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

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 : 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)

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

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

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

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)

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)

__________ mill is not a revolving mill. (A) Pebble (B) Compartment (C) Cage (D) Tube

Description : __________ mill is not a revolving mill. (A) Pebble (B) Compartment (C) Cage (D) Tube

Last Answer : (C) Cage

__________ mills fall in the category of tumbling mills, (A) Ball and pebble (B) Rod and tube (C) Compartment (D) All (A), (B) & (C

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

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)

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

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

__________ 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

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

Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Description : Ball mill is used for (A) Crushing (B) Coarse grinding (C) Fine grinding (D) Attrition

Last Answer : (C) Fine grinding

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

Grinding efficiency of a ball mill is of the order of __________ percent. (A) 1-5 (B) 40-50 (C) 75-80 (D) 90-95

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

Liners of a ball mill are never made of (A) Lead (B) Alloy steel (C) Rubber or ceramic material (D) Cast iron

Description : Liners of a ball mill are never made of (A) Lead (B) Alloy steel (C) Rubber or ceramic material (D) Cast iron

Last Answer : (A) Lead

Pick out the correct statement. (A) Noise from ball mills can be dealt with by fibre glass lined enclosures (B) Noise from vibrating chutes can be reduced by lining the metallic chute with rubber (C) Noise of conveyor belt system is reduced by using urethane coated cloth conveyor belts and rubber/plastic covered metallic rollers (D) All (A), (B) & (C)

Description : Pick out the correct statement. (A) Noise from ball mills can be dealt with by fibre glass lined enclosures (B) Noise from vibrating chutes can be reduced by lining the metallic chute with rubber (C) Noise ... cloth conveyor belts and rubber/plastic covered metallic rollers (D) All (A), (B) & (C)

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

Which one of the following is an example of chemical weathering? w) the splitting of a boulder x) the grinding of pebbles into sand y) the cleavage of a feldspar crystal z) the rusting of hornblende

Description : Which one of the following is an example of chemical weathering? w) the splitting of a boulder x) the grinding of pebbles into sand y) the cleavage of a feldspar crystal z) the rusting of hornblende

Last Answer : ANSWER: Z -- THE RUSTING OF HORNBLENDE

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

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

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

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

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

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

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

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

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

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

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)

Description : 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)

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

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

Description : 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

Last Answer : (A) Has a higher length/diameter ratio

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

Last Answer : (C) Tube mill

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)

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)

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

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'

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'

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

Description : 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

Last Answer : (D) None of these

A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra-grinding (D) Crushing

Description : A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra-grinding (D) Crushing

Last Answer : (C) Ultra-grinding

A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra grinding (D) Crushing

Description : A fluid energy mill is used for (A) Cutting (B) Grinding (C) Ultra grinding (D) Crushing

Last Answer : (C) Ultra grinding

Maintain 850 OC for 1 hour (soaking time).  Cool the material to 60 OC in 4 hours. a) Calculate the efficiency of the furnace, if the specific heat of steel is 0.12 kcal/kgOC and fuel oil consumption per batch is 1400 litres.  GCV of fuel oil - 10200 kcal/kg,  Cost of fuel oil - Rs. 46,000/kL,  Sp. gr. of fuel oil - 0.92. b) Due to high cost of oil, the plant management decides to convert to a lower operating cost LPG fired furnace lined on the inside with ceramic fibre insulation and with an operating efficiency of 80%, for same requirement. The investment towards installation of the new furnace is Rs. 50 lakhs. Calculate the Return on Investment, if the plant operates two batches per day and 250 days in a year.  Cost of LPG - Rs. 75/kg,  GCV of LPG - 12500 kcal/kg.

Description : In a heat treatment shop, steel components are heat-treated in batches of 80 Tons. The  heat treatment cycle is as follows;  Increase temperature from 30 OC to 850 OC in 3 hours.  ... efficiency of 80%, for same requirement. The investment towards installation of  the new furnace is Rs. 50

Last Answer : Quantity of steel treated per batch - 80 Tons a. Efficiency of Furnace: Useful heat supplied to steel - 80000 x 0.12 x (850 - 30)   = 7872000 kcal/batch .1 mark Total heat ... = Rs. 64400/batch Efficiency of new LPG furnace - 80% Heat supplied in new LPG furnace - 7872000/0.8

Should I use a diamond grinding wheel for cutting ceramic tile?

Description : Should I use a diamond grinding wheel for cutting ceramic tile?

Last Answer : Use a wheel specifically rated for grinding concrete or ceramic tile. It doesn't have to be a diamond wheel; titanium-coated, tungsten-coated or carbide coated wheels will also work.

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Description : Spark plugs are made of (A) High alumina ceramic (B) Metallic carbides (C) Corundum (D) Carborundum

Last Answer : (A) High alumina ceramic

Which of the following is the most suitable for preheating combustion air above 650°C? (A) Regenerator (B) Metallic recuperator (C) Ceramic recuperator (D) None of these

Description : Which of the following is the most suitable for preheating combustion air above 650°C? (A) Regenerator (B) Metallic recuperator (C) Ceramic recuperator (D) None of these

Last Answer : (C) Ceramic recuperator

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Last Answer : (B) Occupy more space

In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet? (A) Zirconia (B) Alumina (C) Bakelite (D) Tungsten carbi

Description : In the formation of cermets, the ratio of ceramic material to metallic material is usually 80:20. Which of the following is a cermet? (A) Zirconia (B) Alumina (C) Bakelite (D) Tungsten carbi

Last Answer : Option D

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Description : Ceramic compounds as compared to metallic compounds (A) Crystallise faster (B) Resist greater tensile stress at room temperature (C) Have higher melting temperature (D) Are better conductor of electricity at higher temperature

Last Answer : Option C

In which of the following cases, kinetic energy is being used in performing work? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Description : In which of the following cases, kinetic energy is being used in performing work? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

Last Answer : (2) Driving a car to cover a distance Explanation: The work done on any object goes into changing the kinetic energy of that object. Since the work done by the car engine is equal to the change in ... defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

In which of the following cases, kinetic energy is being used in performing work ? (1) Paddling the bicycle to cover a distance (2) Driving a car to cover a distance (3) Wind mill grinding wheat grain (4) Rowing a boat in the lake

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Last Answer : Driving a car to cover a distance

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

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

Give reason: Lemon juice kept in metallic cup will taste different but not in ceramic cup.

Description : Give reason: Lemon juice kept in metallic cup will taste different but not in ceramic cup.

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A __________ evaporator employs an annular downtake.(A) Basket type (B) Horizontal (C) Long tube vertical (D) None of these

Description : A __________ evaporator employs an annular downtake. (A) Basket type (B) Horizontal (C) Long tube vertical (D) None of these

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For efficient grinding, ball mills must be operated (A) At a speed less than the critical speed (B) At a speed more than the critical speed (C) At a speed equal to the critical speed (D) With minimum possible small balls

Description : For efficient grinding, ball mills must be operated (A) At a speed less than the critical speed (B) At a speed more than the critical speed (C) At a speed equal to the critical speed (D) With minimum possible small balls

Last Answer : (A) At a speed less than the critical speed

Which of the following conditions must be satisfied for lift force to be developed? (A) The body should be bluff body (B) The body should be stream lined (C) Circulation around the body is essentially required (D) The main stream velocity must approach the velocity of sound in that fluid medium

Description : Which of the following conditions must be satisfied for lift force to be developed? (A) The body should be bluff body (B) The body should be stream lined (C) Circulation around the body is essentially required (D) The main stream velocity must approach the velocity of sound in that fluid medium

Last Answer : (C) Circulation around the body is essentially required