MECHANICAL OPERATIONS QUIZ

Which of the follwoing mechanical conveyors does not come under the division 'scrapers'?

Ribbon conveyor

Drag conveyor

Flight conveyor

Bucket elevators

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YOUR ANSWER : ?

Which of the following is not an ultrafine grinder (colloid mill)?

Toothed roll crusher

Agitated mills and fluid energy mills

Hammer mills with internal classification

Micronizers

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YOUR ANSWER : ?

In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing.

Ultrafine

Fine

Secondary

Primary

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YOUR ANSWER : ?

During filtration operation, the filtrate encounters the resistance of the

Cake

All of these

Filter medium

Channel carrying the slurry to the upstream side of the cake and filtrate away from the filter medium

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YOUR ANSWER : ?

In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the

Square root of the velocity

Square of the viscosity

Washing time only

Filtration time only

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YOUR ANSWER : ?

During the washing of cake

All the resistances are constant

Cake resistance decreases

Filter medium resistance decreases

Filter medium resistance increases

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YOUR ANSWER : ?

Washability curve based on float and sink test enables an assessment to be made of the possibility of cleaning a coal fraction based on the

Differential wettability

Size

Volatile matter content

Density separation

TRUE ANSWER : ?
YOUR ANSWER : ?

Bond crushing law

Calls for relatively less energy for the smaller product particles, than does the Rittinger law

States that the work required for the crushing is proportional to the new surface created

Is less realistic in estimating the power requirements of commercial crushers

States that the work required to form particle of any size from very large feed is proportional to the square root of the volume to surface ratio of the product

TRUE ANSWER : ?
YOUR ANSWER : ?

Energy consumption in a crusher decreases with increase in the

Size of feed (at constant reduction ratio)

Capacity of the crushing machine

All of these

Size of the product (at constant feed size)

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YOUR ANSWER : ?

Rittinger number which designates the new surface prduced per unit of mechanical energy absorbed by the material being crushed, depends on the

All of these

Elastic constant of the material

Ultimate strength of the material

State or manner of application of the crushing force

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