Comminution (sa book)

Question 1

The operation of applying a force on the particle to break it is called ____

Answer 1

Size Reduction

Question 2

____ is a general term for size reduction that may be applied without regard to the actual breakage mechanism involved.

Answer 2

Comminution

Question 3

Fracture in the particle occurs as a result of application of a ____.

Answer 3

Force

Question 4

When a force is applied on a particle, ____ will develop within the particle. When this _____ exceeds ultimate____, the particle will break.

Answer 4

Stress

Question 5

As the tensile strength is as little as 1/10 of compressive strength, the ____ occurs primarily because of the tensile stress which results in breakage into a small number of large pieces

Answer 5

Fracture

Question 6

____ fracture occurs when a force (shear force) acts parallel to the surface of the particle.

Answer 6

Attrition or Abrasion

Question 7

In this ____, the edges or corners of a particle will break due to the application of oblique forces, generally impact forces, on the particle.

Answer 7

Chipping

Question 8

____ are concerned with the relationship between energy input and the size of feed and product particles.

Answer 8

Laws of Comminution

Question 9

3 Laws of Comminution

Answer 9

Rittinger
Kick
Bond

Question 10

____ states that the total work useful in breakage that has been applied to a given weight of homogeneous broken material is inversely proportional to the square root of the average size of the product particles, directly proportional to the length of the crack tips formed and directly proportional to the square root of the new surface cre ated.

Answer 10

Bond Law

Question 11

defined as the gross energy in kWhr/short ton of feed necessary to reduce a very large feed to such a size that 80% of product particles passes 100 microns screen.

Answer 11

Work index

Question 12

Bond’s law is applicable reasonably in the range of conventional ____ and ____.

Answer 12

Rod Mill and Ball Mill Grinding

Question 13

is a size reduction operation wherein large lumps are reduced to fragments or smaller particles.

Answer 13

Crushing

Question 14

is considered as size reduction of relatively coarse particles to the ultimate fineness

Answer 14

Grinding

Question 15

It is to be noted that the energy required for comminution of unit mass of smaller particles is more than ????

more then what?

Answer 15

the energy required for unit mass of coarser particles

Question 16

In crushers, the breakage forces are applied either by ____ or ____

Answer 16

Compression or Impact