Q.1
Paddle agitator
Q.2
Tabular bowl centrifuges as compared to disk bowl centrifuges
Q.3
Pick out the material having minimum Rittinger's number.
Q.4
Agglomeration of individual particles into clusters (flocs) is called flocculation. To prevent flocculation, the most commonly used dispersing agents are
Q.5
Which of the following is used for primary crushing of very hard lumpy materials?
Q.6
For spheres, volume shape factor is given by
Q.7
Feed size of ≥ 25 cms can be accepted by
Q.8
The unit of filter medium resistance is
Q.9
Filtration of water in a paper mill is done by a/an __________ filter.
Q.10
Maximum size reduction in a ball mill is done by the, __________ action.
Q.11
Which of the following is not a part of the Blake jaw crusher?
Q.12
Which of the following mechanical conveyors does not come under the division 'carriers'?
Q.13
Which of the follwoing mechanical conveyors does not come under the division 'scrapers'?
Q.14
Trommels are revolving screens which normally operate in the range of __________ rpm.
Q.15
Separation of a suspension or slurry into a supernatant clear liquid (free from particles) and a thick sludge containing a high concentration of solid is called
Q.16
Which of the following mineral dressing operations is termed as 'comminution'?
Q.17
Cumulative analysis for determining surface is more precise than differential analysis, because of the
Q.18
Screen capacity is proportional to (where, S = screen aperture)
Q.19
__________ are used for the separation of coarse particles from a slurry of fine particles.
Q.20
A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index is 4.5, the volume fraction of solids in the suspension is
Q.21
In case of a revolving mill, wet grinding compared to dry grinding
Q.22
Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is
Q.23
Separation of isotopes is generally done using a/an __________ centrifuge.
Q.24
At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5 : Power number Re = ρ N D2/μ: Reynold's number N is the impeller rotational speed, and D is the impeller diameter.
Q.25
The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond's law, Rittinger's law and Kick's law) depend upon the
Q.26
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
Q.27
Which of the following is the most suitable for handling fibrous and dense slurries?
Q.28
Gold ore concentration is mostly done using
Q.29
Rittinger's number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger's number of a material indicates its
Q.30
Filter aid is used to
Q.31
Moore filter is a __________ filter.
Q.32
Size reduction of asbestos and mica is done by
Q.33
Which of the following parts of a jaw crusher is subjected to maximum wear and tear during its operation?
Q.34
For efficient grinding, ball mills must be operated
Q.35
Rittinger's crushing law states that
Q.36
Which of the following clay mixing devices is vacuum operated for deairation of clay?
Q.37
Pick out the correct statement:
Q.38
__________ baffles are provided in ball mills.
Q.39
Crushing efficiency of a machine ranges between __________ percent.
Q.40
Which of the following is a coarse crusher?
Q.41
Which of the following is a vacuum filter?
Q.42
Trommels separate a mixture of particles depending on their
Q.43
Separation of materials of the same density based on their sizes by using then-different rates of flow is called
Q.44
A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is
Q.45
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.
Q.46
Grindability of a material does not depend upon its
Q.47
200 mesh seive size corresponds to __________ microns.
Q.48
The specific surface of spherical particles is given by (where D and ρ are diameter and density of particle).
Q.49
Out of the following size reduction equipments, the maximum feed size can be accepted by the
Q.50
The reduction ratio for grinders is defined as(where, Df and Dp are average diameters of feed and product respectively).
0 h : 0 m : 1 s