Q.1
Cake resistance is
Q.2
Wet seiving is employed, when the product contains __________ materials.
Q.3
The main size reduction operation in ultrafine grinders is
Q.4
Which of the following is not accomplished by agitation of liquids in agitators?
Q.5
__________ centrifuge is the most suitable for separation of non-friable crystals.
Q.6
As particle size is reduced
Q.7
In case of grinding in a ball mill
Q.8
Pine oil used in froth floatation technique acts as a/an
Q.9
What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls?
Q.10
Helical screw agitator is used for
Q.11
The resistance offered by the filter used in a bag filter is proportional to (where, c = dust concentration, and s = particle size )
Q.12
The material is crushed in a gyratory crusher by the action of
Q.13
Length/diameter ratio of a ball mill is
Q.14
The optimum moisture content in solids to be crushed/ground ranges from __________ percent.
Q.15
A pebble mill
Q.16
A propeller agitator
Q.17
In case of a hammer crusher, the final product size depends on the
Q.18
Energy consumed for crushing one ton of material ranges from __________ kWh.
Q.19
A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is
Q.20
A cottrel precipitator makes use of the __________ for dusty air cleaning.
Q.21
Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc) is proportional to __________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance ).
Q.22
Ball mill is used for
Q.23
Apron conveyors are used for
Q.24
Carbon black is pulverised in a
Q.25
In a roll crusher, both the rolls
Q.26
The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μrn is
Q.27
Screen capacity is expressed in terms of
Q.28
Supporting legs of a plate and frame filter is normally made of
Q.29
In classification, particles are said to be equal settling, if they have the same terminal velocities in the
Q.30
In a grinding operation, the limiting particle size is the size of the __________ particle in the sample.
Q.31
Vibrating screens have capacity in the range of __________ tons/ft² .mm mesh size.
Q.32
__________ is a cohesive solid.
Q.33
The operating speed of a ball mill should be __________ the critical speed.
Q.34
Ultracentrifuges running at speeds upto 100000 rpm is normally used for the
Q.35
Basic slag is not ground in
Q.36
Size reduction of moulding powders, waxes, resins & gums are done in a __________ mill.
Q.37
The specific surface of sherical particles is proportional to (where, Dp = diameter of particle).
Q.38
Wet grinding in a revolving mill __________ as compared to dry grinding.
Q.39
Trommels employ __________ for screening of materials.
Q.40
A widely used size reduction equipment for __________ is Bradford breaker.
Q.41
In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing.
Q.42
A compressible cake has the
Q.43
A filter press is
Q.44
Run of mine (ROM) coal is crushed by a __________ for use in domestic ovens.
Q.45
increasing the capacity of a screen __________ the screen effectiveness.
Q.46
To get ultrafine particles, the equipment used is a
Q.47
In bag filters, filter fabrics are never made of
Q.48
In bag filters, filter fabrics are never made of
Q.49
General mechanism of size reduction in intermediate and fine grinder is by
Q.50
The opening of a 200 mesh screen (Taylor series) is
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