Mechanical Operations Questions

• 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?
• Sphericity of raschig ring (whose length and diameter are equal) is
• With increase in the pressure drop across the cake, the specific cake resistance for the compressible sludge
• Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is __________ microns.
• The most efficient equipment for the removal of sub-micronic dust particles from blast furnace gas is the
• Xanthates are used in the froth floatation process as a/an
• A filter press is
• The capacity of a gyratory crusher is __________ that of a jaw crusher with the same gape, handling the same feed & for the same product size range.
• Use of grinding aids results in the
• A __________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream.
• The main differentiation factor between tube mill and ball mill is the
• Introduction of slurry in a plate and frame filter press is done through a plate in each frame. The plate of this filter has a __________ surface.
• 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
• The optimum moisture content in solids to be crushed/ground ranges from __________ percent.
• Pick out the correct statement.
• In classification, particles are said to be equal settling, if they have the same terminal velocities in the