Related MCQs

• Power required to drive a ball mill with a particular ball load is proportional to (where, = diameter of ball mill )
• 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
• Which of the following relationships between co-efficinet of friction (μ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ?
• Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, = impeller diameter)
• Filtration rate through a filter cake is proportional to (where, = filtering surface = specific cake resistance μ = viscosity of the filtrate)
• The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is W, then the same for open circuit grinding will be
• The specific cake resistance for incompressible sludges is (where ΔP = pressure drop over cake)
• rpm of a trommel at critical speed is given by (where, = Diameter of trommel in ft)
• At low Reynold's number, the power () 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: = ρ/ρ : Power number Re = ρ /μ: Reynold's number is the impeller rotational speed, and is the impeller diameter.
• The critical speed of a trommel () is related to its dia () as