JNTU B.Tech II MINERAL PROCESSING Previous Question Paper (May - 2019 - R15)

Define the term Sampling and briefly explain its importance in mineral processing.

Explain Bond’s law.

Name the different sizing techniques.

What does the number on the sieve represent in BSS series of sieves?

What properties of the mineral and gangue are used in heavy media separation?

Distinguish between Normal and difficult to wash coals.

Briefly explain the principle of operation of spiral classifier. Give examples of minerals that can be classified using this method.

The constructional and operational details of an apron feeder are given: Width of hopper: 25 m; Height of the layer of material: 7 m; Bulk density: 2.8 t/m3; Belt speed: 2 m/min; Fill factor: 60%. Determine the volumetric capacity of the above apron feeder (t/hr).

What reagents are used in flotation? Give examples of atleast one reagent of each type.

What precautions are to be taken to efficiently separate the mineral and the gauge while using flotation technique.

Explain the Stokes’ law and Newton’s law related to movement of solids in fluids. Give the equations to compute terminal velocity of particles and mention the fields of application of these laws.

A stainless woven screen had an aperture of 3.20 mm square. The diameter of the wire is 1.6 mm. Determine: i) The percentage of open area (horizontal), ii) The percentage of open area (slope of 20 degree), iii) The Mesh size of the screen.

Describe the rake classifier with the aid of a clearly labelled diagram, showing the various zones that can be distinguished.

A hydrocyclone produces underflow and overflow from the feed. A slurry of density 1140 kg/m3 is fed. Underflow slurry density is 1030 kg/m3. Determine mass flow rate of feed when 3 litre sample of underflow takes 4s. Density of dry solid is 3000 kg/m3. Calculate % solids in feed, underflow and overflow.

Write notes on: i) Coal preparation circuit, ii) Sink-float analysis procedure.

Explain the principle of eddy current separation in the processing plant.

Sketch and explain the operation of a wet high intensity magnetic separator. Name minerals which are suitable for recovery with this device and explain its limitations.

How much 10% FeSi needs to be added to 1L of water to make a heavy liquid of S.G. 2.8? What is the maximum media S.G. that can be used with this solid?

Write briefly about the principle of jigging process. What are the steps involved in jigging operation and how they contribute to jigging?

For a jig treating 5 mm coal and shale of density 1800 and 2500 kg/m3 respectively, calculate the jig stroke amplitude required to expand the bed. The fluid is water at a density of 1000 kg/m3 and viscosity 0.001 Pa s and the Newtonian drag force is 0.44.

Determine the settling rates for spherical particles of quartz settling in water for particles of size 38 µm to 16 mm. Density of quartz: 2650 kg/m3, density of water: 1000 kg/m3, viscosity: 0.001 Pa s.

What is the principle of shaking table? Describe briefly about the Wilfley table.

Explain why flotation is used for fine particles only. Draw a flotation circuit consisting of rougher cells, cleaner cells and scavenger cells.

Estimate the number of mechanically agitated flotation cells required: Ore = 3000 tpd, Density = 3.0 t/m3, Pulp density = 25% solid, Flotation time = 10 minutes, Volume/cell = 3.3 m3, Effective volume = 2.475 m3.