Jawaharlal Nehru Technological University Hyderabad B.Tech II MINERAL PROCESSING Previous Question Paper (April - 2018 - R15)

Mention the various parameters influencing the choice of mineral processing methods.

Calculate the number of increments required in the sampling of silica in iron ore for a desired overall precision of 0.1, if increment standard deviation is 1.5 and the preparation and assay standard deviation is 0.095.

What do you mean by ‘Reduction ratio’ with reference to crushing?

From a crushed quartz sample, the fraction less than 2 mm had to be removed by screening. The feed sample contained 35% of minus 2 mm material. After screening the oversize fraction contained 10% of minus 2 mm size and the undersize contained 82% of minus 2 mm size. Determine the efficiency of the screen.

A cyclone is fed at the rate of 20 t/h of dry solids. The cyclone feed contains 30% solids, the underflow 50% solids, and the overflow 15% solids by weight. Calculate the tonnage of solids per hour in the underflow.

Explain briefly about the polar and non-polar mineral with examples.

Give a flow chart for coal separation from shale by jigging and state the size to which coal is to be crushed for this process.

Give the operating and feed parameters in separation of mineral and gangue using Wilfley table.

Distinguish between mechanical and pneumatic flotation techniques.

Give a classification of the reagents used in flotation like collectors, frothers and regulators.

The samples required of the feed to a zinc concentrating plant, having a copper content of about 2% (4.5% CuFeS2). Top size: 2.5 cm; desired sampling accuracy: +/- 0.1% Cu (+/- 0.05% CuFeS2); specific gravity of Chalcopyrite: 5.6; overall specific gravity: 2.5. Determine the minimum mass of sample required (kg) to represent the ore using Gaudin’s method.

How are the industrial screens classified? Discuss the construction and operation of any one of them with a neat sketch for efficient sizing in the plant.

What do you mean by concentration criterion? Name the materials involved in Heavy Media Separations. Which are the properties influencing the Heavy Media Separations?

An open cast coal mine possessing multiple seam producing coal to a coal beneficiation plant. Explain how the mined material (coal) from the aforesaid mine can be processed effectively for sale.

What do you understand by the 'free settling ratio' and 'hindered settling ratio' of two minerals.

If an ore contains a valuable mineral of density 4500 kg/m³ and a gauge of density 2800 kg/m³ discuss the likely success of separation using gravity separation in potable water (density 998 kg/m³) and bore water (density 1290 kg/m³)? The mean particle size is 100 microns.

Explain the constructional features, operation and applications of Harz Jig with a neat sketch.

Determine the terminal velocity or the settling velocity in water of spherical floccules of 0.4 mm in diameter consisting of 10% solid possessing the specific gravity of 2.7 and 90% water by volume.

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 for a froth flotation process from the following data: Ore for flotation = 3000 tpd. Density of the material = 3.0 t/m³. Pulp density in flotation = 25% solid. Flotation time = 10 minutes. Volume of each cell = 3.3 Cu.m. Effective volume of each Cell = 2.475 Cu.m.