... FIVE questions · All questions carry equal marks · - - - · 1.a) Explain why do we adopt mineral dressing operation.
Set No. Code No: 221804 II B.Tech. II-Semester Supplementary Examinations November -2003.
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MINERAL DRESSING (Metallurgy and Material Technology) Max. Marks: 80 Answer any FIVE questions All questions carry equal marks ---
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Time: 3 hours
Explain why do we adopt mineral dressing operation. State and explain the laws of comminution.
2.a)
Describe the principle of a roll crusher and derive the condition for the feed to enter the roll gap. With a neat sketch explain the working of a cone crusher.
b)
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1.a) b)
What is a screen? How screens are classified? What are the various types of moving screens. Explain the working of the screens. List out the advantages and limitations of vibrating screens.
4.a) b)
Explain the various factors that affect the settling of particles. State Stokes law and Newton’s laws. Explain their importance/significance.
5.a)
Discuss the following in flotation process: (i) Frothers (ii) Activators. Explain the principle of heavy media separation and describe any one of the industrial processes using heavy liquids.
b)
6.a) b)
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3.
What is contact angle? Explain the significance of contact angle? Also explain its significance in flotation process. Derive an expression for the work of adhesion in flotation process. Explain the principle of Electrostatic separation. With a neat sketch describe any one magnetic separation method.
8.
Write short notes on THREE of the following: (a) Reynolds Number (b) Selectivity Index (c) Collectors (d) Depressants and deactivators.
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7.a) b)
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Set No. Code No:221804
b)
3.a)
b)
What do you mean by crushing? Explain the mechanism of crushing. What are the size ranges in crushing operation? What are the conditions for the particles to be nipped or crushed? How are Ball mills classified? Explain the principle of operation of Hardinge cylindroconical mill.
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2.a)
What is a screen? How screens are made? What is the effect of the moisture on screening operation. Explain the factors which determine the capacity of a screen. Define screen efficiency. Derive an equation for the mean arithmetic diameter of sieve analysis sample. Define communication. State and explain the theories of comminution. Derive an expression for the terminal velocity of particles settling under Stoke’s conditions.
5.a) b) c)
What is Tabling? Explain the mechanism of Tabling process. Discuss the role of brothers in flotation process. Define classification. Distinguish between different classifiers. Explain any one type of pneumatic classifier.
6.a) b)
Explain the effect of particle size on flotation process. Explain the flotation process for concentration of copper ores.
7.a) b)
Classify electrostatic separators and describe any one with neat sketch. Write an essay on coal washing and coal washing methods.
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4.a) b)
8.
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II B.Tech. II-Semester Supplementary Examinations November -2003. MINERAL DRESSING (Metallurgy and Material Technology) Time: 3 hours Max. Marks: 80 Answer any FIVE questions All questions carry equal marks --1.a) What is ore sampling? Explain the various hand sampling techniques. b) Explain the scope and objectives of ore dressing. c) What are the main mineral dressing operations? Explain whether the mineral dressing operation is economical or not.
Write short notes on THREE of the following: (a) Collectors (b) Activators (c) Vezin Sampler (d) Davis Zones. ---
Set No. Code No: 221804
How are crushers classified? Describe gyratoy crushers and compare it with Jaw crushers.
3.a)
Explain the factors on which the mechanism of passing of a particle through a screen depend. Explain the methods of sizing by screening and elutriation.
b) 5.a) b)
What is terminal velocity? Explain its importance in gravity concentration process. Derive a relationship between time and velocity of moving solid. Describe the working principle and operation of shaking tables with suitable figures. What is Jigging? Explain the principle features of Jig design.
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4.a)
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2.
b)
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II B.Tech. II-Semester Supplementary Examinations November -2003. MINERAL DRESSING (Metallurgy and Material Technology) Time: 3 hours Max. Marks: 80 Answer any FIVE questions All questions carry equal marks --1.a) What is ore dressing? Explain the scope and objectives of ore-dressing. b) Explain the sampling of ores by various methods.
What is Flotation? Explain the effect of acidity or alkalinity on flotation process. Explain the principle and operation of sorting classifiers.
7.
Write an essay on the prevailing Indian ore dressing practices.
8.
Write short notes on THREE of the following: (a) Theory of Ball Mill. (b) Flotation process for the concentration of Pb-Zinc ores. (c) Equal settling particles (d) Contact angle. ---
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6.a) b)
Set No. Code No: 221804
Discuss the various methods of sampling. Mention and explain the various errors in sampling process.
2.a) b)
What is liberation? Explain the method of determination of degree of liberation. What are various types of gyratory crushers and explain about any one of them.
3.a) b) c)
Explain the various laboratory sizing techniques. What do you mean by Effectiveness of screens? Explain the representation of size analysis data.
4.a) b) c)
What is Choke feeding? What are its advantages and limitations? Explain hindered settling ratio. Discuss the factors that contribute to the stratification of a Jig.
5.a)
List down the various exploitable characteristics used in separation of minerals. Give a detailed account of them with suitable examples. Describe Wilfly table. Explain its operating conditions.
b)
Discuss the effect of surface modification on the physical chemistry of flotation process. Discuss any two heavy media suspension processes used for concentration of ores. Discuss the mechanism of magnetic separation. Also give an account on the various parameters that affect magnetic separation of minerals. Distinguish between Magnetic and Electro static separation process.
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7.a)
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6.a)
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1.a) b)
b)
b)
Write short notes on any THREE of the following: (a) Coal washing (b) Reynolds Number (c) Toothed roll crusher (d) Rod and Tube mill.
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8.
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II B.Tech. II-Semester Supplementary Examinations November -2003. MINERAL DRESSING (Metallurgy and Material Technology) Time: 3 hours Max. Marks: 80 Answer any FIVE questions All questions carry equal marks ---
