R05321802-non-ferrous-extractive-metallurgy

Set No. 1

Code No: R05321802

III B.Tech Supplimentary Examinations, Aug/Sep 2008 NON FERROUS EXTRACTIVE METALLURGY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What are the factors on which the choice of a leaching agent depends? Explain them. (b) Explain the leaching of chalcopyrite mineral using ‘Fecl3 ’ as leaching agent. Also give the flow sheet of the process. What is the distinct advantage of this process over pyrometallurgical process. [6+10] 2. (a) Draw a neat sketch of imperial smelting blast furnace for Zinc extraction and explain the process of extraction. (b) Discuss the various reactions that take place in the blast furnace during the extraction process. What are the advantages? [9+7] 3. With the help of a flow chort describe the lead smelting in a blast furnace. Explain its advantages and limitations. [16] 4. What are the various alternative processes (other than the conventional) available for the production of aluminium from its ores. Explain them in detail. List out their relative advantages and disadvantages. [16] 5. (a) Why fused salt electrolysis is adopted for the extraction of Mg? (b) What is the minimum temperature at which Pidgeon process (as given below) can be carried out with a partial pressure of Mg over solid reactants of 1 mm Hg? [6+10] 2MgO (s) + 2CaO (s) + Si (s) = 2 Mg (g) + 2CaO. SiO2 (s) Given: ∆ G0 = 122,400 + 11.74 T log T 100.38 T 6. (a) During the extraction of Ti, chloridising roasting route is adopted-Justify with reasoning. (b) Discuss the electrochemical principles involved in the electro refining of titanium using molten salts. [6+10] 7. (a) Why uranium ores are not concentrated by ore dressing techniques? (b) With proper reasoning explain why hydrometallurgical process is selected for the extraction of uranium. [6+10] 8. (a) What is Monds Nickel? Give a flow chart for the process ? How does its purity with that of other forms of nickel? (b) Why carbon reduction route was not adopted for the production of Ni?[12+4] ⋆⋆⋆⋆⋆ 1 of 1

Set No. 2

Code No: R05321802

III B.Tech Supplimentary Examinations, Aug/Sep 2008 NON FERROUS EXTRACTIVE METALLURGY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Which ores copper are extracted by hydrometallurgy method? Why? (b) Explain the principle of hydrometallurgy? (c) Describe the hydrometallurgical process of extraction of copper with the help of a flow sheet. Also give the advantages. [4+3+9] 2. (a) Draw a neat sketch of imperial smelting blast furnace for Zinc extraction and explain the process of extraction. (b) Discuss the various reactions that take place in the blast furnace during the extraction process. What are the advantages? [9+7] 3. With the help a flow sheet, explain various processes used in the production of lead base bullion. [16] 4. (a) Waht are the important ores of aluminium? Give their chemical formulae. Give the names of places where aluminium ore deposites are located. (b) Among the many ores, which aluminium ore is mainly used for extraction? Why? (c) Give the composition of cryolite bath? Give the ratio of alumina , cryolite and Fluorspar in the cryolite bath. Explain the importance of cryolite bath in the electrolytic reduction of alumina. [6+4+6] 5. (a) Why Mg CO3 cannot be used for the Pidgeon process? (b) Can Si alone be used as a reducing agent in Pidgeon process? Justify your answer. (c) Discuss the significance of MgCO3 purity in the production of Mg. [4+5+7] 6. (a) Discuss the iodide refining of Ti. (b) Explain the production of Ti Cl4 from rutile concentrates.

[8+8]

7. (a) What are the primary and secondary sources of uranium? (b) Explain the chemistry of alkali leaching of uranium concentrates. (c) What are the advantages of alkali leaching over acid leaching?

[4+6+6]

8. (a) Describe the effect of an increase of pressure on the reaction Ni (c) + 4CO (g) = Ni(CO)4 (g) Calculate the volume fraction of Ni(CO)4 in a CO, Ni(CO)4 Ni(CO)4 gas 1 of 2

Set No. 2

Code No: R05321802

mixture that is in equilibrium with pure nickel at a temperature of 180C and a total pressure of 70 atm. Also calculate the temperature at which the same volume fraction of Ni(CO)4 obtained at a total pressure of one atm. Assume that for the aforementioned reaction, ∆H 0 = -35,000 cal and ∆S 0 = 100 cal/degree mole. (b) Write down a flow sheet for the Sherrit-Gordon process for nickel hydrometallurgy. Explain he process with proper chemical reactions. [8+8] ⋆⋆⋆⋆⋆

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Set No. 3

Code No: R05321802

III B.Tech Supplimentary Examinations, Aug/Sep 2008 NON FERROUS EXTRACTIVE METALLURGY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain about electrolytic refining of copper. What are the advantages and limitations of this method over other methods of extraction. (b) Explain the differences between metal and matte.

[12+4]

2. List the various processes that are in commercial operation for the extraction of Zinc. Explain the relative advantages and disadvantages of these processes. [16] 3. Explain the following processes for lead smelting. (a) WORCRA process (b) Flash smelting with oxygen process (c) Direct smelting in converter.

[6+5+5]

4. (a) With the help of a neat sketch, describe the Half-Heriult process for the extraction of aluminium. Give the electrolytic cell data and explain the variou details. (b) What are the properties and applications of aluminium?

[12+4]

5. (a) Why Mg CO3 cannot be used for the Pidgeon process? (b) Can Si alone be used as a reducing agent in Pidgeon process? Justify your answer. (c) Discuss the significance of MgCO3 purity in the production of Mg. [4+5+7] 6. (a) Why titanium cannot be produced by the direct reduction of rutile concentrate by carbon? (b) Discuss the refining of Titanium.

[6+10]

7. (a) What are the primary and secondary sources of uranium? (b) Explain the chemistry of alkali leaching of uranium concentrates. (c) What are the advantages of alkali leaching over acid leaching?

[4+6+6]

8. (a) What are the sources of gold? (b) Discuss the concentration of gold bearing ores. ⋆⋆⋆⋆⋆

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[8+8]

Set No. 4

Code No: R05321802

III B.Tech Supplimentary Examinations, Aug/Sep 2008 NON FERROUS EXTRACTIVE METALLURGY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What are the factors on which the choice of a leaching agent depends? Explain them. (b) Explain the leaching of chalcopyrite mineral using ‘Fecl3 ’ as leaching agent. Also give the flow sheet of the process. What is the distinct advantage of this process over pyrometallurgical process. [6+10] 2. (a) Explain the various chemical changes that take place when different sulphide ores are subjected to roasting process. Also mention whether the oxidation of sulphide ores is complete or partial. (b) What are the gases evolved during the roasting of sulphide ores. Also explain how these exhaust gases are utilized. (c) What is sphalerite? Explain about it.

[8+5+3]

3. (a) What are the charge materials in to the blast furnace, during the extraction of lead from sulphide ores? Explain about them. Describe the role played by each one of them. (b) Give the normal composition of slag formed in the blast furnace during lead extraction and what are your observation from the composition? Discuss. (c) What are the advantages of having scrap iron in the charge for lead blast furnace. [5+5+6] 4. (a) With the help of a neat sketch, describe the Half-Heriult process for the extraction of aluminium. Give the electrolytic cell data and explain the variou details. (b) What are the properties and applications of aluminium?

[12+4]

5. (a) Why Mg CO3 cannot be used for the Pidgeon process? (b) Can Si alone be used as a reducing agent in Pidgeon process? Justify your answer. (c) Discuss the significance of MgCO3 purity in the production of Mg. [4+5+7] 6. (a) What are the uses of titanium and titanium dioxide? What are the sources of Titanium? (b) Write down a flow sheet for the extraction of Ti. 7. (a) Why uranium ores are not concentrated by ore dressing techniques? 1 of 2

[8+8]

Set No. 4

Code No: R05321802

(b) With proper reasoning explain why hydrometallurgical process is selected for the extraction of uranium. [6+10] 8. (a) What is Monds Nickel? Give a flow chart for the process ? How does its purity with that of other forms of nickel? (b) Why carbon reduction route was not adopted for the production of Ni?[12+4] ⋆⋆⋆⋆⋆

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