JNTU
JNTU B.Tech III NONFERROUS EXTRACTIVE METALLURGY Previous Question Paper (May-2018 - R15)
Note: This question paper contains two parts A and B. Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks and may have a, b, c as sub questions.
Part A
Define the terms smelting and roasting.
Answer
Smelting is a pyrometallurgical process where ore is heated with a flux and fuel to produce a molten metal or matte, typically involving reduction. Roasting is the process of heating sulfide ores in the presence of excess air to convert them into oxides or sulfates, often to remove volatile impurities like sulfur as sulfur dioxide.
Explain in brief about electrolytic refining.
Answer
Electrolytic refining is a purification technique where an impure metal acts as the anode and a pure metal strip acts as the cathode in an electrolytic cell containing a suitable electrolyte. Upon passing an electric current, the impure metal dissolves into the electrolyte, and pure metal ions deposit onto the cathode, leaving impurities as anode mud or in the solution.
What do you understand by the term oxygen flash?
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What are the important ores of zinc? Write application of any two.
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Where are the aluminium ores found in India? What are they?
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Why high silica bauxites are not preferable in Bayer’s process
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Is it possible to directly chlorinate all the titanium ore? Give reasons.
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Write short notes on refining processes.
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Explain the concept of carbonyl process for nickel.
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Why nuclear grade uranium should be halfnium free?
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Part B
Why smelting of roasted copper ore is done? Explain with the help of suitable examples.
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Explain the different processes involved in leaching of hydrometallurgy process.
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Draw a neat sketch of reverberatory furnace? Describe the various parts in it. Explain the working of the furnace for smelting operation.
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Name some non-ferrous metals whose ores are available in the form of sulphides. Give their sulphide ores and Write their chemical formula.
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Describe in detail how Zinc may be recovered from lead slags.
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Bring out the differences between Zinc and iron blast furnaces.
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Explain the working principle for any two processes that are in operation for the extraction of Zinc.
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With the help of a flow sheet, explain the production of aluminium from high silica bauxites.
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What are the important ores of aluminium? Write their chemical formulae and composition.
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Write down the composition of cryolite bath? How the ratio of alumina, cryolite and Fluorspar are divided in the cryolite bath.
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Explain the importance of cryolite bath in the electrolytic reduction of alumina.
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What are the problems arises during electrowinning of magnesium extraction?
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Explain the effect of viscosity and surface tension of the electrolyte on the electrolysis of magnesium.
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Discuss the electrolytic refining of magnesium and titanium.
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Explain in brief about the Kroll’s process for the production of titanium.
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Explain in detail about the production of uranium in India.
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Write down the flow sheet for the production of nickel from its mineral ores. Explain the procedure involved.
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With the help of example explain how chemical uranium ores are beneficial.
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Explain with the help of a flow sheet the flotation of converter Cu- Ni matte.
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