JNTU
JNTU B.Tech III NON-FERROUS EXTRACTIVE METALLURGY Previous Question Paper (January/February - 2023 - R18)
Note: i) Question paper consists of Part A, Part B. ii) Part A is compulsory, which carries 25 marks. In Part A, Answer all questions. iii) In Part B, Answer any one question from each unit. Each question carries 10 marks and may have a,b as sub questions.
Part A
What are the harmful impurities that affect the mechanical and electrical properties of Copper?
Answer
The primary harmful impurities in copper are bismuth, antimony, arsenic, lead, and sulfur. Bismuth is particularly detrimental as it forms brittle films at grain boundaries, causing severe hot and cold shortness. Antimony and arsenic significantly reduce electrical conductivity and ductility, while lead and sulfur promote brittleness and interfere with the fabrication processes of copper alloys.
Write the basic differences between electro-winning and electro refining of metals.
Answer
The primary differences between electro-winning and electro-refining are based on the source of the metal and the nature of the electrodes used:
- Source of Metal: In electro-winning, the metal is recovered from an aqueous leach solution (electrolyte) containing dissolved metal ions. In electro-refining, the metal is recovered from an impure metal anode which dissolves into the electrolyte.
- Anode Material: Electro-winning utilizes an inert, insoluble anode (e.g., lead or DSA) that does not participate in the reaction other than to facilitate oxygen evolution. Electro-refining uses an impure metal anode that is consumed as it dissolves into the electrolyte.
- Process Objective: Electro-winning is used for the primary extraction of metals from ores or concentrates, whereas electro-refining is a purification process used to remove impurities from already produced crude metal to achieve high purity levels.
Write the important minerals of Zinc with chemical formulae.
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What are the applications of Lead?
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Write the reaction of Lime sinter process for treating low grade ores of aluminium.
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Why carbothermic reduction of aluminium oxide is not adopted? Give reasons.
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Write the purposes of using amalgam cathode in Magnesium extraction process.
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What are the important properties and applications of Titanium?
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Give two non-nuclear uses of Uranium.
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What is cupellation process?
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Part B
Explain the step-by-step pyrometallurgical extraction of copper from sulphide ores with flow chart.
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What is continuous copper making process? Explain Noranda process in detail with neat sketch.
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Explain about fire refining and its salient features.
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Differentiate between horizontal retort process and vertical retort process used in Zinc extraction from sulphide ores.
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Explain the extraction of Zinc by Hyrometallurgical route with flow chart in detail.
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Explain the pyrometallurgical extraction of lead from lead ores.
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Explain the distinct four layers of base bullion during smelting operation in lead blast furnace.
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Explain the production of Al - alloy by Hall-Heroult process with flow chart.
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Explain the role of cryolite in electrolysis with reactions.
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Explain DEVILLE-PECHINEY process for treating low grade ores of aluminium.
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Explain ALCOA process for aluminium production from alumina by Bayer process.
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Explain the pidgeon process with constructional features and stages in detail.
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Why MgCO3 cannot be used for pidgeon process?
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What are the various methods for Upgradation of ilmenite ores? Explain production of TiCl4 from ilmenite concentrate.
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Explain the extraction of Uranium concentrate from ores by hydrometallurgical route with flow chart.
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Describe the method for separation of isotopes through gas diffusion in uranium extraction.
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Draw the flow chart for the extraction of gold.
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Explain the carbonyl process for refining nickel.
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