Q7
(a) (i) What is the difference between a sample and a specimen ? (5 marks) (ii) Describe the classification of mineral reserves. (5 marks) (iii) What are the different marine mineral resources ? (5 marks) (b) What is the principle and nature of construction of Wilfley Table ? Which mineral product is separated in tabling ? (15 marks) (c) What do you know about 'Neyveli Lignite Mine' ? Enumerate the methodology of mining and machinery under use in this mine, with neat sketches. (20 marks)
हिंदी में प्रश्न पढ़ें
(a) (i) नमूना (सैंपल) व प्रतिदर्श (स्पेसिमेन) में क्या अंतर है ? (5 अंक) (ii) खनिज भंडार के वर्गीकरण का वर्णन कीजिए। (5 अंक) (iii) विभिन्न समुद्री खनिज सम्पदाएँ क्या हैं ? (5 अंक) (b) विल्फले टेबल के निर्माण का सिद्धान्त व प्रकृति क्या है ? टेबलिंग विधि में किस खनिज उत्पाद को अलग किया जाता है ? (15 अंक) (c) 'नेयवेली लिग्नाइट खान' के बारे में आप क्या जानते हैं ? इस खदान में खनन विधि एवं उपयोग होने वाली मशीनों का साफ चित्रों सहित वर्णन कीजिए। (20 अंक)
Directive word: Enumerate
This question asks you to enumerate. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.
See our UPSC directive words guide for a full breakdown of how to respond to each command word.
How this answer will be evaluated
Approach
The directive 'enumerate' demands systematic listing with explanatory detail, particularly for part (c) Neyveli Lignite Mine (20 marks). Allocate approximately 15% time/words to each 5-mark sub-part (a)(i)-(iii) combined, 30% to part (b) Wilfley Table, and 40% to part (c) with emphasis on neat sketches of mining machinery. Structure: brief definitions for (a), principle-construction-application sequence for (b), and location-geology-methodology-machinery with diagrams for (c).
Key points expected
- For (a)(i): Clear distinction between sample (representative bulk for assay) and specimen (individual rock/mineral for study/display); for (a)(ii): JORC/UNFC classification framework showing measured, indicated, inferred reserves with economic viability criteria; for (a)(iii): Polymetallic nodules, cobalt-rich crusts, hydrothermal sulphides, placer deposits, and gas hydrates with oceanic occurrence
- For (b): Wilfley table principle of differential settling and streaming in thin film flow; deck construction with riffles, longitudinal tilt, and lateral wash water; separation of heavy minerals (cassiterite, wolframite, chromite, gold) from lighter gangue
- For (c): Neyveli Lignite Corporation (NLC) location in Cuddalore district, Tamil Nadu; Gondwana sedimentary basin geology with lignite seams in Cuddalore Formation; opencast mining methodology using BWE-RH system
- For (c): Detailed enumeration of machinery: Bucket Wheel Excavators (BWEs), Spreaders, Conveyors, and Bucket Wheel Reclaimers with their specifications and functions
- For (c): Neat labeled sketches showing: (1) cross-section of lignite seam with overburden and mining benches, (2) BWE working face showing cutting wheel and discharge boom, (3) spreader operation for overburden dumping
Evaluation rubric
| Dimension | Weight | Max marks | Excellent | Average | Poor |
|---|---|---|---|---|---|
| Concept correctness | 25% | 12.5 | Precise definitions distinguishing sample vs. specimen with assay vs. display purposes; accurate JORC/UNFC reserve categories with modifying factors; correct Wilfley table principle of hindered settling and film sizing; exact Neyveli geological horizon (Cuddalore Formation, Mio-Pliocene age) and BWE-RH mining system description | Basic definitions without functional distinction; generic reserve categories without modifying factors; general gravity separation principle without film flow mechanics; correct location but vague geological age or mining method | Confused sample/specimen as synonymous; incorrect reserve classification system; wrong principle (confused with jigging or dense media separation); major errors in Neyveli geology or mining methodology |
| Diagram / cross-section | 25% | 12.5 | Three neat labeled sketches for (c): Neyveli lignite seam cross-section showing overburden-lignite-interburden sequence, BWE with cutting wheel, boom, and discharge chute details, and spreader with receiving boom and discharge boom arrangement; plus clear Wilfley table diagram for (b) showing deck, riffles, and water distribution | Two acceptable sketches with partial labeling; basic Wilfley table outline without construction details; missing one critical machinery diagram for Neyveli | No sketches or unrecognizable diagrams; missing all Neyveli machinery illustrations; diagrams without labels or with major structural errors |
| Field evidence | 15% | 7.5 | Specific field parameters for Neyveli: seam thickness (10-20m), stripping ratio, overburden characteristics; actual BWE models (SchRs 1200, 1400) with operating capacities; marine mineral occurrences citing Clarion-Clipperton Zone for nodules and Indian Ocean prospects | General opencast mining parameters without Neyveli specifics; generic BWE description without model numbers; vague 'deep sea' references without zonal specificity | No field data; incorrect mining method (underground cited); no machinery specifications; confused marine mineral localities |
| Quantitative reasoning | 15% | 7.5 | Wilfley table operating parameters: deck slope (1-5° longitudinal, 0.5-3° transverse), stroke length, frequency, water flow rates; Neyveli production figures (approx. 30 MTPA), stripping ratios (1:4 to 1:6), BWE capacities (6000-12000 m³/hr); reserve tonnage categories in UNFC | Approximate slope angles without ranges; general 'large scale' production without figures; order-of-magnitude machinery capacities | No quantitative data; incorrect units (confusing ore and waste); unrealistic production figures |
| Indian / economic relevance | 20% | 10 | Neyveli as India's largest lignite producer, power generation linkage (TPS-I, II, III), contribution to Tamil Nadu grid; strategic importance of marine minerals for India's Exclusive Economic Zone (EEZ) and Blue Economy policy; environmental considerations of opencast lignite mining; Make in India context for mining equipment | Basic mention of Neyveli power generation; general statement on marine resource potential; limited environmental or policy linkage | No Indian context; treating Neyveli as generic mine; missing marine mineral strategic relevance; no economic or environmental implications discussed |
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