Which of the following main types of iron ores are found in India? 1. Haematite 2. Magnetite 3. Limonite 4. Siderite Select the correct answer using the code given below.

Q: What is the answer to CAPF 2021 Paper I Q63?

A. Correct — A, 1 and 2 only. Four iron ores are named in mineralogy — haematite, magnetite, limonite and siderite — but India's reserves and its entire iron and steel industry rest on the first two. Haematite, the red ore, is the workhorse: it carries roughly 60 to 70 per cent iron and supplies the bulk of production from the Odisha-Jharkhand belt, Chhattisgarh, Karnataka and Goa. Magnetite, the black ore, is richer still at up to about 70 per cent iron and is magnetic, and its main Indian occurrences are in Karnataka, Andhra Pradesh, Tamil Nadu and the Kudremukh field. Limonite and siderite are low-grade ores, carrying much less iron, and although traces occur in India they are neither reserves of consequence nor sources the industry works, so they are not counted among the main types. (Provisional — pending the official UPSC key.)

(a)1 and 2 only
(b)2 and 4 only
(c)1, 2 and 4
(d)1 and 3

Answer

Why

Correct — A, 1 and 2 only. Four iron ores are named in mineralogy — haematite, magnetite, limonite and siderite — but India's reserves and its entire iron and steel industry rest on the first two. Haematite, the red ore, is the workhorse: it carries roughly 60 to 70 per cent iron and supplies the bulk of production from the Odisha-Jharkhand belt, Chhattisgarh, Karnataka and Goa. Magnetite, the black ore, is richer still at up to about 70 per cent iron and is magnetic, and its main Indian occurrences are in Karnataka, Andhra Pradesh, Tamil Nadu and the Kudremukh field. Limonite and siderite are low-grade ores, carrying much less iron, and although traces occur in India they are neither reserves of consequence nor sources the industry works, so they are not counted among the main types.

Why the others are wrong

(b)2 and 4 only — Keeps magnetite but drops haematite, which supplies most of India's iron ore output, and adds siderite, an iron carbonate of about 40 to 48 per cent metal content that India does not work at scale.
(c)1, 2 and 4 — Right on the first two and wrong on siderite. The word 'main' in the stem is doing the work here — a mineral occurring in traces is not a main type.
(d)1 and 3 — Drops magnetite, the highest-grade ore of the four, and promotes limonite, a hydrated iron oxide of low metal content that is a weathering product rather than a worked reserve.

Concept

Iron ores are ranked by their metal content. Magnetite is the finest at up to about 70 per cent iron, black in colour and magnetic. Haematite follows at roughly 60 to 70 per cent, red to reddish-brown, and is the most important industrially because of the quantity available. Limonite, a hydrated oxide, runs about 40 to 60 per cent and siderite, a carbonate, about 40 to 48 per cent, and both carry impurities that make smelting costlier.

India's geography of iron follows the ancient Precambrian rocks. The Odisha-Jharkhand belt around Noamundi, Gua and the Bonai-Keonjhar ranges, the Bailadila and Dalli-Rajhara fields of Chhattisgarh, the Bellary-Hospet region of Karnataka and the Goan deposits together hold most of the haematite. Kudremukh in the Western Ghats is the country's best-known magnetite deposit. The examiner's real question is whether you know that four ore types exist worldwide while only two matter in India, which is a distinction the school geography text draws explicitly.

Key facts

Magnetite is the highest-grade iron ore, up to about 70 per cent iron, black and magnetic.
Haematite carries roughly 60 to 70 per cent iron and supplies most of India's output.
Limonite and siderite are low-grade ores and are not main Indian types.
The Odisha-Jharkhand belt, Chhattisgarh, Karnataka and Goa hold India's principal haematite reserves.
Kudremukh in Karnataka is the best-known Indian magnetite deposit.

Four ores ranked by iron content

Magnetite (Fe₃O₄)→Up to about 70 per cent iron; black; magnetic. A main Indian type.

Haematite (Fe₂O₃)→About 60 to 70 per cent iron; red; the mainstay of Indian production.

Limonite→Hydrated oxide, roughly 40 to 60 per cent iron; a weathering product, not a worked Indian reserve.

Siderite→Carbonate, roughly 40 to 48 per cent iron; low grade and not a main Indian type.

The stem's word 'main' is what separates the top two rows from the bottom two.

Study next

The distribution of India's iron ore belts across Odisha, Jharkhand, Chhattisgarh, Karnataka and GoaIron and steel plants and their siting relative to ore, coal and limestoneManganese, bauxite and other metallic minerals of the peninsular shieldThe National Mineral Policy and the auction of mining leasesBlast furnace inputs — coke, limestone and their functions

Common traps

Ignoring the word 'main' and ticking every ore that exists anywhere in India.
Reversing the grades of haematite and magnetite; magnetite is the richer ore.
Assuming the highest-grade ore is also the most produced; haematite leads on quantity.

A code-based item where the qualifier in the stem decides the answer. Read 'main types' as an instruction, not as filler.

Related PYQs

NDA_GAT_2017_II_Q1022017Open & attempt →

Which of the following statements about magnetite ore of iron is/are correct ? 1. It is known as black ore. 2. It contains 60% to 70% of pure iron. 3. It possesses magnetic properties. Select the correct answer using the codes given below :

(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Answer(d) 1, 2 and 3

One of the two main ores examined on its own properties. Colour, metal content and magnetism are the three facts that separate magnetite from haematite, and all three hold.

Practice

practice — not a real PYQ
Which iron ore is known as black ore and possesses magnetic properties?
- (a)Haematite
- (b)Magnetite
- (c)Limonite
- (d)Siderite
Answer(b) Magnetite — the highest-grade ore, up to about 70 per cent iron.
practice — not a real PYQ
Kudremukh, a well-known iron ore field, lies in
- (a)Odisha
- (b)Chhattisgarh
- (c)Karnataka
- (d)Jharkhand
Answer(c) Karnataka — in the Western Ghats, and known for magnetite.