CDS (II) 2020 General Knowledge · Question 38 of 120

Correct — B, USA. The Climax mine sits at Fremont Pass in Colorado, on the Continental Divide, straddling Lake and Summit counties, and the settlement of Climax takes its name from it. At its peak it was the largest molybdenum mine in the world and supplied about three-quarters of global molybdenum. It is worked by the Climax Molybdenum Company, now a subsidiary of Freeport-McMoRan, and it is still in production: after a seventeen-year shutdown it reopened and resumed shipping molybdenum on 10 May 2012, running a 25,000 tonne-per-day mill with capacity for roughly 30 million pounds of the metal a year.

• (a)Canada — Canada does mine molybdenum, mostly as a by-product of copper, but no mine there is called Climax and none has ever held the position this one held.
• (c)Australia — Australia is a major producer of iron ore, bauxite, gold and coal. Molybdenum is not one of its signature outputs, and Climax is not in Australia.
• (d)South Africa — South Africa's mineral fame rests on platinum-group metals, gold, chromium and manganese. It has no significant molybdenum industry and no Climax mine.

Molybdenum is a hard, high-melting transition metal obtained mainly from the sulphide mineral molybdenite. Most of it goes into alloy and stainless steels, where small additions raise strength, toughness and resistance to corrosion and heat; the rest goes into catalysts for petroleum refining, high-temperature lubricants and pigments. It is also a plant micronutrient, needed for the enzymes of nitrogen fixation and nitrate reduction.

Named-mine questions look impossible until you notice that the name usually carries the place. Climax is a Colorado mining town, and the mine that made it is the one the question means. The exam-hall approach is elimination by mineral reputation: South Africa reads as platinum and gold, Australia as iron ore and bauxite, Canada as nickel and potash, and none of those is molybdenum. That leaves the United States, whose Colorado deposits are the classic molybdenum porphyries. Anchor to the exam year and note that the mine remains an operating Freeport-McMoRan property today.

• The Climax mine is at Climax, Colorado, at Fremont Pass on the Continental Divide, in Lake and Summit counties.
• At peak output it was the world's largest molybdenum mine and supplied about three-quarters of world molybdenum.
• It is owned by the Climax Molybdenum Company, a subsidiary of Freeport-McMoRan.
• After a seventeen-year shutdown it reopened and resumed shipments on 10 May 2012.
• Molybdenite is the principal ore mineral; the metal's main use is alloying steel.

• Guessing by which country is the largest producer today rather than where the named mine actually is.
• Confusing molybdenum with manganese — different metals, different leading producers.
• Assuming a mine that has been shut down at some point is no longer working; Climax reopened in 2012.

As a mine-to-country pick like this one, or as a List-I to List-II match pairing places with the minerals they yield.

• practice — not a real PYQ

  Molybdenum is obtained mainly from which one of the following ore minerals?

  • (a)Bauxite
  • (b)Molybdenite
  • (c)Chalcopyrite
  • (d)Cassiterite

  Answer(b) Molybdenite — a molybdenum sulphide. Bauxite yields aluminium, chalcopyrite copper and cassiterite tin.

• practice — not a real PYQ

  The principal industrial use of molybdenum is

  • (a)as an alloying element in steel
  • (b)in the manufacture of glass
  • (c)as a nuclear fuel
  • (d)in the production of fertilizers

  Answer(a) as an alloying element in steel — small additions raise strength and resistance to heat and corrosion.