Match the unit operation in Column I with the resulting product in Column II:
Column I
Column II
(P) COREX Process
(1) Direct Reduced Iron
(Q) Bayer Process
(2) Pig Iron
(R) Matte Smelting
(3) Alumina
(S) MIDREX Process
(4) Copper
Show Hint
Think about the state of the product (liquid pig iron, solid sponge iron) and the ore treated (bauxite for alumina, sulphide ore for copper) to place each process.
This question tests knowledge of four extraction routes and the product each one delivers. Instead of starting from the process names, let's start from each product in Column II and ask which process gives it.
(1) Direct Reduced Iron: This is solid sponge iron made by reducing iron ore below its melting point using a reducing gas or reactive coal, without going through a blast furnace. The MIDREX process is the world's leading gas-based route for this, so (1) belongs to (S) MIDREX Process.
(2) Pig Iron: This is liquid hot metal, high in carbon, made by smelting iron ore. The COREX process is a smelting reduction technology that skips coke ovens and sinter plants but still delivers liquid hot metal, so (2) belongs to (P) COREX Process.
(3) Alumina: This is aluminium oxide, extracted from bauxite by dissolving it in hot caustic soda and then precipitating and calcining the hydroxide. This is exactly the Bayer process, so (3) belongs to (Q) Bayer Process.
(4) Copper: Copper sulphide ores are smelted to form a molten matte (copper and iron sulphides) separated from slag, which is later blown in a converter to give blister copper. This matte-forming step is matte smelting, so (4) belongs to (R) Matte Smelting.
Putting the pairs together gives P-2, Q-3, R-4, S-1, which is option (B).
Let's summarize:
COREX Process: smelting reduction route that gives pig iron.
Bayer Process: caustic leaching of bauxite that gives alumina.
Matte Smelting: sulphide smelting route on the way to copper.
MIDREX Process: gas-based direct reduction that gives direct reduced iron (sponge iron).
