Correct Option
The correct option is (b).
Explanation
Steel is manufactured by smelting iron ore in a blast furnace. This process requires a precise combination of raw materials to ensure efficient reduction of the ore and removal of impurities. The primary inputs are iron ore, coking coal, and limestone.
Analysis of Input Ratio
According to standard industrial geography, the raw materials required for steel production follow an approximate ratio of:
- Iron Ore : Coking Coal : Limestone = 4 : 2 : 1
This implies that for every 4 parts of iron ore, 2 parts of coking coal and 1 part of limestone are utilized.
Evaluation of Option (b):
- The option lists 8 tonnes of Iron Ore and 4 tonnes of Coal.
- The ratio of Iron Ore to Coal here is 8 : 4, which simplifies to 2 : 1. This aligns perfectly with the standard 4 : 2 ratio.
- While the limestone quantity (1 tonne) is lower than the strict mathematical scaling (which would imply 2 tonnes for this scale), this option is the only one that correctly identifies Iron Ore as the largest component, followed by Coal, and then Limestone.
Evaluation of Incorrect Options:
- Options (a), (c), and (d) present scenarios where the quantity of Coal or Limestone exceeds that of Iron Ore. This is scientifically incorrect, as the metal source (ore) must be the primary input by weight.
Key Takeaway
The standard ratio of inputs for the iron and steel industry is approximately 4 parts Iron Ore : 2 parts Coking Coal : 1 part Limestone.