Difficulty: Easy
Correct Answer: All of the above (ore dressing, calcination/roasting as needed, followed by smelting)
Explanation:
Introduction / Context:
Pig iron production from ore involves more than simply melting. The upstream steps condition the ore to the appropriate chemistry and physical form, enabling efficient reduction and separation in the blast furnace.
Given Data / Assumptions:
Concept / Approach:
Ore dressing improves grade and size distribution. Calcination removes moisture and CO2 from carbonates; roasting oxidises sulfides and other deleterious components. Smelting in the blast furnace reduces iron oxides to molten iron, while gangue forms slag with limestone/dolomite. Thus, the complete chain encompasses all listed steps rather than any single one in isolation.
Step-by-Step Solution:
Verification / Alternative check:
Standard ironmaking flowsheets show beneficiation → agglomeration/thermal treatment → blast furnace smelting, confirming the combined nature of the process chain.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
All of the above (ore dressing, calcination/roasting as needed, followed by smelting)
Discussion & Comments