Metallurgical by-products: Is blast furnace gas produced as a by-product during the manufacture of pig iron in a blast furnace?

Introduction / Context:
Blast furnaces reduce iron ore to pig iron using coke and fluxes. In the process, large volumes of off-gas are generated. Understanding the nature and utilization of this by-product is important for integrated steel plant energy balances and environmental control systems.

Given Data / Assumptions:

• Standard blast furnace operation with iron ore, coke, and limestone/dolomite.
• Counter-current flow of gases and solids.
• Gas cleaning (dust catchers, scrubbers) applied before reuse.

Concept / Approach:
Blast furnace gas (BFG) is a low-calorific-value fuel containing mainly nitrogen, carbon monoxide, carbon dioxide, and small amounts of hydrogen and hydrocarbons. It is indeed a by-product of the ironmaking reaction sequence, recovered and commonly used to fire stoves, boilers, and sometimes mixed with coke-oven or basic-oxygen-furnace gases to stabilize heating value.

Step-by-Step Solution:

Verification / Alternative check:
Plant energy diagrams list BFG production rates and its internal consumption, underscoring its role as a by-product energy stream.

Why Other Options Are Wrong:

• No: Factually incorrect—BFG is characteristic of blast furnaces.
• Other qualifiers: Confuse with different furnaces or raw materials; BFG arises regardless of these variations.

Common Pitfalls:
Assuming BFG is waste only; in practice it is a valuable, though low-grade, fuel when properly cleaned.

Final Answer:
Yes