Ironmaking — typical carbon range in pig iron Select the most appropriate range for total carbon content in pig iron produced from a blast furnace (by weight %).

Introduction / Context:
Pig iron is the immediate product of the blast furnace, later refined into steel or cast iron. Knowing its typical carbon range is foundational for distinguishing pig iron from steels and cast irons and for understanding downstream refining requirements (e.g., basic oxygen or electric arc processes).

Given Data / Assumptions:

• Pig iron chemistry varies with burden, fluxes, and furnace practice.
• Carbon is present both dissolved and as carbides; silicon, manganese, phosphorus, and sulfur are also present to varying levels.
• We seek the commonly cited carbon range for standard blast-furnace pig iron.

Concept / Approach:
Pig iron typically contains high carbon, substantially more than steels. Most references place pig iron carbon between about 3.0% and 4.5% by weight, with special-purpose irons sometimes slightly outside this range. This high carbon content must be reduced during steelmaking to reach levels appropriate for structural or tool steels.

Step-by-Step Solution:
Identify the characteristic: pig iron >> steel in carbon content.Compare the options: 3.0–4.5% matches the standard textbook range.Other ranges are either too low (typical of steels) or unrealistically high for normal pig iron practice.Therefore choose 3.0 to 4.5%.

Verification / Alternative check:
Materials handbooks list typical pig iron C ≈ 3–4.5%, Si ≈ 1–3%, Mn ≈ 0.5–1.5%, with P and S controlled depending on grade.

Why Other Options Are Wrong:
0.1–1.0% are steel-like carbon levels. 5–10% is far above practical solubility and process norms. 1–5% is too broad and includes non-representative low carbon values.

Common Pitfalls:
Confusing pig iron with cast iron; while both are high in carbon, pig iron refers to the crude blast-furnace product prior to refining, not the final casting alloy.

Final Answer:
3.0 to 4.5%