What is the form of iron produced by direct iron reduction?

Direct iron reduction typically involves the process of converting iron ore into iron using a reducing agent, usually without passing through the molten state that is characteristic of other methods. The primary product of this process is pig iron.

Pig iron is an intermediate product that contains a high carbon content along with varying amounts of silicon, manganese, and other elements. It is produced in a blast furnace and is often used as a raw material for further steel production or other iron products.

In contrast, wrought iron is a purer form, produced by further refining pig iron, while cast iron is typically created by casting molten pig iron into molds. Steel, on the other hand, is an alloy of iron and carbon that is derived from pig iron through additional processing and refining to reduce the carbon content and increase desirable properties. These differences highlight why pig iron, as the direct product of iron reduction, stands as the correct answer in this context.