How Was Iron Made in Ancient Times?

Iron is one of the most essential metals that have been used by humans for thousands of years. The history of iron-making dates back to ancient times, where people used various techniques to extract iron from ores. In this article, we will explore how iron was made in ancient times.

Early Iron Making Techniques

The earliest evidence of iron-making dates back to around 2500 BCE in Anatolia (modern-day Turkey). At that time, people used a technique called ‘bloomery’ to produce iron.

In a bloomery, a small furnace is built with clay or stone and filled with charcoal and iron ore. The furnace is then fired up using bellows, which blow air into it to raise the temperature.

Once the furnace reaches its optimum temperature, the iron ore starts getting reduced into metallic iron, which then melts and collects at the bottom of the furnace. This molten metal is then extracted from the bloomery by breaking open the furnace.

The Blast Furnace

The next significant development in iron-making came with the invention of the blast furnace around 1100 CE in China. Unlike bloomeries, blast furnaces could produce larger quantities of iron and were more efficient.

A blast furnace is a tall structure made of steel and lined with heat-resistant bricks. It works by blowing hot air through vents at the bottom of the furnace using bellows or fans. The air oxidizes carbon in coke (a type of coal) to create carbon monoxide gas, which reduces the iron ore into molten metal.

The molten metal collects at the bottom of the furnace and is periodically tapped out as pig iron (a crude form of cast-iron) with impurities like carbon and other elements still present.

Refining Iron

To purify pig iron into wrought iron (a more pure form), ancient people used various techniques like puddling and forging. In puddling, molten pig iron is stirred in a furnace with a long rod to oxidize impurities like carbon and silicon. This results in a more pure form of iron that can be forged into various shapes.

In forging, wrought iron is heated until it becomes soft and malleable, and then hammered or pressed into the desired shape using tools like hammers and anvils.

Conclusion

In conclusion, ancient people used various techniques to extract iron from ores, ranging from simple bloomeries to more sophisticated blast furnaces. Over time, these techniques evolved to produce larger quantities of iron that were more pure and versatile. The history of iron-making is an exciting one that has played a crucial role in shaping human civilization.