On Thursday, June 1, the Department of Foundry Engineering of the Institute of Manufacturing Technology held a traditional historical iron smelting. Participants could come to see a functioning historical furnace used for production of sponge iron or visit the open foundry of FME. The event is not only a reminder of ancient technology, but also a social event organized by the Department for its employees, students and partners.

Every year at the end of the summer semester, a small furnace grows behind the C1 laboratory, around which a big event takes place. This year was no exception, when the traditional historical smelting, which the department has been organizing since 2005, took place again. "Although we call it smelting, paradoxically it is not smelting at all, because we do not make iron in a liquid state, but so-called sponge iron," specifies the head of the Department of Foundry Engineering Antonín Záděra.

A few days in advance, a historic furnace is built on the slope behind the laboratory. "Then, the furnace is fed with iron ore grounded to a coarser dust, up to the size of a pea or lentil. We pour it into the furnace mixed with charcoal in a ratio of approximately 1:1 and start blowing air into the heated furnace. As the ore passes through the furnace, the oxides are reduced from Fe2O3 to Fe3O4, then to FeO and finally to the pure iron. Pure iron has the melting temperature of 1,539 degrees Celsius, but we can only reach about a thousand degrees in this type of furnace, so at the end of the reduction process we obtain iron not in liquid, but in a solid state, it is a so-called sponge iron. We start in the morning with charcoal and ore and finish blowing in the evening," Záděra describes.

The tradition of historical melting was brought to the faculty by Professor Karel Stránský, who devoted his whole life to archaeometallurgy. And the love for the history of the field has remained among the founders. "We want our students to realize how much the human history is intertwined with the history of metals. That in the time of Great Moravia iron was so valuable that they used iron talents as a currency. That the ancient Egyptians knew how to make bronze weapons, but the decline of their empire later was caused by the fact that they could not resist the steel weapons of the aggressive Romans. That the European landscape as we know it today is largely shaped by the deforestation that people have caused over the centuries in order to be able to heat in fuming, and later in blast furnaces. And that even today access to iron ore is important for all countries," says Záděra.

During the day, employees and students of the Master's program Foundry Technology take care of the historic furnace. The faculty is the last university in the country to offer the teaching of "purebred" foundry. By a similar process that students can try, iron ore has been reduced for over centuries. The resulting sponge iron was further processed by blacksmiths, who removed the unwanted slag from the material. It was the production of so-called wrought iron. A similar procedure is still used in our country, for example, by some manufacturers of historical weapons. It was not until the 17th century that liquid, so-called ingot steel was purposefully created.

"Metallurgy has been with humans for five thousand years, so we tend to take it for granted. Nevertheless, it is amazing when we realize the significance it has had in history. If we enlarged our furnace, we would no longer have enough bellows for blowing, so we would use a water wheel and this would get us already in the era of blast furnaces producing pig iron in the 15th to 18th centuries. In the 19th century, coke was used to heat blast furnaces because people had deforested Europe to such an extent that they would soon not have enough wood for the millions of tons of pig iron that were being produced. In 1855, Henry Bessemer came up with a converter for the production of steel from pig iron, without which the scientific-technical revolution could not have begun," explains Záděra, adding that authentic experience is valuable to students. "If we just told them about it, it would just be another lecture again. But personal experiences are often remembered for all life," concludes Záděra.