A note on liquid iron in medieval Europe

Area of Science:

• Metallurgical History
• Archaeometallurgy

Background:

• Medieval alchemical texts mention iron-arsenic alloys for "liquefying" iron.
• Historical understanding of iron's liquid state is often limited to modern metallurgy.

Observation:

• Analysis of swords and written records indicate crucible steel was present in Western Europe during the Early Middle Ages.
• Archaeological findings confirm the operation of blast furnaces producing liquid pig iron in Scandinavia from the 13th century.

Findings:

• Iron-arsenic alloys exhibit relatively low melting points, contributing to their description as "liquid" in medieval recipes.
• The knowledge of liquid iron, particularly crucible steel, existed in Europe significantly earlier than previously assumed, likely via trade.
• Early blast furnace technology in Scandinavia demonstrates a practical understanding of producing liquid iron.

Implications:

• These findings challenge traditional timelines for the understanding and application of liquid iron metallurgy in medieval Europe.
• The study highlights the interconnectedness of alchemical knowledge and practical craft practices in historical metalworking.
• It suggests a broader dissemination of advanced metallurgical techniques across medieval societies than commonly recognized.