Blast furnace and cast iron
Alto horno y hierro fundido (colado)
- Date
- c. 400 BCE · confidence medium
- Place
- State of Wu / Chu, Jiangsu-Hubei, China
- Credited to
- Chinese founders of the Warring States period
- Field
- Matter & energy
What it is
A tall shaft furnace with forced draught reaching over 1,150°C, producing liquid, high-carbon iron that can be cast in moulds like bronze. Europe did not achieve this until the 14th century.
European cast iron arrives in the 14th-15th centuries; phosphorus in the Chinese ore lowered the melting point.
What it led to
- Cheap, mass-produced cast-iron farm tools (ploughs, hoes) that boosted Chinese agriculture
- The Han state monopoly on iron and salt (117 BCE) as a fiscal base
- Decarburisation steelmaking (chao gang) and the co-fusion process
- Cast cauldrons, stoves and machine parts
Built on
- Bellowsc. 3000 BCE
- Widespread iron smeltingc. 1200 BCE
- Double-acting piston bellowsc. 200 BCE
- Mould bronze casting
- Charcoal
Made possible
- Malleable cast iron by annealingc. 400-300 BCE
- Double-acting piston bellowsc. 200 BCE
- Cast-iron mouldboard ploughc. 100 BCE
- Fining cast iron by stirring (chaolian)c. 100 BCE
- Mineral coal as industrial fuel (Han China)c. century I a.C. (discutido)
- Water-powered bellows for blast furnaces31 CE
- Stir-frying in a wok (chao)c. 544
- Co-fusion steel (guangang)c. 550
- Mineral coal in Song iron smelting1078
- Tiangong kaiwu technical encyclopedia1637
- Iron mouldboard plough
- Decarburised steel
- Du Shi's hydraulic bellows