pig iron 
noun [mass noun]
Crude iron as first obtained from a smelting furnace, in the form of oblong blocks. Compare with pig (sense 4 of the noun).Energy-intensive blast furnaces, convert iron ore to pig iron, while coal is converted to coke....
- In the 1780s, Henry Cort developed the puddling furnace, which allowed pig iron to be refined in turn with coke.
- Steel manufactured in electric arc furnaces from scrap uses far less energy than traditional openhearth furnaces using pig iron.
- franger
- frangible
- frangipane
- frangipani
- franglais
- frank
- frankalmoign
- Frank, Anne
- franked investment income
- Frankenfish
- Frankenfood
- Frankenstein
- Frankenstein food
- Frankenstein's monster
- franker
- Frankfort
- Frankfurt
- frankfurter
- Frankfurter, Felix
- Frankfurt School
- frankincense
- franking
- franking machine
- Frankish
- franklin