Iron is extracted from its ore in a blast furnace and then used to produce steel. Iron taken from the blast furnace contains ......1...... as an impurity. To remove this impurity, ......2...... is blown through the molten iron. ......3...... is also added so that the oxides of phosphorus and silicon are removed, as these are ......4...... . Which words complete the sentences about the conversion of iron to steel?
- A1 carbon, 2 nitrogen, 3 calcium carbonate, 4 acidic
- B1 carbon, 2 oxygen, 3 calcium oxide, 4 acidic
- C1 carbon, 2 oxygen, 3 calcium oxide, 4 basic
- D1 sand, 2 oxygen, 3 calcium oxide, 4 basic