Steel is manufactured from cast iron by
(i) bessemer process (ii) open hearth process
(iii) oxygen tip- blowing (iv) electric are process

Answer

b

Explanation

Steel making is undergoing rapid revolation and the old besemer and open Hearthprocesses are becoming obsolete .Among the modern methods are basic oxygen process Electric are process and high frequency laduction process .These processes atllior scrap used and alley acrap for making hightly allyed steels.
1 Bessemer process The molten pig iron is fed into a converter at a temperature of about `1473 K` .A blast of oxygen diluted wit either stemof carbon dioxide is blown though the converter .oxygen reacts with impurities and raises the temperature to `2173 K` .C is oxidized to `CO` which burns off at the mouth of the converter,oxides of `Si` and `Mn` from slag .after about `ten minutes , the flamme at the top of the converter sinks inticating that all carbon has been removed .The flame is stoped , slag is tapped off and then other metals `(Mn,Cr,Ni and W)` may be added toward the and of the operation to produced the required type of steel.