Question $3(20$ marks$)$

The analysis of hot metal from the mixer is $3\%$ C$,1\mathrm{.}5\%$ Si$,1\mathrm{.}2\%$ Mn$,0\mathrm{.}15\%$ S and $0\mathrm{.}9\%$ P$.$

$3\mathrm{.}1$ Explain giving reasons the step by step BOF procedure that you would recommend to achieve a blown metal analysis of $0\mathrm{.}05\%$ C$,0\mathrm{.}25\%$ Mn$,0\mathrm{.}03\%$ S and $0\mathrm{.}03\%$ P$.[5]$

$3\mathrm{.}2$ Explain why there is no silicon in the blown metal? $[4]$

$3\mathrm{.}3$ Calculate the minimum amount of lime required to achieve a slag basicity of $2\mathrm{.}8?[8]$

$3\mathrm{.}4$ How would you correct a turn down temperature that is too low? $[3]$