In an ideal blast furnace, the input and output are as follows:
Input:
Ore, Pure Fe₂O₃, no gaunge : 1357kg/THM^∗
Coke, Pure C, no ash : 400 kg/THM
Blast air, dry : O₂ : 293 kg/HTM, N₂ : 964 KG/THM
Flux : nil
Output :
Hot metal : 5wt% C, rest iron
Slag : nil
Top gas : CO, CO₂, N₂
∗ THM refers ton of hot metal (liquid pig iron) ; Atomic weights: C-12, O-16, Fe-56 The amount of oxygen in CO & CO₂ leaving with the top gas is . . . . . . . . kg.

purpose of flux in blast furnace

A. bring down the softening point of the gangue materials

B. reduce the viscosity of the slag

C. to maintain proper basicity

D. all of these

High top pressure in the blast furnace

A. decreases the time of contact between gas and solid

B. increases the time of contact between gas and solid

C. increases fuel consumption

D. increases the rate of solution loss reaction

Dephosphorisation of molten pig iron is favoured by

A. oxidising and basic slag

B. reducing and basic slag

C. high activity co-efficient of phosphorous in metal

D. oxidising and neutral slag

High top pressure in a blast furnace operation

A. favours the solution loss reaction

B. suppresses the solution loss reaction

C. decreases gas-solid contact time

D. increases coke rate