What is the typical converter size for producing 300 tons of steel in BOF?
A converter with a steel shell of 50 mm and refractory of 450-900 mm.
How is the equilibrium Oxygen concentration calculated?
What is the primary function of a vertical lance in oxygen steelmaking?
To blow oxygen at high pressure (12-15 atm) for steel refining.
How often does a converter needs to be rebuilt?
every 600 heats
What is the advantage of converters with bottom blowing (OBM Q-BOP)?
They offer better oxygen distribution, lower slag oxidation, and lower plant cost.
What is the role of argon or nitrogen in converters with mixed blowing?
They provide efficient stirring by blowing through the vessel bottom.
How long is the typical process time in BOF steelmaking?
Approximately 45 minutes.
What is the target carbon range for the first group in BOF steelmaking?
0.01-0.05%.
What is the composition of burnt lime used in BOF?
Approximately 96% CaO, 1% MgO, and 1% SiO2.
How are charge calculations for the production cycle in BOF done?
Based on the mass and heat balance for each heat.
What are the stages of the BOF furnace and their times?
Charging 5 min
Blowing 20 min
Sampling 8 min
Steel tapping 6 min
Slagging off 6 min
What are the main chemical reactions occurring in the bath during oxygen blowing?
Decarburization (C+O → CO), Si oxidation (Si+2O → SiO2), and oxidation of Fe and Mn.
What is the role of fluxes like lime and dolomite in the BOF process?
They facilitate slag formation and aid in impurity removal.
How is phosphorus typically removed in BOF steelmaking?
Through oxidation and capturing in the slag.
What is the typical extent of desulfurization in BOF?
Limited removal of sulfur, typically between 3-5%.
How is post-combustion managed in BOF and what is the meaning of post combustion?
By converting CO to CO2 using oxygen.
Post-combustion in steelmaking: Burns unburnt gases (e.g., CO) above molten steel for additional heat, improving energy efficiency and reducing emissions.
What are typical heat losses in BOF steelmaking in kcal?
Approximately 15,000 kcal/t.
What is the needed energy per mole of oxidized Si?
202,44 kcal/mol
What is the needed energy per mole of oxidized Fe?
64,39 kcal/mol
What is the needed energy per mole of oxidized Mn?
92,4 kcal/mol
What is the needed energy per mole of oxidized P?
180 kcal/mol
What is the simplified heat balance in an BOF?
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