Pig Iron The main purpose of charging pig iron is to
dilute the residuals contained in the regular scrap, down to
the target required by the steel grade. Pig iron also allows
increased use of chemical energy thanks to its high carbon
and silicon content, as well as to keep a higher tapping
carbon level. Because of its high bulk density (more than
200lb/ft3), it reduces the total scrap charge volume, with
possible benefits in terms of EAF filling and reduction of
the number of buckets per heat (see Figure 15).
Due to its high carbon content and high density the
amount of pig iron that can be charged with conventional
EAFs should be very well balanced, taking into account
the effects of its high density on electrical energy
transfer efficiency and the maximum obtainable
decarburisation rate.
With Consteel®, thanks to the continuous flat bath
conditions and the fact that the incoming material
becomes molten by immersion, there are no limits on the
amount of pig iron that can be charged per heat. Also,
the maximum decarburisation rate can be maintained throughout the heat and the arc efficiency is not affected
by its high density.
Several Consteel® units that need clean metallic raw
material, regularly use about 25% pig iron without having
any issue with decarburisation delays or minimising the
oxygen consumption as the FeO-C relation is much closer
to equilibrium.
A Consteel® unit that produces more than 300,000t/
yr of stainless steel (3-series), charges its 60t furnace with
100% of nickel pig iron, (up to 14% Ni), as shown in Figure
16). Thanks to this metallic charge, the conversion costs
are significantly lower than the ones with stainless steel
scrap, especially in those countries where the availability of
the latter is limited. Such a dense charge mix (completely
without scrap) cannot be handled by conventional EAFs,
both for electrical energy transfer and refractory-related
issues, but also due to decarburisation constraints.
Pig Iron The main purpose of charging pig iron is todilute the residuals contained in the regular scrap, down tothe target required by the steel grade. Pig iron also allowsincreased use of chemical energy thanks to its high carbonand silicon content, as well as to keep a higher tappingcarbon level. Because of its high bulk density (more than200lb/ft3), it reduces the total scrap charge volume, withpossible benefits in terms of EAF filling and reduction ofthe number of buckets per heat (see Figure 15).Due to its high carbon content and high density theamount of pig iron that can be charged with conventionalEAFs should be very well balanced, taking into accountthe effects of its high density on electrical energytransfer efficiency and the maximum obtainabledecarburisation rate.With Consteel®, thanks to the continuous flat bathconditions and the fact that the incoming materialbecomes molten by immersion, there are no limits on theamount of pig iron that can be charged per heat. Also,the maximum decarburisation rate can be maintained throughout the heat and the arc efficiency is not affectedby its high density.Several Consteel® units that need clean metallic rawmaterial, regularly use about 25% pig iron without havingany issue with decarburisation delays or minimising theoxygen consumption as the FeO-C relation is much closerto equilibrium.A Consteel® unit that produces more than 300,000t/yr of stainless steel (3-series), charges its 60t furnace with100% of nickel pig iron, (up to 14% Ni), as shown in Figure16). Thanks to this metallic charge, the conversion costsare significantly lower than the ones with stainless steelscrap, especially in those countries where the availability ofthe latter is limited. Such a dense charge mix (completelywithout scrap) cannot be handled by conventional EAFs,both for electrical energy transfer and refractory-relatedissues, but also due to decarburisation constraints.
การแปล กรุณารอสักครู่..
