Use of Electric Arc Furnace (EAF) technology for
production of steel has consequently increased over last two decades. It
has a major share in world's total steel production. Standing off as a
scrap melting process, the EAF technology has become much more flexible
with regards to handling of the input material such as iron, iron
carbide and hot metals. The technology also provides options for
different input energies like gas, oil and coal in addition to electric
power.
Process Description
Electric Arc
Furnaces
can be either AC or DC powered, and they melt the steel by applying high
ampere of current. The process requires approximately 360 to 400 KwH of
electricity to melt a ton of steel. These metal furnaces demand a
tremendous amount of energy and transformer load may reach 150 MVA.
Highlights Of The Technology
The use of Electric Arc Furnace Technology allows production of steel
from a 100% scrap metal feed stocks. Continual re-engineering and
improvements in the process technology has contributed to the success of
these steel making furnaces. Some of the highlights are ultra-high power
technology, water cooled walls and roofs, foaming slag practice, twin
shell furnace, scrap pre-heating and sophisticated controls. The
development of thin slab and strip casting machines has boosted the
expansion of Electric Arc Furnace technology, thus opening new ways to
mini mills for production of flat products. Further improvements are
expected by introduction of molecular gases in the arcs leading to
substantial increase in arc voltage at constant power. This would lower
the arc current which in turn would reduce graphite electrode wear.
Some of the prime factors that have made Electric Arc Furnace, the
first choice for the steel manufacturers are:
- The establishment of Electric Arc Furnace Steel Making Shop
requires a lower capital cost.
- Electric arc furnaces require significantly less energy as
compared to blast furnace/basic oxygen furnace method of the
integrated steel makers.
- A typical Electric Arc Furnaces can be deployed as a source for
mini mill, which may make steel bar or strip products.
- These high efficiency furnaces provide uniform melting and
considerably reduced refractory consumption.
- Capacity of Electric Arc Furnace ranges from a few tons to as
many as 400 tons, and a steel making unit can have one to five
electric furnaces.
