sponge iron industry –past-present-future - SIMA

is relatively low since it is monitored by export market.
The grade of iron ore fines has also gone down from
65% Fe to 55% Fe. The alternate route for survival
is beneficiation and pelletisation from low grade fines.
In present scenario there are many pellet plants
which are coming up with higher capacity. Some of
them are already commissioned and some of them
are under construction. After commissioning of all
the plants, there may be short fall of iron ore fines
for pellet making, without any export. It is presumed
that the ore fines availability is likely to go up more
than 28.8 million tons produced last year. As the
demand for ore fines will increase, the prices are
likely to go up. Many mines have already reached
the level where the mining product is more of fines
and blue dust than lumpy ore. They themselves are
putting up pellet plants. So the same story of sponge
iron industry is likely to repeat.
The choice left is to beneficiate the ore fines. The
lumps from mines is crushed to produce the
calibrated ore and it should go to the kiln directly.
Fines generated in the process of crushing should
go for beneficiation. After the beneficiation the iron
ore powder becomes concentrate and requires
agglomeration as pellet or briquette for further use.
But instead producing indurate pellet and then
converting it to sponge iron, it is better to convert
directly to sponge iron through tunnel kiln or rotary
hearth furnace. The process of tunnel kiln and rotary
hearth furnace are different but both use coal for
reduction and coal producer gas for heating. The
energy used in Pellet making is around 30 lit per ton
which is saved when direct sponge is produced in
tunnel kiln from the ore concentrate or ore powder
from mines. Tunnel kiln product is more suitable for
induction and arc furnaces where as Rotary hearth
furnace product is more suitable for arc furnaces.
The Tunnel kiln technology and rotary hearth furnace
technology is already in the market and will be
starting in India very soon.
The Itmk3 which produces iron nugget has started
since 2004 and has successfully produced this year.
There are few modifications carried out this year to
declare it as commercial plant. Itmk3 will have an
edge over rotary hearth furnace. The further
development in rotary hearth furnace is to transport
the hot sponge iron in to the melting furnace or to
make HBI instead of cooling it.
The HISMELT is a continuously process of directly
melting iron ore fines up to 100micrones. It has a
minimum capacity of 8,00,000 tons per year. It
operates with semi- anthracite coal and to produce
one ton liquid metal it require 1.7 t of ore with 62%
Fe , 700kg coal , 260 m³ oxygen, 4-5 m³ water, 32
to 35 MW power and 100 to 150kg of lime or dolomite
which is directly melted in the SRV (Smelter
Reduction Vessel) furnace. The plant can generate
30-35 MW power from its waste heat. When 50%
Indian coal having 25% ash is mixed with 50%
imported coal and used in the SRV without pre heater
then the capacity reduces to 0.36 mtpy. The HI-Smelt
process has got a promising future.
Apart from much other process, Midrex is going to
put a synthetic gas plant from coal and a vertical
shaft kiln to produce sponge iron. The plant is very
much capital intensive. The other process like Energy
Iron and Oxycup smelter use iron ore fines to produce
the liquid metal. They will also enter to the market
soon.
In future the plants which have either iron ore mines
or coal block will survive and others will have hard
time to continue. This scenario was well visualised
10 years back which has become the reality of today.
JANUARY-2011/13