sponge iron industry –past-present-future - SIMA

REPORT ON SIMA DELEGATION TO CHINA 14-10 NOVEMBER 2010
A nine member SIMA delegation led by Mr. B L
Agrawal, Vice Chairman and Mr. S S Bhatnagar,
Executive Director visited China during 14-19
November 2010 to explore alternative technology
options for sponge iron making. The objective was
to evaluate the technologies that utilize iron ore fines
and are pollution free. Two technology routes, viz
Rotary Hearth Furnace (RHF) and Tunnel Kiln
process were studied.
On 15 th
November the team visited Rizao Steel, the
second highest producer of liquid metal in private
sector in China. It has a capacity of 20 MT per year.
The steel plant generates lot of solid waste. They
have installed two nos of RHF. Each one is having a
input capacity of 2,00,000 tons per year iron bearing
waste material. Waste of coke ovens having carbon
bearing material is used along with the other waste.
One furnace was under maintenance and the second
one had gone for a forced shutdown on the previous
night due to fusion of briquettes inside the RHF.
All the iron bearing material is dried in a rotary drier
at 200 O
C. Dust from coke oven having 30% carbon
is added to the iron bearing dust in a proportation
and mixed thoroughly in a vertical mixture. Organic
binder is added in the vertical mixture. The output
from mixture machine is converted to briquettes in a
briquetting machine. Then these are transported by
a tubelar belt conveyor and fed to the RHF. The
briquettes are layered on the RHF moving bed. As
the bed rotates, the briquettes pass through a pre
heat zone & reduction zone, before getting
discharged to a rotary cooler by means of a screw
feeder. At this transition point nitrogen gas is
continuously charged for sealing.
The briquettes are cooled in the rotary cooler and
discharged to a pan conveyor at 100 O
C. It is then
transported in that metallic pan conveyor to the
storage bin where DRI fines and briquettes stored
separately.
On 16 th
November team went to China Iron & Steel
Research Institute Group (CISRI) along with Sinokiln.
There was a warm welcome by host CISRI. The main
point of discussion was on the raw materials as the
existing plant operates on steel plant waste material.
To check the Indian raw materials, CISRI wanted to
make all required tests in their laboratory and
accordingly design the RHF on payment basis. CISRI
have already designed another three nos of RHF
which are under construction in China. The capacity
of Rizao Steel single RHF as specified by CISRI is
1,50,000 tons to 1, 60,000 tons of DRI per year with
an input capacity of 2,00,000 tons per year.
The power consumption as mentioned was 10 MW
for two units and nitrogen consumption is 6600 NM/
hr. Nitrogen requirement for cooler sealing is 250
NM3/hr and rest Nitrogen is utilised for gas line
instrumentation etc.
On 17 th
November meeting was conducted in the
office of Sinokiln Engineering & Technology (Beijing)
Co. Ltd. along with CISRI Engineers. Commercial
terms and few technical issues were discussed.
Charging of hot DRI from RHF to furnace was
discussed. In the new design CISRI have given
provision for making HBI below the discharge of RHF
and in the future they will go for hot charging. They
are also considering to produce power from the waste
heat of RHF. The meeting was organized and
concluded with lunch hosted by Sinokiln.
On 18 th
three members went to see Tunel kiln of
CBRF Technology Group Co. Ltd. (CBRF) in
operation at Jinan along with Mr. Chand of Interglobal
Projects & Construction Co. (IPCC). Visit was
completed in the first half and they came back to
Beijing in the evening. On 19 th
morning there was
meeting with Mr. Chunlai Yang, Chairman CBRF. The
doubts on capacity were raised and it was clarified
that the Jinan plant can give 35,000 tons/year per
kiln with only ore fines with right mixture. To achieve
50,000 tons per year the kiln length needs to be
increased. Depending upon the raw materials and
other requirements the kiln can be modified/
redesigned to suit Indian raw material conditions.
From the visit it is now technically clear that for higher
capacity RHF is suitable and lower capacity tunnel
kiln is suitable. Project cost of RHF will be much higher
than Tunnel kiln. It is difficult to conclude the
production cost in RGF until actual trials are
completed.
Member delegates felt that SIMA to conduct similar
technical visits to other countries for the benefit and
exposure of their members.
JANUARY-2011/21