Category

Theme images by Storman. Powered by Blogger.
Best viewed in Google Chrome

Kilns & Furnace related ...

Labels

Labels

Raw Materials related ...

Advertisement

Popular Posts

Services

Showing posts with label Steel Industry Guru. Show all posts
Showing posts with label Steel Industry Guru. Show all posts

Development of FINEX Process and Steel Plants with FINEX in Operation

- No comments

In the present article we give a brief data about how the FINEX process evolved from COREX technology, FINEX plants were started and subsequent developments and changes brought in those FINEX plants with their effects besides, the steel plants with FINEX process in operation (existing & upcoming FINEX Plants). Also Read: 

FINEX® Process, smelting reduction technology of iron making - Features, Merits and Limitations     


Development of FINEX Process and FINEX Plants

The FINEX is the latest addition and an optimized fine-ore smelting reduction (SR) process of iron making developed by POSCO that can be considered as an offshoot of COREX technology. In December 1992, POSCO and Primetals Technologies signed a cooperation agreement for the joint development of the FINEX Process. The first FINEX plant with a pilot scale production was started on November 14th 1995. In 2002 POSCO converted one the existing COREX plant into FINEX F-0.6M demonstration plant with a nominal capacity of 0.6 MTPA hot metal production, which commenced operation in May 2003. In July 2014, POSCO stopped the operation of this plant and at present it is in the final stage of agreement with an Indian steel maker for its reinstallation in India (discussed  under Upcoming FINEX plant in India).

Having successful results and following optimization of equipment and process parameters, POSCO decided to install the industrial FINEX F-1.5M Plant (1.5 MTPA production capacity). The work was started to build the first commercial FINEX F-1.5M plant by POSCO in August 2004 which finally commenced operation in April 2007.

Based on the successful results of the F-1.5M FINEX Plant, POSCO and Primetals Technologies decided to further develop F-2.0M FINEX plant with an annual hot metal production capacity of 2 MTPA. The job was started by POSCO In 2011 to build the first FINEX F-2.0M and the plant has been successfully put into operation in January 2014 and according to POSCO, the F-2M FINEX plant produced 1.5 million tons of hot metal in the first 11 months.


Modifications made in the F-2M FINEX Plant with their achievements

The design of the third generation F-2M FINEX plant is characterized by a simplified plant concept resulting in decreased construction weights compared to the F-1.5M concept. Besides others, following major changes in its design are attributed to its achievement: 

  • Pneumatic ore charging to the fluidized bed reactors including a 3-stage fluidized bed reactor system resulting in a decreased building height of more than 30%
  • Simplified system configuration in the hot compacting system and implementation of dry de-dusting equipment
  • Elimination of HCI bin and related top gas system in the melter gasifier tower
  • Installation of a centre charging system for hot HCI and coal, allowing for homogeneous charging of feed materials to the melter gasifier. The distribution on the char bed surface is realized via a dynamic gimbal distributor.

These modifications helped in reducing overall construction weight of the FINEX F-2.0M plant by approx. 9% and required no larger space in the plant layout. After start-up in January 2014, operation optimization and facility stabilization, the productivity of the F-2.0M plant achieved its target value of 5760 t/d in April 2014. Since then operation targets are achieved and operational optimization is under progress to further optimize coal consumption.

Due to improvements in equipment and operational skills, a target availability of greater than 95% could be achieved in the first few months of operation.


Upcoming FINEX Plants in India

POSCO and USPL

In Aug’15 POSCO signed a memorandum with Uttam Steel and Power Limited (USPL) to set up 3 MTPA integrated steel plant in Maharashtra (India) at an envisaged investment of nearly ₹ 20,000 crore (Approximately 3.07 Billion USD). The proposed project at Satarda in Maharashtra’s Sindhudurg district in India is based on POSCO’s patented Finex process. For complete details please refer to our article POSCO signs MOU with Uttam Steel and Power Limited (USPL) to set up a 3 MTPA Integrated Steel Plant at Satarda, India


POSCO and MESCO 

Earlier in this year Mideast Integrated Steel Limited, the flagship company of Mesco Group, India signed a memorandum with South Korean steel maker POSCO to use FINEX technology at its Kalinganagar plant in Jajpur district of Odisha (India). The first FINEX plant of POSCO which they ceased operating since July 2014, is to be transferred to MESCO. This project is part of the USD 700 million first phase steel expansion project to take Mesco Steel's capacity to 2 million tonnes. Presently, Mesco Steel operates two blast furnaces in its plant at Kalinganagar. The company has its own iron ore mine in Roida Barbil region of Keonjhar District in Odisha and another iron ore mining lease at Malangtoli in Odisha. In this month both Posco and Mesco have agreed for next meeting in November this year to discuss the modalities for transfer of Finex technology. After that, the process of dismantling of Posco's Finex plant in Korea and its subsequent installation at Mesco premises would take off. The Finex plant during operation would need a running 100 Mw captive power plant (CPP) and an oxygen plant of 1,000 tonne per day (tpd) capacity. Finex process is expected to cut hot metal production cost for Mesco by Rs 2000-2500 per tonne.

Available FINEX Modules

Different sizes of FINEX modules and capacity made available by POSCO to meet specific requirements of the customers are:

 Related Articles 

FINEX® Process, smelting reduction technology of ironmaking - Features, Merits and Limitations

- No comments
28-June-2020
What is FINEX ?

The FINEX is the latest addition and an optimized fine-ore smelting reduction (SR) iron making process based on the direct use of the coal and iron ore fines. FINEX Process is a fluidized bed based process using ore fines instead using iron ore lumps and pellets. This is a process with great potential with regard to productivity and the low cost production of hot metal.
In 1992, POSCO and VAI, Austria signed an agreement to work together for a joint development of the FINEX Process. And accordingly, FINEX process was developed jointly by POSCO, Korea and Primetals Technologies to provide the iron making sector with the capability of producing (hot metal) at a reduced cost, lesser environmental pollutions and more flexibility in terms of operation and the choice of raw materials. Primetals Technologies Limited, is a joint venture of Siemens VAI Metals Technologies and Japan’s Mitsubishi Hitachi Metals Machinery (MHMM).
The present article contains about:
  • What is Finex process
  • Benefits or Merits of this technology
  • Some limitations or disadvantages of Finex technology
To know more about the Steel plants with FINEX process in operation as how these FINEX plants were started and subsequent developments and changes brought in those FINEX plants, read: 

https://www.industry.guru
Fig: FINEX Technology (Flowsheet)
FINEX Process of Iron Making - An Overview
In the FINEX process the iron production is carried out in two separate Process steps. In a series of fluidized bed reactors, fine-grained iron oxides are reduced to direct-reduced iron, compacted and then transported to a melter gasifier. Coal and coal briquettes charged to the melter gasifier are gasified, providing the necessary energy for melting in addition to the reduction gas. Fine ore and additives (limestone and dolomite) are dried and then charged to a 3 or 4 stage fluidized bed system where the iron ores are progressively reduced in counter current flow with the reducing gas to fine DRI and the fine additives are partly calcined.

Reactors R4 and R3 are primarily used to preheat the ore fines to the reduction temperature, which can be adjusted by partial combustion of the off-gas (export gas) from R2. In R2 the fine ore is pre-reduced to reduction degree (RD) of about 30%. At the end of the production in R1, the final reduction to DRI takes place (RD about 90%). Operational pressure in R1 to R4 is approximately 4 - 5 bars. The fine DRI is compacted and then charged in the form of Hot Compacted Iron (HCI) into the melter gasifier. So, before charging to the melter gasifier unit of the FINEX unit, this material is compacted in a hot briquetting press to give hot compacted iron (HCI) since the melter gasifier cannot use fine material (to ensure permeability in the bed). Non-coking coal (lumpy and / or briquetted fines) is charged from the top of the melter gasifier, dried and degassed in the upper char bed area and finally the degassed coal (char) is gasified with pure oxygen which is blown in at the tuyere zone of the melter gasifier bed. The gasification supplies the energy required for the metallurgical reactions and for the melting of HCI and coal ash to hot metal and slag. Pulverized coal injection (PCI) system is provided to inject fine coal via the oxygen tuyeres. The gas generated in the melter gasifier of the FINEX unit is used to reduce the ore in the reactors preceding the melter gasifier. The generated FINEX off-gas is a highly valuable product and can be further used in power generation or heating processes. The DRI is charged in the melter gasifier in hot condition, where it is melted, fully reduced and carburized to hot metal. The hot metal and slag produced in the melter gasifier is frequently tapped from the hearth similar to the blast furnace and COREX operations. Also refer COREX Process of Iron Making - its Merits and Demerits.

FINEX Process - Merits and Benefits
In many respects FINEX process can be considered as an offshoot of COREX process and hence, bear the various advantages of the COREX and more as outlined below -  
Flexibility in Raw Materials
  • No blending of ore & coal. Rather direct utilization of coal.
  • Use of Low-grade ore & low-ranked coal. Integration of the coal briquetting technology increases the range of suitable coal blends for the FINEX application. Utilization of 100% coal briquettes offers the possibility to mix different coal qualities for the generation of coal briquettes.
Easy & Flexible Operation
  • Independent control of reduction & melting processes
  • Easy & hassle-free operational control
Environmental Friendliness
  • Far less emission of SOx, NOx, phenols, sulphides, ammonia & dust because the FINEX process does not need sinter plant and the coke oven battery which are the actual sources of emission in a conventional blast furnace route.
  • Applicability to the CO2 sequestration.
Cost Competitiveness
  • Lower cost in both capital investment & operation as compared to the blast furnace route, keeping the quality of the hot metal same.
  • According to POSCO, the capital cost & operating cost of FINEX process are less than by 20 and 15 percent respectively of that of Blast Furnace route. 
  • Need much less land as compared to conventional BF complex.
  • Similar to the Corex export gas, FINEX export gas (with calorific value of 5,500 – 6,250 kJ/m3 STP) can be used to substitute natural gas, oil, coke and coal for metallurgical applications and power generations etc. Depending on the composition of coal and the decision whether gas recycling is applied or not, the amount and the composition of the export gas can vary within definite limits.
Limitations (Demerits) of FINEX Process
As said FINEX, COREX, HISMELT are the latest alternative methods for producing liquid iron (Hot Metal) through Smelting Reduction (SR) process. Some of the limitations (disadvantages) are -
  • Ease of obtaining FINEX technology is uncertain though POSCO has started to extend it.
  • Both COREX and FINEX processes need a large amount of oxygen.
  • The major criteria for an initial evaluation of coals or coal blends for the FINEX Process are: 1. Fix carbon content at a minimum of 55%, 2. Ash content up to 25%, 3.Volatile content lower than 35%, 4. Sulphur content lower than 1%
  • Additional to these qualities the coal must have a good thermal stability to ensure the formation of a stable char bed in the melter gasifier. 
Related Articles

MIDREX - The Most Widely accepted Direct Reduction (DR) Process of Ironmaking

- No comments
2-Oct-2009

Midrex the most widely accepted direct reduction (DR) process of ironmaking in the world was developed by Midland Ross Corporation of Cleveland, USA in 1967 , has the following distinctive features:
Recommended Natural Gas Composition for MIDREX Plants
Components
Vol %
Effects
CH4
C2H6
C3H8
C4H10
+C4 (Hydrocarbon)
CO2
N2
S
75 - 100
0 - 25
0 - 4
0 - 2
0 - 0.5
20 max
20 max
20 ppm.
(max Wt.)
--
--
Above 4% C3H8, water vapour content should be increased.
--

Above 20% CO2, export fuel is produced.
For every 10% of N2, fuel consumption increases by 2%.
Above 20 ppm, carbon deposition on catalyst.

MIDREX Process - Some Features
=> It allows the production of highly metalized DRI (exceeding 92%, see adjacent Table showing typical composition of Midrex DRI) and the carbon content of can be controlled in the range of about 1.0 - 2.0%.
=> Although originally developed for use with high grade pellets, the Midrex shaft furnace is now able to use some amount of lump ores. Optimum process conditions are often obtained by mixing 30-50% of an appropriate type of lump ore with high grade pellets. See adjacent Table showing Physical Characteristics of Pellets and Lump Ores used in the MIDREX Process.  
=> Fuel utilization in Midrex process has steadily decreased from an average of 12.5 - 14 GJ/t of DRI to 9.5 - 10.5 GJ/t. This improvement in energy efficiency has been the result of higher reduction temperatures, enrichment of reduction gas with methane, utilization of in-situ reforming, and pre-heating of the process gas utilizing waste heat from the reformer.
=> Following the advent of in-situ reforming, oxygen carriers from an external source are now not required in the production of reformed gas. Therefore, the investment cost and operating costs of Midrex units have been reduced.
=> The DRI produced is relatively active towards re-oxidation, particularly when moisture is present. Hence it must be deactivated if it is to be stored or transported over a long distance.    
Physical Characteristics of Oxide Feeds
(Pellets and Lump Ores) used in the MIDREX Plants

Pellets
Lump Ores
Screen analysis (wt %)
50 - 31.75 mm
31.75 - 6.3 mm
+ 15 mm
8 - 15 mm
– 8 mm
– 6.3 mm
Bulk Density (t/m3)
Compressive Strength (kg/pellet)
ISO Tumbler Test (wt%)
+ 6.3 mm
– 0.5 mm

--
--
10% max
85% max
5% max
--
2.0 - 2.1
270 min


95% min
4% max

5% max.
93% max.
--
--
--
7% max
2.0 - 2.6
--


--
--

Typical Product Composition of Midrex DRI
Content
Wt %
Fe (total)
Fe (metallic)
Metallization
SiO2
Al2O3
CaO
MgO
S
P
92 -93
84 - 88
93 - 95
2.0 - 3.5
0.5 - 1.5
0.2 - 1.6
0.3 - 1.1
0.005 - 0.015
0.02 - 0.04
Related Articles 

ROMELT - Another No Coke Alternative Smelting Reduction (SR) Process of Ironmaking

- 1 comment
19-Nov-2009
ROMELT - The Process
This process was developed by the Moscow Institute of Steel and Alloys (MISA) in the mid-eighties to produce liquid iron from iron-bearing ores (lumps and fines) as well as waste iron oxides generated in an integrated plant using non-coking coal and oxygen. ROMELT is the only single stage SR process.
Unlike COREX and most other SR processes, the strength of this process is that it is a single stage concept. That is why ROMELT is a robust and simple process, which is also very much environment-friendly, since it operates under a slight negative pressure. As a result the area around a ROMELT plant is extremely clean. However, the process has a few inherent weaknesses being a single stage process, it uses large amounts of coal (1.3 - 1.5 t/thm) as well as oxygen (1100 - 1200 Nm3/thm) and it generates a very rich exit gas, which has to be utilized effectively e.g. in power generation to meet the demand of oxygen plant to make the hot metal production economic.        
ROMELT Process - The Advantages
=> This process can accept iron ore in a wide range of sizes (0 - 20 mm) without any pre-treatment. This would allow operating units to use slimes and other iron-bearing wastes which can be a big advantage for many reasons.
=> Non-cocking coals of size 0 - 20 mm with moisture content less than 10% are acceptable for this process. Although it is preferable to restrict the VM content of the coal up to 20%, higher VM coals can also be used. Then, no separate coal preparation is required.
=> The ROMELT process is capable of achieving fairly high degrees of post-combustion (even more than 70%) of the melter gas (primarily CO and H2) before it leaves the reactor, thus ensuring satisfactory utilization of energy even though it is a single stage process.
=> The quality of ROMELT iron is excellent - Carbon 4%, Silicon 0.6%, Manganese 0.05%, Sulphur 0.04% and temperature 1400 - 1450OC. The process offers particular advantage  in terms of phosphorous in hot metal because in the ROMELT process, instead of 100% phosphorous going to metal (as is the case in Blast furnace), only 60% phosphorous is reported to be in the hot metal while 30% goes to the slag, and 10% forms a part of exit gas.
=> Small scale production of 200000 to 1000000 tpa of hot metal is possible along with flexibility in production. The capacity of the rectangular ROMELT reactor (productivity in the range of 0.95 t/m2 of hearth area) is limited by the penetration of oxygen from the side-wall tuyeres into the bath. Thus, ROMELT unit may be ideal for supplying hot metal in EAF based mini steel plants.
=> The specific investment in a ROMELT plant is not likely to be as high as in many other SR processes because the equipment is simple and easy to operate. For the same reason, the plant availability should be high.

What is FASTMET Process of Ironmaking ?

- No comments
11-Sept-2009
Fastmet The Process Concept and References  
This is a direct reduction process using a Rotary Hearth Furnace (RHF) which was derived from the work done in USA by Midland Ross and Surface Combustion, in the ‘Heat Fast’ process, treated in 1960s. It is a solid reductant based process in which iron ore concentrate, pulverized coal and a binder are mixed together and pelletized. The resulting green pellets are fed either to a drier or directly to a rotary hearth furnace where the pellets are heated to 1250 - 1400OC and reduced to metallic iron. Burners and post-combustion the CO evolved provide the heat required to raise the pellets to the reduction temperature.
The first commercial Fastmet plant was commissioned at the Hirohata Works No.1 of Nippon Steel in April, 2000 and Hirohata Works No.2 in February, 2005 with material processing capacities of 190000 tpa each plant. The second plant established was Kobe’s Steel’s Kakogawa Works started from April, 2001 having a material processing capacity of 16000 tpa.  The Fastmet process has allowed the Kakogawa Works to achieve a zero emission rating of steel mill waste. Waste utilization is the principal application of the Fastmet process in Japan.       
FASTMET Process - Flowchart
Advantages of Fastmet


Some of the advantages of Fastmet process as have been reported are summarized as follows:
=> A wide variety of iron ore as well as steel mill wastes including BF dust, BF Sludge, BOF dust, Sinter dust, EAF dust, mill scale, and etc. can be used as the oxide feed.
=> Elimination of waste disposal cost and landfill liability as wastes is changed to a quality source of iron (DRI).
=> Recovery of Zinc contained in wastes (Zn deriving from scrap) which can be sold to zinc producer. Zinc removal: 95% or higher.
=> A wide variety of energy sources can be utilized including natural gas, LPG, coke oven gas, heavy oil, coke breeze and carbon bearing wastes or pulverized non-coking coal.
=> The short reduction time of less than 12 minutes enables easy plant starting and shut-down, and quick adjustment of production rate.
=> Reclamation of carbon is possible. Carbon contained in dusts will be used as reductant. The carbon content of DRI can be adjusted as per the customer’s requirement.
 Related Articles – 

What is Finmet Process (Technology) of Ironmaking ?

- No comments
9-Sept-2009
What is Finmet ?
Finmet is a fluidized bed iron ore reduction process developed jointly by Fior de Venezuela and Voest Alpine (VAI) of Austria in 1991 based on the original Fior process operated in Venezuela. Two Finmet plants are currently in operation - one 2 Mtpa plant at Puerto Ordaz, Venezuela and another 2 Mtpa plant at Port Headland, Western Australia operated by BHP (now Bluescope).
industry.guru
Fig: Flow-chart of Finmet Process
Finmet The Process Concept


The Finmet process uses a train of four fluid bed reactors marked (A) in the adjacent figure with counter-current gas/solids contacting down the reactor train. The feed concentrate (iron ore fines of less than 12 mm size) is charged to the reactor train via a pressurized lock hopper system. The upper lock hopper in this system cycles continuously from ambient to reactor pressure to feed the ore continuously to the reactors maintained at the reactor pressure of 11-13 bars. The feed enters the topmost reactor (R4) where it is pre-heated to 550-570OC by the reducing gas leaving reactor (R3). Pre-heating, dehydration, decrepitation and reduction of hematite to magnetite take place in reactors R4, R3 and R2. The temperature in R1 is around 780-800OC and final reduction to 93% metallization is accomplished in this reactor accompanied by carburization of some of the Fe to iron carbide. The hot fine DRI (at 650OC) is then transported by a sealed system to the briquetting machine (D) to attain a briquette density of around 5 gm/cm3. The product from any Finmet plant is hence, HBI (Hot Briquetted Iron).
The gas required for reduction is a mixture of recycled top gas and fresh reformer make-up gas processed in a standard steam reformer from natural gas. The recycled gas (taken from the top gas leaving R4), is first quenched to 40-50OC and scrubbed in a wet scrubber to remove dust and water. The make-up gas required to balance the gas consumed by the reduction reactions is supplied from a conventional steam reformer system (C).          
Finmet: Advantages and Disadvantages
Some of the advantages and disadvantages of Finmet process of iron making are :
=> It can use very large reserves of iron ore fines as feed stock unlike Midrex and HyL, which can use maximum 5% fines.
=> The output from a Finmet plant is HBI with Fe content varying from 91-94%, carbon 1-1.5% (or 3% maximum), metallization 91-93%.
=> Finmet’s operating pressure is as high as 12 bars to ensure higher degree of metallization. It has been reported that continuous operation at such high pressures has been a major problem in both the Finmet plants.    
Related Articles –