Understanding Blast Furnace Ironmaking with Pulverized Coal Injection Nov04

Understanding Blast Furnace Ironmaking with Pulverized Coal Injection...

Understanding Blast Furnace Ironmaking with Pulverized Coal Injection Injection of pulverized coal in the blast furnace (BF) was initially driven by high oil prices but now the use of pulverized coal injection (PCI) has become a standard practice in the BF operation since it satisfies the requirement of reducing raw material costs, pollution and also satisfies the need to extend the life of ageing coke ovens. The injection of the pulverized coal into the BF results into (i) increase in the productivity of the BF, i.e. the amount of hot metal (HM) produced per day by the BF, (ii) reduce the consumption of the more expensive coking coals by replacing coke with cheaper soft coking or thermal coals, (iii) assist in maintaining furnace stability, (iv) improve the consistency of the quality of the HM and reduce its silicon (Si) content, and (v) reduce greenhouse gas emissions. In addition to these advantages, use of the PCI in the BF has proved to be a powerful tool in the hands of the furnace operator to adjust the thermal condition of the furnace much faster than what is possible by adjusting the burden charge from the top. Pulverized coal has basically two roles in the operation of a BF. It not only provides part of the heat required for reducing the iron ore, but also some of the reducing gases. For understanding the HM production in a BF with the injection of pulverized coal, it is necessary to understand what is happening inside the BF as well as the chemical reactions and the importance of permeability within the furnace and how the raw materials can affect this parameter. The BF is essentially a counter-current moving bed furnace with solids (iron ore, coke and flux), and later molten...

Tecnored Process for Ironmaking Apr30

Tecnored Process for Ironmaking...

Tecnored Process for Ironmaking Tecnored process was developed by ‘Tecnored Desenvolvimento Tecnológico S.A.’ of Brazil and is based upon a low pressure moving bed reduction furnace which reduces cold bonded, carbon bearing, self-fluxing, and self-reducing pellets. Reduction is carried out in a short height shaft furnace of distinct design at typical reduction temperatures. The process produces hot metal (liquid iron). Tecnored technology has been conceived and developed to be a ‘coke-less’ ironmaking process, thus avoiding the investment and operation of environmentally harmful  coke ovens besides significantly reducing green-house gas emissions in the production of hot metal. Tecnored process uses a combination of hot and cold blast and requires no additional oxygen. It eliminates the need for coke plants, sinter plants, and tonnage oxygen plants. Hence, the process has much lower operating and investment costs than those of traditional ironmaking routes. Tecnored process is flexible with regard to the type of iron bearing and carbon bearing raw materials which it can process. The ability of the process to smelt either pellets or briquettes, or even mixed charges of both, provides means of using a wide range of alternative feed materials. The process has got good productivity and high energy efficiency. Tecnored process is also being claimed to be suitable for producing ferro alloys such as ferro manganese. History of development The history of the development of the Tecnored process comprises different phases with different goals, testing a wide range of raw materials and using distinct sizes and concepts of the reactor. During the period 1979 to 1985, development activities were carried out regarding the use of pyrite cinder containing self-reducing pellets as metallic burden in cupola furnaces. This concept of self-reduction was adapted to develop the new process.  In 1985 the concept of the Tecnored...

Romelt Process for Ironmaking Mar20

Romelt Process for Ironmaking...

Romelt Process for Ironmaking Romelt process for ironmaking is a smelting reduction process for the production of hot metal (liquid iron). The process has been developed by The National University of Science & Technology ‘MISiS’, Russia (formerly known as Moscow Institute of Steel and Alloys). The development work of the process started in 1978 when a group of ‘MISiS’ scientists led by Vladimir Roments began working on designing of this process. The first patent in Russia was obtained in 1979. A pilot production plant having a hearth area of 20 sq m and with a capacity 40,000 tons of hot metal per year was commissioned in 1985 at the Novolipetsk Iron and Steel Works (NLMK). The pilot plant was designed by Moscow Gipromez. The design of the reliable Vanyukov’s furnace was taken as the prototype for this new method of manufacturing hot metal. The process was tested and mastered at this pilot plant between 1985 and 1998. During this period forty-one campaigns were carried out, each of which included startup and slowdown, with full tapping of hot metal and slag from the furnace. More than 40,000 tons of hot metal was produced in the pilot plant during this period and used further in basic oxygen furnace (BOF) for steelmaking. The first industrial plant for hot metal production based on Romelt technology is being built at Myanmar. The plant has been designed by Leningrad Gipromez and being supplied by Tyazpromexport, a subsidiary of Rostec. This plant has a capacity of 200,000 tons per year and is based on the processing of iron ore without its beneficiation from Pang Pet ore deposit. Pang Pet ore deposits have Fe content of up to 29 %. The plant will use non-coking coal from Kye Thee coal fields. The...

Development of Smelting Reduction Processes for Ironmaking Mar08

Development of Smelting Reduction Processes for Ironmaking...

Development of Smelting Reduction Processes for Ironmaking Smelting reduction (SR) processes are the most recent development in the production technology of hot metal (liquid iron). These processes combine the gasification of non-coking coal with the melt reduction of iron ore. Energy intensity of SR processes is lower than that of blast furnace (BF), since the production of coke is not needed and the need for preparation of iron ore is also reduced. SR ironmaking process was conceived in the late 1930s. The history of the development of SR processes goes back to the 1950s. The laboratory scale fundamental studies on the SR of iron ore were started first by Dancy in 1951. However, serious efforts started from 1980 onwards. There have been two separate lines of development of primary ironmaking technology during the second half of twentieth century. The first line of development was centred on the BF which remained the principal process unit for the hot metal production. In general, this line of the development did not encompass any radical process changes in the furnace itself. It proceeded through a gradual evolution which involved (i) increase in the furnace size, (ii) improvement in the burden preparation, (iii) increase in the top pressure, (iv) increase of hot blast temperature, (v) bell-less charging and improvements in burden distribution, (vi) improvements in refractories and cooling systems, (vii) injection of auxiliary fuels (fuel gas, liquid fuel, or pulverized coal) and enrichment of hot air blast with oxygen (O2), and (viii) application of automation as well as improvements in instrumentation and control technology. The continued success of the ironmaking in BF reflects the very high levels of thermal and chemical efficiencies which can be achieved during the production of hot metal and the consequent cost advantages. In fact,...

Corex Process for Production of Iron Feb22

Corex Process for Production of Iron...

Corex Process for Production of Iron During the late twentieth century, several new initiatives have been taken for the development of the smelting reduction technology which can become alternative route for the production of liquid iron (hot metal) since the conventional blast furnace (BF) ironmaking depends on metallurgical coal, which is required for producing BF coke needed for the production of hot metal in the blast furnace. Metallurgical coal is not only costly but is associated with environmental issues during its conversion to BF coke in the coke oven batteries. Smelting reduction process is that process which is based on smelting reduction technology and hence in this process the production of hot metal is carried out without the use of metallurgical coke. Corex process is one of these initiatives. It is the first and the only commercially established smelting-reduction process based on non-coking coal which is available as an alternative route to the blast furnace for the production of hot metal. Corex process was developed by the Austrian technology supplier VOEST in the late 1970s, and its feasibility was confirmed during the 1980s. The first pilot plant was installed in Kehl, Germany, in 1981. Commercialization, however, was reached together with the South African steelmaker ISCOR where the C-1000 (C – 0.5 M) module was commissioned in November 1989 at its Pretoria works. This first generation reactor which is called melter-gasifier had a hearth diameter of 5.5 m and a hot metal production rate ranging from 40 tons per hour to 60 tons per hour. The plant rated capacity was 300,000 metric tons per year. The general applicability of this first generation process was limited and a lot of technical problems had to be solved. Nevertheless, it helped to overcome the critical demonstration stage for...