Ironmaking in Western Europe

Dr.-Ing. Hans Bodo Luengen
Steel Institute VDEh,

Dr.-Ing. Michael Peters
ThyssenKrupp Steel Europe AG,

Dr.-Ing. Peter Schmöle
ThyssenKrupp Steel Europe AG,

Introduction

Today there are remaining 26 integrated works with blast furnaces in the member works of the European Blast Furnace Committee (EBFC: Austria, Belgium, Finland, France, Germany, Italy, Netherlands, Spain, Sweden, United Kingdom) as to be seen in Figure 1. The Redcar plant located in the North of Great Britain is currently stopped.

Figure 1 -  Map of integrated iron and steel works in member works of the EBFC in 2010

Figure 1: Map of integrated iron and steel works in member works of the EBFC in 2010

In the year 1990, there were still 45 integrated works operated. Since then blast furnace works have been shut down in Europe and partly been replaced by electric arc furnaces. Some of these had also a long history of iron and steelmaking.

Evolution of blast furnace hot metal production from 1990 on

Figure 2 demonstrates the dramatic reduction in the number of operated blast furnaces in the EBFC since 1990. In 1990 approximately 94 million t of basic hot metal were produced in 92 blast furnaces and 90 million t by only 58 blast furnaces in 2008. Whilst the average working volume of the furnaces increased only by 26.6 % from 1630 m3 to 2063 m the average production per blast furnace and year increased by 48% from 1.04 to 1.54 million t hot metal. This demonstrates that apart the enlargement of the furnaces also the measures to increase furnace productivity enabled the required hot metal production with fewer furnaces. In the crisis year 2009, production dropped to 60 million t hot metal produced in 49 blast furnaces. In 2010 hot metal production was raised to approximately 80 million t.

Figure 2 - Evolution of hot metal production in the EBFC

Figure 2: Evolution of hot metal production in the EBFC

The changes in hot metal production for the EBFC member countries compared to 1990 shows Figure 3.

Figure 3 - Hot metal production of EBFC member countries

Figure 3: Hot metal production of EBFC member countries

The drop-in total hot metal production from 1990 to 2010 was due to the partly compensation of oxygen steel by electric steel making and an effect of the crisis year 2009. The largest basic hot metal producing locations in 2010 are outlined in Figure 4.


Figure 4 - Hot Metal capacity locations in the EBFC in 2010

Figure 4: Hot Metal capacity locations in the EBFC in 2010

The highest production capacity is reached in Duisburg by ThyssenKrupp Steel Europe and HKM with in total 18.2 million t hot metal in seven blast furnaces, followed by Taranto with 11.4 million t and ArcelorMittal Dunkerque with 6.8 million t.

Evolution of reductant structure

Figure 5 shows the evolution of the reductant rates as a weighted average for operated EBFC blast furnaces since 1990. Whilst the total reductant consumption slightly increased the coke rate was decreased from 408 kg/t HM in 1990 to 383 kg/t HM in 2009 through increased coal injection rates from 50 to 103 kg/t HM. Oil plus others dropped slightly in the same period from 23 to 13 kg/t HM. The increase in total reductants comes from the replacement ratio of coke to coal which is in the range of 0.8 to 0.85 due to the lower carbon content of coal compared to coke and especially for 2009 by the crisis operation mode.

Figure 5 - Average weighted reductant rates of the blast furnaces in the EBFC

Figure 5: Average weighted reductant rates of the blast furnaces in the EBFC

At individual furnaces extraordinary operation modes regarding coke rate and injectants were achieved in 2008, Figure 6.

Figure 6 - Examples for extraordinary operation modes 2008

Figure 6: Examples for extraordinary operation modes 2008
(TKS is today TKSE-ThyssenKrupp Steel Europe; Corus is today Tata Steel Europe)

Highest coal rate was realized at blast furnace 6 in IJmuiden with 235.1 kg/t HM as yearly average. The lowest coke rate with 289.9 kg/t HM with a resulting total reductant rate of 516.9 kg/t HM was achieved at this furnace. The lowest total reductant rate
was achieved at Ruukki blast furnace 1 (458.5 kg/t HM) in oil injecting operation mode.

Today certain amounts of nut coke are charged with the ferrous burden. At TKSE Hamborn Nr. 9 furnace 70.9 kg/t HM nut coke were charged with a grain size of 7 to 35 mm, the remaining bell coke rate being only 262.6 kg/t HM. In former times, nut coke rates of 120 kg/t hot metal have been achieved at bell coke rates down to 220 kg/t hot metal /1/.

Blast furnace ferrous burden

The increase of the gas throughput in the blast furnace necessitates excellent charge material properties. These are related to ferrous burden materials and coke.

Regarding ferrous burden materials, compared to 1990 sinter production dropped more than hot metal production did. The sinter to hot metal ratio changed from 1.23 in 1990 over 1.17 in 1995 to 1.10 in 2008. As a consequence the ratio of pellets and more price favorable lump ores increased. In 1990, Figure 7, many of the furnaces were charged with sinter ratios of over 80% at low lump ore charges using the available sinter capacities. A change over is seen for 2008 with less operated furnaces to a wider range of lump ore use.

With respect to this point it has to be kept in mind that sinter is not a traded material but lump ores and pellets are sold by iron ore suppliers. In Western Europe only Corus IJmuiden possesses an own pelletizing plant which enables a ferrous burden composition of the blast furnaces 6 and 7 with 44 % sinter, 52 % pellets and 4 % lump ores.

Figure 7 - Ferrous burden composition in 1990 and 2008

Figure 7: Ferrous burden composition in 1990 and 2008

As to be seen in Figure 7 there is for 2008 at some furnaces a burden of over 90 % sinter and 100% pellets. SSAB for example use nearly 100% pellet charge with some amounts of briquetted waste materials, Figure 8. High sinter rates are used in Belgium, France, Spain and United Kingdom.


Figure 8 - Average ferrous burden composition of the blast furnaces in the EBFC member countries

Figure 8: Average ferrous burden composition of the blast furnaces in the EBFC member countries

Sintering plants were over the years a welcome possibility to process in-plant waste materials. With the upcoming discussion on dioxin emissions this needed to be proved. There was a limitation to process these byproducts via the sinterplant and suitable solutions have been developed, like cupola furnace route, rotary hearth furnace or the Primus furnace. Nevertheless, sinter plants supply a ferrous product carrying the necessary slag components for the total blast furnace charge materials.

Coke supply

The situation with coke supply for European integrated works is quite different. The range is from 100% own coke availability to a 100% external coke supply. Figure 9 shows the cokemaking within the EBFC countries and the coke demand by the steel industry. The coke production was 31.2 million t, the demand for sinter plants and blast furnaces amounts to 34.5 million t. This was a coke shortage of 3.3 million t to be met by imports.

Figure 9 - Coke capacity and coke demand

Figure 9: Coke capacity and coke demand

Coke surplus was only available in The Netherlands, Italy and Spain. Largest shortage of coke supply is to be seen especially for Germany. 3.3 million t coke were imported from the European and world market. With this the German steel industry is the biggest coke importer in Europe.

In Germany the coke plant Schwelgern with an annual blast furnace coke production of 2.7 million t in Duisburg, was commissioned in March 2003 as replacement for an old coke plant. This plant is designed for using the world’s largest horizontal slot ovens with a useful volume of 93 m3, in total 140 ovens.

Blast furnace constructional features and equipment

The distribution of blast furnace sizes, taking the hearth diameter as a relevant measure, is shown in Figure 10.

Figure 10 - Blast furnace size in the EBFC

Figure 10: Blast furnace size in the EBFC

The majority of the furnaces are medium-sized with hearth diameters between 10.0 and 11.9 m. The large units of 12.0 m and more are listed in Figure 11.

Figure 11 - Largest West European blast furnaces

Figure 11: Largest West European blast furnaces

These seven blast furnaces have a hot metal capacity of 26.6 million t.

Regarding the installed equipment of the 58 operated blast furnaces in 2008, 49 furnaces are equipped with full casthouse dedusting system and 45 furnaces or over 90 % of total hot metal production with a bell-less top device. At 49 blast furnaces slag is granulated. 20 furnaces use the elevated top pressure for power production by a top gas recovery turbine (TRT). As these are all large furnaces 50% share of hot metal production is equipped with a TRT. The operation of only a few large furnaces at high annual output rates requires a long campaign life. Today it is expected that a blast furnace campaign must last 15 to 20 years between two complete relinings. It is always difficult to define the length of a campaign as furnaces are different in size and design.

Especially the 10.2 m hearth diameter blast furnace Hamborn 9 reached excellence performance with a specific production of 20,900 t hot metal per m3 working volume. This furnace possesses only one taphole and has produced since blow-in after a reconstruction in December 1987 proximately 36 million t HM. The 14.9 m blast furnace Schwelgern 2 of TKSE has meanwhile produced over 66 mill t in the running campaign.

The design of a blast furnace influences the duration of its campaign. The main determining factor is the durability of the furnace hearth. The most problematic zone is the transition area between the hearth bottom and hearth wall. When comparing wear patterns of different blast furnaces it is noticeable that there is a pronounced typical wear in this area which is called “mushroom formation or the elephant foot”.

Furnaces without mushroom formation had an even wear in the upper bottom refractory blocks. It appears that, for preventing mushroom formation, the hearth should have refractory qualities at the bottom which enables the hot metal to create a concave flow area over the hearth bottom, Figure 12.

Figure 12 - Typical wear profiles of blast furnaces

Figure 12: Typical wear profiles of blast furnaces

As an example, Figure 13 shows two typical European hearth constructions. On the left side a hearth is shown with walls made of microporous blocks, and in the upper part amorphous carbon bricks.

Figure 13 - Typical hearth construction

Figure 13: Typical hearth construction

Towards the shell, highly conducting graphite bricks are used. The hearth bottom consists of horizontally installed amorphous carbon blocks with graphite underneath.

The right side shows a hearth with a wall made of micro porous blocks, graphite bonded. The hearth bottom has three insulating chamotte layers in the upper part and carbon blocks at the bottom. The hearth is protected right through with a ceramic cup. The shell has a very large inclination angle of 12 degree to make possible thicker refractory lining in the critical transition region.

Another prerequisite for long campaign life is an effective furnace shell cooling. Typical cooling systems are copper cooling boxes, cast-iron staves as well as spray cooling or double jacket cooling for the hearth walls. The latest development for the cooling of a blast furnace is copper staves.

The most highly stressed zones of a blast furnace are the belly and lower stack. The highest heat removal takes place here via the cooling system. The cooling system can be constructed in different ways. Compact plate coolers or plate coolers with intermediate flat coolers, cast-iron staves with integrated refractory material or the newly developed copper staves are used. Copper staves are a European development which had been tested in joint work between SMS and TKSE at two blast furnaces of TKSE from 1983 on and first time installed in industrial scale at the new construction of TKSE blast furnace Schwelgern 2 and blast furnace Salzgitter B /2/.

There is a significant difference between the consistency of heat dispersion of modular cast-iron staves and copper staves. Compared with cast-iron staves, copper staves permit significantly more intensive heat removal thus forming a stable protective layer by the burden materials. The use of expensive refractory materials to increase the service-life of the copper staves can be dispersed with. These protective layers reduce the heat throughput and the wear of the staves to more or less zero. Due to the low thermal expansion coefficient of the copper staves, these can be built longer than cast-iron staves. They are also considerably thinner, so they make an increased furnace volume with unchanged shell size possible. As the first furnace in the world, ArcelorMittal Bremen No. 2 received copper staves for hearth wall cooling during its relining in 1999.

Figure 14 - Copper staves above and below tuyere level - 3

Figure 14: Copper staves above and below tuyere level /3/

Figure 14 shows the cooling construction of this furnace with cast-iron staves in the tuyere zone and copper staves above and below /3/. Also the blast furnaces HKM B and ArcelorMittal Gent B had been equipped with copper staves in the hearth during their relining in 2000 and 2001. At the blast furnaces A and B of ArcelorMittal Gent problems with wear of copper staves and water leakages happened in summer 2006 and 2007 respectively /4/. Here the protecting skull was missing in front of the damaged staves. One reason could have been the abrasive behavior of the descending burden. New copper staves were designed with noses to support skull formation and relined with silacon-bonded SiC bricks.

For optimizing blast furnace operation especially the measuring and process monitoring at the blast furnace has reached a high standard, especially to control the process in the inner part of the furnace, Figure 15. Of special importance are the optimization and control of the gas composition and gas distribution inside the furnace, the material charge distribution at the top, the pressure losses inside the furnace, the evolution of the temperature inside the refractory as well as all tuyere parameters.

Figure 15 - Measuring technique at a blast furnace

Figure 15: Measuring technique at a blast furnace

A hierarchically organized computer network for receiving, evaluating and saving all data enable the use of process models for furnace control in all areas. The steadily correlation of the burden and blast furnace condition data enable the steady optimization of reductant rate efficiency.

Figure 16 - Control room of Hamborn blast furnaces

Figure 16: Control room of Hamborn blast furnaces

Figure 16 shows the modern control room of the blast furnaces Hamborn 8 and 9 of TKSE with the installation of a large screen for the demonstration of different process conditions. The development of process control and instrumentation has largely contributed to an optimized blast furnace operation. It makes the effects of changes in operation more predictable and the distance to the optimum operating point determinable.

Ironmaking in rough times

From September 2008 till May 2009 crude steel production dropped by 40 % and hot metal production by 47 %, Figure 17. A hot metal production of 4.34 million t in May 2009 corresponds to a capacity utilization of 48.5 %. This was achieved by a temporarily stoppage of blast furnaces and a reduction of productivity at the operated blast furnaces.

Figure 17 - Evolution of hot metal and crude steel production in EU 15 in 2008 and 2009

Figure 17: Evolution of hot metal and crude steel production in EU 15 in 2008 and 2009

The number of operated blast furnaces was reduced from 58 in March 2008 to only 33 in May 2009, Figure 18. Generally most of the large furnaces continued production at levels of 50 to 80 % of the capacity. Only 3 furnaces out of the 33 blowing ones produced on a 100 % productivity level just to supply the hot metal demand without restart a second furnace.

Figure 18 - Operated blast furnaces in the EBFC member countries

Figure 18: Operated blast furnaces in the EBFC member countries

At many stopped furnaces the salamander was tapped to prepare the furnace for a longer standstill time. Two furnaces were not blown in after a complete new relining; another furnace was stopped for an earlier relining than initially planned. At the furnaces which were temporarily stopped it has to be decided whether to keep the stoves hot, which is costly, or to cool them down, which needs extra time for heating them up before blowing in the furnace and can be problematic regarding the brickwork lifetime.

Generally speaking the blast furnace operators came from an economical situation where they operated their blast furnaces at such high productivity levels which were before rated to be nearly impossible and later on the productivity level is down to a level which was as well been rated to not being achievable. This also demonstrates the flexibility of a blast furnace and also of the operators, but such operating conditions are not healthy for a blast furnace and its campaign length.

Basically there are two ways to reduce the production. On the one hand a continuously very low operation level and on the other hand a production at a higher level combined with block stoppages to limit output rate. Block stoppages enable short time working of the staff and the carrying through of maintenance work with own staff only. Many block stoppages can lead to the problem that the blast furnace hearth cools down which needs time to achieve a smooth temperature level during operation. To reduce production at stand-alone blast furnaces with only one blower machine and without an integrated blast generation with numerous blowers for several blast furnaces can be the limiting factor as this stand-alone blower can only be reduced to a certain level. Big blast furnaces which possess two blowers are much more comfortable regarding reduced production. The largest West European blast furnace Schwelgern No. 2 of ThyssenKrupp Steel AG, which has a hearth diameter of 14.9 m, was reduced from a production of 12,800 t hot metal per day down to 5,500 t hot metal per day in a more or less continuous operation.

The typical way to reduce blast furnace production is to decrease the blast volume, to reduce the elevated top pressure, to inject less auxiliary reducing agents in combination with reduced oxygen addition to the blast, lower blast temperatures and higher blast moistures. The reductant structure of the blast furnaces has to be adjusted to the coke surplus availability. Coke plants should not be stopped and if they are stopped they have to be hot idled which is very costly. Otherwise they can be destroyed. As a general experience the production of a coke plant can be reduced to a level of 70 to 80% capacity only. Therefore, the reductant structure of the German blast furnaces has changed with decreasing hot metal production, Figure 19. Auxiliary reducing agents injection was reduced at all furnaces, at some furnaces the operation mode was changed to 100 % coke operation as reductant. In April 2009 the total average reductant consumption of the German blast furnaces exceeded the 500 kg/t hot metal level for the first time since the second oil crisis beginning to middle of the 1980s. The coke rate increased from 354 kg/t hot metal in 2008 to 458 kg/t hot metal in April 2009.

Figure 19 - Average consumption of reducing agents of the blast furnaces in Germany

Figure 19: Average consumption of reducing agents of the blast furnaces in Germany

There was just a minor effect on the ferrous burden composition of the German blast furnaces, Figure 20. As all German integrated iron and steel works operate their own sinterplants there was a slight increase on the use of sinter in the ferrous burden from 60.7 % in 2008 to 69 % in May 2009. As a general result of the experience gained by the blast furnace operators in Germany it can be highlighted, that even with a dramatic reduction in the productivity level a smooth furnace operation was achieved.

Figure 20 - Average ferrous burden composition of German blast furnaces.

Figure 20: Average ferrous burden composition of German blast furnaces.

Figure 21 shows a map of Germany with all blast furnaces for basic hot metal production, in which the white ones are identified as temporary stopped furnaces. These are ArcelorMittal Bremen blast furnace No. 3 (newly relined in 2008), ArcelorMittal Eisenhüttenstadt blast furnace No. 1, Hüttenwerke Krupp Mannesmann blast furnace A (under relining from January to April 2008), Rogesa (AG der Dillinger Hüttenwerke) blast furnace No. 4, Salzgitter Flachstahl blast furnace No. C and ThyssenKrupp Steel blast furnace Hamborn No. 9.

Figure 21 - Locations of the blast furnaces in Germany 2009

Figure 21: Locations of the blast furnaces in Germany 2009

For this reason, two general groups of alternatives for reducing the production in blast furnace plants will be dealt with, which have ultimately also been applied worldwide in a variety of ways:

    Operation on a reduced productivity level by

      changing specific influencing parameters and/or by
      reducing the absolute operating parameters

as well as

    reducing the production by

      short downtimes of the plants for one to two days or
      shutting down plants over extended periods of time.

Operation on low productivity level:

The adjustment of outputs by changing the specific process parameters exemplified by the blast furnace process, has often been analyzed. In the past, the main question was, however, how to enhance the output of blast furnaces /5/. The “normal operation“ of blast furnaces in the past few years, namely the high-output operation at a maximum injection rate of coal dust, for instance, is – for the sake of the flame temperature – coupled with high blast temperatures and high amounts of additional oxygen. In order to abandon this high-output operation, the amount of additional oxygen is reduced to zero in a first step while the injection rate is reduced, in a second step the blast temperature is reduced while the coal rate is further reduced, and finally the blast moisture is increased when the switch-over to 100 % coke operation takes place, in order to keep the flame gas temperature on a constant level, Figure 22, which would be the ideal case.

Figure 22 - Lower productivity by changing specific factors, constant RAFT

Figure 22: Lower productivity by changing specific factors, constant RAFT

After the theoretical study of the specific influencing parameters the results in the plants, for instance at the blast furnace of ArcelorMittal Bremen, point to further possibilities. As from mid-October 2008, the output of blast furnace 2 was reduced by decreasing the volume of oxygen added, along with in part lower specific quantities of injection coals, as well as considerably less absolute blast rates. The blast rate of normally about 300,000 m³/h was temporarily reduced to about 150,000 m³/h. These changes both of specific and absolute process parameters led to a reduction of the blast furnace 2 output by up to 70%, starting from the initial normal productivity level of 70 down to a level of 25 t HM/m² of hearth surface and 24h, especially in the period from beginning of March through mid-May, 2009, Figure 23.

Figure 23 - Changing specific factors and absolute volumes, AM Bremen BF 2

Figure 23: Changing specific factors and absolute volumes, AM Bremen BF 2

Reducing coke plant productivity, Figure 24 /6/:
There is practically no prior experience with production cuts on present-generation coke oven batteries since cokemaking has always been run at full capacity in iron and steelmaking facilities during the last 20 to 30 years. Only Prosper as an “isolated” coking plant had any historical experience to draw on.

To resolve this issue, the operators of the five coking plants started to meet regularly with experts from the plant supplier and refractory industries to share experience and know-how that would enable them to cut back production safely and without causing damage to the oven structures.


Figure 24 - Reducing coke plant productivity

Figure 24: Reducing coke plant productivity

In a first approach, the cokemaking experts all agreed that a cut in production to 80 % of full capacity would be feasible without major problems from a coking plant technology viewpoint. On the other hand, to preserve the full operability of each battery, strict compliance with certain boundary conditions was mandatory since the cutback represented a deliberate departure from the rating data underlying the design of the battery. The optimum operating point of a battery or coking plant combines numerous parameters such as coking time, charge volume, underfire gas quantity, stack draught, heating flue temperature, offgas temperature, collecting main pressure, gas generation, gas temperatures, gas qualities, gas composition, etc. To cut back output, all of the above-mentioned parameters must necessarily be adapted to the altered conditions.

As a general rule, changes in battery operating regime must always be made slowly to allow the complex brick structure to adapt to the new conditions.

The most critical aspect of the entire project lies in the temperature drop associated with the output reduction. It is necessary to preserve the temperature distribution over the height and length of the chamber heating walls, to keep up minimum temperatures at the head heating flues (i.e., the first and last two heating flues of each heating wall) so as to prevent pre-head failures in the refractory brickwork, and to ensure adequate temperatures in the regenerators and offgas system.

On a battery with circulation flow combination ovens, meeting these conditions calls for an adjustment of the gas-air distribution on no less than 2414 burners – i.e., 71 heating walls with 34 heating flues each.

Taking into account the above requirements, the output reduction proceeded in essentially the same manner in all coking plants:

The coking time was stepped up by approx. 15 minutes per day. The number of ovens pushed each day was thus decreased gradually, and coking times were lengthened by 35 to 50%. Given these longer coking times, the energy supply to the batteries had to be adapted to altered conditions. A change in gas flows, gas pressures, calorific values, etc., was implemented on the heating systems originally set for full-load operation. Such far-reaching interventions in the complex coking plant system were feasible only by continuous monitoring of all temperature profiles in the battery structure and by taking appropriate countermeasures, e.g., changing nozzle cross-sections in the heating flues, adapting calorific values, inspecting and adjusting the oven bracing system, and adapting the coal byproducts system to the altered gas situation, which included adjustments to the entire energy network linking the cokemaking operation to the iron and steelmaking plant and external customers.

Besides the reduced number of ovens pushed per day, bulk weight was decreased by grinding the coal to a finer grade and by discontinuing the admixture of oil to the charge. These measures brought down the production rate by another 5% approximately.

CO2 Benchmarking for ironmaking plants in Europe

For the CO2 trading period in Europe from 2013 on the steel industry made the proposal to realize this on the basis of plant benchmarking. The main idea behind this was to leave the cap and trade system in favor of a system with driving character to reduce specific CO2 emissions. The European Commission first required that the benchmark value should be the average of the best 10%, listed in Figures 25, 26 and 27 /7/ for coke, sinter and hot metal benchmarking. In addition it was required, that 25% of the coupling export gas used for power production only gets allocation on the basis natural gas CO2 load. End of October 2010 the European Commission published a draft decision determining transitional Union-wide rules for the harmonized free allocation of emission allowances under the EU emissions trading directive starting in 2013, which dispensed the gas regulation but decreased the benchmark values by another 10 to 14%. The sinter benchmark also includes one pellet plant. It is clearly to be seen, that none of participating plants in the EU 27 reach the required benchmark values set by the European Commission.

Figure 25 - Coke benchmarking curve CO2 intensity

Figure 25: Coke benchmarking curve CO2 intensity

Figure 26 - Sinter benchmarking curve CO2 intensity

Figure 26: Sinter benchmarking curve CO2 intensity

Figure 27 - Hot metal benchmarking curve CO2 intensity

Figure 27: Hot metal benchmarking curve CO2 intensity

This draft makes free CO2 allocation for operating plants and also for new capacities impossible and loads the production plants in Europe with additional costs. This increases the danger for carbon leakage. Carbon leakage is assumed if trade intensity with regions outside EU is over 10 % and cost increases through CO2 burden including electricity in comparison to gross value added is over 5 % or trade intensity is over 30 % or cost increase is over 30 %. Then companies may transfer of production capacities to locations outside Europe.

Figure 28 - CO2 emission trading countries (in dark blue) in the world

Figure 28: CO2 emission trading countries (in dark blue) in the world

Europe is currently the only region of the world which tries to reduce CO2 emissions by an emission trading system, Figure 28. Generally speaking the driving character of such a system to reduce specific CO2 emissions remains questionable, because money used for buying CO2 certificates is not available for technological and process developments. These scenarios do not exist outside Europe. The CO2 emission trading restricted to Europe covers only 11% of world crude steel production in 2009.

Blast furnace – further outlook

In the EU (15) the share of oxygen steelmaking remains dominant. A steady increase of electric steel share is seen for the past years but further growth rate may be limited by scrap availability.

Therefore the blast furnace will remain the dominant pre-product supplier especially for high-grade steel production. The costs for hot metal to a great extent determine the economic result of an integrated iron and steelworks working with the BF/BOF route. The trend to a change over from some smaller to remaining economical large-sized furnaces may continue. The operating time factor of a blast furnace is very important. Frequent unscheduled stoppages are not only unhealthy for the life of the furnace, but also negatively influence hot metal costs.

The situation with extreme bad economics has led to drastic decreases in steel and hot metal production. 28 blast furnaces out of 58 were stopped in May 2009, the others operated at reduced production in the rage of 55 to 80 %. Only three furnaces operated at full capacity to supply the demand as other furnaces of the plants were stopped. Hot metal production dropped by 50 %. As too much coke was available in many works the auxiliary reductant injection rate was reduced or partly stopped and the furnaces operated with 100 % coke as reductant. Fortunately the situation has become better in 2010. uncertainties for the location Europe remain by the draft of the European Commission for the CO2 emission trading period from 2013 on. This increases the danger for carbon leakage.

Summary

This presentation focuses on the evolution of ironmaking in Western Europe and highlights some aspects, like: Introduction into the development in hot metal production, progress of the structure of reductants and ore burden materials, evaluation of constructional features and equipment of the blast furnaces and further outlook for the European ironmaking scenario. The integrated steel works in Western Europe operate modern plants for the production of a wide variety of high grade steel products. The blast furnace/converter route will remain dominant. With respect to the international finance crisis which also affected the steel industry the question is answered “How flexibly can metallurgical plants be operated”. The plunge in order intakes in late 2008 called for decisions which produce immediate effect, in order to adapt the entire chain to the requirements, beginning with logistics and warehousing of raw materials down to the linked production units of integrated works. Suitable measures realized at coke oven batteries and blast furnaces are described. One main focus is set on the future CO2 trading system based on benchmarks with non reachable values as set by the European Commission.

References

1. Großpietsch, K.-H.; Lüngen, H. B.: Coke quality requirements by blast furnace operators; IISI seminar on coke, Brussels, 4 and 5 September 2001
2. Heinrich, P; Hille, H: Der Kupfer Stave – Ein wesentlicher Beitrag zur Wirtschaftlichkeit des Hochofenverfahrens; Fachausschussbericht No. 1031 des Stahlinstitutes VDEh, July 1998.
3. Ringel, D; Janz, J; Trecker, H: Relining of blast furnace 2 at Stahlwerke Bremen; stahl u. eis en 120 (2000) No. 6, p. 27/32
4. van Campe, Stefan: Stave concerns at ArcelorMittal Gent BF A; Meeting of the General Managers of Blast Furnace Works of VEDh member companies, Lulea, Sweden, 21 March 2007
5. Schmöle, P.: From high productivity operation to reduced output: How flexibly can metallurgical plants be operated?, stahl und eisen 130 (2010), no. 8
6. Beckmann, H.-B.; Dombrowski, G.; Jager, H.-W.; Liszio, P.; Lüngen, H.B.; Masuth, M.; Nelles, L.; Schulte, H.: Possibilities and limits of cutting back coking plant output; stahl und eisen 130 (2010), no. 8
7. Source of curves: Phillip Townsend Associates Inc.; report on Eurofer CO2 intensity data 2010



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