Any improvement in Blast Furnace productivity under a given set of operating conditions is fundamentally related to better flow distribution of gas through layered burden structure in Blast Furnace. Flow distribution and hence pressure drop of gas in granular zone of blast furnace is dependent on number and thickness of alternating layers of coke and metallic burden. A significant part of this total pressure drop in granular zone can be attributed to interfacial resistance between two successive layers. Whereas, pressure drop in porous layers of materials can be described by well known Ergun's equation in terms of all physical parameters, interface resistance needs specific treatment. Systematic study to investigate the effect of interfacial resistance on gas flow between two successive layers of different material has been attempted in this work. Laboratory scale experiments in scale down model of blast furnace were conducted to establish and quantify interface resistance for different layer configurations.   

The proceedings contain 86 papers divided into the following topical sections: Coal and coke; Cokemaking operations; Cokemaking research; Cokemaking -- Process innovations; Blast furnace general; Blast furnace -- Improvements/optimization; Blast furnace injection; Blast furnace -- Rebuilds/repairs/relines; Blast furnace -- Campaign extension; Pelletizing; Sintering; Waste oxide recycle; Battery operations; Burden control; Direct reduction and smelting; Temperature control from ironmaking through finishing; Expert systems; Steelmaking; and Casting. Papers within scope have been processed separately for inclusion on the database.

This annual report describes the Blast Furnace Granular Coal Injection project being implemented at Bethlehem Steel Corporation`s (BSC) Burns Harbor Plant. The project is receiving cost-sharing from the US Department of Energy (DOE), and is being administrated by the Morgantown Energy Technology Center in accordance with the DOE Cooperative Agreement No. DE-FC21-91MC27362. This installation is the first in the United States to employ British Steel technology that uses granular coal to provide part of the fuel requirement of blast furnaces. The project will demonstrate/assess a broad range of technical/economic issues associated with the use of coal for this purpose. These include: coal grind size, coal injection rate, coal source (type) and blast furnace conversion method. To achieve the program objectives, the demonstration project is divided into the following three Phases: Phase I -- design; Phase II -- construction; and Phase III -- operation. Preliminary design (Phase I) began in 1991 with detailed design commencing in 1993. Construction at Burns Harbor (Phase II) began in August 1993 and was completed at the end of 1994. A 100% construction review meeting was held in December and attended by representatives of DOE, Fluor Daniel and Bethlehem Steel. The coal preparation mills were started up in December, 1994, and the first coal was injected into ``D`` blast furnace on December 19, 1994. Near the end of the year, the grinding mills and injection facility were being prepared for performance testing during the first quarter of 1995. The demonstration test program (phase III) will start in the fourth quarter of 1995.

It is attempt in pulverized coal injection (PCI) in blast furnace tuyeres to increase the injection rate without increasing the amount of unburned char inside the stack of the blast furnace. The unburned char can cause problems in the blast furnace operation, such as reduced permeability, undesirabl...

No. 13 Blast Furnace at US Steel`s Gary Works is a 35 tuyere furnace with a 36.5 ft. hearth capable of producing over 9,000 tons of hot metal per day. The current casthouse design was placed in service following the second reline in the fall of 1979. This design anticipated daily production rates averaging 7,500 tons of hot metal per day and provided for removable troughs at two of the three tapholes. At the time, the troughs were rammed with a high alumina/silicon carbide granular ramming material that provided the operators with trough campaign lives between 60,000--70,000 tons of hot metal produced. As refractory technology progressed, low cement/low moisture castables were introduced to the trough systems on No. 13 Blast Furnace. The immediate success of the castables was tempered by emergence of a new unexpected problem. That problem was the thermal expansion of the castable. The paper describes the problems that resulted in the need to modify the trough design, the new design of the trough, and its improvement in iron trough campaign life and reliability.

Increasing the Al2O3 content in the blast furnace slag, the blast furnace operations tend to make troubles such as excess accumulation of molten slag in the blast furnace hearth and increasing pressure drop at the lower part of the blast furnace. So, it will be important to keep good slag fluidity at the blast furnace operations such as, drainage of tapping and keeping good permeability.In order to clarify the effect of high Al2O3 slag fluidity on the blast furnace, high Al2O3 slag (20%) test operations of experimental blast furnace have been carried out. Investigation results of the test operation are as follows;1) Slag MgO improves the hearth drainage rate at high Al2O3 slag operation.2) Permeability of the dripping zone is improved by decreasing slag CaO/SiO2, at high Al2O3 slag operation of the blast furnace.3) It was verified that the slag drainage phenomena were able to described by the fluid model.4) The optimum composition of high Al2O3 slag of the blast furnace is high MgO and low CaO/SiO2.   

Herein, we report on the development of a cement comprising ground granulated blast furnace slag, soda ash (sodium carbonate), and up to 68wt.% granular limestone. Mixture Design of Experiment (DOE) was utilized, with analysis of compressive strength, modulus of elasticity, hydraulic properties, cost, CO"2 production, and energy consumption. Models were derived to understand the impact of mix design on performance and for optimization. Successful formulations are hydraulic and cure at room temperature, with strengths as high as 41MPa at 3d and 65MPa at 28d. These formulations, compared to OPC, are competitive in cost and performance and can reduce both CO"2 production and energy consumption by up to 97%.

Ground granulated blast furnace (GGBF) slag: A byproduct of iron blast furnaces. The slag is ... Polyurethane: Rigid Foam ... Scrap. – Rubber. Tire Rubber. 60-90% . 60-90%. Flowable Fill Containing ... Due to variations in cement, strength requirements, costs, and construction practices, EPA is not recommending recov- ...

The objective of this paper is to analyze the solid particle flow in a blast furnace having bell-type charging system by using large-scale Discrete Element Method (DEM). About 500000 particles were calculated in this work. The particle discharging behavior of laboratory-scale blast furnace was compared to confirm the material properties used in the simulation work, and the simulated trajectories of tracer particle correlated with those of experimental very well. The melting behavior of iron ore and combustion of coke in the actual blast furnace were modeled by shrinking particles. The simplified bell-type charging system in this simulation mimicked the actual blast furnace, the collapse of coke layer at the top was observed, and the time change of stock level was quite similar. The particle pulsating flow was observed at the upper area of blast furnace, and the descending velocity near side wall was much larger than that of center in this calculation. The melting position of ore was mapped and the most of iron ore were melting above the raceway. This area should be cohesive zone. This modeling is the first step of the analysis of blast furnace by using Discrete Element Method. Although only contact force was considered and simplified melting zone or raceway were introduced, this large-scale simulation has a high potential to analyze the solid flow in the blast furnace, and the abnormal phenomena or serious problem in blast furnace operation will be analyzed in the future by considering gas flow or heat transfer.   

A newly developed gas-liquid two-phase model has been employed to simulate the flow of gas and liquid in a blast furnace. This model accounts for the existence of impermeable fused layers in the blast furnace cohesive zone and treats the liquid as a discrete phase as revealed by experimental observation. The model has been run with a variety of assumed cohesive zones under a given blast furnace condition, giving the flow pattern and the distributions of liquid flow rates and liquid holdup. The results demonstrate the localized horizontal or upward flow characteristics of discrete liquid in and below the blast furnace cohesive zone. These characteristics are affected by the cohesive zone structure that can he described in terms of shape, position and the numbers of fused layers. The study reinforces the need to implement liquid flow in blast furnace modelling. (author)

The hydrogen contained in blast furnace gases exerts a variety of physical, thermochemical, and kinetic effects as the gases pass through the various zones. The hydrogen is derived from two sources: (1) the dissociation of moisture in the blast air (ambient and injected with hot blast), and (2) the release from partial combustion of supplemental fuels (including moisture in atomizing water, steam, or transport air, if any). With each atom of oxygen (or carbon), the molar amounts of hydrogen released are more than six times higher for natural gas than for coal, and two times higher for natural gas than for oil. Injection of natural gas in a blast furnace is not a new process. Small amounts of natural gas--about 50--80 lb or 1,100--1,700 SCF/ton of hot metal--have been injected in many of the North American blast furnaces since the early 1960s, with excellent operating results. What is new, however, is a batter understanding of how natural gas reacts in the blast furnace and how natural gas and appropriate quantities of oxygen can be used to increase the driving rate or combustion rate of carbon (coke) in the blast furnace without causing hanging furnace and operating problems. The paper discusses the factors limiting blast furnace productivity and how H{sub 2} and O{sub 2} can increase productivity.

New technology now operating in the metal industry of Russia is overviewed. Included are articles on the optimization of charge basicity distribution across blast furnaces; the use of personal computers to control blast furnaces operation; introduction of a new uniflow furnace in an open hearth shop; new techniques in the repair of electrical machinery; and the effect of recrystallization on brittleness in intermetallic compounds due to impurity segregation.

Features particular to the technology of using a blast furnace for the recycling of plastic waste are reported, and the behavior of plastic waste injected into a blast furnace is described. The plastic waste is injected into the furnace borne on a 1200degC hot blast through the tuyere. The plastic is converted into a reducing gas in the furnace, and the gas on its way up in the furnace is utilized as a reducing agent in the iron ore reducing reaction. The process is described below. All kinds of plastic waste may be utilized in this fashion, with the exception of polyvinyl chloride. As for polyvinyl chloride, efforts are under way to develop a technology to recycle this plastic. The method using the blast furnace tolerates a wide range of impurities, and the plastic waste is only to be crushed and granulated before use in the furnace. Plastic waste coarsely granulated but not pulverized may be completely gasified when the blast furnace raceway function is utilized. Since plastic waste in a blast furnace may be used as an iron ore reducing agent, it enjoys a high recyclability rate. Plastic waste produces less CO2 than coal does. 7 refs., 15 figs.

Most of the world`s high productivity blast furnaces operate with the blast humidity ranging between 15--20 grams/Nm{sup 3} in conjunction with high amounts of tuyere injectants. Compared with this approach, Tata Steel has adopted high blast humidity (60--80 grams/Nm{sup 3}) operation in view of the limitations imposed by the physico-chemical characteristics of the raw materials available which do not allow the furnaces to be operated at high RAFTs. Low RAFT operation as is being followed at Tata Steel, is advantageous for the production of low silicon hot metal while maintaining the hearth heat conditions required for smooth furnace operation. The effect of high blast humidity on bosh gas composition, efficiency of gas utilization, coke rate, productivity and hot metal quality has been studied based on thermo-chemical considerations. High blast humidity has markedly improved the furnace performance in terms of coke rate, productivity and hot metal quality at Tata Steel.

The research aimed to characterise the permeability to gas of the blast furnace burden during softening and melting, to develop an improved model of the blast furnace cohesive zone, and to introduce this model into a general model of the blast furnace in order to assess ways to increase PCI rates. Softening and melting experimental tests were carried out on five types of materials: olivine pellets, acid pellets, and sinters of three different basicities. The conclusion of the test is that the two main factors controlling the reduction of the burden material, and with that the meltdown properties, are the hydrogen content, resulting from the PCI rate, and the temperature increase rate, resulting from the rate of descent in the blast furnace. Based on these experimental results, a model of the cohesive zone was developed, which compares very well with the observations made on dissected blast furnaces. Finally, the blast furnace model has been used to study the influence on the cohesive zone and on some blast furnace performances of the variables affecting the cohesive zone permeability, essentially burned composition and chemistry. The influence of the layers thickness has also been assessed.

Lining erosion is one of the key factors affecting the campaign life of the blast furnace. With the computer developments and CFD improvements, numerical simulation has already been the main way to study the refractory erosion of blast furnace. Here the most recent research results of numerical simulation and controlling on blast furnace lining corrosion were reviewed since 1960s, and some important problems of present were discussed, and some proposes for future development were given, Which will be helpful for the future theory and experiment research.   

The development and application of a 1-dimensional static blast furnace model, “Masmod”, written in a common spreadsheet environment, is described. The model includes blast furnace, hot stove, and burden models with recent additions of other operations including CO2 stripping and top gas recycle. Although blast furnace modelling has become increasingly sophisticated, a relatively simple and flexible model is shown to be useful for evaluating burden options, equipment and operational strategies, and process development. Furthermore the Masmod model has been integrated with global steel plant optimization models and Process Integration models for more complex system analysis and optimization.   

Process improvements, capacity increases and the use of modern measuring and process control techniques have helped to ensure that the blast furnace will remain an indispensable means of supplying steelworks with hot metal until well into the next century. The survival of a future-oriented company such as Thyssen Stahl AG depends on long-term improvements in economic viability. Today, Thyssen Stahl AG operates two blast furnace plants comprising a total of five blast furnaces with hearth diameters ranging from 9.3 to 14.9m. This choice of furnaces permits flexible adjustment to changing workload situations and enables about ten million tons of hot metal to be produced each year. The wide range of measuring devices specially fitted on Schwelgern blast furnace No. 1 made a vital contribution to the development of blast furnace models. The purpose of these models was to make a general assessment of the state of the furnace and so create an objective basis for furnace operation. The paper describes the development of these measuring techniques and process model and the application of the model.

This article describes a system using a television camera fitted with a high-speed shutter for measuring coke behaviour and particle size in raceways associated with blast furnace tuyeres. (2 refs.) (In Japanese)

Studies in a degreased, lean coal B and in gaseous G coal showed that the ICEM method may be used to produce formed coke for different uses, including as a replacement for classical blast furnace coke.

Global warming is a common subject in steel industry in every country. International cooperation will be required using the Kyoto Mechanism from global aspect. In the integrated steel works, there are various means to decrease reducing agent at blast furnace, however, preferable way to reduce CO2 emissions must be chosen considering energy balance in whole steel works, and energy saving must be actively pursued. Injection of waste plastics and carbon neutral materials such as biomass is better alternative. In the near future, hydrogen will attract attention as a clean energy source even in the steel works. Regarding oxygen blast furnace and smelting reduction, the possibility of CO2 reduction is dependent on optimum system design of total process including outside process. Charge of prereduced sinter and high reactivity coke to blast furnace leads to reduction of CO2, keeping current blast furnace facility and capability.   

The immobilization of hexavalent chromium in wastewater using blast furnace slag as the immobilizing agent was investigated by using hydrothermal treatment. The results showed that immobilization was not attained without a hydrothermal treatment, while hexavalent chromium in solution could be immobilized through the process of hydrothermal treatment with the blast furnace slag at 250°C for 18 h. In particular, the reducing condition was attributed to the presence of sulfur in the blast furnace slag, which indicated that the sulfur could plays key role in the immobilization of hexavalent chromium in the present study. In addition, the leaching test was carried out to evaluate the level of immobilization of hexavalent chromium in the products after the hydrothermal treatment, and it was found that the degree of immobilization was very high. Based on the results obtained in the present study, the immobilization mechanism of the hydrothermal treatment of blast furnace slag in wastewater was elucidated.   

may contain coal fly ash or ground granulated blast furnace (GGBF) slag. ... Motor Vehicle Tires – Tire means the following types of tires: Passenger car tires, light and ..... Steel from the EAF process contains a total of 100% recovered steel ...

Engineering Innovations. Special computational fluid dynamics programs appropriately model the complex chemically reacting ... NASA used the Direct Simulation Monte Carlo. method to ..... the blast furnace of plasma building. up outside of ...

a model where it could be separated into components and studied individually and then ...... "The Effectiveness of. Night Driving Glasses under Part-task Simulation," ..... 01 Blast furnace, steelworks, and rolling and finishing mills. 02 Iron and ...

To simulate the burden distribution of the COSIPA blast furnace II, a physical model has been developed in a 1:16 scale of furnace upper stack. Dimensional analysis combine with mechanical modeling rules were employed to guarantee similarity conditions concerning to raw materials, blast air flow, movable parts velocity, etc. The model has shown to be of great utility for the development of burden distribution methodology for the blast furnace II. This paper presents some results obtained in studies involving the influence of several burden distribution parameters, such as movable armour position, burden level, coke base, and others, as well as the application of these results to the blast furnace II 16 refs., 19 figs., 5 tabs.

This paper analyzes changes in the physico-mechanical properties of coke obtained under various conditions during coke delivery into blast furnaces. Coke tends to crumble during transportation while its quality improves insignificantly. To improve coke quality as it is being fed into blast furnace, it is recommended that the crushing effect be reduced and the abrasion effect be increased. Diagrams show the effects of crushing and abrasion. Grain size classes 60-40 and 80-60 mm are considered to be more suitable for blast furnace smelting than the 40-25 mm class, which shows weaker physico-mechanical qualities. It is suggested that size class over 80 mm be separated and either subjected to additional preparation or sent to other users. A schematic diagram shows the coke handling process starting at the coke sorting machine to its delivery into the blast furnace. (4 refs.)

A continuously recording carbon monoxide monitoring system with fully automatic alarms is described for use in blast furnace areas. The equipment comprised the Mines Safety Appliances Model 200 infra-red analyser, pumping system, recorder, extension meter, and alarm unit.

The rates of gasification of charcoal produced from native forests and eucalyptus were compared. Using a mathematical model for heat and mass transfer between solids and gas, the effects of these different rates of gasification in blast furnace operation were investigated in terms of the degree of iron ore reduction in the upper part of blast furnace and carbon consumption. (author) 4 refs., 3 figs.

The chemical composition of slags of charcoal and coke blast furnaces is optimized considering the quality constraints for the maximum efficiency of the process, specified by means of pseudo-ternary diagrams. Aiming the best chemical composition, mass balances were also developed to determine the minimum weight of slag that can be produced. The results were compared to the industrial data from Brazilian charcoal and coke blast furnaces and possible changes are suggested. (author). 5 refs., 8 figs., 2 tabs.

This volume includes the following appendices for documentation of the dynamic blast furnace model: Input Files to the Dynamic Simulation; Computer Program for the Dynamic Simulation; Computer Program of the Overall Mass Balance on the Final State of the Dynamic Model Verification Tests; Data Inputs and Results of the Mass Balance Program; Input Files and Computer Programs Necessary in Plotting the Dynamic Simulation Results; and Kinetic Expressions Used in the Shaft Region of the Blast Furnace Dynamic Model.

A mathematical model based on the equating of the blast furnace reduction process according to the methodology suggested by Rist (and others) was developed and applied to the COSIPA number 2 blast furnace. The results show that this model is a useful tool to the operator. A clear vision of the thermal and chemical efficiency of this equipment is showed. (author). 7 refs., 10 figs.

The three hot blast stoves of the large-sized blast furnace in Schwelgern have been automatically controlled by a microprocessor since early 1983. The control programm required therefore has been developed with the aid of a simulation model capable of reproducing the actual thermal and flow processes in the checkerwork of hot blast stoves. The individual steps required to ensure an extensive energy optimization of the whole process taking into account both plant and over-head requirements are presented. The efficiency of the top-gasfired hot blast stoves can be improved by more than 5% by computer-assisted operation, and this resulted in an actual reduction of energy consumption by 0.3 GJ/t hot metal, i.e. by 0.35 MJ/m/sup 3/ blast. On the basis of a yearly output of 2.8 million t hot metal of the blast furnace Schwelgern this represents a saving in energy costs of over 6 million DM/year.

Currently low reducing agent operation of blast furnace has been actively pursued in ironmaking due to the global warming. The precise and reliable control of blast furnace aiming at the low reducing operation is required to attain smoothly the stable operation. It is considered that the mathematical model on the ironmaking process can play an important role to ensure the stable blast furnace operation. A mathematical model is a powerful tool to improve conventional processes and to design new processes in ironmaking. These tendencies and requirements are common to every country. Thus, the development of advanced mathematical models of blast furnace like DEM (Discrete Element Method) has attracted a special attention in ironmaking field. Moreover, the combined model of DEM with the continuum model is under development for the purpose of the accurate understanding of inner state of blast furnace. In this paper, the recent activity and progress on the development of advanced mathematical model of blast furnace and future perspective for desirable model are described.   

In order to increase its industrial competitiveness and to satisfy blast furnace requirements, the cokemaking industry needs to produce coke of a higher quality. The injection of coal, oil, gas and plastics to replace coke at the tuyeres has now become a widely accepted technology in modern blast fu...

Factors are discussed which influence coke consumption by a blast furnace: furnace capacity, permeability of the charge to gases, and coke quality. Effects of grain size distribution of coke, in particular, content of coke fines with a diameter below 5 mm, coke mechanical properties (the M40 compression strength index, coke abrasion wear), coke reactivity and ash content on coke consumption rates and blast furnace output are analyzed. Ash content increase in coke increases coke consumption rates (on the average a 1% increase in ash causes a consumption rate increase of 2 to 2.5%). Evaluations carried out in Poland by Janik and Pawlik show that ash content increase in coke from 8 to 12% improves coke combustion intensity which partly compensates the negative effects of a high ash content. Factors which influence coke consumption rates are analyzed using a blast furnace with a capacity of 862 m/sup 3/. Intensity of blast furnace operation is determined as the coke consumption rate per 1 m/sup 3/ furnace volume in 24 h. Evaluations show that coke consumption is minimum when 0.7 t coke is used. Blast furnace output is maximum when 0.78 t coke is used. The results of evaluations are given in a table and diagram. 5 references.

Alternative materials for use as TES media in electric storage furnaces have been evaluated and selected. Selections were based on: low cost; availability; durability; and energy storage density. The materials selected were: taconite pellets; river gravel; crushed stone; and crushed (air-cooled) blast furnace slag. Essential material properties and energy storage densities were established. A conceptual design for an electric storage furnace using these low-cost materials has been developed. The performance of this conceptual furnace has been characterized by use of an analytical model. A computer code for the model has been developed. Existing performance data for present-day electric storage furnaces have been evaluated, and performance and design comparisons between present-day furnaces and the prototype furnace have been made. With the limited data at this time, a significant cost advantage for the proposed furnace, with equivalent performance, over existing electric storage furnaces cannot be established. Future work required for materials testing and component development has been identified.

The rhythmic noises of the turning water wheel and the roar of the furnace blast never stopped at Hopewell Furnace (Pennsylvania) during its years of operation (1771-1883). As long as the furnace was in blast, the ironworkers' jobs were safe. In case of trouble, they could escape to the woods, fields, and creeks of rural Pennsylvania. Now a national historic site, Hopewell Furnace lies in a setting of forested hills and valleys along a French Creek in Berks County in southeastern Pennsylvania. It provides a glimpse into the early days of the iron and steel industry that played a central role in the growth of the United States as an industrial nation. This lesson plan on Hopewell Furnace can be used in U.S. history, social studies, and geography courses in units on the growth of the U.S. economy during the early national period. The lesson plan is divided into eight sections: (1) "About This Lesson"; (2) "Getting Started: Inquiry Question"; (3) "Setting the Stage: Historical Context"; (4) "Locating the Site: Maps" (Pennsylvania and Surrounding Areas; Southeastern Pennsylvania); (5) "Determining the Facts: Readings" (Works at Hopewell Furnace; Owner and Iron Master; Hopewell Furnace Community); (6) "Visual Evidence: Images" (19th Century Blast Furnace in Operation; 'Jumping the Pit,' 1936; Artist's View of Hopewell Furnace, 1950s; Ironmaster's House with Outbuildings; Tenant Houses; Typical Hopewell Furnace Products); (7) "Putting It All Together: Activities" (Working at Hopewell; Economic History in the Local Community); and (8) "Supplementary Resources." (BT)

This paper shows the behaviour of the performance of a charcoal blast furnace, when the crucible volume was reduced and the drainage times was increased. Thus, the performance of the system became satisfactory, optimizing the permeability of the crucible and increasing the profit of the charcoal in the furnace. 6 refs., 9 figs., 1 tab.

from model tests and full-scale launches and are based on the effects of specific SRMs ..... Ash pits, hoppers and ducts, annealing furnace car tops, tunnel kiln car bottoms, oil refining vessel linings, cyclones, iron blast furnace mains ..... When enclosing rein- forcing, care will be taken to remove loose sand or rebound from ...

A prediction model has been developed based on the simulation model presented previously. These models are the two components of the KTH Blast Furnace Process Model. The concept of this prediction model is to use the same fundamental equations as in the simulation model and to use some output of a simulation of a blast furnace. Certain assumptions should be made for an individual change in operational conditions in order to build up the mass balance and heat balance submodels for the determination of the boundary conditions in a prediction. The ore to fuel ratio and the CO utilization are adjustable parameters in the model. The furnace internal state as well as furnace productivity and fuel consumption in the last iteration are considered to be the predicted results. The prediction model has been designed for the following five cases: (1) increased blast temperature, (2) oxygen enrichment of the blast, (3) coal injection, (4) coal injection combined with oxygen enrichment and (5) changed coke quality. Moreover, this model can also be used for analysis of the thermal conditions in a blast furnace when an operational parameter, such as blast temperature, coke moisture and iron content in the ore, fluctuates. The predicted operational indices were compared to the ones from industrial tests. The validity of the KTH model is indicated by this comparison. 6 refs., 12 figs., 5 tabs.

This work describes the development and further validation of a model devoted to blast furnace hot metal temperature forecast, based on Fuzzy logic principles. The model employs as input variables, the control variables of an actual blast furnace: Blast volume, moisture, coal injection, oxygen addition, etc. and it yields as a result the hot metal temperature with a forecast horizon of forty minutes. As far as the variables used to develop the model have been obtained from data supplied by an actual blast furnaces sensors, it is necessary to properly analyse and handle such data. Especial attention was paid to data temporal correlation, fitting by interpolation the different sampling rates. In the training stage of the model the ANFIS (Adaptive Neuro-Fuzzy Inference System) and the Subtractive Clustering algorithms have been used. (Author) 9 refs.

Coal injection into the blast furnace as a coke substitute was pioneered in the US by National Steel Corp. Difficulties encountered with the technology and the availability of low-cost alternative fuels prevented its further development. The problems encountered were catastrophic tuyere failures, hanging, furnace rolling, and carbon-black carry over and injection-system inadequacies. Investigations led to corrective measures. Optimization of coal injection must be based on good blast-furnace operating practice. Selection of the proper coal for injection is imperative. Injection equipment must be reliable, maintenance free, and provide a distribution system to each tuyere with a minimum of variation.

Correct prediction of material trajectory is a pre-requisite for effective burden distribution in a blast furnace. A mathematical model based on single particle approach has been developed to estimate the material trajectory for Tata Steel's 'F' Blast Furnace, fitted with a compact bell-less top (CBLT). The model has been validated with actual in-furnace measurements. Initial results about the applicability of the model are promising; however, further refinement is in the pipeline. 28 refs., 14 figs., 2 tabs.

Two measures for coke saving and increase in blast furnace efficiency related to coke characteristics - reactivity and size - are discussed in this paper. Modern blast furnace operation with low coke rate and high injection rate causes a change in coke quality requirements. A discussion has arisen recently about highly reactive coke. Here, a theoretical analysis of influence of coke reactivity on the thermal reserve zone, direct reduction and carbon consumption in the blast furnace has been undertaken. Experiments have been performed using non-standard test scenarios that simulate coke behaviour under real blast furnace operating conditions. Coke reactivity and microstructure have also been investigated under the impact of alkali and pulverised coal ash and char. Operation of many blast furnaces has proved the possibility of coke saving and increase in productivity when using small-sized coke (so-called nut coke) mixed with the burden, but the reasons for this phenomenon, and consequently the limit for nut coke consumption, are still not very clear. An analytical method and cold model simulations have been used to quantify the change in shaft permeability and furnace productivity when using nut coke.

A model for estimation of erosion and skull profiles of the blast furnace hearth is presented. The model, which is based on thermocouple measurements in the hearth bottom and wall lining, estimates the most severe erosion of the lining experienced during the campaign and also the present thickness of the skull material. The model is illustrated on process data from two Finnish blast furnaces. Complementary measurements and calculations are used to verify the results. Based on the findings, conclusions are drawn about the internal state of the blast furnace hearth, for instance, whether the dead man floats or sits at the bottom. Finally, some suggestions on how to control the state of the furnace hearth are given. (author)

When increasing fuel injection in a blast furnace in order to reduce coke consumption and/or to increase production, the blast furnace operator tries to keep similar raceway conditions, for instance, an equivalent flame temperature. To compensate for the cooling effect due to the higher injection rate, two solutions can be selected or combined: to raise the temperature of the blast and/or to increase the level of oxygen in the blast. Whatever the choice, the Blast Furnace manager will certainly try to reduce the resulting investment and operating costs to a minimum. Air Liquide and Kvaerner Davy are trying to provide a new way to address these needs by offering a new technology for blast heating. A higher blast temperature will not only allow a higher fuel injection at tuyere level, a lower coke consumption, but also a lower oxygen consumption. Air Liquide and Kvaerner Davy are now able to offer a new heat regenerator with major advantages over conventional stoves. This new device can be used as a permanent substitute for a stove, or as a temporary one during repair, or stove improvement. It can also be added to an existing set of stoves to increase the average blast temperature.

Accretions in the bosh, belly and shaft have a significant influence on blast furnace performance and on the service life of the refractory lining and the cooling system. To analyse the mechanisms of formation and dislodging of accretions, investigations were carried out at four different blast furnaces. Three blast furnaces were equipped with additional measurements to investigate the accretion formation process and to provide information for the development of accretion estimation models. Installation activities included thermocouples, heat-flux meters, staves with instrumentation for heat-flux measurement and a small horizontal lance. The distribution of accretions in the shaft was documented. Samples were taken out of accretions during blast furnace stoppages. Their acquisition was simplified with newly developed sampling devices. The samples were analysed to determine chemical and mineralogical properties and thermal conductivity. Samples were mainly made up of reduced iron or of coke and sinter structures glued together by zinc or alkali compounds. Together with a newly developed offline model for the simulation of accretion formation, different parameters influencing the formation process were identified. The main parameters are: burden material composition, blast furnace operating conditions; and the cooling system. Countermeasures to prevent excessive accretion growth were determined. They offer a better operational control of accretions. Different models to identify accretion formation were developed and an overview was presented. Different models were necessary to distinguish between the various measurement, cooling-system and blast-furnace setups. Most of the models are already implemented and in operational use. For some of them application at other blast furnaces was already realised or is possible. 9 refs., 18 figs., 20 tab.

Bethlehem Steel's Burns Harbor Div. operates two 89,000-cu ft blast furnaces, D and C, built in 1969 and 1972. These furnaces have been in the forefront of blast furnace performance since they were blown-in. To maintain a credible operation throughout the past 25 years their performance has been improved continuously. Production was increased approximately 3%/year while fuel rate decreased 1%/year. This presentation summarizes the early repairs, relines and improvements that have sustained and enhanced the furnace's performance. The fourth reline of both furnaces will be discussed in detail. As part of the 1991 reline of D furnace its lines were improved and modern penstocks installed. The bosh, tuyere jacket, hearth jacket and both cast floors were replaced. The furnace now has a larger hearth making it easier to control and, liquid level is no longer a problem when pulling the wind to shut down. The new cast floor with its increased trough length has much improved separation of slag from iron and lowered refractory consumption. Since the cast floors on D furnace were changed, there has been a reduction in accidents and absenteeism. This may be related to the change in work practices on the new cast floors. The 1994 reline of C furnace incorporates those improvements made on D furnace in 1991. In addition, C furnace will have high-density cooling which is expected to double its campaign from 6 to 12 years, without interim repairs.

The furnace bottom brick temperature which controls the brick erosion of blast furnace bottom and the heat transfer condition of blast furnace hearth relating directly to the tapping, are studied by laboratory experiments and plant data analysis using cylindrical furnace as experimental apparatus. The temperature of the blast furnace hearth is repeated by two conditions, high temperature period and low temperature period. It is found that a zone of low permeability against the molten iron and the slag flow has existed over a wide area when the temperature at furnace bottom is low. The reason for the formation of low permeability zone has not been cleared, however it has been formed from the crystallized kiss graphite from low temperature molten iron at furnace bottom, ashes left at the furnace bottom while quenching the coal, pulverized coal and unburnt char during injection of powder coal, and this has caused the choking of coke packed bed. The concept of low permeability zone has made possible to interpret the transition of bottom bricks temperature, differences in the metal tap hole and the correlation between the flow-out index of slag and the bottom brick temperature. 17 refs. 18 figs., 2 tabs.

The project consisted of four parts performed at different research centres: study of blast furnace dead man at high PCI (CSM); experimental studies on raceway dimensions and gas circulation in relation to the combustion of injected coal (CENIM and Aceralia); further productivity increase by injection of metallised ore fines at high PCI (RWTH Aachen); and modelling of gas and char flows at high PCI (CRM). Several mathematical models of the dead man were developed, but only two were sufficiently reliable for the simulation of the whole blast furnace descent in terms of descent velocity, stress field and material segregation. The experimental studies of the raceway have been carried out in two methacrylate models and in a coke gasification chamber placed on a weighing platform. These models contributed to an understanding of the physics of blast furnace raceways. A coal-based metallisation process for iron ore fines has been designed for sticking-free operations. The simulated injection of metallised fines into the blast furnace or the charging of briquetted metallised material from the top, leads to noticeable increases of productivity at slightly reduced costs. At CRM, a mathematical model simulation the main phenomena of the blast furnace was calibrated by vertical probing and by gas tracings. The model shows the strong influence of the burden distribution pattern on the gas distribution and on the different operating results. Simulations of coal rate increase no significant modification of the gas distribution.

The purpose of this study is to evaluate the combustion of Illinois coal in the blast furnace injection process in a new and unique pilot plant test facility. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This study is unique in that it is the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. It is intended to complete the study already underway with the Armco and Inland steel companies and to demonstrate quantitatively the suitability of both the Herrin No. 6 and Springfield No. 5 coals for blast furnace injection. The main feature of the current work is the testing of Illinois coals at CANMET`s (Canadian Centre for Mineral and Energy Technology) pilot plant coal combustion facility. This facility simulates blowpipe-tuyere conditions in an operating blast furnace, including blast temperature (900 C), flow pattern (hot velocity 200 m/s), geometry, gas composition, coal injection velocity (34 m/s) and residence time (20 ms). The facility is fully instrumented to measure air flow rate, air temperature, temperature in the reactor, wall temperature, preheater coil temperature and flue gas analysis. During this quarter a sample of the Herrin No. 6 coal (IBCSP 112) was delivered to the CANMET facility and testing is scheduled for the week of 11 December 1994. Also at this time, all of the IBCSP samples are being evaluated for blast furnace injection using the CANMET computer model.

Steel makers routinely inject alternate fuels into their blast furnaces that remain the heart of the integrated steel mill. Throughout the 1990's, gas industry sponsored tests at integrated steel mills demonstrated that natural gas injection could successfully provide up to 50% of a blast furnace's total energy requirements, reduce coke usage by 34% per kg of iron produced, increase productivity up to 30% and reduce operating costs by $4.40 to $5.50 per 10{sup 3} kg of iron produced. The success of these tests was instrumental in increasing total natural gas blast furnace injection in North America from under 850 10{sup 6} m{sup 3} (30 billion cubic feet) per year in 1985 to over 3.3 10{sup 9} m{sup 3} (116.5 billion cubic feet) per year currently. Pulverized coal injection (PCI) has been clearly demonstrated to reduce coke consumption and therefore operating costs although the use of PCI provides little or no flexibility in production levels from a particular furnace. Worldwide steel demand/use is cyclical and to remain competitive, plants must adjust production to match market demands while controlling total production costs and maintaining the operation's profitability. Recent blast furnace operating practices demonstrate that co-injecting natural gas along with pulverized coal can provide the benefits of each individual fuel. This paper provides a historic perspective on North American blast furnaces, their operation and the use of natural gas in relation to other fuels routinely injected into the blast furnace. The perspective leads to a projection of the impact of natural gas co-injection in North American integrated steel plants over the next 5 years. (authors)

AHMSA (Altos Hornos de Mexico) is the largest integrated Steel Plant in Mexico, with its 3.1 MMMT of Liquid Steel production program for 1995. AHMSA operates two coke plants which began operations in 1955 and 1976. Total coke monthly production capacity amounts to as much as 106,000 Metric Tons (MT). The coke plants working philosophy was discussed and established in 1986 as part of the Quality Improvement Program, where its ultimate goal is to give the best possible coke quality to its main client--the blast furnaces. With this goal in mind, a planned joint effort with their own coal mines was initiated. This paper deals with the implementation process of the Quality Program, and the results of this commitment at the coal mines, coke plants and blast furnaces. The coke quality improvement is shown since 1985 to 1994, as well as the impact on the blast furnace operation.

A controlling method of the radial mixed coke ratio distribution under high coke mixed charging, which is called FCG (Flow Control Gate) dynamic control method was studied with the aim of stable operation with high productivity and low RAR at Chiba No. 6 blast furnace. For this purpose, scale model experiments and mathematical burden distribution model calculations were performed. The effects of FCG dynamic control with ore and coke simultaneous discharging from the respective top bunkers on the mixed coke ratio distribution were examined and applied to Chiba No. 6 blast furnace. After application of FCG dynamic control, improvements of gas utilization efficiency: +0.2%, gas permeability at cohesive zone (the part of lower shaft): –14.7% and coke ratio: –4.2 kg/t (with constant RAR) were confirmed. Since June 2007, high productivity operation with low RAR has been conducted at Chiba No. 6 blast furnace.   

Lining erosion is the most important factor for determining the campaign life of a blast furnace. To provide information about the heat transfer of the copper stave in the belly of the No. 1 blast furnace at CSC (China Steel Corporation), a conjugate heat transfer model, including the heat transfer of the stave and sensor bar in thermal conduction and radiation transmission from the gas temperature inside the blast furnace and convection heat transfer in cooling pipe, was developed for the steady state process. The simulations focus specifically on the effects of the gas temperature, the geometric thickness of the cooling stave, the slag layer thickness and the material and diameter of the sensor bar. The results show that the refractory lining and the slag shell provide significant protec...

In order to develop an efficient process for the treatment of waste slag, the behavior of hydrothermal reaction of blast furnace slag has been investigated. For blast furnace slag, an experiment was conducted under various hydrothermal conditions with a liquid and vapor phase in the presence of saturated water steam pressure using an autoclave.The results indicated that calcium silicate hydrate (C-S-H) and tobermorite (Ca5Si6O16(OH)2·4H2O) were the major phases formed in the treated samples. It was also confirmed that the hydrothermal reaction process was strongly affected by the hydrothermal conditions. In particular, the hydrothermal reaction proceeded more rapidly in vapor phase than in liquid one. Accordingly, the reaction mechanism of the hydrothermal treatment of blast furnace slag has been clarified.   

High performance control of blast furnace (BF) ironmaking process is a difficult problem due to the high temperature and hostile measurement conditions for measuring devices in the process. Previous research focused on developing of accurate predictive models for silicon content in hot metal ([SI]) while control of the whole process is seldom discussed. In the present work, a data-driven predictive control method based on subspace method is presented for the blast furnace ironmaking process. The algorithm is based on input-output data and easy to implement. Simulation results show the algorithm is effective for the control application. Finally, various practical issues concerning predictive control of blast furnace ironmaking process are also addressed, such as constraint handling, control...

In order to monitor the thermal status of a blast furnace stave, an intelligent simulation technique is developed. The intelligent simulation model is built using a combined model based on the mathematical model of heat transfer and the technique of artificial intelligence. The intelligent simulation model of blast furnace cast steel stave is based on correction factor of parameters obtained by training the samples of test data of the cast steel cooling stave. Simulating currently existing blast furnace stave situation which is only a monitoring point on the stave and the velocity and temperature of cooling water are difficult to real-time be detected, the experimental verification of the model is done. The results show that the data of intelligent simulation model is nearly consistent wit...

The expediency of using various amounts of nut coke in blast-furnace smelting is evaluated in relation to the quality of the skip coke. Data from blast-furnace operation are analyzed to obtain relations expressing the dependence of the consumption of nut coke on the unit consumption of skip coke and its abradability index M10. A blast furnace can run smoothly with the use of nut coke if its concentration in the charge does not exceed 20?kg/ton pig iron and the abradability index of the skip coke is satisfactory (M10???9.0%). The average value of the coke-substitution equivalent was determined to be 0.67?kg/kg nut coke.

Blast gas discharge from the taphole in the course of the blast furnace hearth drainage was experimentally studied using a packed bed cold model. It was found that gas break-through time was strongly influenced by the furnace operating conditions and coke bed structure. Gas break-through time decreases with (a) increasing draining rate; (b) decreasing slag and iron levels in the hearth; and (c) increasing slag viscosity. It increases with an increase in the coke-free layer depth and coke-free space width. Under certain conditions, the gas-liquid interface in the region directly above the taphole becomes unstable, leading to viscous finger formation and subsequently early blast gas discharge from the taphole. The amount of blast gas entrained into the taphole due to viscous fingering, when it occurs, is sufficient to cause a splashy taphole stream.   

Sakota et al. examined the ocean periphyton quantity to the mortar specimen which was exposed to under marine environment. The contamination of the coal ash reported that the periphyton quantity is the most abounding to 2 m water depth from the intertidal zone and that it is little with the water depth deepening, and that it does not affect ocean periphyton quantity and the type. Saeki et al. examined the prediction of calcium hydroxide quantity in the concrete which mixed fly ash and ground granulated blast-furnace slag from the relationship between chemical composition and hydration characteristic of the admixture. It was reported that a chemical abundance of the admixture could be expressed as a parameter in respect of the constant in calcium hydroxide consumption kinetic equation. MATSUSHITA et al. reported that there was the possibility degree of the small by minuteness crack which the concrete using blast furnace slag generated at the initial stage and latent hydraulic property of afterwards ground granulated blast-furnace slag. Plums have discussed on basis of experimental result the relationship between specific surface of ground granulated blast-furnace slag on the neutralization and effect of substitution ratio, Tsumugi hole quantity and neutralization speed of the mortar. The mortar in which the substitution ratio used ground granulated blast-furnace slag within 50 % the specific surface is over 8000cm{sub 2}/g, and the pore quantity is smaller than the result which it does not use, and the neutralization speed slows down. And, it was reported that there was the relation in which class hole quantity and neutralization speed over 0.03 {mu}m pore diameter are close. Persimmon swamps investigated on basis of experimental result on the physical property in using given fly ash and blast-furnace were reported that long term strength of the mortar was improved by the heat treatment. (translated by NEDO)

With the increased industrialization, generation of industrial by-products has increased significantly. There are many types of industrial by-products depending upon the industry. Utilization of such types of by-products has become an enormous challenge. One such type of by-product is ground granulated blast furnace slag (GGBS) which is produced from the blast-furnaces of iron and steel industries. GGBS is very useful in the design and development of high quality cement paste/mortar and concrete. This paper presents comprehensive details of the physical, and chemical properties, and hydration reaction. It also covers the workability, setting times, compressive strength, chloride and sulfate resistance of cement paste and mortar.

Temperature distribution in the crucible of a blast furnace is an important operation variable that is a function of the materials used in its construction, temperatures reached in the pig iron-refractory interface, and cooling-system performance. Defining the crucible zones where high shear and tensile stresses are reached is an important step in developing a tribological model to understand and predict high wear zones and crucible life. In this work, temperature distribution was simulated using the finite-element method for a blast furnace built following the ceramic solution (oxide and nitride ceramics in contact with the pig iron and carbon and microporous graphite blocks in contact with the refrigeration system).

Technique for high ratio coke mixed charging was developed and applied at JFE Steel's East Japan Works (Chiba District) No. 6 blast furnace as the first case of application to a large blast furnace. Simultaneous discharging of ore and coke from the top bunkers, and the precise control of burden distribution technique with the mathematical model considering the segregation behabior of mixed layer have made it possible. Since April 2002, high productivity operation with the world's lowest level of sinter ratio has been conducted using high ratio coke mixed charging technique.   

An integrated steel plant with two blast furnaces with the option to use biomass to partially substitute fossil reductants was simulated. A thermodynamic blast furnace model was used, combined with simpler models of the other unit processes (sintermaking, cokemaking, basic oxygen furnace, hot stoves and power plant) and a nonlinear model of the biomass conversion with respect to the processing temperature. Given an aim steel production rate for the plant, the economics of the plant was optimized by minimizing the specific costs of liquid steel, considering costs of raw materials, energy and CO2 emissions. Limited supply of sinter and coke was optimally allocated to the two blast furnaces and the effects of restrictions in the biomass, oxygen and oil supply on the operating states were studied. An analysis was also undertaken to study how the production rate of the plant would affect the optimal state. The results demonstrate that a non-uniform distribution of the resources can be economically justified, in particular for cases where the blast furnaces operate under different constraints.   

Rautaruukki Oy Raahe Steel rebuilt its blast furnaces in 1995 (BF1) and 1996 (BF2) after 10 year campaigns and production of 9,747 THM/m{sup 3} (303 NTHM/ft{sup 3}) and 9,535 THM/m{sup 3} (297 NTHM/ft{sup 3}), respectively. At the end of the campaigns, damaged cooling system and shell cracks were increasingly disturbing the availability of furnaces. The goal for rebuilding was to improve the cooling systems and refractory quality in order to attain a 15 year campaign. The furnaces were slightly enlarged to meet the future production demand. The blast furnace control rooms and operations were centralized and the automation and instrumentation level was considerably improved in order to improve the operation efficiency and to reduce manpower requirements. Investments in direct slag granulation and improved casthouse dedusting improved environmental protection. The paper describes the rebuilding.

Normally, blast furnace and COREX operate with all tuyeres. However, often, for various reasons it is required to operate the furnace by blocking one or multiple tuyeres. This induces asymmetric transport phenomena at the environs of the blocked tuyere. A 3D mathematical model of the COREX melter gasifier has been developed analyzing this phenomenon. Predicted result shows that even though there exists asymmetry around the blocked tuyere zone, the hot metal temperature is not affected significantly.   

Innovative blast furnace operations with top gas recycling after CO{sub 2} scrubbing were numerically examined. The fully kinetic mathematical model was applied to the operations with recycled gas injections into the tuyere and stack parts of the furnace, and the top gas recycling combined with waste plastics injection. The simulation results showed that the top gas recycling decreased the reducing agent rate and increased the productivity. (authors)

In the blast furnace process, material losses are caused by particles that are blown out of the furnace by the off-gas. In order to reduce these losses, it is important to understand the correlations between furnace conditions and off-gas dust formation. Off-gas dust, as flue dust and sludge, were collected during shaft probe sampling in LKAB Experimental Blast Furnace (EBF). Process data was used to evaluate the relationship between off-gas dust amounts and furnace conditions. The graphitization degree (Lc value) of shaft coke and coke in flue dust was determined using XRD measurements. Solution loss in the shaft had a negligible effect on coke degradation and the coke particles which ended up in the flue dust were mainly derived from abrasion at low temperatures. The amount of alkali and SiO2 in sludge increased with higher PCR and flame temperature, which confirmed that submicron spherical particles in sludge originated from the high temperature area around the raceway. Theoretical critical particle diameters of materials, which could be blown out with the off-gas, were estimated. Flow conditions in the top of the shaft as well as and the properties of fine particles in terms of size and density are important when outflow of mechanical dust, such as flue dust, is concerned. Low off-gas temperatures, and thus lower off-gas velocities, are favourable for low flue dust amounts expelled from the blast furnace.   

Nowadays the use of charcoal in metallurgy is intimately linked to small blast furnaces in Brazil. Due to the challenge for CO2 mitigation, interest for charcoal use as a renewable energy source is rising. In the scope of European efforts to mitigate carbon dioxide emissions in the steel industry in the post-Kyoto period, the use of charcoal in cokemaking and ironmaking has been investigated. This paper presents results of an experimental study on charcoal behaviour under the blast furnace simulating conditions performed at the Department of Ferrous Metallurgy, RWTH Aachen University and at the National Centre for Metallurgical Investigations, Madrid. Conditions in the raceway and in the furnace shaft were simulated using thermo-analytical, laboratory and pilot facilities. Charcoal samples were produced in two furnaces for pyrolysis from different wood types at various carbonisation conditions. Furthermore technological and ecological assessment of blast furnace process when injecting different types of charcoal was performed using a mathematical model. All the experiments and calculations were also performed with reference mineral coals for injection. Conversion efficiency of all the tested charcoals is better or comparable with coals. Change in coke rate, furnace productivity and further operation parameters when replacing pulverised coal with charcoal depends on charcoal ash content and composition.   

The pig iron nugget process was developed as an alternative to the traditional blast furnace process by Kobe Steel. The process aimed to produce pig iron nuggets, which have similar chemical and physical properties to blast furnace pig iron, in a single step. The pig iron nugget process utilizes coal instead of coke and self reducing and fluxing dried green balls instead of pellets and sinters. In this process the environmental emissions caused by coke and sinter production, and energy lost between pellet induration (heat hardening) and transportation to the blast furnace can be eliminated. The objectives of this research were to (1) produce pig iron nuggets in the laboratory, (2) characterize the pig iron nugget produced and compare them with blast furnace pig iron, (3) investigate the furnace temperature and residence time effects on the pig iron nugget production, and (4) optimize the operational furnace temperatures and residence times. The experiments involved heat treatment of self reducing and fluxing dried green balls at various furnace temperatures and residence times. Three chemically and physically different products were produced after the compete reduction of iron oxides to iron depending on the operational furnace temperatures and/or residence times. These products were direct reduced iron (DRI), transition direct reduced iron (TDRI), and pig iron nuggets. The increase in the carbon content of the system as a function of furnace temperature and/or residence time dictated the formation of these products. The direct reduced iron, transition direct reduced iron, and pig iron nuggets produced were analyzed for their chemical composition, degree of metallization, apparent density, microstructure and microhardness. In addition, the change in the carbon content of the system with the changing furnace temperature and/or residence time was detected by optical microscopy and Microhardness measurements. The sufficient carbon dissolution required for the production of pig iron nuggets was determined. It was determined that pig iron nuggets produced had a high apparent density (6.7-7.2 gr/cm3), highly metallized, slag free structure, high iron content (95-97%), high microhardness values (> 325 HVN) and microstructure similar to white cast iron. These properties made them a competitive alternative to blast furnace pig iron.

Increased levels of blast furnace coal injection are needed to further lower coke requirements and provide more flexibility in furnace productivity. The direct injection of high temperature oxygen with coal in the blast furnace blowpipe and tuyere offers better coal dispersion at high local oxygen concentrations, optimizing the use of oxygen in the blast furnace. Based on pilot scale tests, coal injection can be increased by 75 pounds per ton of hot metal (lb/thm), yielding net savings of $0.84/tm. Potential productivity increases of 15 percent would yield another $1.95/thm. In this project, commercial-scale hot oxygen injection from a ''thermal nozzle'' system, patented by Praxair, Inc., has been developed, integrated into, and demonstrated on two tuyeres of the U.S. Steel Gary Works no. 6 blast furnace. The goals were to evaluate heat load on furnace components from hot oxygen injection, demonstrate a safe and reliable lance and flow control design, and qualitatively observe hot oxygen-coal interaction. All three goals have been successfully met. Heat load on the blowpipe is essentially unchanged with hot oxygen. Total heat load on the tuyere increases about 10% and heat load on the tuyere tip increases about 50%. Bosh temperatures remained within the usual operating range. Performance in all these areas is acceptable. Lance performance was improved during testing by changes to lance materials and operating practices. The lance fuel tip was changed from copper to a nickel alloy to eliminate oxidation problems that severely limited tip life. Ignition flow rates and oxygen-fuel ratios were changed to counter the effects of blowpipe pressure fluctuations caused by natural resonance and by coal/coke combustion in the tuyere and raceway. Lances can now be reliably ignited using the hot blast as the ignition source. Blowpipe pressures were analyzed to evaluate ht oxygen-coal interactions. The data suggest that hot oxygen increases coal combustion in the blow pipe and tuyere by 30, in line with pilot scale tests conducted previously.

Applications of radioisotopes in process analysis in the chemical and metallurgical industries are reviewed. Applications discussed include studies in electrolysis of chlorine caustic; analysis of the flow pattern of electrolyte in the potassium chlorate cell; process analysis in an alumina plant, studies on the flow of glass in melting and working furnaces; the behavior of sulfur in butyl rubber; measurement of the residence time of ore pulp in flotation cells, determination of gas transit time in a blast furnace, measurement of the flow of molten metal in a copper refractory furnace, and measurement of the iron-tin alloy layer of tinplate. (C.H.)

A mathematical model of the ironmaking blast furnace (BF) is presented. The model describes the steady-state operation of the furnace in one spatial dimension using real process data sampled at the steelworks. The measurement data are reconciled by an interface routine which yields boundary conditions obeying the conservation laws of atoms and energy. The simulation model, which provides a picture of the internal conditions of the BF, can be used to evaluate the current state of the process and to predict the effect of operating actions on the performance of the furnace.

Mixes of granulated blast-furnace slag and fly ash, ground to the specific surface of about 3400 cm/sup 2//g, give a material with advantageous engineering properties when activated with aqueous solution of Na/sub 2/CO/sub 3/ or water glass and exposed to an adequate thermal treatment.

Gases formed in the raceway by injection of reducing agents into the tuyere affect the blast furnace process in several ways. Energy set free by conversion in the raceway helps the melting of the burden and has beneficial effects on reaction kinetics. The formation of CO and H2 helps to save blast furnace coke. The aim of this work is to study effects of the gases formed after the injection of coke oven gas (COG) and heavy oil into the tuyere of a blast furnace and after conversion in the raceway when entering the active coke zone. For this reason a gas conversion simulation is developed including description of the zones of the lower blast furnace part. The cases studied have the same melting rate at which the injection of COG is accomplished with one and two lances while those of oil is studied with one lance. The simulation predicts that the available amount of species for the reduction of iron ore and the reduction potential is similar for the studied reducing agents COG and heavy oil. Evaluating the potential to save coke a theoretical exchange ratio of 0.84 can be determined for comparable cases in terms of the same reduction progress so that the same consumption of coke has to be expected if no difference between the agents exists.   

This paper shows the operational performance development of the blast furnace of the Belgo-Mineira Steel Company, Brazil. The major modification introduced in this period was the substitution of its roof for a without- cone one. The results of the partial coke utilization was also analyzed. 5 figs., 7 tabs.

In this work, it is shown the optimum composition of charcoal blast furnace slag using phase diagrams. The results are compared with industrial data and some possible changes in slag composition and mass are also suggested. (author) 3 refs., 5 figs., 3 tabs.

The behavior of hot metal flow in the hearth of a blast furnace is always considered as one of the key factors for determining blast furnace campaign life. To provide a useful insight into the hearth of No. 2 blast furnace at China Steel Corporation (CSC), a numerical model has been developed to analyze the flow and heat transfer under various cooling and operational conditions. The model solves three-dimensional Navier–Stoke equations with conjugate heat transfer and Darcy's law for hot metal flowing through the deadman with porous structure by computational fluid dynamics (CFD). The calculated results indicate that the circulatory hot metal is enhanced when the deadman becomes sitting with gutter coke-free space. As a result, the temperature at the hearth corner increases. This suggests the existence of gutter coke-free space may cause elephant foot type erosion. With drainage of hot metal, the heat flux of taphole significantly increases. For the sake of safety, it may be needed to individually monitor the cooling water temperature flowing through the copper staves, as well as to install thermocouples around the tapholes. The prediction shows that the heat flux of the hearth is insensitive to the temperature of cooling water before the refractories are eroded. It implies that the performance of the water chiller may be limited in the beginning of the blast furnace campaign.   

The strength, reactivity, and technical analysis of coke nuts are discussed. Nuts from gross coke contain 20% more of the (19?25)-mm size class than for blast-furnace siftings. Compared to wet-slaked coke nuts, dry-slaked coke nuts are characterized by higher hot and cold strength, higher carbon content, and reduced reactivity.

The report gives results of a laboratory study to develop basic information on the emission of organics from iron ore sinter beds. Samples of sinter bed mix components (including several types of iron ore fines, blast furnace flue dust, rolling mill scale, anthracite coal, and li...

This presentation is confined to a discussion of the manufacture of coke for the iron blast furnace. Today all such coke is made in batteries of by-product recovery ovens, although a small amount of coke for other purposes is still made in the older beehive non-recovery ovens.

An evaluation of protective coatings proposed for application to the interior of blast furnace stove shell plates to prevent stress corrosion cracking was carried out. A heat and chemical-resistant polyurethane primer-pitch polyurethane top coat gave superior results to all coatings tested, including coal tar epoxy, particularly when applied over a hot sprayed ceramic.

The U(VI) uptake in degraded cement pastes was undertaken in the laboratories of CEA/L3MR and SUBATECH in order to check the reproducibility of the study. Two well hydrated cement pastes, CEM I (Ordinary Portland Cement, OPC) and CEM V (blast furnace slag (BFS) and fly ash added to OPC) were degrade...

The softening and melting test is widely used to assess the behaviour of ferrous materials in the cohesive zone of a blast furnace. It is generally agreed that the performance of lump ores is inferior to sinter in the test. To understand the factors determining material behaviour, tests were terminated by quenching samples at different temperatures. The samples were then studied under an optical microscope. The formation of a low temperature liquid fayalite caused beds of lump ores to rearrange and contract earlier. Beds of fluxed sinter remained essentially intact with reduction until higher temperatures. The study also showed that results obtained for a mixed burden of 80% sinter and 20% lump ore – a ratio used in many blast furnaces – are not different to results obtained from tests using only sinter. This difference increases as the lump ore level is increased. These findings indicate that there is significant interaction between the material types in the test and that results from single material tests should not be used in isolation assess material performance in a blast furnace. Any prejudice against lump ores as a blast furnace feed material based on softening and melting test results for single materials is clearly incorrect.   

This work describes how the use of charcoal as a fuel in the blast furnaces may diminish the greenhouse effect. It also discusses how this technique may diminish the deforestation of the tropical regions. Calculations were performed in order to quantify the benefits of the fuel substitution. An economic analysis was performed, and the implementation process is presented. 8 refs., 3 figs., 2 tabs.

The chemical composition of the sinter obtained without Bakal siderite concentrate in the batch is calculated. The influence of Bakal siderite in the batch on the sinter composition is assessed. The sinter content in the blast-furnace batch, the MgO content in the slag, the slag yield, and the slag basicity are plotted against the content of siderite concentrate in the sintering batch.

Mossbauer spectra have been measured for the hydrated blast-furnace slag cement and Portland cement pastes at different times of hydration of 1. 3. 7. 28 and 90 days. The spectra showed the existence of iron atoms, Fe3 (T) and Fe3 (0) states of iron. It was found that, as the time of hydration was...

This paper studies the potential of using expanded clay lightweight aggregate impregnated with sodium monofluorophosphate (Na2FPO3) solution which is eventually encapsulated by a cement paste layer to produce a self-healing system in blast furnace slag cement mortars. It was found that the technique...

The present work focuses on mineral reactions and slag formation of LKAB olivine iron ore pellets (MPBO) subjected to reducing conditions in the LKAB experimental blast furnace (EBF). The emphasis is on olivine reactions with surrounding iron oxides. Many factors influence the olivine behaviour. ...

Abstract in english In the present study, flexural strength together with pore structure, thermal behavior and microstructure of concrete containing ground granulated blast furnace slag with different amount of ZnO2 nanoparticles has been investigated. Portland cement was replaced by different amounts of ground granulated blast furnace slag and the properties of concrete specimens were investigated. Although it negatively impact the properties of concrete, ground granulated blast furnace sla (more) g was found to improve the physical and mechanical properties of concrete up to 45 wt. (%). ZnO2 nanoparticles with the average particle size of 15 nm were added partially to concrete with the optimum content of 45 wt. (%) of ground granulated blast furnace slag and physical and mechanical properties of the specimens was measured. ZnO2 nanoparticle as a partial replacement of cement up to 3 wt. (%) could accelerate C-S-H gel formation as a result of increased crystalline Ca(OH)2 amount at the early age of hydration and hence increase flexural strength of concrete. The increased the ZnO2 nanoparticles' content more than 3 wt. (%), causes the reduced the flexural strength because of the decreased crystalline Ca(OH)2 content required for C-S-H gel formation together with unsuitable dispersion of nanoparticles in the concrete matrix. ZnO2 nanoparticles could improve the pore structure of concrete and shift the distributed pores to harmless and few-harm pores.

A Portland fly ash cement containing 20% of a fine fly ash and a blast furnace slag cement of approximately 290 days old were examined with analytical transmission electron microscopy, in order to examine the (local) microstructure in these cements in detail. In the Portland fly ash cement the fly a...

This paper describes the theoretical development of a 1:16 scale slice model designed to simulate the charging system and upper stack region of blast furnace 2. The determination of model parameters and selection of model raw materials was based on similarity criteria developed from basic principles of dimensional analysis. (author). 14 refs., 2 figs., 3 tabs.

This volume includes computer code listings for the data development subsystems (for blast and top pressure, furnace geometry and cooling, casting, common data base and fundamental functions), exiting both simulations, opening, closing and reading data files, and writing data files. (DLC)

A simulation model for the blast furnace is applied to predict the behavior of the process under different operation actions. The model includes a set of parameters that is adapted to process data. The influence of the boundary conditions on the reaction rate parameter is considered in the predictions. A preliminary scheme for on-line prediction of the hot metal temperature is also outlined.

A simulation model for the blast furnace is applied to predict the behavior of the process under different operation actions. The model includes a set of parameters that is adapted to process data. The influence of the boundary conditions on the reaction rate parameter is considered in the predictions. A preliminary scheme for on-line prediction of the hot metal temperature is also outlined.

Steel production is an extremely complex process and determining coherent schedules for the wide variety of production steps in a dynamic environment, where disturbances frequently occur, is a challenging task. In the steel production process, the blast furnace continuously produces liquid iron, whi...

Argonne National Laboratory has joined a $1.29 million project to develop technology software that will use advanced computational fluid dynamics (CFD), a method of solving fluid flow and heat transfer problems. This technology allows engineers to evaluate and predict erosion patterns within blast furnaces (1 page).

In this overview, we present examples of the use of high volume waste materials in catalysis or for catalyst synthesis. Waste materials derived from both industrial and biological sources have attracted interest and this is briefly summarized. The materials described include red mud, aluminium dross, fly ash, blast furnace slag, rice husk and various kinds of shell.

Workers employed in a graphite electrode producing plant (n = 16) and a coke oven (n = 33) were compared with a control population of maintenance workers in a blast furnace (n = 54). The following parameters were analyzed: concentration of 13 different PAHs in the work environment measured by person...

8 pages, 9 figures, 2 tables.-- Printed version published Nov 2008.-- A preliminary version of this work was presented at the 2007 International Conference on Coal Science and Technology held in Nottingham 2007. | Pulverized coal injection (PCI) is employed in blast furnace tuyeres attempting to max...

A three-dimensional mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance-blowpipe-tuyere-raceway-coke bed to simulate in-furnace phenomena of pulverized coal injection in an ironmaking blast furnace. The model integrates not only pulverized coal combustion model in the blowpipe-tuyere-raceway-coke bed but also coke combustion model in the coke bed. The model is validated against the measurements under different conditions. The comprehensive in-furnace phenomena are investigated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. The underlying mechanisms for the in-furnace phenomena are also analysed. The simulation results indicate that it is important to include recirculation region in the raceway and the coke bed reactions for better understanding in-furnace phenomena. The model provides a cost-effective tool for understanding and optimizing the in-furnace flow-thermo-chemical characteristics of the PCI operation in full-scale blast furnaces. 32 refs., 10 figs., 3 tabs.

The high energy requirements in primary steelmaking make this industrial sector a major contributor to the global emissions of carbon dioxide. Ways to suppress the use of fossil reductants and the emissions from the processes should therefore be developed. The present work applies simulation and optimization for studying the economic feasibility of recycling blast furnace top gas to the combustion zones after CO2 stripping. The study comprises the unit processes in an integrated steel plant, paying special attention to the blast furnace and the preheating of the blast or the recycled top gas. The system is optimized with nonlinear programming with respect to some central variables under different CO2 sequestration and emission costs, which yields information about the economic feasibility ...

Numerical simulation of blast furnace phenomena has significantly contributed to the better understanding of iron making process. Recent interest on minimizing fuel consumption and reducing environmental problems have also benefitted from the development of comprehensive simulation models based on physical principles. One of the under-developing fields, however, is related with the internal phenomena in the lower part of the blast furnace under the cohesive zone, where the liquid phase of metal and slag flows downward over the bed of solid coke particles. Hot flow of sluggish liquid phase is further complicated by the chemical reactions including the transfer of silica into the silicon in the hot metal. Silica enters the furnace as a constituent of coke ash and ferrous gangue, and exits as either molten silica in slag or dissolved Si in the hot metal. Silica reduction is an endothermic reaction, which would alter the heat transfer in the lower furnace, thus affecting the hot metal temperature.Effective flow in the dripping zone is important for stable operation of the blast furnace with high productivity of iron. Study of the liquid flow behavior and secondary reactions in a packed bed allows to investigate the effect of various operational changes in the dripping zone. In this research, a systematic numerical approach for the liquid flow is presented where the flow behavior is solved along with heat transfer associated with physic-chemical reactions among representative components.   

The integrated blast furnace and oxygen steelmaking (BF-OSM) route is still a dominant process for worldwide steel production, currently producing more than 60% of the world's total output of crude steel. The counter-current principle on which the blast furnace operates makes it reliant heavily on the quality of its burden to maintain a sufficient level of gas permeability in its upper shaft and of liquid and gas permeability in its lower part. Iron ore sinter, constituting a major proportion of blast furnace burden in most countries, particularly in the Asia-Pacific region, is therefore expected to have a significant impact on blast furnace performance.The chemical composition of iron ore fines, together with the thermal conditions that sinter blends are subjected to, plays an important role in forming the primary melt during the sintering process and consequently determines the sinter structure and quality. Considerable emphasis has therefore been placed on the chemical composition and consistency of iron ore fines, particularly in terms of alumina content. However, due to the limited reserves and increasing depletion of high-grade iron ore resources, the alumina content of iron ores is expected to increase gradually. While the increase in such constituents is relatively slow over a long period, it has still caused problems for blast furnace operators.This paper attempts to clarify the role of different types of alumina present in iron ore fines and their effects on melt formation, sinter structure and sinter quality, as well as the sintering process itself. Mechanisms responsible for the deterioration of the low temperature reduction degradation characteristics (RDI) of sinter due to the increasing alumina content are also reviewed. In addition, potential measures to counter the adverse impacts of alumina on sintering performance of hematite iron ore fines are also discussed.   

This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.

Studies of Si transfer in blast furnaces have shown that the Si level in pig iron is influenced more by the reaction of silicon oxide gas generation in the raceway than the chemical reaction between hot metal and slag at the drop zone. Specifications require a Si content of pig iron below 0.15% at the Kwangyang Works, but the use of soft coking coal in the blend for coke ovens, high pulverized coal injection rate into the blast furnace, and the application of lower grade iron ore has resulted in the need to develop methods to control Si in hot metal. In this paper, the results of in furnace Si control and the desiliconization skills at the casthouse floor are described.

Coke classification used in Poland is described: blast furnace coke, foundry coke and fuel coke. Eight size classes and three quality classes in each of the three coke trade grades are described. Coke classification is given in 4 tables. The following tests and methods for determining coke properties are characterized: determining coke grain size and grain size distribution, determining coke bulk density, the Micum test, the Shatter test, the Irsid test, the ASTM drum test (USA) and the JIS drum test (Japan). Polish standards for coke storage and storage facilities are given. New methods for testing coke mechanical properties under temperature conditions similar to those in a blast furnace used in Poland are reviewed. A Micum drum is placed in a test furnace with a temperature of 1,000 C. Revolution number during temperature increase and temperature decrease is evaluated. Test equipment developed in Japan and in the United Kingdom is described. (4 refs.) (In Polish)

Slag corrosion and erosion has been a major wear factor for refractories wear in contact with molten iron and steel. In blast furnace ironmaking, the slag/iron interface plays a more important role than does the slag/refractory interface. On the other hand in steelmaking, the slag in the ladles and tundish predominantly affect refractory wear. This paper presents the results of a detailed microstructural evaluation of (a) slag and slag/iron interactions with A1{sub 2}O{sub 3}-SiC-C refractories for ironmaking in blast furnaces, (b) basic oxygen furnace and ladle slag interactions with alumina spinel refractories for steelmaking, and (c) slag interactions with working refractory lining for continuous casting tundishes. Results will also be presented on refractory wear/failure due to simultaneous corrosion and penetration by the slag.

Low reducing agent operation of the blast furnace is an essential method for mitigating CO2 emissions in ironmaking. Because the coke rate is reduced in low reducing agent operation, gas permeability tends to deteriorate. Recently, blast furnaces with inner volume larger than 5000 m3 have become usual not only in Japan, but also in other Asian nations. Under these conditions, detailed information on in-furnace phenomena is required to attain stable operation.In the present study, a combination model using the discrete element method and computational fluid dynamics (DEM-CFD) was introduced to understand the fully three-dimensional in-furnace phenomena in the whole blast furnace. Due to the limitations of computational resources, the number of DEM particles must be reduced when applying DEM to the whole blast furnace. On the other hand, small cells must be used in the continuum model in order to calculate the gas flow in detail. Thus, mutual conversion between the location of particles in DEM and the property of the cells in the continuum model is needed. In this study, a method of converting information on the locations of cluster-approximated particles treated in DEM to continuum cells was proposed. Furthermore, optimization in which cells could be obtained without conversion parameters was performed to avoid losing local information obtained by DEM calculations. Simulations of solid movement and gas flow were successfully carried out with this coupled DEM-CFD model. As a result, it became possible to understand the three-dimensional stress field among particles under gas flow, transient gas flow and pressure distribution caused by charging of the burden materials, as well as solid motion.   

This paper describes recent testing conducted to evaluate the performance of high-temperature intumescent materials under adverse fire and blast conditions. Results from fire performance evaluations currently protecting offshore oil platforms are presented. Extensive fire and blast qualification testing of epoxy-based intumescent materials has been conducted utilizing specially designed blast chambers, jet fire facilities, and laboratory furnaces. Blast chambers are capable of loading up to a 3 x 3-m insulated bulkhead assembly to a 2 bar over pressure and having a duration of approximately 250 millisecond generated by a controlled flammable vapor cloud explosion. The jet fire test exposes an insulated test specimen to a fire environment characterized by temperatures of approximately 1100 C, sonic gas velocities, and peak heat flux levels in excess of 300 kW/m{sup 2}.

Results obtained by an one-dimensional simulation analysis of the process taking place inside an oxygen blast furnace are reported as follows: first, the heat flow ratio increases, the temperature falls and the reduction is retarded inside the furnace as the concentration of oxygen in air blasts is increased, and the injection of preheating gas required in case the heat flow ratio exceeds 0.90; second, by imposoing a certain restriction on the volume and temperature of preheating gas the furnace conditions are brought about under which the direct reduction rate is low, thereby the fuel ratio being lowered; third, changes in the composition of preheating gas produce little effect on the temperature and reaction rate in the furnace; fourth, the temperature of solid material locating at the tuyere level of the furnace can be controlled by changing the theoretical flame temperature at the location and also is controlled by adjusting the volume and temperature of preheating gas in case of low fuel ratio; fifth, the furnace can be operated with the fuel ratio covering a fairly wide range, the maximum value being more than twice as large as the minimum one. Furthermore, an account is given of the verification of the model used for the present simulation. 22 refs., 13 figs., 1 tab.

Iron in the United States is largely produced from iron ore mined in the United States or imported from Canada or South America. The iron ore is typically smelted in Blast Furnaces that use primarily iron ore, iron concentrate pellets metallurgical coke, limestone and lime as the raw materials. Under current operating scenarios, the iron produced from these Blast Furnaces is relatively inexpensive as compared to current alternative iron sources, e.g. direct iron reduction, imported pig iron, etc. The primary problem the Blast Furnace Ironmaking approach is that many of these Blast furnaces are relatively small, as compared to the newer, larger Blast Furnaces; thus are relatively costly and inefficient to operate. An additional problem is also that supplies of high-grade metallurgical grade coke are becoming increasingly in short supply and costs are also increasing. In part this is due to the short supply and costs of high-grade metallurgical coals, but also this is due to the increasing necessity for environmental controls for coke production. After year 2003 new regulations for coke product environmental requirement will likely be promulgated. It is likely that this also will either increase the cost of high-quality coke production or will reduce the available domestic U.S. supply. Therefore, iron production in the United States utilizing the current, predominant Blast Furnace process will be more costly and would likely be curtailed due to a coke shortage. Therefore, there is a significant need to develop or extend the economic viability of Alternate Ironmaking Processes to at least partially replace current and declining blast furnace iron sources and to provide incentives for new capacity expansion. The primary conclusions of this comparative Study of Alternative Ironmaking Process scenarios are: (1) The processes with the best combined economics (CAPEX and OPEX impacts in the I.R.R. calculation) can be grouped into those Fine Ore based processes with no scrap charge and those producing Hot Metal for charge to the EAF. (2) A pronounced sensitivity to Steel Scrap Cost was felt less by the Hot Metal Processes and the Fine Ore Processes that typically do not utilize much purchased scrap. (3) In terms of evolving processes, the Tecnored Process (and in particular, the lower-operating cost process with integral co-generation of electrical power) was in the most favorable groupings at all scrap cost sensitivities. (4) It should be noted also that the Conventional Blast Furnace process utilizing Non-Recovery coke (from a continuous coking process with integral co-generation of electrical power) and the lower-capital cost Mini Blast Furnace also showed favorable Relative Economics for the low and median Scrap Cost sensitivities. (5) The lower-cost, more efficient MauMee Rotary Hearth Process that uses a Briquetted Iron Unit Feed (instead of a dried or indurated iron ore pellet) also was in the most favorable process groupings. Those processes with lower-cost raw materials (i.e. fine ore and/or nonmetallurgical coal as the reductant) had favorable combined economics. In addition, the hot metal processes (in part due to the sensible heat impacts in the EAF and due to their inherently lower costs) also had favorable combined economics.

Among different ways to reduce the coke consumption in the blast furnace, not so much attention was paid for decreasing the coke losses through finding suitable application of small size coke called “nut coke”. In meantime modern blast furnaces use nut coke with different amount (10–140 kg/t hot metal) and different grain size (10–40 mm) in the sinter layer to reduce the coke losses. The objective of this paper is to clarify the influence of nut coke on the shaft permeability and sinter reducibility under blast furnace simulating conditions. The effect of various factors such as nut coke rate, gas flow rate, and layer thickness on the shaft permeability was estimated using cold model rig. The influence of nut coke on the isothermal and non-isothermal reduction of sinter was estimated under different gas compositions and temperatures using muffle reduction furnaces. The isothermal reduction of sinter with 30%CO–70%N2 exhibited reduction retardation at elevated temperatures (>1373 K). The reduction retardation increased by the presence of CO2 gas in the reducing atmosphere while decreased by participation of H2 gas. Mixing nut coke in the sinter bed improves the sinter reducibility and inhibits the reduction retardation phenomenon.   

Usinor-Dunkirk coke-ovens plant is short for supplying blast furnace when hot metal output increases above 4 Mt. Pulverised coal injection was the cheapest process to meet blast furnaces fuel requirements. Grinding and drying coal facilities, with only one ball-mill, monitored from a distant control room and located on a part of raw materials yard, has a daily pulverized coal capacity of 700 tons for supplying two blast furnaces. Pulverised coal is pneumatically transported between the pulverized coal bin, and the ''ARBED-Wurth type'' coal injection equipment, over a distance of 750 m. The equipment is air pressurized and coal dispatching to the tuyeres is obtained by honeycomb type rotary distributors achieving a very satisfactory distribution between tuyeres and also a high injection rate. This equipment has been in operation since the end of July 83 without any significant wear of pipes and rotary distributors. The coal rate is, in March 1985, 131 kg/tHM with a replacement ratio practically equal to the theoretical ratio for this kind of coal. The furnace operation is very smooth with this coal injection rate which leads to a coke rate below 350 kg/tHM.

Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%-50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi-fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

In high-rate oil injection operation, a large amount of soot will be formed, the mechanism of soot formation is extremely complicated, the present report describes simply the mechanism. Based on the knowledge, the factors affecting soot formation are analyzed in blast furnace operation, it shows that partial shortage of oxygen, small combustion space, poor dynamic conditions for oil combustion and structure of dead-man are important factors affecting oil combustion in the raceway. Then, some suggestions improving oil combustion such as improvement of injection way, improvement of blast way and development of detecting and controlling dead-man techniques are presented. (orig.)

The pig iron nugget process is gaining in importance as an alternative to the traditional blast furnace. Throughout the process, self-reducing-fluxing dried greenballs composed of iron ore concentrate, reducing-carburizing agent (coal), flux (limestone) and binder (bentonite) are heat-treated. During the heat treatment, dried greenballs are first transformed into direct reduced iron (DRI), then to transition direct reduced iron (TDRI) and finally to pig iron nuggets. The furnace temperature and/or residence time and the corresponding levels of carburization, reduction and metallization dictate these transformations. This study involved the determination of threshold furnace temperatures and residence times for completion of all of the transformation reactions and pig iron nugget production. The experiments involved the heat treatment of self-reducing-fluxing dried greenballs at various furnace temperatures and residence times. The products of these heat treatments were identified by utilizing optical microscopy, apparent density and microhardness measurements.

The ratio of the use of monolithic refractories is increasing in Japan, reaching about 60%. This paper presents the trends of monolithic refractories, by referring to monolithic refractories of ladle and the repairing technologies of various furnaces. In the method to repair a ladle, the flow-in method, in which molding is made under vibration, is the main stream, and usually a small quantities of clay or hume silica is added to give fluidity to the material. Recently, self-flow materials, which do not require vibration, has been also developed. As the flow-in material, alumina - magnesia is used in most cases recently. The importance of the repairing technology is increasing more and more for the purpose of prolonging the life of a furnace. The exchange of the brick is sometimes carried out, but the monolithic refractory method is commonly used. This paper prescribes techniques used in blast furnace sluice, coke oven, converter, and degasification furnace. (NEDO)

US Steel Iron Producing Div. consists of four operating blast furnaces ranging in process control capabilities from 1950's and 1960's era hardware to state of the art technology. The oldest control system consists of a large number of panels containing numerous relays, indicating lights, selector switches, push buttons, analog controllers, strip chart recorders and annunciators. In contrast, the state of the art control system utilizes remote I/O, two sets of redundant PLC's, redundant charge director computer, redundant distributed control system, high resolution video-graphic display system and supervisory computer for real-time data acquisition. Process data are collected and archived on two DEC VAX computers, one for No. 13 blast furnace and the other for the three south end furnaces. Historical trending, data analysis and reporting are available to iron producing personnel through terminals and PC's connected directly to the systems, dial-up modems and various network configurations. These two machines are part of the iron producing network which allows them to pass and receive information from each other as well as numerous other sources throughout the division. This configuration allows personnel to access most pertinent furnace information from a single source. The basic objective of the control systems is to charge raw materials to the top of the furnace at aim weights and sequence, while maintaining blast conditions at the bottom of the furnace at required temperature, pressure and composition. Control changes by the operators are primarily supervisory based on review of system generated plots and tables.

The combustion behaviour of charcoal under blast furnace conditions, the influence of charcoal ash on and the effect of uncombusted charcoal on the flow conditions in the lower furnace are investigated. It was shown that the degree of combustion decreases because of oxygen deficits whenever large quantities of fuel are blown in. Larger grain size, however, improve combustion. Flow experiments show that pressure losses may occur in the area below the cohesive zone during blow-in. The flow temperature of the drop-off slag was proved to decrease if larger amounts of charcoal with alkaline ash are blown in. (BWI).

In 2005?2007 a change-over was accomplished OAO NMLK blast furnaces to the use of contemporary poured and rammed trough mixes. Results are provided for manufacturing technology, operation and repair of rammed and poured trough linings made from low and ultralow mixes of corundum-silicon carbide composition. The existing structure of troughs and casting yards for BF-2, BF-3, BF-4, and BF-6 do not permit use of refractory concrete linings, and therefore in order to line the main troughs of these furnaces ramming mixes produced by OAO Dinur and the firm Calderys are used.

Pulverized coal injection technology is widely used in blast furnace ironmaking due to economic, operational and environmental benefits. High burnout within the tuyere and raceway is required for high coal injection rate operation. In order to analyze the flow and combustion in the tuyere and raceway more accurately and reliably, a three-dimensional model of coal combustion is developed. This model is validated against the measurements from two pilot scale test rigs in terms of gas species composition and coal burnout. The gas-solid flow and coal combustion are simulated and analysed. The results indicate that compared to our previous model, the present model is able to provide more detailed gas species distributions and better describe the evolutions of coal particles. It is more sensitive to various parameters and hence more robust in examining various blast furnace operations.

Forty-nine papers presented at the 1994 SPE Annual Technical Conference and Exhibition are included in Volume 1 of the proceedings. The papers cover such topics as vertical multiphase flow correlations, gas-lift optimization, gas production optimization, data gathering systems, velocity and turbulence intensity profiles for Newtonian annular flows, gas entry into cemented wellbores, control of gas-tightness of cement slurries, performance of blast furnace slag-based cements, blast furnace slag technology, thickening, time of oil well cement, hydrate formation/inhibition during deep-water subsea completion operations, wax deposition of waxy live crudes, flowline insulation, blistering of thermoplastic materials, electronic, fiber-optic technology, flow in horizontal wellbores, pressure behavior and productivity of horizontal gas wells, thru-tubing inflatable packer systems, formation damage due to suspended solids, injectivity decline in water injection wells, economic refracturing candidates, wellbore tortuosity and premature screenouts, hydraulic fracturing for solid waste injection, perforation friction pressure, multiphase metering systems, and two-phase pump performance.

This paper presents the radiation attenuation coefficients expressed as mass attenuation coefficients for Portland cement, zeolite, blast furnace slag, silica fume and their mixed types in function of the Photon energy over the energy range of 1keV to 2MeV. It was observed that different percentages of constituents in cement and cement mixed with different additives such as zeolite, silica fume and blast furnace slag, lead to significant variations in total mass attenuation coefficients. The elemental compositions of samples were analyzed using a wavelength dispersive XRF spectrometer. The calculated values of total mass attenuation coefficients were discussed on the basis of different percentages of constituents of cement and cement mixed with different additives.

This study examined the effects of using ground-granulated blast furnace slag (GGBFS) and calcium nitrite-based corrosion inhibitor (CNI) on the mechanical and durability properties of concrete (compressive strength, splitting tensile strength, chloride ion permeability). Concrete specimens containing only blast furnace slag, calcium nitrite-based corrosion inhibitors, and a combination of these components in different ratios were produced with reference specimens. On the 28th, 56th and 90th days following production, tests were administered that involved allowing all specimens to cure via two different methods, which include the condition under uncontrolled relative humidity (air cure - K1) and temperature, as well as the standard cure condition (water cure - K2). The effects of cure type...

The cementitious fireproof material is widely used to protect concrete structures against fire. However, there has lately been interest in developing more environmentally friendly construction materials that have lower cement content, since cement manufacture has a large carbon footprint. One approach, formulated here, makes use of eco-friendly fireproof high-strength polymer cementitious composites made from blast furnace slag (an industrial by-product). And we were used the activator which is necessary to function as a catalyst to induce the hydration of blast furnace slag. In addition, we were used the polypropylene fibre, and porcelain to improve the fire-resistance. To evaluate the properties of eco-friendly fireproof high-strength polymer cementitious composites, we tested mechanical...

This project deals with the demonstration of a coking process using proprietary technology of Calderon, with the following objectives geared to facilitate commercialization: (1) making coke of such quality as to be suitable for use in hard-driving, large blast furnaces; (2) providing proof that such a process is continuous and environmentally closed to prevent emissions; (3) demonstrating that high-coking-pressure (non-traditional) coal blends which cannot be safely charged into conventional by-product coke ovens can be used in the Calderon process; (4) conducting a blast furnace test to demonstrate the compatibility of the coke produced; and (5) demonstrating that coke can be produced economically, at a level competitive with coke imports. The activities of the past quarter continued to be focused on the following: Drafting of Contracts among the Stakeholders of the Team, Completion and Delivery of Proposal for Phase 2 Permitting and Environmental Work Engineering Progress Preparation of Final Report for Phase 1 DCAA Audit Funding for Phase 2.

This project deals with the demonstration of a coking process using proprietary technology of Calderon, with the following objectives geared to facilitate commercialization: (1) making coke of such quality as to be suitable for use in hard-driving, large blast furnaces; (2) providing proof that such process is continuous and environmentally closed to prevent emissions; (3) demonstrating that high-coking-pressure (non-traditional) coal blends which cannot be safely charged into conventional by-product coke ovens can be used in the Calderon process; (4) conducting a blast furnace test to demonstrate the compatibility of the coke produced; and (5) demonstrating that coke can be produced economically, at a level competitive with coke imports. The activities of the past quarter were focused on the following: Detailed studies of LTV's site for the installation of the commercial Demonstration Unit with site specific layouts; Environmental Work; Firm commitments for funding from the private sector; and Federal funding to complement the private contribution.

Effect of coal rank, bulk density (degree of comminution), and moisture content of the batch on coke quality and heat consumption are investigated. In one series of tests the heating of the coke oven was accomplished by a mixture of blast furnace and coal gases; in the second series, by a mixture of blast furnace and natural gases. Batch composition was varied in favor of more gas coal and less coke coal. It was demonstrated that coke of the required quality can be produced from batches with 36-38% gas coal and by increasing the percentage of the larger size classes in the batch. The increase in coke quality compensated for the increased consumption of heating gases. 4 references.

The continuous cooling crystallization of a blast furnace slag was studied by the application of the differential scanning calorimetry (DSC) method. A kinetic model describing the correlation between the evolution of the degree of crystallization with time was obtained. Bulk cooling experiments of the molten slag coupled with numerical simulation of heat transfer were conducted to validate the results of the DSC methods. The degrees of crystallization of the samples from the bulk cooling experiments were estimated by means of the X-ray diffraction (XRD) and the DSC method. It was found that the results from the DSC cooling and bulk cooling experiments are in good agreement. The continuous cooling transformation (CCT) diagram of the blast furnace slag was constructed according to crystallization kinetic model and experimental data. The obtained CCT diagram characterizes with two crystallization noses at different temperature ranges.

This paper describes a group of products derived from coal tar pitch and original tars: combined tars and technical oils. The combined oils are a mixture of oil, oil fractions and 45-48% of coal tar pitch. The selection of derived products includes: roofing tar, road tar (standard and stabilized or modified with additives), blast furnace tar, tar used as a protective coating (anticorrosion), fuel tar for carburetion of low-caloric gases in blast furnaces, roofing paper tar, tar mastic, coal tar varnish. Oils of coal origin include: cleaning oils, oil used for wood saturation, flotation oil, fuel oil, gas-holder oil, coal carbolineum, dissolving oils, coal tar pitch oil. Given are techniques for deriving the listed products and their essential properties.

Process efficiency in the blast furnace is influenced by the gas flow pattern, which is dictated by the burden profile. Therefore, it is important to control the burden distribution so as to achieve reasonable gas flow in the blast furnace operation. Additionally, the charging pattern selection is important as it affects the burden trajectory and stock profile. For analysis of the burden distribution, a new analysis model was developed by use of the spreadsheet program, Microsoft® Office Excel, based on visual basic. This model is composed of the falling burden trajectory and a stock model. The burden trajectory is determined by the burden type, batch weight, rotating velocity of the chute, tilting angle, and friction coefficient. After falling, stock lines are formed by the angle of repos...

A method has been developed for optimizing ironmaking in the blast furnace with the aim to minimize costs and CO2 emissions. These two goals are pursued by a genetic algorithm yielding states of operation on a Pareto-optimal front with nondominated solutions. The blast furnace process is described mathematically by a thermodynamic simulation model, where realistic operational constraints are imposed. The states on the Pareto-optimal fronts evolved are analyzed in more detail, considering the constraints of the process. The solutions are found to give rise to clearly different specific emissions but very similar specific costs as long as the production stays within the limits of the granted CO2 emissions allowances of the plant. However, this also implies that the costs of ironmaking may ri...

The molten liquid flow inside a packed bed is a familiar momentum transportation phenomenon in a blast furnace. With regard to the reported mathematical models describing the liquid flow within a packed bed, there are some obstacles for their application in engineering design, or some limitations in the model itself. To overcome these problems, the forces from the packed bed to the liquid flow were divided into appropriate body and surface forces on the basis of three assumptions. Consequently, a new mathematical model was built to present the liquid flow inside the coke bed in a blast furnace. The mathematical model can predict the distribution of liquid flowrate and the liquid flowing range inside the packed bed at any time. The predicted results of this model accord well with the experi...

A method is proposed for making a filtering material (FM) through applying bitumen or tar to a porous substance and subsequent roasting. Blast furnace slag, pumice and other inorganic substances are used as the porous substance. The method makes it possible to acquire an inexpensive filtering material with a developed surface (Pv), which replaces activated charcoal. Example. Blast furnace slag is heated to 200 to 300 degrees and with mixing is impregnated by 5 to 15 percent bitumen or tar. The impregnated slag is roasted at 800 to 1,000 degrees until full carbonization of the bitumen or tar, acquiring in this way a filtering material, which is characterized by a specific surface of 700 to 1,000 square centimeters per gram and suitable as a replacement for activated charcoal for removing organic components and heavy metals from gaseous and liquid phases. The cost of the filtering material is one eighth to one tenth of that of activated charcoal.

An experimental technique to investigate the fundamental mechanisms taking place on a microscale in the softening and melting zone in the blast furnace, is presented. In the present paper, attention is focused on determination of the softening viscosity of porous wustite. The technique may be potentially useful to investigate more complex samples of ironbearing material, as occurring in the blast furnace. In comparison with the results obtained by other researchers the viscosity of porous wustite found in the present work is substantially higher than reported elsewhere for sinter and pellets. This may be an indication that softening is not merely a reflection of the solid state deformation under load of wustite. An important factor may be local melting of some of the phases present within the sinter and pellet structures.

Pulverized coal injection technology is widely used in blast furnace ironmaking due to economic, operational and environmental benefits. High burnout within the tuyere and raceway is required for high coal injection rate operation. In order to analyze the flow and combustion in the tuyere and raceway more accurately and reliably, a three-dimensional model of coal combustion is developed. This model is validated against the measurements from two pilot scale test rigs in terms of gas species composition and coal burnout. The gas–solid flow and coal combustion are simulated and analysed. The results indicate that compared to our previous model, the present model is able to provide more detailed gas species distributions and better describe the evolutions of coal particles. It is more sensitive to various parameters and hence more robust in examining various blast furnace operations.   

The use of a multi-zone mathematical model developed by the Institute of Ferrous Metallurgy (of the Ukrainian National Academy of Sciences) to study blast-furnace smelting with the injection of coal-gasification products showed that the processes which take place in the furnace change under the influence of the same tendencies as are seen with the injection of pulverized-coal fuel. The amount of coal that can be injected can be increased significantly if it undergoes preliminary gasification and the ash is fluidized in tuyere-mounted gasifiers. Such a practice would make it possible to achieve the targeted savings of coke even if low-grade coals are used instead of higher grades. The replacement of hot blast by cold oxygen would be problematic only if the initial and projected coke and win...

Fuel injection techniques have been extensively used in the commercial blast furnaces, a number of publications concerning the fuels injection have been reported. This present report only summarizes the study achievements of oil injection due to the research need the of authors, it includes the following parts: First, the background and the reasons reducing coke rate of oil injection are analyzed. Reducing coke rate and decreasing the ironmaking costs are the main deriving forces, the contents of C, H and ash are direct reasons reducing coke rate. It was also found that oil injection had great effects on the state of blast furnace, it made operation stable, center gas flow develop fully, pressure drop increase, descent speed of burden materials decrease and generation of thermal stagnation phenomena, the quality of iron was improved. Based on these effects, as an ideal mean, oil injection was often used to adjust the state of blast furnace. Secondly, combustion behavior of oil in the raceway and tuyere are discussed. The distribution of gas content was greatly changed, the location of CO, H{sub 2} generation was near the tuyere; the temperature peak shifts from near the raceway boundary to the tuyere. Oxygen concentration and blast velocity were two important factors, it was found that increasing excess oxygen ratio 0.9 to 1.3, the combustion time of oil decreases 0.5 msec, an increase of the blast velocity results in increasing the flame length. In addition, the nozzle position and oil rate had large effects on the combustion of oil. Based on these results, the limit of oil injection is also discussed, soot formation is the main reason limiting to further increase oil injection rate, it was viewed that there were three types of soot which were generated under blast furnace operating conditions. The reason generating soot is the incomplete conversion of the fuel. Finally, three methods improving combustion of oil in the raceway are given: Improvement of oil atomization, increased blast temperature and oxygen and injection of reducing gases into the bosh zone. (orig.) 25 refs.

Shaft gas injection of reducing gas in the blast furnace is one of favorable ways to greatly decrease CO2 emissions from steel works, and this approach is used for the top gas recycling and oxygen blast furnace processes. In these processes, the penetration effect of the gas injected from the auxiliary tuyeres is important for attaining effective gas reduction or making up the heat balance in the upper part, and so it is useful to analyze the dynamic behavior of the gas injected into the shaft. In the present study, the penetration effect of injected gas was three-dimensionally simulated by a hybrid model of the discrete element method (DEM) and continuum model (CFD). In particular, the CFD model was used to quantitatively analyze the dynamic gas flow and the pressure distribution in the burden layers calculated by DEM. Although the area influenced by the injected gas from the auxiliary tuyeres was restricted to a specific area due to insufficient horizontal inertial force of the gas, the penetration area gradually enlarged as the gas velocity from the auxiliary tuyeres increased. In a small blast furnace, the injected gas can easily reach the center with the higher gas velocity, and it was shown that the relative penetration depth of the injected gas depends on the inner volume of the blast furnace. However, the overall behavior of the injected gas did not show any remarkable change. In conclusion, the penetration area of shaft gas was almost proportional to the ratio of shaft gas and the upward gas from the conventional tuyeres.   

A review is presented of the basic process of fissuring within a coke oven charge during carbonisation and the raw material and oven operating variables that affect the lump size of the product. It also discusses the shape of the lumps, the definition and representation of size, the variation in other coke properties with size, and the desirable or actual sizes for blast furnace use. 82 refs.

Recent research regarding the use of computerized X-ray tomography to obtain a three-dimensional distribution of the density within coke samples is reviewed. Tomographic data provide a detailed three-dimensional picture of the coke?s pore structure. The changes in coke structure due to its production technology and subsequent treatment may also be established. Together with other physicochemical data, computerized X-ray tomography provides a more complete characterization of blast-furnace coke.

In a three-week operating test high-strength lignite high-temperature coke (BHT coke) in a proportion of about 11% of the total amount of coke was used in the blast furnace. Although first test results proved positive, they do not yield safe information on the suitability of BHT coke in continuous operation and on possible exchange rates. Tests are planned to be continued with a proportion of at least 25% BHT coke of the total amount of coke.

The combustion behaviour of pulverized coal injected into the blast furnace has been observed using high-speed camera. The combustion flame is not uniform across the cross-section and fluctuates with space and time. Ways to improve the combustibility are indicated. A one-dimensional mathematical model has been developed. This influence of particle dispersion and lance arrangement can be simulated. (authors). 2 refs., 10 figs., 1 tab.

The quality of steel depends to a large extent on the quality of the input materials in the production process. The Studiengesellschaft fuer Eisenerzaufbereitung (SGA) performs scientific and practical studies on the economical utilisation and smelting of iron ores and agglomerates. For its research the SGA operates a burner installation to simulate blast furnaces. In the course of modernisation, this installation underwent partial re-instrumentation and was fitted with a completely new, modern process automation system by Eurotherm. (orig.)

Decreasing the carbon dioxide emission from steel industries is an important issue. It is considered that due to the high reactivity of carbon iron ore composite, it can control the thermal reserve zone temperature and decrease the consumption of reducing agents in blast furnace. In the present study, a reaction model of the carbon iron ore composite based on a lumped system is proposed to analyze the reduction behavior in the blast furnace. This model is composed of several reaction steps between carbon, iron ore, and gas phase. The carbon solution loss reaction rate of the small particles of reducing agents is determined by the thermogravimetric method. It is found that the gasification of reducing agents is the rate-determining step in the reduction of the carbon iron ore composite. Accordingly, the particle size and reactivity of reducing agents such as coke have an influence on the reduction rate of the carbon iron ore composite. The influence of the gas composition in the atmosphere around the composite on the reduction is analyzed by using the reaction model. Moreover, the reduction behavior of the carbon iron ore composite in the blast furnace is quantitatively examined by comparison of reduction degree and gas composition change in order to investigate the reduction mechanism of reducing agents.   

The cohesive zone, where the ore fed into the blast furnace softens and melts, is critical to the blast furnace performance and stability due to its influence on the gas and solid flow. Here we describe a project for the development of a process model to predict the cohesive zone properties and results of an important part of the work; the solid and gas flow models. The process model will be developed to describe a realistic solid burden flow and the formation of the cohesive zone, its shape, location, structure and permeability. This will be achieved using various simulation and computing tools: a combination of the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD), the coupled DEM-CFD approach, together with models for the thermodynamics and reaction kinetics. The key benefits of the coupled approach lie in the coupling of the continuous phase and the discrete particles, and the possibility of introducing thermodynamics and reaction kinetics into the system in a more realistic manner. DEM and coupled DEM-CFD simulations in several geometries are presented for reduced scale blast furnace investigation on the influence of non-spherical particles and gas flow on the solid flow. A large influence of the geometry shape and boundary conditions on the solid flow was also found.   

Increasing coke gasification rate can lowers the temperature of the thermal reserve zone, resulting in a decrease of carbon consumption and a reduction of the reducing agent rate of blast furnaces. To achieve this increase, the enhancement of coke reactivity itself or the close arrangement of iron ore and carbonaceous materials has been investigated in Japan. Against this, RCA, "Reactive Coke Agglomerate," having a high carbon content, has been developed, and it was found that the agglomerate mixed-in sinter layer had two functions: one having high reducibility itself and the other enhancing the reduction of the surrounding sinter. As a result of the two functions, a significant decrease of the temperature of the thermal reserve zone and an increase of gas utilization by using the agglomerate mixed-in sinter layer in a BIS test was achieved. As for the strength after reaction, disintegration was fairly small in comparison with that of the sinter both in the laboratory scale test and in a basket test using a plant's vertical probe. Long-term plant trials have been conducted at the Oita Works No. 2 Blast Furnace with a maximum use of 54 kg/tHM. It was found that RCA could lower the temperature of the thermal reserve zone and carbon consumption in a commercial blast furnace. Carbon consumption was decreased along the relationship of 0.36 kgC/tHM per 1 kgC/tHM of input carbon from RCA.   

The paper evaluates effects of thermal and chemical coke degradation in blast furnaces on fluctuations of ash content in coke, its structural strength, porosity, apparent density and density. The evaluations are based on the results of laboratory tests using the gasification system developed by DMetI. Test results are given in 5 tables. Analyses show that coke gasification in blast furnaces in the highest degree influences the finest grain size whereas structural strength of coke with size from 40 to 60 mm is only marginally influenced. Changes in coke porosity and ash content are also most intensive in the finest coke fractions. Changes in coke apparent density are caused by increase in porosity. Porosity changes depend on the initial coke porosity. Comparative evaluations show that under the influence of gasification processes in a blast furnace porosity of coke class with size from 40 to 60 mm is 2 to 3 times higher than that of the finest size fractions. This is probably caused by easier contact between the gases and coke body. Effects of gas composition on changes in coke properties are also analyzed. (4 refs.)

A new system for the dynamic simulation of the blast furnace has been constructed. The major advantages of the new simulation over the previous one are: The FORTRAN programs are extensively documented; improved execution speed; an interface system for the required operating data has been developed; and top pressure rather than blast pressure is a control variable. The improved execution speed has involved a speedup of approximately seven to one. The new simulation has been constructed to allow reasonable ease in changes or additions to reaction rates and other phenomenon, such as silicon transfer to the hot metal via silicon gas species. It should be possible to apply the simulation to a laboratory furnace. This volume covers the six chapters (conceptualization, reactions considered in simulation model, solution of state equations of working volume and hearth, system structure of the blast furnace simulations, sensitivity analysis of simulation) and the first 5 appendices (transport equations for smetter simulation, pressure drop equation, hearth simulation, computer code listings for material properties and charging). (DLC)

This paper explains combustion phenomena in ironmaking process. The paper describes briefly the following items on the combustion mechanism of dust coal at the lower part of a blast furnace: a bi-competitive reaction model to express a volatile matter discharge process, an evaluation on volatile matter combustion velocity by using the generalized reaction velocity formula, and an evaluation on char combustion velocity by using the generalized reaction velocity formula that considers chemical reaction velocity and diffusion of O2 onto particle surface. In relation to the coke combustion mechanism at the lower part of a blast furnace, the paper also gives a brief description on an evaluation on reaction velocities in the reactions in gaseous phase (combustion reaction of the above volatile matters, CO oxidizing reaction, water gas shifting reaction, and H2 oxidizing reaction), and an evaluation on the reaction velocities in the non-uniform reaction of coke particles (reaction of O2, CO2 and H2O with C) by using the generalized reaction velocity constant. In addition, the paper introduces examples of estimating calculations of the combustion condition at the lower part of the blast furnace including raceway by means of a simulation model. 29 refs., 5 figs.

In Mizushima steel works, many attempts have been made to achieve more than 10 years of campaign life of the blast furnace. This paper reports our experience in repairing the damage at the throat. In April 1984 (6 years after commissioning) the Mizushima blast furnace No.3 suffered the red heat of the sheet iron shell at the throat due to the falling of the throat bricks by height of 2-3 meters directly under the wearing plate. After making an emergency repair to the red heat of the sheet iron shell by water spraying, we discussed how to establish the permanent measures to protect the steel plate supporting wearing plate. In addition to the protection of wearing plate, adoption of the anchor panel, board, and spraying of the castable refractory were made. They proved to be effective to prolonging the campaign life of the blast furnace. We also succeeded in prolonging the life and the stability of the operation by the reconstruction of the profile by the combination of casting and spraying the castable panel. 8 figs., 4 tabs.

The coal composite iron ore hot briquette made by utilizing thermal plasticity of coal is recently developed as agglomerates without binder, which has several advantages to retain high density and strength during reaction at high temperatures.In this work, several hot briquettes mixed with coal and ore fines were prepared to elucidate influence of more coal amounts than molar ratio C/O=3/3 on their reaction behavior in a laboratory scale blast furnace simulator. Reaction and softening-melting tests of the briquettes were carried out in N2 stream under load with heating from room temperature to 1400°C.It was found that final gasification and reduction degrees decreased and increased with increasing coal contents mixed in the briquettes, respectively. The reduction finalized around 1000–1100°C. Larger proportion of coal provided completion of reduction at lower temperatures and more remained char, leading to smaller shrinkage of the briquettes even in higher temperatures.The crushing strength of briquettes after partial reaction decreased with reaction time as a whole, whereas it was kept above a value permitted in blast furnace operation.From gasification test of partial reacted briquettes, it was found that the rate constants were proportional to Fe/C molar ratio in the briquettes, likely due to a catalytic effect of metallic iron.The results will be overall discussed with the viewpoint of a feasible utilization of these briquettes to a blast furnace.   

Nuclear hydrogen steelmaking (NHS) and nuclear hydrogen partial reduction steelmaking (NHPRS) systems were proposed using very high temperature reactor, and thermochemical hydrogen production iodine-sulfur process. Heat input and CO2 emissions of these systems were analyzed by heat and mass balance calculation. Total net heat input to the NHS system was 28.4 GJ/t-high quality steel (HQS), including material production, material transportation, and power generation. This value was much larger than that of a blast furnace steelmaking (BFS) system of 17.6 GJ/t-HQS. Reduction of hydrogen consumption in the shaft furnace and electricity consumption in the electric arc furnace were desired for lowering the heat input. Total net heat input of a NHPRS system was 31.9 GJ/t-HQS. Optimization of operation parameters such as the reduction ratio of partial reduced ore (PRO) and ratio of the PRO input to the blast furnace is desired to decrease the heat input. CO2 emissions of the NHS system and the NHPRS system were 9% and 50% of that from the BFS system. Substitution of coal by hydrogen and reduction of transportation weight contributed to the reduction. Steelmaking cost was also evaluated. When steelmaking scale of each system was unified to one million t-HQS/y, NHS was economically competitive to BFS and Midrex steelmaking. And NHS was advantageous at higher cost of resources.   

Exhaust gases from the primary operations in the steel making process are almost exclusively utilized as supplemental fuels within the steel plant. These by-product fuels include blast furnace gas (BFG) and coke oven gas (COG) which contain mixtures of H{sub 2}, CO, CH{sub 4} and trace amounts of some heavier hydrocarbons and the impurities NH{sub 3} and HCN. These fuels are burned alone or in combination with natural gas to fire the coke ovens, blast furnace stoves utility boilers and metal working furnaces. The utilization of these by-product fuels reduces the waste gas emissions at the steel mill and reduces the requirements for outside fuel sources. However, as with primary fuel sources, the combustion of these by-product fuel blends does produce hazardous pollutants, in particular nitrogen oxides, and because these are atypical fuel blends of varying composition, the pollutant formation is not well understood. The objective of this research was to develop an understanding of the mechanisms controlling NO{sub x} formation from the combustion of by-product fuels from the steel industry and investigate control and design options to minimize emissions. The minimization strategies investigated were constrained by limits on CO and hydrocarbon emissions, both of which increased under fuel-rich combustion scenarios that resulted in reduced NO{sub x} emissions. Also, the minimization strategies were constrained by the need for reasonable heat generation rates in the furnaces that employ these by-product fuels, so that product steel quality is not adversely affected.

Pig iron nuggets were produced in a laboratory-scale furnace at Michigan Technological University. The process was intended to replicate Kobe Steel's ITmk3 direct ironmaking process. These nuggets were produced from pellets that were made from a mixture of iron oxide, coal, flux and a binder and heated in a furnace with a chamber temperature of 1450{sup o}C. The pellets then self-reduced to produce a solid, high-density, highly metallized (96.5% Fe) pig iron. During the nugget production process, a separate liquid slag phase formed that cleanly separated from the molten metal. The physical and chemical properties of the pig iron nuggets were similar to pig iron produced by blast furnaces, which is distinct from direct reduced iron (DRI).

The potential of using biomass in ironmaking is investigated by simulation. Biomass is used to partially replace fossil reductants in the blast furnace process, which is described mathematically by a thermodynamic model. The model is cast in linear form to facilitate an efficient economic optimization of the production of raw steel, considering costs of raw materials, energy and CO2 emissions of the unit processes up to the basic oxygen furnace. The high oxygen content and low heating value of biomass makes it necessary to study a possible external pyrolysis of it prior to injection into the furnace. The economy of biomass injection and its dependence on the price structure of raw materials and emissions are investigated. The results throws light on how the prices of biomass and emission rights, compared to the price of coal and coke, affect the optimal biomass pre-processing (pyrolysis) and injection rate.   

An ironmaking blast furnace (BF) is a moving bed reactor involving counter-, co-, and cross-current flows of gas, powder, liquids, and solids, coupled with heat exchange and chemical reactions. The behavior of multiple phases directly affects the stability and productivity of the furnace. In the present study, a mathematical model is proposed to describe the behavior of fluid flow, heat and mass transfer, as well as chemical reactions in a BF, in which gas, solid, and liquid phases affect each other through interaction forces, and their flows are competing for the space available. Process variables that characterize the internal furnace state, such as reduction degree, reducing gas and burden concentrations, as well as gas and condensed phase temperatures, have been described quantitativel...

Since granulated blastfurnace slag hardens in the existence of water and alkali constituent, it has so far been positively used as reinforced roadbed material, but at present, development of the treatment of basic oxygen furnace slag which is used less than the above slag and the way of its effective utilization are the important issues. In this article, since compacted powdered basic oxygen furnace slag, which is generated in association with the recent improvement of steel-making, has physical and chemical properties somewhat different from the conventional converter slag and also has hydraulic property, a series of experiments were conducted on whether or not the mixture of this slag and granulated blastfurnace slag could be utilized as roadbed material for utilizing it possibly. As a result, concerning the mixtures of compacted powdered basic oxygen furnace slag and granulated blast furnace slag, expandability due to water immersion of compacted powdered basic oxygen furnace slag was greatly reduced and at the same time, improvement of the strength property was expected by introduction of the hydraulic property of granulated blastfurnace slag, hence when both of them are used in mixture. it was elucidated that basic oxygen furnace slag could be utilized as roadbed material without an ageing treatment. 8 refs., 14 figs., 2 tabs.

A center coke charging method from the top of blast furnace is known for a novel approach to burden distribution and coal combustion. This method is considered as one of the key technologies for keeping gas permeability of deadman in the lower part of blast furnace and producing iron liquid with a stable furnace operation. In recent years, the center charging method is also expected as improving the unsteady behavior with bridging/slipping of solid bed in low reducing agents operation of blast furnace. In the present study, a center charging method with different particle density or friction coefficients is carried out numerically by using a 3-dimensional Discrete Element Method (DEM). Before the numerical analysis, an experimental approach using a two-dimensional cold model is also examined. Alumina sphere was used as representative particle of coke/ore packed bed and the glass sphere was for the center charge. From the experiment, it was found that the height of deadman is reduced dramatically by using the center charging method with the glass sphere. This experimental result was compared with the numerical approach, although the gas flow was not considered in the numerical method. In the numerical results, the void fraction was calculated more precisely compared to the previous numerical two-dimensional calculation. Almost uniform particle flow distribution called a piston flow pattern was fairly maintained by the numerical center charging method, and as the result, the height of deadman was also confirmed reduced numerically compared to the alumina bed only. This result was qualitatively coincident with the experimental flow pattern except for the particle velocity descending faster in the experimental center-charging region, which could be available for the operation of deadman control.

It is a common point that "soft" condensed matter (like granular materials or foams) can reduce damage caused by impact or explosion. It is attributed to their ability to absorb significant energy. This is certainly the case for a quasistatic type of deformation at low velocity of impact where such materials are widely used for packing of fragile devices. At the same time a mitigation of blast phenomena must take into account shock wave properties of "soft" matter which very often exhibit highly nonlinear, highly heterogeneous and dissipative behavior. This paper considers applications of "soft" condensed matter for blast mitigation using simplified approach, presents analysis of some anomalous effects and suggestions for future research in this exciting area.