Blast Furnace Performance Research Articles

Effect of coke strength on blast-furnace performance indices

Effect of coke strength on blast-furnace performance indices

Effect of coke quality on blast-furnace performance

Effect of coke quality on blast-furnace performance

Pellet property requirements for future blast-furnace operations and other new ironmaking processes

The reducibility of iron-bearing burdens was emphasized for improving the operation efficiency of blast furnace. The blast furnace operation of charging the burdens with high reducibility has been numerically evaluated using a multi-fluid blast furnace model. The effects of reaction rate constants and diffusion coefficients were investigated separately or simultaneously for clarifying the variations of furnace state. According to the model simulation results, in the upper zone, the indirect reduction of the burdens proceeds at a faster rate and the shaft efficiency is enhanced with the improvement under the conditions of interface reaction and intra-particle diffusion. In the lower zone, direct reduction in molten slag is restrained. As a consequence, CO utilization of top gas is enhanced and the ratio of direct reduction is decreased. It is possible to achieve higher energy efficiency of the blast furnace, and this is represented by the improvement in productivity and the decrease in consumption of reducing agent. The use of high-reducibility burdens contributes to a better performance of blast furnace. More efforts are necessary to develop and apply high-reducibility sinter and carbon composite agglomerates for practical application at a blast furnace.

96/01920 Pulverized coal injection facilities for blast furnaces, replacement with energy saving sintering furnace in steel works, and optimization of

Combustion efficiencies of pulverized coal in blowpipes and tuyeres under various operational conditions are numerically predicted to recognize the performance of pulverized coal injection in a blast furnace. A variety of parameters including the injection pattern of the pulverized coal, oxygen content in the hot blast, inlet temperature of the hot blast and mass flow rate of coal carrier gas are taken into consideration. The effect of installing a ceramic sleeve around the tuyere on pulverized coal combustion is also evaluated. The predictions indicate that pulverized coal combustion is highly related to the injection pattern, hot blast temperature, mass flow rate of the carrier gas and installation of the ceramic sleeve, whereas it is insensitive to the oxygen concentration. The present study is conducted based on the practical operational conditions of the blast furnace at the China Steel Corporation. Consequently, the obtained results have provided a useful insight into the operation of pulverized coal injection, and they enable us to further improve the blast furnace performance in the future.

Peak bed temperature prediction on a lead/zinc sinter plant

Of great interest for improved sinter plant control is the definition and online measurement of sinter quality. The ultimate measure of this is blast furnace performance and previous work at Sulphide Corporation has shown that stable furnace operation with good coke utilization is dependent upon the sinter microstructure being dominated by a network of either zincite or calcium ferrite. Formation of the correct phases during sintering is primarily controlled by the feed chemistry. The temperature history is also important however, leading to the concept of a peak bed temperature which must be reached to maximise melting, reaction and recrystallization of the desired chemical species. Improved sinter composition control has been achieved ar Sulphide Corporation by the use of a charge calculation computer program which includes as a target, the theoretical peak bed temperature. However, this technique depends on good assay data - both for raw material inputs and for the return sinter. At the present time, much of the required information is not available on-line and the charge calculation approach is thus vulnerable to the effects of short-term fluctuations. It was therefore seen to be important to develop a separate method which, could measure peak bed temperature on-line. This paper describes a series of investigations conducted on the sinter machine at Sulphide Corporation, to develop such a method. After a number of initial, unsuccessful attempts (which are described), the approach adopted was to infer from bulk gas temperatures (where these could be reliably measured) the temperature profile of the gas leaving the surface of the bed. The location of the peak gas temperature is the burnthrough point. In order to do this, a mathematical model of the gas flow pattern in the sinter machine hood was prepared, and, based on the results from plant experiments, was progressively modified until adequate agreement between prediction and experiment was obtained. Based on limited experimental data, it is assumed that the gas temperature at burnthrough is equal to the temperature of the sintering solids. The use of this model, in conjuction with a suitable two-parameter search algorithm, in both off-line and on-line mode is discussed.

Effect of the number and diameter of tuyeres on blast-furnace performance

Effect of the number and diameter of tuyeres on blast-furnace performance

Effect of alkalies on the performance of blast furnace.

The influence of alkalies on the blast furnace operation has been discussed from the data collected from the Iron and Steel Co., Helwan, Egypt. The stability of the alkali compounds formed in the blast furnace was calculated from the thermodynamic data. The model of alkali circulation in the different zones of the furnace, as a function of temperature is proposed. Statistical analysis of alkalies from the input and output materials was calculated and discussed. The effect of alkalies on the partition of manganese and sulphur as well as on the rate of coke consumption was investigated. The relations between the alkali loadings, the basicity and the efficiency of alkali removal by the slag were discussed. Mathematical relations between these different parameters were given and correlated.

Effect of coke strength on blast furnace performance

The authors report on results of a study, conducted from 1979 to 1982, analyzing the effect of the strength of commercially produced coke on furnace performance, for furnaces of different volumes. The effect of coke strength on blast-furnace performance was analyzed in two directions: determination of the dependence of coke loss from fragmentation on coke strength indices; evaluation of the effect of the coke strength on melting indices. It is found that high-strength coke is needed for large-volume furnaces and that reduction in coke strength helps cause tuyere burning.

Performance of blast furnaces on a charge with a high content of alkalis

Performance of blast furnaces on a charge with a high content of alkalis

Pitch and petroleum coke additions to coke oven charges

AbstractSeveral pitch materials and a petroleum coke were added to coke oven charges in an attempt to make good metallurgical coke from Canadian coal of poor coking quality. Coal and petroleum pitches were added to a low fluid western Canadian coal of medium volatile bituminous rank, and the blends coked in a technical‐scale moveable wall test oven having a 230‐kg charge capacity. Pitches improved coke tumble test indices, the principal coke quality parameter related to blast furnace performance. Varying levels of petroleum coke were added to an eastern Canadian coal of high volatile bituminous rank, and the blends, some partially briquetted, were carbonized in a test oven. Tumble indices of coke from the partially briquetted charges approached an acceptable level. These investigations confirm that petroleum products as well as coal derivative can play a useful part in the production of a metallurgical strength coke from poor or non‐coking coals.

Blast-furnace performance indices with a charge containing 80?100% pellets

Blast-furnace performance indices with a charge containing 80?100% pellets

Blast-furnace performance with high burden ratios

Blast-furnace performance with high burden ratios

Blast furnace performance with periodic changes in the burden

Blast furnace performance with periodic changes in the burden

1970 Ironmaking Award Paper

The quality and uniformity of metallurgical coke are becoming increasingly important as blast furnace burdens and operating practices are improved. Under such conditions, and with the continuing decrease in the amount of coke required to produce a ton of iron, small changes in the character of the coke can have a relatively large influence on blast furnace performance. To minimize the possible disruptive effects of such changes, one must develop adequate means to control the quality and uniformity of the coke. To this end, we have been conducting research to identify the important influencing factors and determine the effect of these factors on the character of the coke produced.

Remarks on the effect of coke fraction variability on blast furnace performance

Remarks on the effect of coke fraction variability on blast furnace performance

Effect of moistening of the blast on the performance of blast furnaces operated with natural gas

Effect of moistening of the blast on the performance of blast furnaces operated with natural gas

Operating practices required to optimize blast furnace performance

Operating practices required to optimize blast furnace performance

Coal Slurry Injection into Blast Furnace

One of the methods for reducing blast furnace iron-making cost is to inject auxiliary fuels throngh the tuyeres.As for the fuel used, heavy oil is commonly used with one exception or two.In using heavy oil as auxiliary fuel, however, there arises the problem of an increase in sulfur content in the pig iron, and of heat compensation to increase the fuel used.These problems can be solved by using coal produced in Hokkaida, where the Muroran Works of Fuji Iron and Steel Co., Ltd. is located.On the other hand, however, since coal price fluctuation in Japan is wide, it would be far more advantageous, in reducing cost, to set up a technique for injecting a slurry-form fuel, a mixture of coal and heavy oil.In the summer of 1961, research on studying the selection of coals, viscosity of slurry and critical velocity in piping was launched to ascertain the properties of slurry.On the basis of the knowledge gained, slurry equipment was provided for the No.1 blast furnace at the Muroran Works, with an inner volume of 1, 042m3, (afterwards relined to 1, 126m3) and actual slurry injection test was carried on, and now slurry of 50wt% coal concentration is being injected quite satisfactory into blast furnace through 16 tuyeres.By means of slurry injection, the sulphur content of pig iron thus produced has been reduced. The effect of using slurry on the out-put of pig iron and other blast furnace performance is about the same as in the case of using heavy oil alone. But, since slurry is cheaper than heavy oil, the use of slurry has cut down the cost of pig iron production.

Chemical reactions of coke in the iron blast furnace

The term solution loss is discussed and defined. Examples are given showing that solution loss may either have a favorable or unfavorable effect on blast furnace performance. A theory is advanced explaining the contradictions encountered during earlier studies of the problem.