Blast Furnace Burdens Research Articles

Influence of inner wall profile on descending and melting behavior of burden in blast furnace.

The influences of the inner wall profile and ore/coke distribution on the descending and melting behaviors of burden were analyzed by using a three-dimensional semicircular warm model of the blast furnace under conditions set as similar as possible to the physical phenomena in the furnace. It is confirmed that in the case of a profile with blocks installed on the belly where the horizontal stress acting to wall is at its maximum, a sluggishly descending zone of a thickness 2-5 times of the projecting length of the blocks is formed near the wall just above the blocks. It is estimated that the thickness of sluggishly descending zone near the wall increases with increasing projecting length of the blocks on the wall and with decreasing installation interval of distance between the blocks and it decreases with increasing ore/coke near the wall. It is estimated that the height of the dead man decreases with the formation of the wall sluggishly descending zone due to the blocks on the wall. For decreasing the thickness of the sluggishly descending zone near the wall, the ore/coke near the wall should preferably be increased as far as the heat-flow ratio is permitted. Such a burden distribution is effective for pulverized coal injection operation in which the melting capacity near the wall is large.

高炉内における装入物の降下と溶融の挙動に及ぼすOre/Coke分布の影響

高炉内における装入物の降下と溶融の挙動に及ぼすOre/Coke分布の影響

高炉内における装入物の降下と溶融の挙動に及ぼす炉体内壁面形状の影響

高炉内における装入物の降下と溶融の挙動に及ぼす炉体内壁面形状の影響

In-furnace phenomena in oxygen blast furnace

Results of the dissection of the quenched burden in a small experimental blast furnace are reported. The furnace was operated with a low-temperature oxygen blast, a coal injection rate of 300 kg/t iron and injection of preheating gas into the stack. Salient features were high productivity (iron output over 5 t/m{sup 3}d), absence of a cohesive zone, and low Si content of the iron. Scale-up to commercial size by simulation is discussed.

高炉用新塊成鉱の製造条件に関する基礎的検討及び品質の評価

高炉用新塊成鉱の製造条件に関する基礎的検討及び品質の評価

Softening and melting behavior of sinter and pellets.

To evaluate high temperature properties of blast furnace burdens, a series of reduction under load tests was carried out under the conditions simulating blast furnace processes, using sinter, self-fluxed pellets and acid pellets.To investigate the softening and melting mechanism, structural analysis was conducted on those samples taken after interrupting the test.The results obtained are summarized as follows:(1) Generation of molten slag is involved in the assimilation process of slag during softening and melting of samples, and the basic path for this assimilation is considered to be toward the final composition (average gangue composition before reduction) along the direction expanding the liquid phase area with heating.(2) The difference in softening and melting behavior of these burden materials is directly due to the quantity of molten slag formed in the slag assimilation process. It is indirectly due to the differences in reducibility at about 1000°C in addition to the composition and volume of gangue before reduction.

実物大模型実験に基づく高炉の装入物およびガス分布の改善

実物大模型実験に基づく高炉の装入物およびガス分布の改善

Testing Method of High-temperature Properties of Blast Furnace Burdens

Regarding the reduction under load test for measuring high temperature properties of blast furnace burdens, the test conditions, i.e. the load, gas flow rate, particle size and bed height were examined through tests and calculations based on a reduction model for fixed bed. Examinations covered also evaluation criteria of test results for high temperature properties.The results obtained are summarized as follows:(1)Test results are influenced by each of the load, gas flow rate, particle size and bed height conditions.(2) It is desirable to minimize the longitudinal difference of degree of reduction and the dependence on load of test results. The optimal test conditions (Fig. 2) were decided from such a point of view.(3) The following evaluation criteria of test results for high temperature properties were proposed: (i) the temperatures at the beginning of softening and melt-down are high, with a small temperature difference; (ii) the integral and average values of index of permeability resistance between softening and melt-down are small; and (iii) the degree of reduction achieved at 1000 to 1200°C is high.

高炉装入物の高温性状測定法

Regarding the reduction under load test for measuring high temperature properties of blast furnace burdens, the test conditions, i.e. the load, gas flow rate, particle size and bed height were examined through tests and calculations based on a reduction model for fixed bed. Examinations covered also evaluation criteria of test results for high temperature properties.The results obtained are summarized as follows:(1)Test results are influenced by each of the load, gas flow rate, particle size and bed height conditions.(2) It is desirable to minimize the longitudinal difference of degree of reduction and the dependence on load of test results. The optimal test conditions (Fig. 2) were decided from such a point of view.(3) The following evaluation criteria of test results for high temperature properties were proposed: (i) the temperatures at the beginning of softening and melt-down are high, with a small temperature difference; (ii) the integral and average values of index of permeability resistance between softening and melt-down are small; and (iii) the degree of reduction achieved at 1000 to 1200°C is high.

The Structure and Flow Resistance of Layer Charged Particulate Systems in the Modeling of Gas Flow through Simulated Blast Furnace Burdens

The Structure and Flow Resistance of Layer Charged Particulate Systems in the Modeling of Gas Flow through Simulated Blast Furnace Burdens

Theoretical Prediction of Non-uniform Gas Flow through Simulated Blast Furnace Burdens

Theoretical Prediction of Non-uniform Gas Flow through Simulated Blast Furnace Burdens

The porosity of systems consisting of layers of different particles

Experimental measurements are reported on the spatial dependence of the local void fraction for systems where particles of different size form horizontal layers in packed beds. This problem is of practical importance in estimating the flow resistance of blast furnace burdens. It was found that marked local minima in porosity occur in the interfacial region when a layer of smaller particles is placed upon a bed of larger spheres. In contrast, the local minima in porosity are much less marked when larger particles are placed on a bed of smaller spheres. From a technological viewpoint, the most important finding of the work is that the penetration of smaller particles into the interstices of the larger spheres occurs readily when the particle size ratio exceeds about two. Under these conditions the interfacial regions will contribute appreciably to the overall flow resistance.

Measurement of Apparent Viscosity of Various Blast Furnace Burdens at Softening Temperature

Measurement of Apparent Viscosity of Various Blast Furnace Burdens at Softening Temperature

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.

Blast furnace operation with prereduced burdens

The prereduction of blast furnace burdens results in large coke savings and greatly increased productivity. These benefits are obtained whether the raw material is a high-grade pellet or a low-grade ore. The percent changes in coke rate and production rate are a function of prereduction. Reduced material can be injected through the tuyeres and yield both coke savings and increased productivity.

(38)高炉装入物の還元性状について(高炉装入物の性状に関する研究-I)

(38)高炉装入物の還元性状について(高炉装入物の性状に関する研究-I)

Economics of Raw Materials Preparation for the Blast Furnace

An economie evaluation of different types of blast-furnace burdens, based on representative materials cost figures and production results of tests and actual blast-furnace operations.

製鐵所に於けるA.I.B.式粉鑛燒結に就いて

Reoently various sintering methods are used, however the A.I.B. Sintering System is one of the most modern down draft system.In The Imperial Government Steel Works that plant was started 2 yesrs ago. The nominal capacity is 150 tons of sintered ore per day, when treated with mainly pu ple ore aud pyrite cinders.The author has herewith int roduced the present aspect of that system in the world, and described about our equipments raw materials, the result of the sintering operations, on some problems for sintering actions and the final product in our works. Also moreover denoted the consumption of the sintered-ore in the blast furnace burdens. Lastly he advocates that the adquate moiature in the raw materials is one of the greatest important factors for successful sintering operations, it is described as following articles, (A) on the effect of raw material handling, (B) the action during sintering and (C) the result on the character of product.