Carbon Bricks Research Articles

Mathematical Modeling of Iron and Steel Making Processes. Mathematical Model for Transient Erosion Process of Blast Furnace Hearth.

A mathematical model that can estimate the transient erosion process of the blast furnace hearth has been developed. This mathematical model can treat the molten iron flow, heat transfer and the brick/refractory erosion at the hearth. To verify the availability of the mathematical model, comparisons of computational final erosion profile of the hearth were made with the investigation results of the dissection blast furnace and computational results gave good agreement with the measured one. The effects of the distribution profile of the dripping molten iron flow rate into the hearth, the coke free layer size, production rate of the molten iron, thermal conductivity of the carbon brick and the fluid flow resistance through the coke packed bed were examined by using this mathematical model.

98/01540 Silicon in a blast furnace: Wladyslaw, S. et al. Hutn.-Wiad. Hutn., 1997, 64, (1), 7–11. (in Polish)

At the beginning of 1990s, Shougang blast furnaces (BFs) No. 2, No. 4, No. 3 and No. 1 were rebuilt sequently for new technological modernization in succession. The campaign life of BFs No. 1, No. 3 and No. 4 reaches 16. 4, 17. 6 and 15. 6 years, respectively, and the hot metal output of one campaign reaches 33. 8, 35. 48 and 26. 37 Mt, respectively; the hot metal output of BF effective volume of one campaign reaches 13328, 13991 and 12560 t/m3, respectively, which reaches the international advanced level of BF high efficiency and long campaign life. In BF designing, several advanced BF long campaign technologies were adopted. BF proper inner profile was optimized, reasonable inner profile was adopted, and closed circulating soften water cooling technology was applied in 4 BFs. Double row cooling pipe high efficiency cooling stave was developed which could prolong the service life of bosh, belly and stack. Hot pressed carbon brick and ceramic cup hearth lining structure were applied and optimized. BF operation was improved continuously to ensure stable and smooth operation of BF. Hearth working condition control was strengthened, burden distribution control technology was applied to achieve reasonable distribution of gas flow, and heat load monitoring was strengthened to maintain BF reasonable working inner profile. Proper maintenance at the end of BF campaign was enhanced. Hearth and bottom service life was prolonged by adding titaniferous material and enhancing hearth cooling. Gunning of lining was carried out periodically for the area above tuyere zone.

98/01549 Manufacture of carbon-ceramic composites, and the composites obtained and their use: Manocha, L. M. Ger. Offen. DE 19,644,678 (Cl. C04B35/577), 30 Apr 1997, IN Appl. 95/DE1,967, 27 Oct 1995, 9 pp. (in German)

At the beginning of 1990s, Shougang blast furnaces (BFs) No. 2, No. 4, No. 3 and No. 1 were rebuilt sequently for new technological modernization in succession. The campaign life of BFs No. 1, No. 3 and No. 4 reaches 16. 4, 17. 6 and 15. 6 years, respectively, and the hot metal output of one campaign reaches 33. 8, 35. 48 and 26. 37 Mt, respectively; the hot metal output of BF effective volume of one campaign reaches 13328, 13991 and 12560 t/m3, respectively, which reaches the international advanced level of BF high efficiency and long campaign life. In BF designing, several advanced BF long campaign technologies were adopted. BF proper inner profile was optimized, reasonable inner profile was adopted, and closed circulating soften water cooling technology was applied in 4 BFs. Double row cooling pipe high efficiency cooling stave was developed which could prolong the service life of bosh, belly and stack. Hot pressed carbon brick and ceramic cup hearth lining structure were applied and optimized. BF operation was improved continuously to ensure stable and smooth operation of BF. Hearth working condition control was strengthened, burden distribution control technology was applied to achieve reasonable distribution of gas flow, and heat load monitoring was strengthened to maintain BF reasonable working inner profile. Proper maintenance at the end of BF campaign was enhanced. Hearth and bottom service life was prolonged by adding titaniferous material and enhancing hearth cooling. Gunning of lining was carried out periodically for the area above tuyere zone.

Elevated Indoor Exposure in Chinese Carbon Brick and Cave Dwellings

In two rural provinces of China residents are exposed to significantly elevated levels of natural radiation: in Gansu Province millions of people have been living in earth-dug cave dwellings for several generations; in Jiangxi Province several hundred thousand inhabitants reside in carbon-brick dwellings, containing elevated levels of 238U and 226Ra. In a pilot study regional lung cancer mortality rates were investigated in the affected areas and were found to be higher than for control groups in normal dwellings in the same area.

Composites of activated carbon for refrigeration adsorption machines

To improve the performance of adsorption machines using the activated carbon-methanol pair, a new procedure for shaping adsorbent materials as bricks was developed. In this paper, research activity on the preparation of composite carbon samples is described together with the results on methanol adsorption capacity and on thermal conductivity measurements. Carbon bricks of a pre-defined form were prepared using PTFE as a binder and three types of activated carbon as an adsorbent. The samples present good mechanical properties, a methanol adsorption capacity higher than 40% and an effective thermal conductivity ranging between 0.13 and 0.20 W/m K.

Thermal Diffusivity and Porosity of Solid Materials by the Electromagnetic Ultrasonic Technique. 1st Report, The Principle of Measurement.

Carbon-cabon composites are important structural materials at high temperature. Their thermal properties and microscopic structures change with the temperature and the time required for heat treatment. It is expected that the thermal diffusivity and porosity show different values at every moment during heat treatment. The objective of this study is to evaluate the time dependence of the thermal diffusivity and porosity simultaneously using the electromagnetic ultrasonic technique. This report describes the principles of measurement of the properties and the experiment to confirm the principles separately at room temperature. The longitudinal ultrasonic velocities of aluminum and carbon brick in the evaluation of porosity are 6350 m/s and 2530 m/s with precision of ±1.6% and ±0.4%, respectively. Is was confirmed that the aluminum and the carbon electrodes were able to be heated by the electromagnetic ultrasonic transducer. The thermal diffusivity of carbon brick measures 8-9 mm2/s but the accuracy of measurement will have to be investigated using the standard material in the future.

Some Special Considerations on Magnesia-Carbon Refractories

Rotary drum erosion test has been developed which provides information on corrosion, abrasion and oxidation properties of magnesia carbon bricks. Textural properties of magnesia-carbon bricks have also been determined through this test The result obtained is correlated with service performance in LD converter.

Wetting conditions and microstructural characteristics of a fired B4C‐containing MgO carbon brick

This investigation is a continuation of the studies of the use of boron carbide as an antioxidant in refractory carbon‐containing materials. The previous studies were concerned with the stability of boron carbide at high temperatures. The present work gives an account of the wetting conditions and microstructural characteristics of a fired MgO‐C brick containing boron carbide additive. The results obtained show that a contribution may be made to the oxidation‐inhibiting protective action of the carbide by the formation of a continuous network of dense bridges of borate melts between periclase grains. A white layer with a high percentage of magnesium borate is produced between the decarbonized and non‐decarbonized material. The nature of this layer is similar to that from secondary MgO in MgO‐C bricks with no additive. The occurrence of this layer is the subject of further research.

ＬＦプロセスにおける極低炭素鋼の溶製改善

Some improvements for making ultra low carbon steel have been obtained since AF-LF duplex refining process coupled with vacuum degassing was induced in Hoshizaki plant, Daido Steel Co., Ltd.Main points of the improvements are as follow;(1) Carbon pick-ups during LF processings are eliminated by the choice of low carbon bricks, the application of long arc heating and the usage of low carbon alloys.(2) Decarburization reaction is controlled by the αFeO. In order to reach the minimum carbon level, αFeO must be kept as higher as possible.

Deformation and Failure Behavior of Refractories for the Blast Furnace at Elevated Temperatures

A complete stress-strain curve for brittle materials cannot be obtained with conventional testing machines because of their low stiffness and difficulty in strain-control. In this paper, the deformation and failure behavior of refractories for use in blast furnace under strain-controlled uniaxial compression measured with a stiff testing machine is discussed.It was found that the refractories retain some strength and still have appreciable elasticity even after the maximum stress is reached. Fireclay brick shows anisotropy with regard to the stress-strain curve. It has good deformability and superior resistance to failure under thermal stress applied parallel to the direction of press forming. Carbon brick fractures with little deformation after the maximum stress is applied. At temperatures above 800°C, fireclay brick exhibits visco-elastic behavior, which is substantially explained by the Burgers model.

On the Standardisation of A Method for Determining Abrasion Resistance of Refractories

The investigation was undertaken with a view to ascertaining the feasibility of determining reproducible results on abrasion resistance of refractories. Attempts for designing standard instrument are, so far, based on the relatively simple method of impingement of abrasive grain on the test specimen. Numerous variables associated with this method render it difficult to obtain accurate data. However, in consideration of the relative advantage of fabrication, and the ease of conducting experiments, one such apparatus was installed at CGCRI essentially as per BS method. Keeping other variables, e.g. type of abrasive, rate of abrasive-feed and air velocity constant, impingement with abrasives of relatively finer fractions provided an improvement of reproducibility in terms of material loss. The samples included in this investigation comprise aluminosilicate, silica, basic and carbon bricks. An attempt was made towards correlating abrasive resistance with such properties as porosity, bulk density, cold crushing strength, tensile strength, modulus of rupture and modulus of elasticity in addition to textural aspects. © 1978, Taylor & Francis Group, LLC.

高炉におけるカーボン煉瓦の使用について

This paper presents the carbon brick-work and its wear during operation of Nos.1, 2, 3, and 4 blast furnaces at Wakayama Steel Works. Carbon bricks in the following parts are quickly worn out;(1) the part where is inadequately cooled from outside, (2) the part where carbon brick may be oxidized by charged oxide materials, (3) the part where carbon brick receives mechanical abrasion by charged materials.Therefore, the followings are concluded:(1) Carbon brick should be used for the parts where cooling effect is sufficient, i. e. the lower part of furnace bottom and the peripheral part.(2) In the upper part of bosh, schamotte brick is rather suitable, while carbon brick can be used at the lower part of bosh.On the basis of the above conclusion, the brick-work of No4 blast furnace and No1 blast furnace (reconstructed) was designed. Since No4 blast furnace was blown-in (March, 1967), there have not been observed any troubles in brick-work, and the furnace operation is going well.

高炉用炭素レンガの使用後性状と損耗機構

高炉用炭素レンガの使用後性状と損耗機構