Major determinant of service life in magnesia-graphite slagline refractory lining in secondary steelmaking ladle furnace

The cChromic shaped bricks have been used as the refractory lining in alumina kiln for long time, whose service life is about 120~250 days. Besides the short working time, the environmental pollution led to by the chromic component is also serious. In this thesispaper (thesis 是硕士论文), some materials are were chosen based on the actual situation of the usage of the refractory lining in the current alumina kiln. The choosing principals are were the extensive source and the relatively low price. Finally, a new formula of the refractory castable is was acquired based on the orthogonal test and has passed the properties testing.

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A real-time ferroalloy model for the optimum ladle furnace treatment during the secondary steelmaking

Ironmaking & Steelmaking ◽

10.1080/03019233.2017.1368952 ◽

2017 ◽

Vol 46 (3) ◽

pp. 211-220 ◽

Cited By ~ 3

Author(s):

Anil Kumar Kothari ◽

Rajeev Ranjan ◽

Rama Shankar Singh ◽

Gaurav Kumar ◽

Ashutosh Kumar ◽

...

Keyword(s):

Real Time ◽

Ladle Furnace ◽

Furnace Treatment ◽

Secondary Steelmaking

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Impact of Temperature and Oxygen Partial Pressure on Aluminum Phosphate in High Chrome Oxide Refractories

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.92.248 ◽

2014 ◽

Vol 92 ◽

pp. 248-257 ◽

Cited By ~ 2

Author(s):

James P. Bennett ◽

Kyei Sing Kwong ◽

Jinichiro Nakano ◽

Hugh Thomas ◽

Anna Nakano

Keyword(s):

Service Life ◽

Oxygen Partial Pressure ◽

Partial Pressure ◽

Refractory Lining ◽

Industrial Process ◽

Aluminum Phosphate ◽

Chemical Dissolution ◽

Chemical Production ◽

Low Oxygen ◽

Chrome Oxide

Gasifiers are reaction vessels used to process carbon feedstock such as coal and/or petcoke at elevated temperature, high pressure, and in a reducing atmosphere (low oxygen partial pressure) to form CO and H2, called synthesis gas or syngas. Syngas is used as a fuel in power generation or as a feedstock material in chemical production. By-products of the gasification process include unreacted carbon, gases such as CO2 and H2S, and slag formed from mineral impurities or organic metallic compounds in the carbon feedstock that liquefy during gasification. In the gasifier, slags interact with the high chrome oxide refractory liner, causing wear and eventual failure of the refractory lining by two primary means - spalling (structural and chemical) and chemical dissolution. Failure of the refractory lining causes the gasifier to be shut down for repair, with increased service time identified by users as important for greater usage of gasification as an industrial process. Phosphate additions to high chrome oxide refractories have been found to increase service life during commercial service by reducing spalling and lowering chemical dissolution of the refractory liner. The mechanism of how they improve service life is not well understood. The microstructure and physical properties of high chrome oxide refractories with and without phosphate additions removed from a commercial gasifier after approximately eight months of exposure to a coal slag are evaluated in this report, with the emphasis on evaluating slag/refractory interaction in refractory pores. Details of the investigation are presented and possible mechanisms of how phosphate additives improve wear resistance discussed.

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95/00736 Titanium-containing aggregates for addition to metallurgical furnaces for extending the service life of the refractory lining, and their use

Fuel and Energy Abstracts ◽

10.1016/0140-6701(95)95991-2 ◽

1995 ◽

Vol 36 (1) ◽

pp. 43

Keyword(s):

Service Life ◽

Refractory Lining ◽

Metallurgical Furnaces

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Possible ecological advantages from use of carbonless magnesia refractory bricks in secondary steelmaking: a framework LCA perspective

International Journal of Environmental Science and Technology ◽

10.1007/s13762-021-03553-2 ◽

2021 ◽

Author(s):

F. Boenzi

Keyword(s):

Life Cycle ◽

Resource Scarcity ◽

Steel Ladle ◽

Ladle Furnace ◽

Impact Categories ◽

Product Systems ◽

Refractory Consumption ◽

Secondary Steelmaking ◽

The Impact ◽

Refractory Bricks

AbstractIn the present paper, two types of magnesia-based refractory bricks for the wear lining of a steel ladle furnace are considered, with the aim of comparing their ecological performances. The adopted methodology is the Life Cycle Assessment (LCA) approach from cradle-to-gate of the two brick product systems, in accordance with the European and International Standard EN ISO 14044:2006, and the chosen methodology for the Life Cycle Impact Assessment (LCIA) is ReCiPe 2016, considering the midpoint impact categories and the hierarchist perspective. The conducted study is part of a European industrial research project aimed at investigating the possibility of cleanliness improvement of the steel produced in secondary steelmaking, by reducing the refractory contamination in the steel ladle furnace. The compared refractory bricks consist of a reference, currently used, MgO-C type and a more innovative "carbonless" one, containing magnesia and MA sintered spinel as principal components, on the basis of recipe data provided by the industrial partners of the project. The results attained so far in industrial practice are preliminary, because of the lack of a full-ladle lining experimentation, even though the application of the conceived innovative bricks in the upper part of the slag line of the ladle presents promising aspects. The results of the LCIA comparison between the two brick product systems highlight better performances for all the impact categories, except for "Human carcinogenic toxicity" and markedly for "Mineral resource scarcity." Besides these results, a general framework for shifting the ecological analysis to the steel production is provided. Calculations, referred to the production of one tonne of steel, are therefore performed, involving scenario assumptions not only regarding the refractory consumption but also the forecast operational features of the steel ladle with the "carbonless" lining. In this second set of results, it is clear how the principal contribution to almost all the impact categories is the electrical energy consumption of the ladle, while the contribution from the brick product systems remains important for the above-mentioned worsened impact categories, whose magnitude is strongly dependent on the refractory consumption.

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Measurement of erosion state and refractory lining thickness of blast furnace hearth by using three-dimensional laser scanning method

Metallurgical Research & Technology ◽

10.1051/metal/2020085 ◽

2020 ◽

Vol 118 (1) ◽

pp. 106

Author(s):

Lei Zhang ◽

Jianliang Zhang ◽

Kexin Jiao ◽

Guoli Jia ◽

Jian Gong ◽

...

Keyword(s):

Blast Furnace ◽

Laser Scanning ◽

Refractory Lining ◽

Three Dimensional ◽

3D Laser Scanning ◽

Scanning Method ◽

Blast Furnace Production ◽

Severe Erosion ◽

Residual Thickness ◽

Minimum Depth

The three-dimensional (3D) model of erosion state of blast furnace (BF) hearth was obtained by using 3D laser scanning method. The thickness of refractory lining can be measured anywhere and the erosion curves were extracted both in the circumferential and height directions to analyze the erosion characteristics. The results show that the most eroded positions located below 20# tuyere with an elevation of 7700 mm and below 24#–25# tuyere with an elevation of 8100 mm, the residual thickness here is only 295 mm. In the circumferential directions, the serious eroded areas located between every two tapholes while the taphole areas were protected well by the bonding material. In the height directions, the severe erosion areas located between the elevation of 7600 mm to 8200 mm. According to the calculation, the minimum depth to ensure the deadman floats in the hearth is 2581 mm, corresponding to the elevation of 7619 mm. It can be considered that during the blast furnace production process, the deadman has been sinking to the bottom of BF hearth and the erosion areas gradually formed at the root of deadman.

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Liver Blood Flow as a Major Determinant of the Clearance of Recombinant Human Tissue-Type Plasminogen Activator

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648385 ◽

1992 ◽

Vol 67 (01) ◽

pp. 083-087 ◽

Cited By ~ 44

Author(s):

A de Boer ◽

C Kluft ◽

J M Kroon ◽

F J Kasper ◽

H C Schoemaker ◽

...

Keyword(s):

Blood Flow ◽

Rat Liver ◽

Healthy Subjects ◽

Liver Blood Flow ◽

Major Determinant ◽

Tissue Type ◽

Perfused Rat Liver ◽

Liver Model ◽

Type Plasminogen Activator ◽

Proportional Change

SummaryThe influence of changes in liver blood flow on the clearance of rt-PA was studied both in healthy subjects and in a perfused rat liver model. Liver blood flow in healthy subjects was documented indirectly by the clearance of indocyanine green (ICG). Exercise reduced liver blood flow on average by 57% with a 95% confidence interval (95% Cl) ranging from 51% to 62% (n = 5) and increased plasma levels of rt-PA activity (after an i. v. infusion of 18 mg of rt-PA over 120 min) by 119% (95% Cl, 58% - 203%) and rt-PA antigen by 91% (95% Cl, 30% - 140%). In the perfused rat liver model it was shown that halving or doubling of the physiological flow rate of a perfusate, containing rt-PA caused a proportional change in the clearance of rt-PA, while the extraction of rt-PA by the liver remained similar. In conclusion, liver blood flow is a major determinant of the clearance of rt-PA. This may have important implications for dosage of rt-PA in patients with myocardial infarction.

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Fibrinopeptide A (FPA) Level and Fibrinogen Kinetics in Patients with Malignant Disease

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653457 ◽

1981 ◽

Vol 46 (04) ◽

pp. 706-709 ◽

Cited By ~ 51

Author(s):

Yasuhiro Yoda ◽

Tsukasa Abe

Keyword(s):

Fibrinolytic Activity ◽

Turnover Rate ◽

Malignant Disease ◽

Major Determinant ◽

Fibrinopeptide A

SummaryFPA level, fibrinogen turnover rate, and fibrinolytic activity were studied on 18 patients with malignant disease. It was found that the FPA levels were significantly elevated and were correlated with fibrinogen turnover rate (r=0.74, p<0.001) and FDP (r = 0.58, p<0.02). Estimated FPA turnover rate was also correlated with fibrinogen turnover rate (r = 0.70, p<0.001). These results suggest that fibrinogen catabolism in patients with malignant disease is related with thrombin proteolysis. However, ratios of 1/2 FPA turnover rate to fibrinogen turnover rate suggest that intravascular thrombin proteolysis is not the major determinant of fibrinogen catabolism. It is suspected that extravascular thrombin proteolysis is responsible for the elevation of plasma FPA level which is correlated with acceleration of fibrinogen catabolism.

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