Dissolution of carbon from coke and char in liquid Fe-C alloys

• Autorzy: Xing X. , Jahanshahi S. , Yang J. , Ostrovski O.

Identyfikatory

DOI

10.5604/01.3001.0012.5508

• Języki publikacji: EN

Abstrakty

EN

Purpose: The aim of this paper was to study dissolution of carbon from carbonaceous materials of different origin with different morphology, microtexture and microstructure in the liquid Fe-C alloys. Design/methodology/approach: The dissolution of carbon from coke, char and glassy carbon in the molten Fe-C alloy (initial carbon concentration 2.46 wt.%) at 1350°C was measured and compared with that from graphite. The dissolution of carbon from demineralised coke and char in the Fe-C solution was also examined to study the effect of mineral matter on the carbon dissolution. Findings: The concentration of carbon in the Fe-C solution dissolved from graphite was higher than that from coke and char. Demineralisation of coke and char had a significant effect on the carbon dissolution. The concentration of carbon dissolved from demineralised coke and char in the Fe-C alloy approached the solubility of graphite in this alloy under the same conditions. Results obtained in this work confirmed that ash has a strong effect on the carbon dissolution. Research limitations/implications: Investigations in this paper were conducted at 1350°C. At higher temperatures; (1) the degree of coke and char graphitisation increases changing the microstructure of carbonaceous materials; (2) the ash can melt, and (3) some of the metal oxides in the ash can be reduced by carbon to the metal phase, thereby weakening the effect of ash on the carbon dissolution. Demineralisation of coke was incomplete; it reached 70-80% with some effect on the carbon dissolution. The effect of ash composition and further coke demineralisation on the carbon dissolution at higher temperature will be investigated in the future study. Originality/value: This study demonstrated that dissolution of carbon from coke and char was strongly affected by ash. Reactions of dissolution of carbon from coke and char in liquid Fe-C alloy reached a steady state within 1-2 hours. In this state, the coke/char - metal system was far from equilibrium. The “apparent” activity which can be assigned to carbon in the steady state is below one for graphite with significant implications for metallurgical processes.

Słowa kluczowe

EN

carbon dissolution; coke; char; ash; demineralisation

PL

rozpuszczanie węgla; koks; zwęglanie; popiół; demineralizacja

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2018
• Tom: Vol. 92, nr 1
• Strony: 22--27
• Opis fizyczny: Bibliogr. 14 poz.

Twórcy

autor

Xing X.

• School of Materials Science and Engineering, UNSW Australia, NSW 2052, Australia b Meta-Logical Solutions, Armadale, Victoria 3143, Australia

autor

Jahanshahi S.

• School of Materials Science and Engineering, UNSW Australia, NSW 2052, Australia b Meta-Logical Solutions, Armadale, Victoria 3143, Australia

autor

Yang J.

• School of Materials Science and Engineering, UNSW Australia, NSW 2052, Australia b Meta-Logical Solutions, Armadale, Victoria 3143, Australia

autor

Ostrovski O.

• School of Materials Science and Engineering, UNSW Australia, NSW 2052, Australia b Meta-Logical Solutions, Armadale, Victoria 3143, Australia

Bibliografia

• [1] R.I. Olivares, The effect of sulfur on the dissolution of graphite and carbons in liquid iron-carbon alloys, PhD Thesis, The University of Newcastle, 1996.
• [2] R. Khanna, F. McCarthy, H. Sun, N. Simentao, V. Sahajwalla, Dissolution of carbon from coal-chars into liquid iron at 1550°C, Metallurgical and Materials Transactions B 36B (2005) 719-729.
• [3] S.T. Cham, V. Sahajwalla, R. Sakurovs, H. Sun, M. Dubikova, Factors influencing carbon dissolution from cokes into liquid iron, ISIJ International 44 (2004) 1835-1841.
• [4] S. Gupta, V. Sahajwalla, J. Burga, P. Chaubal, T. Youmans, Carbon structure of coke at high temperatures and its influence on coke fines in blast furnace dust, Metallurgical and Materials Transactions B 36B (2005) 385-394.
• [5] B. Kim, S. Gupta, D. French, R. Sakurovs, V. Sahajwalla, Effect of thermal treatment on coke reactivity and catalytic iron mineralogy, Energy & Fuels 23 (2009) 3694-3702.
• [6] S.T. Cham, R. Khanna, V. Sahajwalla, R. Sakurovs, D. French, Influence of mineral matter on carbon dissolution from metallurgical coke into molten iron: interfacial phenomena, ISIJ International 49 (2009) 1860-1867.
• [7] M.W. Chapman, B.J. Monaghan, S.A. Nightingale, J.G. Mathieson, R.J. Nightingale, Formation of a mineral layer during coke dissolution into liquid iron and its influence on the kinetics of coke dissolution rate, Metallurgical and Materials Transactions B 39B (2008)418-430.
• [8] M.W. Chapman, B.J. Monaghan, S.A. Nightingale, J.G. Mathieson, R.J. Nightingale, Observations of the mineral matter material present at the coke/iron interface during coke dissolution into iron, ISIJ International 47 (2007) 973-981.
• [9] D. Jang, Y. Kim, M., Shin, J. Lee, Kinetics of carbon dissolution of coke in molten iron, Metallurgical and Materials Transactions B 43B (2012) 1308-1314.
• [10] R.J. Nightingale, R.J. Dippenaar, W.K. Lu, Develop¬ments in blast furnace process control at Port Kembla based on process fundamentals, Metallurgical and Materials Transactions B 31B (2000) 993-1003.
• [11] B.S. Terry, X. Yu, Determination of thermodynamic stability of metallurgical cokes, with respect to graphite, Ironmaking and Steelmaking 18 (1991) 27-32.
• [12] K.T. Jacob, S. Seetharaman, Thermodynamic stability of metallurgical coke relative to graphite, Metallurgical and Materials Transactions B 25B (1994) 149-151.
• [13] J.P. Harvey, A.E. Gheribi, Process simulation and control optimization of a blast furnace using classical thermodynamics combined to a direct search algorithm, Metallurgical and Materials Transactions B 45/1 (2014) 307-327.
• [14] V. Guencheva, E. Grantscharova, I. Gutzow, Thermodynamic properties of the amorphous and crystalline modifications of carbon and the metastable synthesis of diamond, Crystal Research and Technology 36/12 (2001) 1411-1428.