Articles

Phase transformations in bituminous coals under the influence of weak electric and magnetic fields

User Rating:  / 0
PoorBest 

Authors:

G.G. Pivnyak, Academician of the National Academy of Science of Ukraine, Dr. Sci. (Tech.), Professor, State Higher Educational Institution “National Mining University”, Rector, Dnipropetrovsk, Ukraine

V.V. Sobolev, Dr. Sci. (Tech.), Professor, State Higher Educational Institution “National Mining University”, Professor of the Department of Building and Geomechanics, Dnipropetrovsk, Ukraine

A.O. Filippov, State Higher Educational Institution “National Mining University”, Research Fellow of the Department of Building and Geomechanics, Dnipropetrovsk, Ukraine

Abstract:

Purpose. To detect the emergence of mobile components in coal under the influence of electric fields and determine their possible effect on transition to the solid phase under action of a weak magnetic field.

Methodology. Samples were prepared from coal crushed to fractions of 200/100 mm with folowing characteristics: C – 86.6 %, N – 5.7 %, R0 - 1.03 %, Y = 18 mm, W = 1,1 %, Vdaf = 33.2 %, Qdaf = 36.4 MJ/kg. The maximum heating temperature during the electrophysical treatments did not exceed 400 K. The potential difference and the magnitude of the current were provided by the power source and were 1, 10, 100 V and 0.1 A, respectively. The current flowing through the heating coal excited the magnetic field strength up to 240 A/m in the sample. Duration of treatment of each sample did not exceed 4 hours. We used the following equipment: instrument of thermogravimetric analysis and differential scanning calorimetry, TGA/DSC METTLER TOLEDO, optical microscope LEICA DM ILM, a laser diffraction particle size analyzer SHIMADZU SALD-301V and calorimeter C-2000 IKA. Infrared spectra of coals have been made in the FTIR spectrometer FSM-1201 with the transmission in the spectral range of 400-5000 cm-1. X-ray diffraction studies on coal were carried out on DRON-3 installation.

Findings. Passage of a weak electric current triggers chemical reactions in the coal of the type ‘solid phase > gas’, increasing the concentration of paramagnetic centers (PMC) in aliphatic and aromatic structures. Under the influence of a weak magnetic field, the chemical reactions in the coal substance mainly aimed at increasing the number of solid phase and the formation of stable gas molecules resulting from recombination of free radicals.

Originality. In coals with a large number of aliphatic chains (low degree of coalification) under action of electric field the destruction processes of nanostructure occur as intensively as, for example, under heat, mechano-chemical and radiation-chemical transformations.

Practical value. The results of coal treatment in a weak electric field can be used in the processes of its decomposition and gasification, the influence of a weak magnetic field can be used to create a new way of ‘deactivation’ of the outburst hazard in coal.

References:

1. Образование газа как результат механодеструкции органической массы угля / В.В. Соболев, А.В. Чернай, Н.В. Билан, А.О. Филиппов // Форум гірників – 2009. Матер. міжнар. конф. 30.09–03.10. – Дніпропетровськ: Національний гірничий університет, 2009. – С. 186–191.

Sobolev, V.V., Chernay, A.V., Bilan, N.V. and Filippov, A.O. (2009), “Formation of gas as a result of mechanical degradation of organic mass of coal”, Proceedings of International Conference “Forum of miners – 2009”, September 30 – October 3, National Mining University, Dnipropetrovsk, pp. 186–191.

2. Батраков Н.Ф. Физическая модель системы уголь–газ / Батраков Н.Ф. – Ростов-на-Дону: Из-во СКРЦНВШ, 1992. – 272 с.

Batrakov, N.F. (1992), Fizicheskaya model sistemy ugol-gaz [Physical Model of the System ‘Coal–Gas’], SKRTsNVSh, Rostov-on-Don, Russia.

3. Соболев В.В. Образование новых фаз в измельченном кальците с добавками кремния при нагревании и пропускании электрического тока / Соболев В.В. // Минералогический журнал. – 2008. – №4. – С. 25–32.

Soboliev, V.V. (2008), “The formation of new phases in the powdered calcite with the addition of silicon during heating and an electric current”, Mineralogicheskiy zhurnal, no.4, pp. 25–32.

4. Бучаченко А.Л. Магнитные и спиновые эффекты в химических реакциях / А.Л. Бучаченко, Р.З. Сагдеев , К.М. Салихов– Новосибирск: Наука. – 296 с.

Buchachenko, A.L., Sagdeyev, R.Z. and Salikhov, K.M., Magnitnye i spinovye effekty v khimicheskikh reaktsyiakh [Magnetic and Spin Effects in Chemical Reactions], Nauka, Novosibirsk, Russia.

5. Белявский В.И. Магнонный механизм реакций дефектов в твердых телах / Белявский В.И., Иванов Ю.В., Левин М.Н. // ФТТ. – 2006. – Т.48, вып. 7. – С. 1255–1259.

Belyavsky, V.I., Ivanov, Yu.V. and Levin, M.N. (2006), “Magnon mechanism of reactions of defects in solids”, Physics of Solid Fuels, Vol.48, no. 7. – p. 1255–1259.

Files:
2012_5_pivniak
Date 2013-10-17 Filesize 377.18 KB Download 1367

Visitors

6233560
Today
This Month
All days
7392
60237
6233560

Guest Book

If you have questions, comments or suggestions, you can write them in our "Guest Book"

Registration data

ISSN (print) 2071-2227,
ISSN (online) 2223-2362.
Journal was registered by Ministry of Justice of Ukraine.
Registration number КВ No.17742-6592PR dated April 27, 2011.

Contacts

D.Yavornytskyi ave.,19, pavilion 3, room 24-а, Dnipro, 49005
Tel.: +38 (056) 746 32 79.
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
You are here: Home