EARTH SCIENCES. General and regional geology
Selivanova T., Pechnikov V., Ken-ichi Itakura
TATYANA V.SELIVANOVA, Candidate of Geological and Mineralogical Sciences, Associate Professor, Sub-Department of Geology, Geophysics and Geoecology, School of Engineering, Far Eastern Federal University, Vladivostok. 8 Sukhanova St., Vladivostok, Russia, 690950, e-mail: Selivanova_d@mail.ru
VLADIMIR S. PECHNOKOV, Candidate of Physical and Mathematical Science, Associate Professor, Sub-Department of of Physics, School of Natural Science, Far Eastern Federal University, Vladivostok. 8 Sukhanova St., Vladivostok, Russia, 690950, e-mail: pech_vs@mail.ru
KEN-ICHI ITAKURA, Professor, Department of Computer Science and System Engineering, Muroran Institute of Technology. 27-1 Mizumoto, Muroran 050-8585, Japan, e-mail: itakura_aewg47@hotmail.com
The coal thermo-magnetic analysis of coal samples to evaluate the resolution of geomagnetic method when monitoring the combusting area
One of the most important problems of coal thermochemical conversion technologies is evaluation of the combustion area in coal seams and rock masses. The modern sensing and control techniques used to monitor the combustion area in coal seams are expensive and technically complicated.
The thermo-chemical conversion of coal mineral components has an effect on magnetic characteristics of coal seam and can be used for a real-time control of combusting area. To specify this, laboratory experiments aimed to investigate the regularities of the magnetic properties of coal in the process of their thermal decomposition were carried out at Far Eastern Federal University. The obtained results were backed up by a theoretical analysis and laboratory measurements. When heating coal samples, thermoremnant magnetisation emerges in them, the magnetic characteristics of coal vary between submagnetic and ferromagnetic ones. The paramagnetic pyrite present in the coal mass converts into magnetite under high temperatures, the smallest quantities of it increases the magnetic properties of coal. So, the magnetometry may be a useful geophysical tool to evaluate the combustion volume and its migration for underground coal gasification.
Key words: coal, laboratory experiment, coal specimen, magnetic behavior, thermal action, thermo-magnetic conversion.
REFERENCES
1. Baybatsha A.B. Models of nonferrous metals deposits. Almaty, Ministry of education and science of Republic of Kazakhstan, KazNTU. 448 p. (in Russ.).
2. Beseda A.P., Dudnik V.A., Korchemagin V.A., Pavlov I.O. Features of paleotectonic stress fields in outburst-hazardous zones of Donetsk–Makeevka and Central regions of Donbas. Proceedings of the Donetsk National Technical University. Mining Geology Series, 125, p. 19–23. (in Russ.).
3. Ermakov N.I. Causes of mining shock origin on ore deposits (on NUBR example). Mining information-analitical newsletter. 2001;8:218-228. (in Russ.).
4. Sim L.A. Overview of the state of knowledge on paleotectonic stresses and their implications for solution of geological problems. Geodynamics&Tectonophysics. 2013(4);3:341-361. (in Russ.). doi:10.5800/GT-2013-4-3-0105. URL: http://gt.crust.irk.ru/images/upload/tblarticle114/magazin114.pdf
5. Sim L.A. Some methodological aspects of tectonic stress reconstruction based on geological indicators. Comptes Rendus Geoscience. 2012(3–4):174-180. URL: http://dx.doi.org/10.1016/j.crte.2011.11.003.
