Characterization and Classification of Coals and Rocks Using Terahertz Time-Domain Spectroscopy

Being the key unaddressed problem in unmanned mining condition, a new method for the coal-rock interface recognition was proposed in the study. Firstly, terahertz time-domain spectroscopy (THz-TDS) was employed to measure 10 kinds of coals/rocks which were common in China. Secondly, the physical properties of coals/rocks such as absorption coefficient spectra, refractive index, and dielectric properties in THz band were studied. The different responses in THz range caused by diverse components in coals/rocks were discussed, and the dielectric property of coals/rocks in THz band was well fitted by the Lorentz model. Finally, by the means of principal component analysis (PCA), support vector machine (SVM), and THz spectral data, the recognition rate of coals/rocks reaches to 100 % and the recognition rate of different bituminous coals reaches to 97.5 %. The experimental results show that the proposed method is fast, stable, and accurate for the detection of coal-rock interface and could be a promising tool for the classification of different bituminous coals.

[1]  Honglei Zhan,et al.  Spectral characterization of the key parameters and elements in coal using terahertz spectroscopy , 2015 .

[2]  Lanlan Fan,et al.  A novel ADPSO-SVM combined with terahertz spectroscopy for recognition of transgenic organisms , 2016 .

[3]  Yuan Zhang,et al.  Identification of wheat quality using THz spectrum. , 2014, Optics express.

[4]  Joseph S. Melinger,et al.  The underlying terahertz vibrational spectrum of explosives solids , 2008 .

[5]  L. Luo,et al.  Dual control of active graphene–silicon hybrid metamaterial devices , 2015 .

[6]  Shou Xiang Zhang,et al.  Augmented Reality on Longwall Face for Unmanned Mining , 2010 .

[7]  Yuki Sato,et al.  Comparative dielectric study of monohydric alcohols with terahertz time-domain spectroscopy , 2010 .

[8]  Yuhong Xiang,et al.  Application of terahertz time-domain spectroscopy combined with chemometrics to quantitative analysis of imidacloprid in rice samples , 2015 .

[9]  Kun Zhao,et al.  A spectral-mathematical strategy for the identification of edible and swill-cooked dirty oils using terahertz spectroscopy , 2016 .

[10]  Yuan Zhang,et al.  Characterization of Wheat Varieties Using Terahertz Time-Domain Spectroscopy , 2015, Sensors.

[11]  Xiaoping Liu,et al.  A Cluster Number Adaptive Fuzzy c-means Algorithm for Image Segmentation , 2013 .

[12]  R.L. Chufo,et al.  A radar coal thickness sensor , 1991, Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting.

[13]  Bo Su,et al.  Coal–rock interface detection on the basis of image texture features , 2013 .

[14]  M. Cain,et al.  Dielectric constants of bulk ferroelectric PZT measured by terahertz time-domain spectroscopy , 2016 .

[15]  H. Cui,et al.  Dielectric properties of coals in the low-terahertz frequency region , 2015 .

[16]  G. L. Mowrey.  A new approach to coal interface detection: the in-seam seismic technique , 1988 .

[17]  H. Hübers,et al.  Identification of Unknown Substances by Terahertz Spectroscopy and Multivariate Data Analysis , 2016 .

[18]  Yong Du,et al.  Identification of GMOs by terahertz spectroscopy and ALAP–SVM , 2015 .

[19]  M. Kurlenya,et al.  Gutenberg velocity section of the earth and its possible geomechanical explanation. I. Zonal disintegration and the hierarchical series of geoblocks , 1994 .

[20]  Dennis G. Watson,et al.  Distinguishing Gasoline Engine Oils of Different Viscosities Using Terahertz Time-Domain Spectroscopy , 2015 .

[21]  Fang Ren.  Study on the coal-rock interface recognition method based on multi-sensor data fusion technique , 2003 .