introduction maceral is a term to introduce organic components visible under a microscope (stopes, 1935). the physical and chemical characteristics of macerals such as elemental composition, moisture content, hardness, density and petrographic characteristics differ. the differences in the physical and chemical characteristics of macerals are reflected in their industrial behavior.(parkash, 198...

Coal gangue is residual abandoned coal, produced after the pre-processing steps of mining. It is an amalgam of several unwanted substances. It is important to separate coal gangue from lump coal before fed to thermal power plants. In this paper, investigation on the fundamental characteristics of coal images and gangue images with digital image processing technology is proposed. The system dete...

Precisely describing the formation and evolution rules of coal-rock fracturing crack have great value on reservoir fracturing improvement and highly efficient mining of coal bed methane well. In this paper, a non-linear dynamic method is used to study crack damage evolution behavior of coal-rock fracturing. Considering distribution characteristics of natural cracks in coal-rock, and based on da...

the volumetric changes in the coal matrix (coal shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. the shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. the shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted ...

Indian high-ash coal contains alpha-silica components of the mineral matter. When coal is transported in the form of a slurry, alpha-silica adds to the settling properties of coal and enhances erosion of pipelines. As such any technique that will contribute to changing the characteristics of mineral matter by selective demineralization is bound to supplement the knowledge of coal slurries in th...

X-ray photoelectron spectroscopy was used to investigate the characteristics and evolution of sulfur (S) in mixtures of bituminous coal and sewage sludge (SS) and their chars during isothermal combustion. Five groups of mixtures with SS content of 0%, 10%, 20%, 30% and 100%, were examined at different burn-off ratios (beta) of 0, 30%, 50%, 70% and 100%. The S in the coal mainly exist as the for...

The paper divided the whole coal life cycle, explained each phase characteristics, and took coal mine in China as a study case to assess the ecological risk in coal utilization phase. The main conclusions are as follows: (1) the whole coal life cycle is divided into coal mining, processing, transportation, utilization, and waste disposal. (2) The key points of production organization and charac...

The volumetric changes in the coal matrix (Coal Shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted ...

An underground coal mine medium frequency (MF) communication system generally couples its electromagnetic signals to a long conductor in a tunnel, which acts as a transmission line, and exchanges signals with transceivers along the line. The propagation characteristics of the transmission line, which is usually the longest signal path for an MF communication system, play a major role in determi...

The purpose of this study was to determine the pyrolysis characteristics and gas properties of woody biomass and coal. The main gases from the pyrolysis of biomass, coal, and mixtures of different ratios of the two were identified using TGA-FTIR. The evolution of gases and their characteristics were investigated in real time. Thermal analysis demonstrated that the biomass sources decomposed eas...