Pseudovitrinite: Possible Implications for Gas Saturation in Coals and Surrounding Rocks
Coal Petrography is for many a black science using terms that are for some not only incomprehensible but also in flux. For utilization purposes, the organic component of coal is generally broken down into reactive and non-reactive macerals, often with little further differentiation of the macerals. The main incentive to differentiate further is the recognition that the degree of reactivity in vitrinite macerals and the degree of non-reactivity in inert macerals, both vary.
Sorption of methane in moist coal
The dependence on moisture content of the methane sorption capacity of four American coals has been investigated. Bituminous coals from Virginia, West Virginia, Oklahoma and Pennsylvania were studied at a temperature of 30 °C, and at pressures up to 60 atm. Methane capacity decreased with increasing moisture content up to a certain value of moisture content that was characteristic for each coal. Moisture present in excess of the critical value had no further effect on methane sorption. The critical values of moisture content, mc (wt %), were related to coal oxygen content, xo (wt %), by the expression mc = (XO + 1.51 )/(3.98 − 0.229 XO).
Geological, mineralogical and chemical characterization of Devonian kaolinite-bearing sediments for further applications in the ceramic (tiles) industry in La Paz, Bolivia
Clay minerals are widely distributed in Bolivia; among them, illitic clays are most common in the Altiplano where they are mined for use in the ceramic industry that has been growing in the last few years. In addition to illitic sediments, kaolinitic sediments have been recently discovered in sedimentary units in the Bolivian Altiplano. Residual ball clay occurrences in Devonian sedimentary units were studied as part of this work. Geological mapping and geophysical studies (ERT and GPR) were done for better understanding the origin of the deposits and were part of a preliminary study of the mineral potential to define the relationship with the host rock. Chemical and mineralogical techniques such as X-Ray Diffraction, Scanning Electron Microscopy and Inductively Coupled Plasma analyses were performed in samples from the studied area to verify the presence of kaolinite. Atterberg limits and behaviour of the raw material in ceramic specimens supported by chemical analyses show that this material is suitable for manufacturing tile ceramics. This study provides fundamental knowledge for deposit exploitation and future generation of an alternative source of employment for the inhabitants of Micaya.