[en] Published in summary form only

[en] The specific activities of some natural radionuclides in twenty two samples of lignite with different ash contents, three samples of bottom ash and three samples of fly ash from Mae Moh, and four samples of lignite from other locations were determined using gamma spectrometry with hyper pure germanium detector. The results indicate that for lignites from Mae Moh, the ranges of uranium-238, thorium-232 and potassium-40 are 5.0 - 36.5 Bq/kg, 7.6 - 61.2 Bq/kg and 24 - 687 Bq/kg respectively. In bottom ash, a slightly depletion is indicated whereas in fly ash, a lightly enrichment is shown. These values are not greatly different from the values found in other countries except for K-40 which is relatively high. An upward trend for natural radioactivity in lignite and lignite ash toward ash content is also shown. A subsidiary finding is that for lignites from Mae Moh Mine, the specific activity of thorium-232 is higher than that of uranium-238

[en] The described method is aimed at detecting deviations from the nominal value in operating a radiometric belt weigher by comparing the results of measurements during operation with a calibration curve obtained from measurements with a number of different absorbers

[en] Underground coal gasification (UCG) experimentation was carried out on low-rank lignite coal of Eastern Salt Range. Chakwal, Punjab Province, Pakistan. A simulation reactor was designed in laboratory environments and gas input volume, type of gas input, gasification linkage and mode of combustion were investigated. Geological characteristics of the coal were also studied. The composition of emitted gases was evaluated and the syngas having calorific value of 2.42 MJ/m/sup 3/ was produced. (author)

[en] On the basis of the forward scattering of photon radiation the invention is aimed at determining the content of bulk material, in particular the ash content of lignite, independently of the height of the material conveyed by belts. This could be achieved by making the radiation source support movable, so that the distance between source and conveyor belt is variable and adaptable to the mean height of the bulk material

[en] Lignite, a kind of low rank coal, has the characteristics of high moisture, high volatile, high ash and low heat value. The low-temperature pyrolysis technology is potential to improve the utilization efficiency of lignite. Therefore, a lignite-based energy system integrated with pre-drying and low-temperature pyrolysis was proposed in this paper. To assess the influence of pre-drying process, theoretical models were developed based on thermodynamics, and a case analysis was then performed to get the quantitative effect of pre-drying on efficiency of energy utilization. Results show that pre-drying on PPPS theoretical model can significantly improve the utilization of lignite by 1.46%. (Author)

[en] Brown coal, lignite of Siberia and the East of Russia, are able to provide the country’s energy and markets of the surrounding developing countries with affordable and cheap energy. But this will require to overcome the factors of large distances from the main consumers, update the generating capacities and introduce new technologies, solve environmental problems. The work contains assessments of how this can be effectively implemented. (paper)

[en] Full text: In this theme our purpose is to explain thermo-differential analysis of lignite's irradiated. During experiment Caraman Ermenek (washed), Caraman Ermenek (crude), Nevshehir (crude), Slopi (crude), Trakya Harman (washed) lignite coals were used. Five of five kinds of coal samples with 3mm and 1 gr of each sample were obtained. Then they were filled into the Tubes after having dried total 25 samples with 1 gr at 1000C temperature for one hour. Air in the tubes was pumped out and closed. Coal samples in vacuum medium were irradiated by gamma rays of Co-60 at 5.5 kGy, 19.2 kGy, 65.7 kGy, 169.6 kGy, 411.2 kGy, doses to the normal conditions. At the end coal irradiated samples were compared with original coal samples. At the result of experiment it was revealed that in comparison with original coal samples coal samples irradiated from exothermic and endothermic curves at very reaction pick and temperature intervals of these pick were large. Besides loss of weight was observed to begin at low temperatures in samples irradiated and especially momentary weight loss at some heats in the rang of known temperatures was observed in the coal Slopi contain in bitumen. Because of heat the weight loss in the non irradiated samples forms parabolic curve and because of heat the weight loss in the samples irradiated forms stepped curves. It was shown that the coal irradiated can be easily departed by heat because of the chemical structure in comparison the original one.

[en] The application of the magnetic separation method in the process of cleaning of the coal and the effect of the particular size of coal on the method was investigated in this study. The method is based on the fact that coal is weakly diamagnetic, while most of the minerals present are weakly to moderately paramagnetic. In the experimental studies, Manisa and Can lignites which have three different particular sizes (-1500+1000, -1000+500, -500+100 micron) were used. For the particular size of -1500+1000 micron, the magnetic fraction which was separated from Can lignite contained 24 % pyritic sulfur which was less than that of the ground coal. The amount of pyritic sulfur increased in the non-magnetic fraction of Manisa coal. The ash content of non-magnetic fraction which was separated from the particular size of -1000+500 micron of the Manisa coal reduced 20 %, while the value of calorie of coal was enhanced 15 % according to the ground coal. The amount of ash reduction in the non-magnetic fractions of Can lignites was slightly increased along with the value of calorie of coal was a little enhanced. (author)

[en] The aim of the study is to measure the diffusion coefficients at temperatures about 20-27 ^oC, and determine the type of transport mechanism of diffusion of pyridine in macromolecular structure of Turkish Cayirhan lignite (C: 57.1 wt %, dmmf). The raw coal sample was demineralized with HCl and HF by standard methods. The raw and demineralized coal samples were extracted with pyridine. In order to investigate the diffusion of pyridine vapour in coal samples, the mass of pyridine uptake per mass of coal sample (M_t/M_∞) was calculated as a function of time. The diffusion coefficients were measured from the slope of graphs of M_t/M_∞ versus t^1/2. The diffusion coefficient of pyridine in the raw coal increased from 10.04 x 10^-15 m²/s to 11.86 x 10^-15 m²/s when the temperature was elevated from 21.1 ^oC to 26.9 ^oC, respectively. The diffusion coefficients of pyridine raw coal, treated with HCl and HF were 11.86 x 10^-15 m²/s, 4.26 x 10^-15 m²/s, 4.75 x 10^-15 m²/s at 26.9 ^oC, respectively. the studies in the present work on pyridine vapor diffusion in raw coals have generally indicated that the diffusion obeyed the Fickian diffusion mechanism at the temperature 20-27 ^oC. Generally, The values of diffusion exponent increased when the temperature elevated from 20 ^oC to 27 ^oC. But this raise placed the diffusion of pyridine between the Fickian diffusion mechanism and Case II diffusion mechanism. (author)