Lignite Field Research Articles

Lignite resource estimations and seam modeling of Thar Field, Pakistan

Thar lignite field in Pakistan contains more than 175billiontons thus far not exploited. To date, the coalfield has been divided into 12 exploration blocks and each block is studied and investigated separately by different agencies. As a result of exploration programs, a large exploration database containing geological and coal quality information is constructed, but geostatistical studies regarding to quantify entire Thar lignite resources is not available yet. This paper aims to generate 3D solid model of main Thar seam and to produce spatial distribution maps for various coal quality attributes by geostatistical method, ordinary kriging. 3D seam model has a volume of 17.71billionm3. The resulting spatial map of ash content shows structured distribution and LCV map shows fair agreement with ash map except in block VI where high and low values of ash and LCV occur in close proximity. The moisture distribution reveals higher values in northern and southern parts whereas the central portion possesses lower moisture values. The sulfur content shows homogenous distribution with some higher sulfur patches at places. The kriging variance maps are generated to delineate areas of higher uncertainty. These maps could be helpful to devise further exploration programs. Blocks were checked on the basis of global averages and swath plot comparison.

Assessing the Potential of the Mesohellenic Trough and Other Sites, in Greece, for CO2 Storage

The Greek CO2 storage potential is composed mainly of aquifers as well as a few hydrocarbon fields. The potential for CO2 storage capacity in oil and gas fields in Greece lies offshore, in the Prinos-Kavala basin, in NE Greece, whereas the biggest share of the point source CO2 emissions come from NW Greece. There is also potential for storage in lignite fields, which have been extensively mined for power generation. This paper presents an overview of the potential CO2 storage of the Mesohellenic Trough (MT), in north-western Greece. Geological modelling assessed the CO2 storage potential in the (MT) and provided an estimation for the Pentalofos reservoir. According to the geological model, characterized by horizontal maximum dimensions of 47km by 100km and covering a surface area of 3813 km2, the deepest point where we can store CO2 corresponds to the base of the Tsarnos member, at -2544 m depth. We estimate that we can store up to 1435 Gt of CO2 in the Pentalofos Fm (Tsarnos and Kalloni Members) in the MT. The location of the potential storage sites, relative to emission points, forms interesting combinations, which are briefly presented in this paper. The results presented here will serve as a basis for pursuing this worthwhile piece of research in order to determine the most reliable and most cost efficient ways of transporting and storing CO2 in Greece and developing the right legal framework for achieving these goals.

An overview of Turkish lignite qualities by logistic analysis

As an indispensable energy source, lignite is almost exclusively used in power generation in Turkey. To assess the quality level of Turkish lignite, a multivariate statistical analysis was conducted. The relationship among the lignite quality parameters has been investigated using a response method that is the logistic regression method. The analysis determines the effect of multiple predictor variables such as moisture, ash and sulphur presented simultaneously to predict membership of the two calorific value categories. By this way, a reliable binary response regression structure was constructed considering all the lignite fields in Turkey. Both the experiments on identifying the influential measurements and the measure of goodness of fit indicated that the overall model has a big capability to exhibit the relationship among the parameters of the Turkish lignite.

Hydrogeological Issues Concerning the Thar Lignite Prospect

The paper is concerned with the hydrogeological appraisal of the proposed mining operations in theThar lignite field in Sindh, Pakistan. The Thar coalfield covers an area of approximately 9000km2 andcontains three lignite seams lying at depth of 130m to 250 m. In the Thar lignite field, the presence ofthree main aquifers induces pore pressure in the rock mass surrounding the lignite seams and makes highwall slopes potentially unsafe. It is, therefore, necessary to dewater the rock mass before commencingmining excavations. The paper describes the proposed mine dewatering scheme to facilitatedepressurising of the rock mass surrounding the mining excavations. Inflow prediction of groundwater tothe surface mining excavation was carried out using a SEEP/W finite element software package. Thesimulation results show that the ground water inflow from the Top aquifer is 114m3/d, from theIntermediate confined aquifer is 141m3/d and from the Bottom confined aquifer is 1.28 x 105 m3 /d. Theseresults were compared with the analytical solutions which indicated that the relative error of estimation ofinflow quantities varies from 3.4 % to 6.4%.

Desulfurization of Selected Hard and Brown Coal Samples from India and Indonesia withRalstonia SpandPseudoxanthomonas sp

The present paper entails the investigations on the removal of total sulfur (St) from the coal samples of four coal and lignite fields of India and Indonesia by Ralstonia sp and Pseudoxanthomonas sp. Minimum desulfurization (in relative%) was observed in Nagaland coals (India) which contain maximum quantity of St(6.86%) among the samples of the studied area while higher removal (in relative%) was observed in coals containing relatively low quantity of St. Nevertheless, a positive correlation exists between Stand removal percentage in samples of all coalfields indicating an increase in removal% with increasing concentration of St. The removal percent (with respect to its initial St) by Pseudoxanthomonas sp in the investigated area is in order of: Vastan (mean 41.84%) > Indonesian (mean 34.16%) > Nagaland (mean 18.26) coals. In case of removal by Ralstonia sp the order of removal % can be put as: Vastan (mean 45.50%) > Rajpardi (mean 42.93%) > Indonesian (mean 20.22%) > Nagaland (mean 11.83%) coals.

Determination of mining-induced hearing loss with otoacoustic emission method at Tki-Eli lignite field

Noise at the working environment is highly affecting the human health, especially in mining. Continuity of this noise causes hearing loss of miners. In this study, hearing loss based on noise is researched by audiometry and otoacoustic emission on casual staff of TKI-ELI coal mines. The difference of this method is taking the otoacoustic emission measurements before audiometry measurements. In 2007, audiometry and otoacoustic emission measurements were made on 639 miners at Ege Lignite Enterprises. It is determined that conductive hearing loss had seen at 32 miners and sensorineural hearing loss had seen at 83 miners. It was decided to dispatch 9 miners to Occupational Diseases Hospital after making tests to these 83 miners at Soma State Hospital. It is revealed that these 9 miners shouldn’t be allowed to work at loud environment according to the first report of Occupational Diseases Hospital. The detection of the possible and occupational disease group hearing loss has become very easy with this method.

Drmno lignite field (Kostolac basin, Serbia): Origin and palaeoenvironmental implications from petrological and organic geochemical studies

The objective of the study was to determine the origin and to reconstruct the geological evolution of lignites from the Drmno field (Kostolac Basin, Serbia). For this purpose petrological and organic geochemical analyses were used. Coal from the Drmno field is typical humic coal. Peat-forming vegetation dominated by decay of resistant gymnosperm (coniferous) plants, followed by prokaryotic organisms and angiosperms. Coal forming plants belonged to the gymnosperm families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Phyllocladaceae and Pinaceae. Peatification was performed in neutral to slightly acidic, fresh water environment. Considering that organic matter of Drmno lignites was deposited at the same time, in the relatively constant climate, it could be supposed that climate probably had only small impact on peatification. Therefore, variations in compositions of macerals and biomarkers indicate changes in the water level, due to seasonal drying of the mire, which caused vegetation differences in the palaeoplant communities and changes of redox conditions (from anoxic to slightly oxic) during peatification. Diagenetic transformations of the organic matter were mainly governed by microbial activity, rather than thermal alteration.

An Investigation of Evaluation Possibilities of Muş-Elmakaya Lignite

Lignite is the most important source of energy in Turkey. Turkish lignite is usually low in heating value and burning characteristic with high sulfur and ash content. They are unable to conform to air protection regulation requirements if burned as mined. Generally, they are used in power plants causing environmental problems. In this study, evaluation possibilities of Muş-Elmakaya lignite are investigated. For this purpose, experimental studies were performed with lignite samples taken from a lignite field in Muş-Elmakaya, Turkey. First, petrographic analysis, major element analysis, and proximate analysis of lignite samples were done. Afterwards, washability properties of lignite samples were determined. Evaluation of the washability properties was done by using washability number, calorific value, and sulfur content of the clean coal obtained from float-sink tests and the obtained results were presented.

Determination of uranium isotope concentrations in precipitation in the vicinity of lignite-fired power plants

Coal- and lignite-fired power plants produce significant amounts of fly ash, which in many cases contains high concentrations of naturally occurring radionuclides such as 238U. This is of importance from the radio-environmental point of view since a small portion of the fly ash escapes from the power plant filtering system and disperses in the surrounding atmosphere. In addition, coal- and lignite-fired plants related activities such as fuel mining and ash deposition contribute to the suspended matter in the air with particles containing naturally occurring radionuclides. In this study, rainwater samples were collected in the Megalopolis lignite field basin of the Arcadia prefecture in Greece, where lignite-fired power plants are in operation and related activities are fully developed. The samples were preconcentrated and analyzed with alpha spectrometry and kinetic phosphorescence analysis in order to determine the levels of uranium isotope concentrations in precipitation in the Megalopolis basin. A control rainwater sample was also collected in the Athens area to account for reference purposes. Concentrations determined via the two techniques were found to be in statistical agreement. The concentration of 238U in the samples collected at the Megalopolis basin varies from 2.2 ? 0.6 to 90 ? 14 mBq/L, and is 5-40 times higher than the concentration of 238U in the sample collected in Athens. This could be attributed to the operation of the lignite-fired power plants, the fossil fuel mines, and the ash depositories.

Geomorphological investigation of the excavation‐induced dündar landslide, bursa — turkey

.This paper discusses the occurrence and development of the excavation‐induce deep‐seated landslide, which took place near Dündar village, located west of Orhaneli town in northwestern Turkey. The event occurred in the Bursa‐Orhaneli lignite field, which has been actively operating since 1979. Due to undermining of a gently inclined slope (10°) to extract a coal seam, primary tension cracks, which were precursors of the movement, were first observed in the northern head area in mid‐ to late October 2003. This movement happened simultaneously with precipitation that was significantly above long‐term average measured at a nearby climatology station (Keles). This precipitation amount is characterized statistically by a significant standardized anomaly of 1.6. The majority of the monthly precipitation total in October 2003, which mainly consisted of rain showers and thunderstorms, occurred in the last week of the month. By April 2004, rotational failure continued intermittently. After a relatively wet (rainy and snowy) period from January 2004 to April 2004, the main rotational slump occurred in late April 2004, causing the entire destruction of Dündar village's cemetery. Daily climatic and synoptic meteorological data have proved that heavy showers in late April may had triggered the last slump by producing rain showers of 19.3 mm and 19.9 mm daily total on 27 and 28 April 2004, respectively.Field observations carried out along the main head scarp have shown that the slope failure was facilitated by a pre‐existing normal fault with an east‐ west direction and 80° dip. Grain‐size analysis showed that the failure occurred on clayey silt, which forms 55% of the slip surface material. Based on the evidence from X‐ray fluorescence and energy dispersive X‐ray spectroscopy results, smectite‐type clay ‐ a product of the chemical weathering of tuff ‐ was the main constituent of the slip surface material. The landslide occurred over an area of 600 m × 650 m with a total volume of 8775 000 m3. Approximately 28 hectares of farm land were entirely destroyed and the excavated coal seam was buried. The mining operation was moved to 100 m north of the landslide area near Gümüşpınar village. From morphological evidence, it is concluded that excavation activities caused the failure to extend in more than one direction as an enlarging sliding mechanism; this produced a high landslide risk for Gümüşpınar village, where the most significant normal fault with a 75 m vertical displacement in a coal‐bearing sequence is found in the lignite field.

New species of pinaceous fossil wood from the Pliocene of southern Primorye (Russian Far East)

New species of the Pinaceae, Abies chavchavadzeae and Piceoxylon ussuriense, are described on the basis of fossil woods from the Pliocene of the Pavlovka lignite field (southern Primorye). For the first time, fossil wood of Abies is reported from the Russian Far East.

Turkey's Major Lignite Fields and Significance of Lignite for Energy Necessity

The objective of this study is to determine the lignite use for Turkey's energy necessity. Lignite is the most important energy resource of Turkey when compared with others according to the amount of reserves. Lignite is the dominant source of energy produced (43%) in Turkey. Lignite deposits are encountered in almost every region of Turkey. Total lignite reserves are estimated at 8,375 million tons, of which 7,340 million tons (88%) is economically feasible. Share of lignite reserves of Turkey are 2% in the world. Lignite deposits are encountered in almost every region of Turkey. Afsin-Elbistan, Mugla, Soma, Tuncbilek, Seyitomer, Beypazari and Sivas basins constitutes the most important known lignite reserves. The biggest lignite deposits, 40% of the total, are in Afsin-Elbistan. Lignite extraction is expected to increase as the government feels pressure to close down unprofitable hard coal mines that are geologically difficult, increasing the cost of extraction.

The possible hydrologic effects of the proposed lignite open‐cast mining in Drama lignite field, Greece

AbstractThe present study investigates the possible hydrologic effects of the proposed lignite open‐cast mining in Drama lignite field (north Greece). Recent years have seen a rapid increase in surface mining. This activity has generated a growing concern for the potential environmental impacts associated with large scale surface mining.In order to achieve a safe mine operation and allow extraction of lignite to considerable depths, extensive dewatering by pumping will be necessary, while at the same time it is desirable to avoid presence of overpumping conditions in the broader area. Based on stratigrafic, hydrologic and hydrogeologic data, a three‐dimensional finite difference model was developed in order to simulate the dewatering process of the western part of the lignite open‐cast mine in Drama and to predict both spatially and temporally the decline of ground water level down to the lignite surface. The dewatering of the part of the aquifer which underlies the mine area will influence the hydrological conditions of the broader region. The most important anticipated effects will be the abandonment of shallow wells as well as the decrease of ground water pumping rates of deep wells. Aquifer discharge towards the ditches of the study area will cease and there will be an inversion of ground water flow from the ditches towards the underlying aquifer. Dewatering activities will probably result in minor subsidence of the nearby peat deposits of Drama Philippi marshes. Moreover, sand pumping as well as the presence of gasses is likely to cause local subsidence phenomena, mainly in the pit slopes. Copyright © 2007 John Wiley & Sons, Ltd.

Properties and Reserves of Lignite in the Aydin-Sahinali Field, Turkey

This study focuses on some lignite properties and calculation of lignite reserves with two classical (isopach and polygon) methods in the Aydin-Sahinali field, Turkey, which is located in the western Turkey. This field has been mined by a private coal company since 1960 by open-cast and mainly underground mining methods. The producing lignites are consumed in domestic heating and industrial factories around Aydin. The metamorphic rocks of Palaezoic age form the basement of the coal field. The lignite-bearing unit of Miocene age, from bottom to the top, consists mainly of pebblestone, lignite and clayey lignite, siltstone with sandstone lenses, white colored claystone, clayey limestone and silisified limestone lenses. This unit in the lignite field was unconformably overlain by Pliocene unconsolidated sands and gravels. Three hundred seventy-three borehole data have been evaluated, and this study shows that a relatively thick and lateral extensive lignite seam has a mineable thickness of 1.6–14.4 m. The core samples from boreholes in panels in the lignite field indicate that the coal seam, on an as-received basis, contains high moisture contents (17.95–23.45%, average), high ash yields (16.30–26.03%, average), relatively high net calorific values (3,281–3,854 kcal/kg, average), and low total sulfur contents (1.00–1.22%, average). The remaining lignite potential in the Aydin-Sahinali lignite field was calculated as a 4.7 Mt of measured and a 2.9 Mt of mineable lignite-reserves.

Chemical investigation of lignite samples and their ashing products from Kardia lignite field of Ptolemais, Northern Greece

Twenty-six lignite samples were collected from the Kardia lignite field (Ptolemais, Greece). Ash content, moisture and CO 2 were determined. The lignite samples were heated at 900 °C producing 26 ash samples. The chemical composition (major and trace elements) both of the lignite samples and ash products was determined using INAA, ICP-OES and ICP-MS. CaO, SiO 2 and Al 2 O 3 are the dominant oxides both in lignite and ash samples. A relative decrease of SiO 2 and Al 2 O 3 as well as an increase of CaO was noticed in the deeper lignite samples. Sr, Cr, Ni, V and Ba were found to be the most abundant both in lignite and ash samples. Sr displays a relative increase while Ni and Cr decrease with depth in the lignite samples. In the ash samples, Ni shows the most obvious decrease with depth.

QUATERNARY DEFORMATION OF THE MAVROPIGI LIGNITE FIELD (WESTERN MARGIN OF PTOLEMAIS - KOZANI GRABEN, NW MACEDONIA, GREECE)

The present study aims to analyse in details the tectono-sedimentary processes of the western borderline of the intra-continental graben of Ptolemais-Kozani in NW Macedonia, given the presentday mining activity of Public Power Corporation. Field studies in combination with drilling analysis revealed the extremely geometrical complexity of the sedimentary fill as the result of the recent Quaternary deformation. Bearing in mind, the recognition of left-lateral strike-slip component of movement in the western border fault zone-Mavropigi shear zone, the geometrical coincidence of the morphological shapes of the present-day morphology-of the top-of the bottom of the Pliocene earthy lignite sequence and of the sub-surface morphology of the pre-Cretaceous Pelagonian basement as well as the discovery of several reverse faults in the surrounding area have allowed us to accept the action of a composite Quaternary deformational pattern. For the first time in NW Macedonia, ductile-brittle type macrostructures (mega-anticlines) with NE-SW axis direction are confirmed, showing the simultaneous and progressive action of ductile and brittle deformation of all the geological formations of the western borderline, sedimentary fill and metamorphic basement. The aforementioned geometrical complexity and also the observed field structures strongly reveal the action of a rotational couple-type stress field in Ptolemais-Kozani graben, enclosed in the incapiate in-type deformation of NW Macedonia. In this framework, the occurrence of the extensional post-orogenic structures, which seems that they have been overestimated by previous researchers in the literature, is considered of secondary importance and constitutes part and expression of the complicated Quaternary tectonic structures of the sedimentary fill. This complex deformational pattern controls and also defines the spatial distribution of the lignite reserves in the Mavropigi Lignite Field with a southward increasing of them as well as causes regions with a composite or a simple post-orogenic geometry and evolution, directly reflected by the sub-surface geometry of the Pliocene lignite sequence. The aforementioned complicated geometry is of great importance, either for the planning and the future expansion of the Mavropigi Lignite Field in the western borderline, or for the better approach of the intra-plate deformational processes of Ptolemais-Kozani graben.

Deaths from Neoplasms and Detection of Radionuclides in Excised Human Lungs in the Eordea Basin, Greece

Lignite contains various trace-metal natural radioactive contaminants. In the Eordea Basin, the most important lignite field in Greece, the authors conducted a proportional mortality ratio (PMR) study that compared the mortality rates of individuals who lived in the basin vs. a control group who resided in the city of Kilkis, over a 30-yr period. The following information was used in the study: (a) municipal registrations of deaths from neoplasms during the period from 1971 to 2000, and (b) detection of radioactive substances in samples obtained from excised lungs of individuals living in Eordea Basin who suffered from neoplasm. The corresponding registrations of deaths from neoplasm of the inhabitants of Kilkis, a city located outside the Eordea Basin, formed the control group. A diachronic increase of the PMR was detected as a result of neoplasms and, particularly, as a result of lung cancer in Eordea Basin. However, the above ratio did not exceed the corresponding PMR recorded in Kilkis. In 20 lung samples obtained from patients who had lived in Eordea Basin, and in 19 lung samples from patients in Kilkis, the activity of the radionuclides of uranium and thorium radioactive decay series, potassium-40, and cesium-137 was not higher than expected. No statistically significant difference was found between the inhabitants of the 2 regions, thus it was concluded that the increase in respiratory-system neoplasms was likely associated with the high prevalence of smoking among the regions' inhabitants. In future studies, a longer observation period and examination of more cases will be necessary to further investigate a possible association between radionuclides and lung neoplasms in the Eordea Basin.

Bootstrap estimation of the daily mean pick consumption in mechanical excavation

The aim of this study was to set confidence intervals for the daily mean pick consumption which is a useful parameter in designing a longwall panel and also deciding the critical storage level of new picks. For this purpose, the bootstrap is introduced and the method is applied to the daily mean pick consumption data recorded at the longwall panels of the Cayirhan lignite field, Ankara. Serial correlation for the data was tested by means of the experimental variograms. Finally, 95% confidence intervals for the daily mean consumption were constructed from sampling distributions obtained by bootstrapping. The results show that the upper seam leads to higher pick consumption and wider confidence intervals than the lower seam.

Lignite Quality Prediction Techniques in the Southern Lignite Field Mine, Ptolemais, Greece

The prediction of lignite quality, especially when no online analyzers are used, is a complicated problem. Certain time- and money-consuming laboratory parameters have to be taken into account in order for the recoverableor/and run-off mine lignite quality to be determined. Apart from lignite quality, the quality of lignite ash is of prime importance. This article deals with some simple techniques based on proximate analysis data for a quick and reliable prediction of both lignite and lignite ash quality.

Lignite Quality Prediction Techniques in the Southern Lignite Field Mine, Ptolemais, Greece

The prediction of lignite quality, especially when no online analyzers are used, is a complicated problem. Certain time- and money-consuming laboratory parameters have to be taken into account in order for the recoverable or/and run-off mine lignite quality to be determined. Apart from lignite quality, the quality of lignite ash is of prime importance. This article deals with some simple techniques based on proximate analysis data for a quick and reliable prediction of both lignite and lignite ash quality.