Lignite Resources Research Articles

Isolation of native microorganisms from Shengli lignite and study on their ability to dissolve lignite.

To more greenly and efficiently utilize the abundant lignite resources and explore the microbial degradation and transformation potential of lignite for its environmentally friendly and resourceful utilization, Shengli lignite from the Hulunbuir region of Inner Mongolia, China, was selected as the research subject. Through the dilution plating method and streaking method, 31 native microorganisms were successfully isolated from the Shengli lignite, including 16 bacteria and 15 fungi. After microbial coal dissolution experiments, it was found that certain microorganisms have a significant dissolving effect on lignite, with some bacterial and fungal strains showing strong dissolution capabilities. In particular, the bacterium SH10 Lysinibacillus fusiformis and the fungus L1W Paecilomyces lilacinus demonstrated the best coal-dissolving abilities, with dissolution rates both reaching 60%. The products of microbial dissolution of lignite were analyzed using gas chromatography-mass spectrometry (GC-MS) technology, identifying a variety of small molecular organic compounds, including alkanes, alcohols, esters, and phenols. The results of this study provide a new perspective on the biodegradation of lignite and lay the foundation for the development of new lignite treatment and utilization technologies.

Extraction and volatilization mechanism of germanium (Ge) during lignite pyrolysis

Germanium is a critical strategic metal that plays an important role in various industries. Currently, the combustion method is the main method for extracting germanium from germanium-containing lignite, however, its extraction rate of germanium is low, with the form of SiO2-GeO2 solid solution due to covolatilization of both germanium and arsenic. To address these problems, this paper proposes to activate and enrich germanium in lignite through pyrolysis. The results show that the pyrolysis temperature and time are positively correlated with the volatilization rate of germanium, and the optimal pyrolysis conditions are at temperature of 1100°C with the time of 360 min. The volatility of germanium can reach up to 96.85%, and its grade in germanium-rich product is 25.51%, while arsenic content is 0.71%. The germanium-rich product is primarily present as GeS, with no SiO2-GeO2 solid solution, which is conducive to the subsequent chlorinated distillation. The kinetics and thermodynamics of the pyrolysis process are investigated, and the volatilization of germanium during lignite pyrolysis is modeled. These results verify the feasibility of germanium extraction from lignite by pyrolysis, which anticipates to realize the high-grade enrichment of germanium in lignite and the high-value utilization of lignite resources.

Integrated use of lignite resources to provide fuel for the energy sector of Ukraine in the war and post-war periods

The object of research is technological processes for the complex development of lignite resources, including extraction, processing and the possibility of further use of derived products in the energy sector. The problem solved in the work is related to the underestimation of the complex use of lignite resources of Ukraine to provide fuel for the energy sector, which is suffering significant damage as a result of military operations. In the course of research, the current state, prospects for the development and use of lignite as an energy resource at thermal power plants (TPP) were analyzed. Using the example of the Myronivka lignite deposit, new technological solutions for its complex development are proposed, which include the following stages: – development of technological schemes for conducting mining operations with the possibility of selective extraction of minerals; – identification of promising areas of lignite processing technologies with the involvement of carbonaceous clays; – calculation of technical and economic indicators, social and economic efficiency of field exploitation. It is proposed to determine the rational parameters of the overburden zones during the extraction of at least two minerals in the deposit with the use of internal dumping of overburden rocks in the produced space. In order to minimize the impact of field waterlogging, various options for draining the quarry field will be considered based on three-dimensional modeling. Based on the methodology of expected operating costs, a preliminary economic assessment of the attractiveness of the proposed technological solutions was calculated for a conventional mining enterprise. Graphs of the dependence of mining costs and cost on the productivity of the cut and the overburden ratio were constructed, which made it possible to assert the feasibility of comprehensive development of lignite deposits of Ukraine. It has been established that the expansion of lignite raw materials due to accompanying minerals (coal clay) will lead to an increase in production by mass from 30 to 100 %, and in some cases even more.

Study on integration of drying and separation for lignite by hot airflow gas–solid fluidized bed

With the continuous consumption of high-quality coal, the efficient development of lignite resources is an important guarantee for the stable and sustainable development of coal industry. Due to the characteristics of lignite with high moisture content, its efficient separation is still a great challenge faced by the current industry. In this study, to improve the dry beneficiation efficiency of lignite, hot airflow and impeller were introduced into the gas–solid fluidized bed to achieve the integration of drying and separation for lignite. Effects of the impeller diameter, airflow velocity, airflow temperature and impeller speed on the drying features and the fluidization characteristics of hot airflow gas–solid fluidized bed were investigated. Drying and fluidization tests indicated that the appropriate operational factors of impeller diameter of 61 mm, airflow velocity of 1.2Umf (that is, Umf is the minimum fluidizing airflow velocity), airflow temperature of 110 °C and impeller speed of 60 r/min should be adjusted to obtain the optimum fluidization environment for the drying and separation of lignite. Under the optimal operating conditions, a high-quality clean coal with ash content of 9.72 %, moisture content of 13.13 %, and calorific value of 4318.33 cal/g was obtained for 25–13 mm lignite, while that with ash content of 13.41 %, moisture content of 12.70 %, and calorific value of 4120.22 cal/g was obtained for 13–6 mm lignite. Efficient drying and separation of lignite could be realized by using the hot airflow gas–solid fluidized bed. This study provides theoretical guidance for efficient beneficiation of lignite resources with high moisture content by hot airflow gas–solid fluidized bed.

Energy Transition of the Coal Region and Challenges for Local and Regional Authorities: The Case of the Bełchatów Basin Area in Poland

The transition to a climate-neutral economy presents a particular challenge for the areas where the economy is based on rich lignite resources. One of them is the Bełchatów Basin Area in Poland. The complexity of the phenomena occurring in the area of transformation requires an interdisciplinary and integrated approach to development planning and managing. It is important to create stable conditions, allowing for the introduction of necessary changes, including the involvement of various stakeholders. The research is aimed at identifying the challenges faced by the region with a lignite-based economy, the inhibitors of the transformation process, and recommendations for public policy. During the research, secondary and primary data were analysed with the use of triangulation, which allowed to combine various techniques and sources, as well as an in-depth description and multi-faceted understanding of the case under study. The study poses a key question as to whether the public authority is capable of implementing the energy transition that would protect the global public interest. The conducted research showed deficiencies negatively affecting its implementation. There are barriers affecting cooperation in the public sphere and with other stakeholders. An analysis of the limitations in cooperation showed the dysfunction of energy policy implementation at the regional level. Vertical and horizontal actions between different stakeholders of the transformation are necessary to identify seed industries representing a transformational opportunity in the Bełchatów Basin. Renewable energy sources may play a key role in this process. Their share in electricity production should be increased. A clear and precise vision of the development of this territory, as well as a stable and diversified system of financing are important elements of change. The article draws attention to the lack of a transformation leader. Identifying an actor responsible for the protection of the global public interest is essential.

Effective adsorption of Pb(II) from wastewater using facile enclosed pyrolysis strategy for defect-rich lignite-based carbon-coated zero-valent iron

In recent years, nanoscale zero-valent iron has been widely applied to treat the Pb(II)-laden wastewater. And the catalytic pyrolysis is an important way to convert coal into carbon based functional materials. However, it still remains challenging for designing a novel carbon-based composite structure to effectively control nanoscale zero-valent iron oxidation and agglomeration problems. For this purpose, a defect-rich lignite-based carbon-coated nano-zero-valent iron structure (AC4) was synthesized by the one-step pyrolysis of lignite catalyzed by K2FeO4 in a closed environment. During the pyrolysis process, K2FeO4 not only promoted the formation of defective carbon and zero-valent iron, but also formed a special structure of carbon-coated iron. The larger the ratio of K2FeO4, the easier it is to generate adsorption sites. Adsorption experiments showed that AC4 exhibits a large adsorption capacity. The higher adsorption amount was due to the synergistic effect between zero-valent iron and defective carbon. The Langmuir isotherm model fitted the true experimental data successfully and the best adsorption amount of Pb(II) was 1118.54 mg/g at 298.15 K and pH 5. The true experimental situation was more accurately fitted by the pseudo-second-order model and chemisorption was the main reason for the adsorption. From a thermodynamic point of view, adsorption was an endothermic reaction and a spontaneous process. This work demonstrates that lignite resources can be converted into high value-added adsorbents.

The influence of the synergistic effect of airflow and vibration in compound dry separation bed on upgrading of 6–0 mm fine-grained low-grade high-sulfur lignite

Coal is the important support to guarantee the national energy security system. China is the largest coal producer and consumer country and the lignite reserves are abundant. In recent years, as the high-quality coal resources decrease and the difficulty in mining increases, low-grade lignite resource has been the important component of China’s energy production and supply. Promoting the clean and efficient utilization of low-grade lignite is an important approach to realize the goal of carbon peak and carbon neutrality. In this paper, compound dry separation bed was used for the desulfurization and ash reduction of fine-grained low-grade high-sulfur lignite. The synergistic effect of airflow and vibration on particle force characteristics was emphatically investigated and the leading action stage under different airflow and vibration conditions was determined. The spatial migration acceleration variation rule and spatial migration trajectory of particles in different areas under the synergistic effect of airflow and vibration were systematically analyzed. Meanwhile, the spatial distribution characteristics of sulfur content of fine-grained low-grade high-sulfur lignite on the compound dry separation bed and the segregation rule of particles on the different areas along the bed transverse direction were explored, and the spatial distribution layer of the materials on the bed area was determined. The experimental results demonstrate that under condition of Γ = 10.14, when the gas velocity U = 0.125 m/s, vibration plays a leading role in the particle migration on the bed surface; when the gas velocity U = 0.148 m/s, vibration plays a leading role and the airflow plays a surrounding role; when the gas velocity U = 0.229 m/s, the synergistic effect of airflow and vibration dominates in the particle migration. The motion trajectories of particles in each cross section are all oval shape. The variation of acceleration amplitude along OX-axis determines the transverse migration trajectory of particles; the variation of acceleration amplitude along OY-axis determines the peak force characteristics of particles; the variation of acceleration amplitude along OZ-axis determines the stratification law of particles. Meanwhile, it is determined that the top layer of area Ⅰ is the low density particle distribution layer; the top layer of area II is the medium–low density particle distribution layer; all of the top, middle and bottom layer in area III are the high density particle distribution layer. The separation and upgrading for fine-grained low-grade high-sulfur lignite were conducted and the results were as follows. The yield of clean coal is 66.56 % and its sulfur content is 0.97 %; the yield of gangue is 33.44 % and its sulfur content is 22.41 %; the probable error Ep is 0.105 g/cm3, which means that the efficient and clean desulfurization and ash reduction for fine-grained low-grade high-sulfur lignite have been realized.

Exploitable wind power potential in Turkey with technological advancement and resulting environmental-economic aspects

This work's focus is determining how the improvements in wind power technology alter current onshore wind power potential and exploitable electrical energy in Turkey. Then, consequent environmental and economic benefits through substitution of imported hard coal, natural gas and local lignite resources in the Turkish electricity mix have been analyzed. Lack of potential, environmental and economic data kept offshore wind calculations out of the scope of this work. Increasing hub height and power coefficient due to better blade designs of wind turbines can increase 114 thousand MW of onshore wind power potential at 50 m up to 418 thousand MW at 300 m. Consequent wind electricity generation can change in the range of 2.3 × 105–1.95 × 106 GWh. Acknowledging several different conditions operating wind turbines can be subject to and that the whole capacity may not be used, mean value of 1.09 × 106 GWh wind electricity generation is assessed as the limit providable to the Turkish electricity grid. Installable wind power capacity (IWPC) and electricity generation potential (EGP) are both most sensitive to the changes in spacing followed by CP and aging. The level of sensitivity increases at higher hub heights for both IWPC and EGP. Environmentally, substitution of lignite and after 2040 hard coal and lignite by wind power is the most feasible option in improving environmental performance of Turkish electricity mix compared to sole substitution of hard coal, natural gas or lignite. In 2040, wind can replace all lignite hence in the years following 2040, wind can substitute lignite and a second fossil resource. Economically, hard coal and natural gas substitution result in 10.85 billion $ and 7.93 billion $ gain from 2021to 2050. Local job creation and carbon tax mechanisms to be employed in favor of wind power can create additional economic and social benefits for the country.

Upgrading of low-grade high-sulfur lignite using differential dynamic field dry cascade cleaning apparatus

Coal is an important cornerstone to ensure national energy security under the new situation. China is rich in lignite reserves. In recent years, with the increasing consumption of high-quality coal resources, the development and utilization of low-grade lignite resources has become extremely urgent. Promoting the clean and efficient utilization of low-grade lignite resources is an important way to achieve the goal of carbon emission peak and carbon neutrality. In this paper, the low-grade high-sulfur lignite is desulfurized and ash-reduced by using the differential dynamic field dry cascade separation bed. The temporal and spatial migration and distribution law of material sulfur content in the cascade separation bed are mainly studied, and the dominant period of particle migration is determined. The effects of vibration intensity and airflow velocity on the density uniformity and stability of differential dynamic field cascade separation bed are systematically analyzed. At the same time, the cascade distribution characteristics of low-grade high-sulfur lignite in different transverse areas of the separation bed are explored, and the transverse separation functional area is determined. The experimental results show that when the separation time T = 0–6 s, the particle system is dominated by mixed migration; when T = 0–12 s, the particle system is dominated by mixed-regional layering migration; when T = 0–18 s, the particle system is dominated by stratified migration; when T = 0–24 s, the particle system is dominated by inspective stratification. It is determined that the area of 0–700 mm along the X axis is the transverse separation domain of the materials; the area of 700–1400 mm along the X axis is the transverse transition domain of the materials, and the area of 1400–2000 mm along the X axis is the transverse diffusion domain of the materials. When the operating parameters are in the range of A = 3.1 mm, f = 29 Hz, and v = 0.212–0.314 m/s, the uniformity and stability of the bed density are the best. The low-grade high-sulfur lignite was separated and upgraded by cascade separation bed and the separation result are shown as follows. The sulfur content of clean coal was 0.98%, the ash content was 8.96%; the yield was 67.32%. The sulfur content of gangue was 16.77%, the ash content was 69.59% and the yield was 32.68%. The probable error Ep is 0.1 g/cm3, which means that the high-efficiency desulfurization and ash reduction of low-grade and high-sulfur lignite are realized.

The Energy Landscape versus the Farming Landscape: The Immortal Era of Coal?

This article explores the land use conflict. Coal exploitation precludes agricultural production and, as a result, mining-energy projects come across NIMBY (Not In My Back Yard) opposition from the farming community. An investigation was carried out in two rural communes: Krobia and Miejska Górka in the Wielkopolska Region in Poland. The aim was to obtain an answer to the following questions: (1) if acting in the name of energy security, should we accept the state government interest and start exploitation of the lignite resource? (2) If acting in the name of landowners’ rights, should we accept the local community interest and maintain the current farming production? and (3) is it possible to reconcile the interests of the conflict beneficiaries? The following qualitative methods were used: keyword and content analysis of word data, such as scientific papers, legal documents, and parliamentary questions (PQs), while the discourse analysis was focused on the policy and procedural conflicts. In the results section, possible solutions for heading off the conflict are presented. The results contribute to an integrated understanding of conflicts over mining and farming land use.

Effect of 0–1 mm pulverized coal on desulfurization and upgrading of low grade lignite in dry cascade separation bed with compound force field

Coal is the important pillar of national economic development. China has a rich variety of coal resources, of which low-grade lignite resources have huge reserves. As the consumption of high-quality coal resources intensifies and its output is declining, strengthening the efficient use of low-grade lignite is an important measure to ensure energy supply and safety, and to stabilize industrial energy production. This paper mainly studies the influence of the characteristics of 0–1 mm coal powder in the dry cascade separation bed with compound force field on the spatial migration law of low-grade lignite and the uniformity and stability of the density of the autogenous medium bed. The regional spatial distribution of sulfur content of low-grade lignite under different autogenous medium content was systematically studied. The emphasis is on the influence of the particle size and density composition of 0–1 mm coal powder on the uniform stability of the autogenous medium bed density. At the same time, the spatial distribution and cascade separation of low grade lignite in the variable distance regional autogenous medium bed are analyzed. The test results show that when the content is 12.5–20%, the sulfur content of the upper and lower materials is relatively stable in the high and low density material enrichment areas, and the sulfur content of the middle material has a large fluctuation range. At this time, a autogenous medium fluidized bed with uniform and stable density can be formed; The 0.125–0.25 mm coal powder particles are uniformly distributed along the XOY section and XOZ section, which is the dominant particle size fraction for forming an autogenous fluidized bed; Coal particles with a density of 1.6–1.8 g/cm3 can form a fluidized bed with stable density, which is the dominant density fraction for forming an autogenous medium bed. During the dynamic sorting process, the materials in zone I present a differentiated distribution, realizing the separation of low-density materials. The spatial distribution of materials in zone II fluctuates greatly, realizing the separation of medium and high-density materials. The materials are distributed relatively evenly in zone III, which realizes the conveying and separation of high-density materials. The yield of clean coal is 65.12%, the ash content is 9.89%, the sulfur content is 0.99%, the gangue yield is 34.88%, the ash content is 44.98%, and the sulfur content is14.89%. The probable error of E is 0.07 g/cm3, and the high-precision desulfurization, ash reduction and quality improvement of low-grade lignite by the dry cascade separation bed is realized.

Modeling of Polish energy sector – tool specification and results

The focus of this study is to specify different visions of the Polish energy sector development. The first is a traditional model based on existing coal and lignite resources complemented more or less by alternative technologies (wind, biomass, PV and nuclear power). The second is deeper and faster decarbonization of the Polish energy sector. And third an alternative approach where the economic impact of air emissions is considered. Here, the optimization criterion is based on maximizing social welfare, defined as the sum of consumer and producer surplus less the negative externalities associated with energy production. The paper presents the methodology used to forecast the development of the Polish energy sector. Both the IED standards and RES limits for ‘baseline’, additional limit of CO2 in ‘CO2’ scenario and high external costs for an ‘effective’ scenario force substantial changes in the structure of energy production. The extensive use of solid fuels in system power plants should be reduced and replaced by RES sources and nuclear energy. It has been proven that, in the case of system power plants, IED standards and RES limits are as effective as potential internalization of external costs, but if the external costs of CO2 emissions are higher (€65/Mg for CO2). Post-combustion technologies are economically efficient, but the scale of these investments must be correlated with the expected path of decommissioning coal-based technologies. The model results confirm that, in an ‘effective’ scenario, old coal-fired small heating plants should be completely replaced by gas technologies, small-scale geothermal heat plants and PV farms. All of these measures could improve social welfare by 4% as compared to the ‘baseline’ scenario and 6% in case of ‘CO2’ scenario.

Study on the industrial feasibility of adding lignite for blast furnace

Lignite resources in China are abundant and cheap. The application of lignite resources is one of the promising solution for the energy crisis of industries in China. In the present work, the resources of coal mines around Kunming, Yunnan Province, P.R. China were investigated. After considering various factors, the Mile coal was selected as the supply for the lignite experiment. Conducting the industrial analysis and properties experiments on the single lignite and mixed coal of different proportions. On the basis of ensuring safety, and the coal blending structure of 60% anthracite-35% bituminous coal-5% lignite has been selected for the industrial test in no. 3 blast furnace of a steel plant. At the same time, the data of the blast furnace condition in the reference period and the test period were collected and compared. We can conclude that the blast furnace with 60% anthracite-35% bituminous coal-5% lignite injection test was stable, safe and feasible. Finally, according to the replacement ratio of lignite and bituminous coal, the economic benefits of lignite instead of bituminous coal was evaluated, and the results were more optimistic, which achieved the effect of reducing costs for the factory.

Car-Parrinello molecular dynamics study on the interaction between lignite and water molecules

Water-desorption from lignite surface is an important issue in energy usage, however, corresponding researches are inadequate. Herein, in order to comprehensive understand the process of water-desorption from lignite surface, the interaction between water molecules and carboxyl group of lignite were investigated systematically from 298.15 K to 440 K, by using Car–Parrinello molecular dynamics (CPMD) method. The result indicated that in the key carboxyl group, the hydrogen site (H51) showed stronger adsorption capacity for water molecules than the oxygen site (O23) of the carboxyl group. Based on the statistical result, the water molecules adsorbed at H51 and O23 were considered as removed after 360 K. Vibration analysis was performed to acquire stretching frequencies of carboxyl group before and after water adsorption. The NBO analysis was used to study the reorientation of water molecules in a 0.14 ps trajectory when they replace with each other. The NBO orbitals obtained show that when water molecule is replacing, the two lone pair orbitals of O31 and O32 interact with the σ antibonding orbital of O24H51 bond at the same time. It enhances the formation of new H-bond and facilitates the fracture of old H-bond. This work can not only reveal the mechanism of water desorption from lignite, but also lay valuable foundations for efficient utilization of lignite resource.

A comparative study of lignite resource estimation based on 1D drill-hole mineable lignite compositing of uncorrelated seams and 3D mineable lignite aggregation of correlated seams

A comparative study of lignite resource estimation based on 1D drill-hole mineable lignite compositing of uncorrelated seams and 3D mineable lignite aggregation of correlated seams

Transformation behaviors of C, H, O, N and S in lignite during hydrothermal dewatering process

Lignite resources are abundant in China, but high moisture contents limit their utilization. With a view to making optimal use of beneficial elements (C, H, O) and effectively control the release of harmful elements (N and S) in lignite during drying, two lignites, one from Inner Mongolia (IM) and one from Yunnan (YN) province, were hydrothermally dewatered (HTD) at 230 °C, 270 °C and 300 °C. The solid, liquid and gaseous products were characterized by proximate and ultimate analyses as well as Fourier transform infrared spectroscopy (FT-IR), chemical oxygen demand (COD) analysis, Raman laser analysis and gas chromatography. Based on these data, the transformation behaviors of C, H, O, N and S contained in the raw lignite as they partition into the HTD products (solid, liquid and gas) were investigated. Results show that the effects of HTD on the elemental transformations depend on the coal properties. HTD is more effective for YN lignite than for IM lignite. IM liquid products have lower COD contents, resulting from less dissolution of IM lignite. CO2 and CO are released during HTD and their amounts increase with temperature for both IM and YN lignites. High temperature leads to a significant loss of carbon in the solid product; this corresponds with increases of the carbon content in the gas and liquid phases. Hydrogen, nitrogen and sulfur in lignite are mainly transferred into the liquid phase. A large proportion of the oxygen-containing functional groups in the lignite decompose, causing its transfer out of the solid and into the gas and liquid phases.

Fundamentals of 3D modelling and resource estimation in coal mining

The prerequisite of maintaining an efficient and safe mining operation is the proper design of a mine by considering all aspects. The first step in a coal mine design is a realistic geometrical modelling of the coal seam(s). The structural features such as faults and folding must be reliably implemented in 3D seam models. Upon having a consistent seam model, the attributes such as calorific value, ash and moisture contents, volatile matter, and sulfur must be estimated in the block model. Considering the geotechnical and hydrogeological conditions, the most appropriate mine design strategy can be selected and implemented. Application of the above steps to three coal basins in Turkey are presented in this paper. The Soma-Eynez and Tuncbilek-Omerler basins are the two most important lignite resources having an on-going production and prospect for future underground mining. Comprehensive 3D coal seam modelling is carried out at both basins. As both are extensively faulted due to tectonism, it is a challenging task to realistically model their structures. On the other hand, the Karapinar basin has a considerably different geological, structural, and coal measure rock conditions in comparison to the Eynez-Omerler basin. The Karapinar basin is a relatively recently explored brown field site suitable mainly for surface mining. Coal seam(s) geometry and quality-related attributes certainly play the most important role for production planning and mining activities. The influence of the inherent characteristics of each site on the modelling and mine design strategy are also briefly discussed. This paper presents the fundamentals of coal seam modelling at various geological and structural conditions. It is believed that the methodology presented in this paper can be considered as a guiding example for a comprehensive 3D modelling and resource estimation of coal seams around the world.

Sustainable lignite resource planning at Thar coalfield, Pakistan

Thar coalfield is a new coalfield in Pakistan with estimated lignite resource of more than 175 billion tons. Resource planning is an essential part of the strategic plan for optimal and economical exploitation of Thar lignite. Main objective of the present research is to assess Thar coalfield as a single deposit and identify the areas suitable for surface mining, underground mining and waste dump at Thar coalfield. The cumulative stripping ratio distribution map has been developed for Thar coalfield, covering an area of 1691.04 km2 around 12 exploratory blocks. Lithological data of 693 drill holes have been used to calculate the cumulative stripping ratio in every borehole, which varies from 3.7 m:m to 88.1 m:m with an average value of 12.85 m:m. Cumulative stripping ratio is divided into six ranges, viz: 4–6, 6–8, 8–10, 10–15, 15–20 and >20 m:m. Contours are digitized around all boreholes showing various ranges of stripping ratios. From the cumulative stripping ratio distribution map, it is concluded that 665.72 km2 area, which constitutes 39.37% of the total assessed area, is suitable for surface mining and 989.82 km2 area, constituting 58.53%, is appropriate for underground mining and outside waste dumps. Whereas, 2.1% area is no coal zone, only suitable for outside waste dumping. The developed map of cumulative stripping ratio distribution may be used as a guide map for the preparation of mining master plan for Thar coalfield.

Metagenomic analysis of microbial community in coal samples from Kazakhstan using Illumina NGS technology

The development of micro- and biotechnological processes for fossil energy utilization has received increasing attention in recent years. There are abundant coal resources in Kazakhstan; in particular, low-rank coal resources of lignite and leonardite. These coal types are not exploited commercially due to their low energetic power. However, they are considered as a rich source of humic substances (HS). The HS in the soil play an important role in physical and chemical quality, carbon capture and stabilization and in the inactivation of pesticides, heavy metals, as well as other polluting agents. Bioprocessing of lignite also involves the production of clean energy. Research on coal microbes is essential for microbial ecology and applied microbiology with regard to the sustainable utilization of coal resources. Nevertheless, the inability of culturing vast amount (around 99%) of microorganisms in vitro counteract the research procedures. Currently, there is tremendous advances in using non-culturing techniques based on omics to the examination of microbial diversity of environmental compartments, such as soil, sediment, minerals, etc. Different omics tools, including FISH, SIP, next generation sequencing (NGS), microarray, mass spectrometry, etc., evolve instant results to provide comprehensive insight of the coal microbiome. This paper discusses the findings and challenges in the study of Kazakhstan coal microbes, highlighting Illumina NGS platform. Based on the results of the metagenomic analysis of coal samples (Oikaragai, Lenger, Karaganda, Yekibastuz), 10 taxonomic groups of bacteria belonging to Proteobacteria, Tenericutes, Actinobacteria, Firmicutes, Bacteroidetes, Nitrospirae, Chloroflexi, Gemmatimonadetes, Acidobacteriaand Fusobacteria were identified and analyzed. Key words: lignite, leonardite, microbial diversity, microbial community, metagenomics, Illumina Miseq sequencing.

Natural lignite resources in Kosovo and Metohija and their influence on the environment

Natural lignite resources in Kosovo and Metohija and their influence on the environment