Opencast Lignite Mine Research Articles

Proposal of a new species for a previously described elmine larva (Coleoptera, Elmidae) from the Lower Eocene of Rajasthan (India, Palana Formation)

A single elmid larva reported from a laminate maroon shale bed of Gurha opencast lignite mine (Palana Formation, early Eocene, Bikaner District, north-western Rajasthan, India: Kumar et al., 2016) is the first preimaginal fossil known up to date. It was thoroughly examined and published by Kirejtshuk et al. (2023). However, because of the absence of any unambiguous diagnostic character for a strict generic attribution of this fossil, its rather described larva remained unnamed. Taking into consideration the scientific importance of this fact for different aspects of our knowledge it is rather advisable to introduce the description of this specimen to scientific community with a concrete specific name and probable generic attribution.

Enormous headward and gully erosion in a floodplain area reclaimed for open-cast lignite mining during the July 2021 flood in the Inde River valley (Western Germany)

BackgroundThe July flood 2021 at the mountain front of the Eifel-Ardennes Mountains and their foreland resulted in the flooding of the lignite mining area of Inden in Germany. The mining activities resulted in large-scale anthropogenic changes to the relief and fluvial system, leading to a landscape that is no longer adjusted to the recent process-response system. This paper concentrates on the Inde River, where lignite mining led to the relocation of a 5-km-long river section. The flood event resulted in the temporary avulsion of the Inde River into the former channel and, ultimately, in the flooding of the open-cast lignite mine Inden.ResultsThe flooding of the open-cast lignite mine Inden led to headwall erosion and enormous sediment mobilisation, mobilising more than half a million cubic metres of sediment within a few hours, forming a 700-m-long deeply incised channel cut. Thereby, the underlying bedrock, near-subsurface man-made structures, and former river channels influence the erosional processes to different degrees. Surface erosion is likely to be the decisive process, and subsurface erosion is likely to play a secondary role. In both cases, former channels and mill ditches were likely impacting the course of erosional processes.ConclusionsDuring high flood events open-cast mining sites in floodplains are endangered by enormous erosion and sediment transport within a short period of time (several hours). Understanding such complex erosion and depositional processes in open-cast mining areas could provide a blueprint for geomorphological processes and hazards in these anthropogenically shaped fluvial landscapes. Further, information on historic impact in the area is crucial to estimate potential risks.

Synsedimentary Compaction of Peat Under the Load of Alluvial System Sediments in the Most Basin (Czech Republic, Lower Miocene): From Weak Compaction to Strong Local Deformation of Clastics and Peat

Alluvial systems affected by peat layer compaction of a variable degree are studied all over the world, especially in areas of large river deltas and coastal plains. Ordinarily studied Holocene peat accumulations do not reach thicknesses of more than 6–10 m. This paper documents four ancient alluvial systems affected by peat compaction during the Lower Miocene in large exposures of open-cast lignite mines within the Most Basin, Czech Republic. Field observations and the study of 3000 borehole sections showed a clear dependence of the thickness and composition of the underlying peat on the scale of the accommodation space for loading by younger alluvial sediments. If the underlying partly compacted peat was tens to hundreds of meters in thickness, significant deformations of the peat appeared during its loading, leading up to the formation of growth faults. In such cases, missing parts of the coal seams were also observed below the alluvial systems. Especially borehole data showed that a linear correlation exists between the thickness of the alluvial sediments and the maximum instantaneous available compaction capacity of the underlying peat.

Facies and statistical analyses of a crevasse-splay complex at the Tomisławice opencast lignite mine in central Poland

The studied crevasse-splay complex, situated within the 1st Mid-Polish lignite seam (MPLS-1), ranks amongst the best-developed and most readily accessible for direct research of all hard coal and lignite occurrences worldwide. The sandy-coaly sediments constituting it required a number of field and laboratory tests. However, the present article focuses solely on sedimentological and statistical analyses of sediments along a selected key section, the most important results of which are presented below. First of all, data obtained in previous sedimentological studies have been confirmed, in that individual segments of this complex represent both subaerial and subaqueous types of crevasse splays. On the one hand, their sediments are characterised by an extremely high content of coalified organic matter, reaching 20–40 wt.% in some samples; on the other, these crevasse splays are composed of fine sands with a median and mean grain size of 0.15 mm. In addition, the remaining statistical parameters (standard deviation, skewness and kurtosis) indicate a very good sorting of these sands, no significant so-called ‘tails’ and a better sorting close to the sediment mean grain size value, respectively.

Renaturierung des Tagebaus Schöningen mit verschiedenen Megaherbivoren in Form von unterschiedlichen Landschafts- und Klimawandelszenarien

This paper examines a renaturation of the former Schöningen opencast lignite mine into a wilderness area. Megaherbivores are to be used to maintain an open landscape. Types of animals selected are based on their use in helping to emulate a prehistoric landscape. In order to establish a wilderness area with consideration to the carrying capacity of the landscape, the WoodPaM simulation programme was employed to help adjust for climate change and grazing scenarios. The results show that the intensity of grazing as well as the influence of climate change have a strong impact on the development of the landscape. Human intervention is excluded in the simulation in order to tie the findings into the debate on wilderness in Germany and to recreate a prehistoric landscape. Animal species simulated were bison (Bos bonasus), red deer (Cervus elaphus), fallow deer (Dama dama) and horse (Equus przewalski) with numbers ranging from 28 (0.05 LSU per hectare) to 105 (0.2 LSU per hectare) individuals. Drought stress due to climate change is considered to be the limiting factor for plant growth. Even small changes in grazing intensity alter growth in the tree and field layers. In summary, the model calculations in WoodPaM reflect the real landscape as accurately as possible, but individual points in a complex ecosystem cannot be simulated. The results provide starting points for the future handling of the Schöningen opencast mine and can possibly be transferred to other opencast mines.

Intense game grazing shapes epigeic spider communities of pedunculate oak Quercus robur plantations in anthropogenic environments

Game browsing affects nature conservation because the interests of hunters and gamekeepers often lead to high game stocking rates. However, the compositional effects of game browsing on invertebrates are insufficiently understood. We addressed the dynamics of epigeic spider communities in oak stands planted in newly formed anthropogenic environments under the facultative pressure of browsing game. The study site consisted of an open-cast lignite mine and an overburden deposit in NW Czechia. Using pitfall traps, we examined five habitat types (four transects per habitat type): Quercus robur stands ≥ 25 years of age, 12–24 years of age, and 0–2 years of age; Q. robur stands 12–24 years of age that were heavily damaged by game browsing; and sites subject to spontaneous succession for 12–22 years. We captured 9459 individuals from 134 spider species distributed unevenly across the examined habitat types. The young stands were dominated by Pardosa agrestis, Pardosa monticola, and Oedothorax apicatus, whereas Pardosa prativaga, Pardosa lugubris, Pisaura mirabilis, and Alopecosa cuneata dominated the old stands. The stands damaged by browsing had the highest species richness and were dominated by Alopecosa pulverulenta, Xerolycosa miniata, A. cuneata, and Trochosa ruricola. All the oak stands were rich in threatened species, with most (26) found in habitats damaged by browsing, whereas the youngest stands hosted the lowest number of threatened species (11). The species dominating old stands still included species that prefer greater canopy openness, such as P. lugubris, whereas numerous species of central European climax oak forests were lacking. In conclusion, we identified oak stands heavily damaged by game browsing as a unique environment that shapes the community of epigeic spiders and that differs from epigeic spider communities of oak stands of various ages and those colonizing areas that are allowed to undergo spontaneous succession.

Effectiveness of Protein and Polysaccharide Biopolymers as Dust Suppressants on Mine Soils: Large-Scale Field Trials

Recent laboratory studies have shown that biopolymers have the potential to act as dust suppressants on barren mine soils. However, there is a lack of field trials investigating the effectiveness of biopolymer treatments under real field conditions on a large scale. This study performed field trials to examine the potential of three biopolymers—corn starch (CS), xanthan gum (XG), and fava bean protein concentrate (FBPC)—as dust suppressants. The field trials started in August 2022 with spraying of low doses of the selected biopolymers on trial areas of an overburden dump at the Inden open-cast lignite mine, Germany. The field trials were conducted over 45 days. They included repeated measurements of dust emissions from soil plots exposed to different airflows generated by an electric blower, visual inspections, and penetrometer tests. The results showed that all biopolymer treatments effectively suppressed dust emissions in the short term up to 8 days after application. Total suspended particle emissions measured on the biopolymer-treated trial plots were significantly reduced and ranged from 0.05 to 0.27 mg/m3 compared to the untreated control (4.5 to 39.2 mg/m3). The visual inspections and penetrometer tests supported these results. After day 8, rainfall-induced leaching of the biopolymers resulted in the rapid degradation of the treatments’ effectiveness. The results suggest that the treatments would have lasted longer under dry conditions. Thus, the field trials provide practical evidence that biopolymers can effectively mitigate dust emissions on exposed, undisturbed mine soils in the short term, making them a bio-based alternative to traditional dust suppressants, such as chloride salts or petroleum-based products.

Distribution of rare earth and other critical elements in lignites from the Eocene Jackson Group, Texas

Coal is increasingly evaluated as a source of rare earth elements (REEs) in the United States to address the overreliance on imported REEs. The objective of this study was to assess the distribution of REEs in lignites from selected mining areas in the Texas Gulf Coastal Plain region. Thirty-one archived lignite and rock samples previously collected by the U.S. Geological Survey were analyzed for their rare earth element and critical mineral content. These include samples from one core (5400 and 5500 lignite horizons) and two opencast lignite mines (Gibbons Creek 3500 and 4500 horizons, and San Miguel horizons A to D) in the Eocene Jackson Group of the Texas Gulf of Mexico Coastal Plain. Some lithologies in the Gibbons Creek 3500 and 4500 lignite-bearing sections have high total rare earth, yttrium (Y), and scandium (Sc) (REYSc) values, up to 7800 ppm (ash basis) REYSc. The lignite lithologies show an enrichment in rare earths, [samarium (Sm) through gadolinium (Gd)]. The basal Gibbons Creek 3500 lignite bench shows a heavy rare earth element enrichment pattern resembling that often seen in peats through high volatile A bituminous coals. The 5500 lignite sequence, overlying the latter lignite sections, shows a light rare earth enrichment. The San Miguel lignite benches have heavy rare earth enrichments with a negative europium (Eu) anomaly.

Discovery of the oldest known elmid larva (Coleoptera, Elmidae) from the Lower Eocene of Rajasthan (India, Palana Formation)

A single elmid larva is reported from a laminate maroon shale bed of Gurha opencast lignite mine (Palana Formation, early Eocene, Bikaner District, north-western Rajasthan, India). It is the first fossil larva that can be attributed to Elmidae with certainty. A generic assignation is not possible, because the larva is strongly compressed, and the most important characters are not visible or poorly preserved. The larva is described morphologically and illustrated by photographs and line drawings. A larva of a holometabolous insect from Baltic amber, which was published recently as a member of Elmidae by Zippel et al. (2022), possesses no structural characters that would clearly suggest placement in this family. A photograph of the hitherto unknown larva of the extant Grouvellinus rioloides from Kyrgyzstan is included for comparison.

Dormice (Rodentia, Gliridae) from the Middle Miocene of Hambach 6C, Northwest Germany

Glirid dental material is described from the Middle Miocene channel fill of the Hambach open-cast lignite mine in northwestern Germany. The fauna Hambach 6C shows a high diversity with seven species in six genera: Glirudinus undosus, Muscardinus thaleri, Muscardinus sansaniensis, Miodyromys aegercii, Paraglirulus werenfelsi, Microdyromys koenigswaldi, and Paraglis astaracensis, which are characteristic taxa in Middle Miocene European localities. Regarding the faunal composition and high diversity, the Hambach 6C assemblage is closest to that of the MN 5 locality Schönenberg in southern Germany, but also shares many taxa with late Middle Miocene faunas. The species richness of glirids, combined with other vertebrate remains in Hambach 6C indicates a warm, humid forested environment during the Mid-Miocene Climate Optimum (MCO).

Assessment of soil loss using RUSLE around Mongolian mining sites: a case study on soil erosion at the Baganuur lignite and Erdenet copper–molybdenum mines

Mining constitutes an integral part of Mongolia’s national economy and dominates the country’s export revenue. At the same time, a wide range of mining impacts on soil, water resources, the atmosphere and the biosphere have been documented across the country. This case study addresses the long-term soil degradation around two mining sites located in the semi-arid steppe zone of Mongolia: the open-cast lignite mine of Baganuur about 140 km east of Ulaanbaatar, and the open-pit copper–molybdenum mine of Erdenet about 240 km northwest of Ulaanbaatar, both of which started commercial extraction in the late 1970s. For the assessment of soil erosion, the RUSLE model was applied in different seasons for the period from 1989 to 2018 at 3-year intervals, considering both climatic variation and the expansion of the mines based on maps and satellite imagery. Rainfall erosivity was identified as the most dominant factor driving soil erosion in the study regions, with mining leading to local increases in soil erodibility. The highest soil erosion rates were found in both areas in July 2018, reaching 7.88 t ha–1 month–1 in the Erdenet area and 9.46 t ha–1 month–1 in the Baganuur area. The spatial patterns of soil erosion showed higher soil loss rates were in the vicinity of the mines and adjoining industrial sites. Particularly high soil losses were identified in July 1998, July and August in 2013 and July 2018 in both mining areas. The combination of the RUSLE model, remote sensing and ground truth data as and their processing by GIS was found to be a time-saving and cost-effective technique for continuous monitoring of soil erosion and planning of preventive measures in and around mining areas.

Changes in Physical and Water Retention Properties of Technosols by Agricultural Reclamation with Wheat–Rapeseed Rotation in a Post-Mining Area of Central Poland

During opencast lignite mining, the natural landscape is damaged, along with soils, and new anthropogenic landforms are created which require reclamation. Usually, the evaluation of the effects of reclamation (mostly forestry) is concerned with changes in chemical properties in the first years, mainly in the surface horizon. This study analyzed the effect of long-term agricultural reclamation (43 years) on the physical and water retention properties of Technosols. The experiment involved cultivation of winter wheat and winter oilseed rape under 3 fertilization variants. After 43 years, an Ap horizon (Ap1 and Ap2) developed in fertilized Technosols, but was not clearly formed in unfertilized minesoil. In Ap1, there was improvement in the physical quality (S), bulk density (BD), particle density (PD), structural stability index (SI), soil porosity (SP), air-filled porosity (AFP), field capacity (FC) and plant available water capacity (PAWC). In Ap2, properties were comparable to those in the surface horizon of unfertilized Technosols and to those observed before reclamation. Regardless of fertilization, there was deterioration in physical quality in parent materials. In general, the properties of fertilized Technosols have improved in the surface horizons, but increasing fertilization above plant requirements does not lead to their further enhancement.

Concept and Implementation of Solutions Improving Water Relations in the Area of the Flooded Opencast Lignite Mine Kazimierz Północ in the East Wielkopolska Region (Central-West Poland)

Over a period of 30 years, the surface water level in the north-west of Konin, in the east of the Wielkopolska region, decreased by almost 6 m, resulting in a reduction of the surface area of the majority of nearby lakes, the disappearance of smaller water bodies and wetlands, and the drying out of streams draining the area. The causes of the decrease in the surface and groundwater level in the region are complex. They include both natural and anthropogenic factors, among others broad-scale mining activity. Based on knowledge of the hydrostructural composition of the analysed region and the functioning drainage system of opencast lignite mines, a concept was developed of a change in water supply to the flooded opencast lignite mine, Kazimierz Północ. The task of redirecting waters from the drainage of a nearby opencast mine, Jóźwin IIB, was implemented in 2020. Current observations and forecasts suggest that, owing to the applied solutions, the analysed opencast mine will be flooded in 2023, and not, as previously assumed, at the end of 2021. As a result, groundwater levels in the vicinity of the opencast mine as well as in lakes and rivers within the range of impact of the related depression cone will be restored faster, particularly in the Lake Powidzkie catchment. The objective of the study is to present stages of flooding of the former opencast lignite mine Kazimierz Północ, identify factors determining the process, and describe solutions accelerating it, with a simultaneous environmental impact assessment of the undertaken activities.

Fenton oxidation of biochar improves retention of cattle slurry nitrogen.

Nitrogen (N) losses during fertilization with livestock slurry, mainly in the form of ammonia (NH3 ), can cause environmental problems and reduce fertilizer efficiency. Leonardite, which is characterized by oxygen-rich functional groups and low pH, has been found to decrease losses of slurry N. However, leonardite, as a byproduct of open-cast lignite mining, is not a renewable resource. The objective of this study was to modify biochar by chemical surface oxidation in order to find a sustainable but similarly effective substitute for leonardite. Biochar was produced from spruce sawdust in a pyrolysis oven at a maximum temperature of 610°C. Then the biochar was oxidized using the Fenton reaction, with a ratio of Fe2+ /H2 O2 of 1:1,000, as a source of highly reactive HO· radicals to introduce oxygen-rich functional groups to the biochar surface. The ammonium (NH4 + ) adsorption capacity of biochar, oxidized biochar, and leonardite was tested in ammonium sulfate [(NH4 )2 SO4 ] solution, pH-adjusted (NH4 )2 SO4 solution, and cattle slurry. The results showed that biochar had the highest total NH4 + adsorption of 1.4mg N g-1 in (NH4 )2 SO4 solution, whereas oxidized biochar had the highest reversible NH4 + adsorption of 0.8mg N g-1 . In the pH-adjusted ammonium solution, all materials reduced NH3 emissions by ≥90%, and oxidized biochar reduced NH3 emissions by 99.99%. In contrast, leonardite reduced NH3 emissions the most in cattle slurry, and oxidation of biochar increased the reduction in NH3 emissions from 22 to 67% compared with non-oxidized biochar. In conclusion, biochar oxidized by means of the Fenton reaction greatly decreased NH3 emissions by increased adsorption of NH4 + in cattle slurry compared with non-oxidized biochar, indicating the great potential of oxidized biochar for reducing N losses during slurry application.

Effects of mixture and management on growth dynamics and responses to climate of Quercus robur L. in a restored opencast lignite mine

Opencast mining is currently one of the most destructive economic activities of natural ecosystems. Many restoration techniques have been developed to promote the recovery of terrestrial ecosystems degraded by mining, and afforestation and reforestation are among the most important methods to this purpose. In this study, we evaluated the combined effect of tree species mixture and thinning intervention on growth dynamics and responses to the climate of a target native planted oak (pedunculate oak, Quercus robur L.) about 40 years after reforestation of an opencast lignite mining area in Central Italy. The species used for reforestation were a native tree species (Q. robur L.), two valuable broadleaved trees (Fraxinus angustifolia Vahl. and Prunus avium L.) and a nitrogen-fixing tree (Alnus cordata Loisel.) to improve timber quality and restore the ecological and environmental value of the degraded land. Climate-growth relationships for precipitation, the Standardised Precipitation-Evaporation Index (SPEI), and temperature (on a monthly and seasonal scale) were tested together with indices based on tree-ring responses to drought. Thinning improved the stem quality and promoted a significant long-term increase in basal area increment (BAI, +31.0%) only in the mixture with alder. The thinning effect slightly mitigated radial growth reductions of oak trees during drought (resistance) and produced a general improvement in the magnitude of resilience and post-drought growth recovery (+37% and +27% on average, respectively). This effect was most evident when oak trees were mixed with only the N-fixing alder species, both after shorter- and longer-term drought or rainfall reduction. In conclusion, the mixture with alder combined with thinning practices resulted in the best management option to produce good-quality stems, improve growth performances, and mitigate drought effects in the recovery of opencast lignite mines through reforestation.

Monitoring fotogrametryczny z wykorzystaniem bezzałogowego statku powietrznego na przykładzie osuwiska zlokalizowanego na zboczach poeksploatacyjnego zbiornika wodnego w KWB Adamów

The article presents the results of monitoring of landslides related to opencast mining. The landslides formed on the slopes of an artificial water reservoir in the Adamów open-cast lignite mine. The photogrammetric method was used for monitoring. The study of landslide activity was performed on the basis of six photogrammetric surveys made with the DJI Phantom 4 Advanced UAV. Changes in the landslide extent and vertical displacements were determined in five measurement periods. For four periods, differential digital terrain models were made and the volume of displaced earth masses was calculated. The future extent of the landslide was determined on the basis of cracks visible in high-resolution optical photos. The research has shown that UAVs equipped with an optical camera are very useful in monitoring the stability of slopes of post-mining water reservoirs. The applied method provided detailed data on the size of displacements without compromising on safety of people involved in field surveys.

Investigations of spoil dump soils in selected areas of the internal spoil heaps of the „PAK Konin Lignite Mine S.A”

The article presents the scope and methodology of investigations carried out in selected two locations of the internal spoil heaps of Jóźwin IIA and Jóźwin IIB open pits, PAK Konin S.A. Lignite Opencast Mine. The results obtained are also discussed. The studies carried out included geological drilling with undisturbed specimen sampling and borehole core sampling, SCPTu static soundings, and laboratory tests.The work was carried out in the frame of the international project „SUMAD Sustainable Use of Mining Waste Dumps”, financed by the Research Fund of Coal and Steel and co-financed by the Polish Ministr y of Science and Higher Education.

Quaternary and geoarcheology in Lower Lusatia

Abstract. Open-cast lignite mines in Lower Lusatia provide unique insights into human-induced environmental changes in the Northern European Lowland and improve our understanding of Quaternary landscape dynamics. The excursion will focus on soils and sediments of Late Pleistocene and Holocene age that have been modified by land use since the Slavic Middle Ages. In the vicinity of the open-cast mine Jänschwalde and in the Tauer forest north of Cottbus characteristic remains of historical charcoal production, a ridge-and-furrow system and late Quaternary rubification in soils are presented.

Wymagania stawiane mechanizmom napędów kół czerpakowych koparek wielonaczyniowych kołowych eksploatowanych w utworach trudno urabialnych

State of the art and reasons for undertaking modernization activities of bucket wheel drive mechanisms of BWEs operating of domestic lignite open cast mines have been discussed in the paper.The distribution of loads and mass moments of inertia acting on the BWE mining system has been given. The applied overload protections in bucket wheel drive mechanisms in the form of various types of clutches have been presented. The gears and motors of bucket wheel drives have been described. Examples of modernized bucket wheel drive mechanisms have been given. List of requirements for bucket wheel drive mechanisms which should be met by BWEs operating in hard mineable soils has been presented.

Towards an energy alternative solution through opencast lignite mine reclamation

Towards an energy alternative solution through opencast lignite mine reclamation