Shengli Coalfield Research Articles

Assessing the Depositional Environment of Cretaceous Ge-Rich Coals in the Wulantuga Mine, Shengli Coalfield, Northeastern China

Assessing the Depositional Environment of Cretaceous Ge-Rich Coals in the Wulantuga Mine, Shengli Coalfield, Northeastern China

Analysis of Eco-Environmental Quality and Driving Forces in Opencast Coal Mining Area Based on GWANN Model: A Case Study in Shengli Coalfield, China

Opencast coal mine production and construction activities have a certain impact on the ecological environment, while the development and utilization of large coal bases distributed in semi-arid steppe regions may have a more direct and significant impact on the eco-environment. Therefore, in-depth studies of the ecological impacts of human activities and natural environmental elements in opencast coal mines in typical semi-arid steppe regions and analyses of their driving forces are of great significance for protecting and restoring regional fragile steppe ecosystems. In this paper, the mining area southwest of the Shengli coalfield, a typical ore concentration area in eastern Inner Mongolia, was selected as the research object. Its remote sensing ecological index (RSEI) was calculated using the Google Earth Engine (GEE) platform to analyze the eco-environmental quality in the mining area and its surrounding 2 km from 2005 to 2021. The geographically weighted artificial neural network model (GWANN) was combined with the actual situation of mining activity and ecological restoration to discuss the driving factors of eco-environmental quality change in the study area. The results showed that: (1) the proportion of the study area with excellent and good eco-environmental quality increased from 20.96% to 23.93% from 2005 to 2021, and the proportions of areas with other quality grades fluctuated strongly. (2) The change in eco-environmental quality in the interior of the mining area was closely related to the reclamation of dump sites and migration of the mining area. (3) The maximum contribution rate of the mining activity factor to the external eco-environmental quality of the mining area reached 43.33%, with an annual average contribution rate of 34.48%; as the distance from the mining area increased, its contribution gradually decreased. This quantitative analysis of the driving forces of RSEI change in the mining area will complement future work in ecological evaluations of mining areas while also improving the practicality of ecological evaluation at the mining scale, thereby further helping the ecological management of mining areas.

Multiscale in-situ elemental characterization of critical elements in low rank coal, implications for modes of occurrence

This study investigated the distribution characteristics and modes of occurrence of rare elements (Li, V, Co, Mo, Ni, Sb, W, Nb), dispersed elements (Ga, Ge), and rare earth elements (REEs) in two selected coal samples: the Al-Li-Ga-rich coal from the Jungar Coalfield in the Ordos Basin, China, and the Ge-rich coal from the Shengli Coalfield in the Erlian Basin, China. Multiscale in-situ elemental characterization techniques, including BSE-EDS, EMPA mapping, and LA-ICP-MS mapping, were used for this purpose. The results showed that in the Al-Li-Ga-rich Jungar coal, Li was mainly associated with kaolinite with various origins, dominated by epigenetic kaolinite, followed by syngenetic kaolinite. Gallium was highly concentrated in organic matter, led by collodetrinite, followed by collotelinite. The majority of Nb was associated with organic matter, while a minority was distributed in Al-bearing minerals, including boehmite and epigenetic and syngenetic kaolinite. In the Ge-rich Shengli coal, Ge, W, and Sb were consistently distributed in coal and concentrated in organic matter, mainly semifusinite. V was widespread in organic matter, including textinite, fusinite, and semifusinite. Cobalt, Mo, and Ni occurred in a similar distribution and were associated with organic matter, led by collodetrinite in the Al-Ga-rich coal and cutinite in the Ge-rich coal. REEs, except for La and Ce, were associated with organic matter, led by vitrinite in Al-Ga-rich coal and huminite in Ge-rich coal. Lanthanum and Ce were highly concentrated in La, Ce-rich minerals, even if they were widespread in organic matter as well. The visualized results of this study confirm most of the previous findings obtained from indirect analyses but also reveal some differences. Gallium was rarely detected in Al-rich minerals such as boehmite and kaolinite, but highly concentrated in organic matter. Lithium was detected in both epigenetic and syngenetic kaolinite. Ge, W, and Sb were organically associated and concentrated in semifusinite in Shengli Ge-rich coal. Overall, this study provides a way to determine the modes of occurrence of trace elements in organic matter in coal, and these findings could be applied to coal from other geological backgrounds.

A New Method for Quantitative Analysis of Driving Factors for Vegetation Coverage Change in Mining Areas: GWDF-ANN

Mining has caused considerable damage to vegetation coverage, especially in grasslands. It is of great significance to investigate the specific contributions of various factors to vegetation cover change. In this study, fractional vegetation coverage (FVC) is used as a proxy indicator for vegetation coverage. We constructed 50 sets of geographically weighted artificial neural network models for FVC and its driving factors in the Shengli Coalfield. Based on the idea of differentiation, we proposed the geographically weighted differential factors-artificial neural network (GWDF-ANN) to quantify the contributions of different driving factors on FVC changes in mining areas. The highlights of the study are as follows: (1) For the 50 models, the average RMSE was 0.052. The lowest RMSE was 0.007, and the highest was 0.112. For the MRE, the average value was 0.007, the lowest was 0.001, and the highest was 0.023. The GWDF-ANN model is suitable for quantifying FVC changes in mining areas. (2) Precipitation and temperature were the main driving factors for FVC change. The contributions were 32.45% for precipitation, 24.80% for temperature, 22.44% for mining, 14.44% for urban expansion, and 5.87% for topography. (3) Over time, the contributions of precipitation and temperature exhibited downward trends, while mining and urban expansion showed positive trajectories. For topography, its contribution remains generally unchanged. (4) As the distance from the mining area increases, the contribution of mining gradually decreases. At 200 m away, the contribution of mining was 26.69%; at 2000 m away, the value drops to 17.8%. (5) Mining has a cumulative effect on vegetation coverage both interannually and spatially. This study provides important support for understanding the mechanism of vegetation coverage change in mining areas.

Remote Sensing Monitoring and Driving Force Analysis of Salinized Soil in Grassland Mining Area

To deal with the problem of soil salinization that exists widely in semi-arid grassland, the Shengli Coalfield in Xilinhot City was selected as the study area. Six periods of Landsat remote sensing data in 2002, 2005, 2008, 2011, 2014, and 2017 were used to extract the salinity index (SI) and surface albedo to construct the SI-Albedo feature space. The salinization monitoring index (SMI) was used to calculate and classify the soil salinization grades in the study area. The soil salinization status and its dynamic changes were monitored and analyzed. Combined with the logistic regression model, the roles of human and natural factors in the development of soil salinization were determined. The results were as follows: (1) The SMI index constructed using the SI-Albedo feature space is simple and easy to calculate, which is conducive to remote sensing monitoring of salinized soil. R2 of the SMI and soil salt content in the 2017 data from the study area is 0.7313, which achieves good results in the quantitative analysis and monitoring of soil salinization in the Xilinhot Shengli Coalfield. (2) The study area is a grassland landscape. However, grassland landscapes are decreasing year by year, and town landscapes, mining landscapes, and road landscapes are greatly increased. The areas of soil salinization reversion in the Shengli mining area from 2002–2005, 2005–2008, 2008–2011, 2011–2014, 2014–2017, and 2002–2017 were 65.64 km2, 1.03 km2, 18.44 km2, 0.9 km2, 7.52 km2, and 62.33 km2, respectively. The overall trend of soil salinization in the study area was reversed from 2002 to 2017. (3) The driving factors of salinized land from 2002 to 2008 are as follows: the distance to the nearest town landscape > the distance to the nearest mining landscape > the distance to the nearest road landscape. The driving factors of salinized land from 2008 to 2017 are as follows: the distance to nearest mining landscape > the distance to the nearest water landscape > the distance to nearest town landscape > altitude > aspect. Coal exploitation and town expansion have occupied a large amount of saline land, and petroleum exploitation and abandoned railway test sites have intensified the development of saline land. This study provides a reference for the treatment and protection of soil salinization in semi-arid grassland mining areas.

Influence of management on vegetation restoration in coal waste dump after reclamation in semi-arid mining areas: examining ShengLi coalfield in Inner Mongolia, China.

Conservation management usually carried out for a period of time to maintain the vegetation restoration of coal waste dumps after reclamation. However, the natural restoration of vegetation is faced with great challenges in semi-arid mining areas without management, due to the fragile ecological environment. Therefore, it is necessary to determine a reasonable management plan so that vegetation restoration can reach a stable state although the abandonment of the management. The objective was to explore the difference of vegetation restoration under different management modes in a typical semi-arid mining area. Two reclaimed coal waste dumps under different management measures, the north waste dump (ND) and the south waste dump (SD), were examined in the ShengLi coalfield in Inner Mongolia, China. The normalized difference vegetation index (NDVI) dataset based on Landsat series imagery was obtained using the Google Earth Engine (GEE) platform, and the landscape metrics were also calculated based on different vegetation coverage. The results proved that 3 years of management was not enough to stabilize vegetation restoration. A serious vegetation degradation occurred at the ND after the management stopped, with 40.1% of the pixels recorded a significant decrease (ρ = 0.05). The vegetation coverage became fragmented, and there was a tendency of succession to lower coverage. On the contrary, the vegetation restoration of SD was better under continuous management, and no significant degradation trend was observed. Furthermore, the results indicated that rainfall is the main influencing factor on vegetation restoration in semi-arid mining areas. The coal waste dump was more susceptible to weather change in natural restoration. By contrast, continuous management measures will resist such climate disturbances, even in dry years. This research will provide support for the formulation of the reclamation management plan of coal waste dumps in semi-arid mining areas.

The origin, migration, and accumulation mechanism of germanium and the metallogenic model of coal-hosted Ge ore deposits in Wulantuga, Erlian Basin, China

To explore the source, migration, and enrichment mechanism of germanium (Ge) and the metallogenic model of the Wulantuga coal-hosted Ge ore deposits in the Shengli Coalfield, this study analyzed the geochemical parameters of Ge-rich coal seams, including major element, trace elements, and rare earth element (REE) compositions, with X-ray fluorescence (XRF) spectrometry, inductively coupled plasma mass spectrometry (ICP-MS) and instrumental neutron activation analysis (INAA). An isoline map of Ge concentration and a cross-section map of sedimentary strata and Ge element distribution were drawn with the sampling data. The results showed that there were three periods of Ge accumulation in the Wulantuga coal seam. The enrichment coefficients of the low-content Ge samples and high-content Ge samples displayed that Ge was enriched together with As, Mo, Sb, and W. Compared with the Ge-bearing parent rocks located southwest of the Wulantuga area, the Ge-rich samples are clearly enriched in heavy REEs relative to light REEs in the REE distribution pattern, with positive anomalies of Tb, Ho, Tm, (La/Yb)n and (La/Sm)n > 1, as well as a very high positive δEu anomaly, which indicated that the Ge ore deposit in Wulantuga was indeed likely affected by hydrothermal fluids with a left-slanting REE distribution pattern. In addition, based on the sulfophilic affinity and organic affinity of Ge and the geochemical characteristics of Ge in hydrothermal fluids, the authors speculate that the Ge-rich fluids originated from thermal convection and the interaction between surface freshwater carrying O2 and hydrothermal fluids from the mantle.

Strontium isotopes in high- and low-Ge coals from the Shengli Coalfield, Inner Mongolia, northern China: New indicators for Ge source

The coal-hosted Ge deposit (Early Cretaceous) at Wulantuga, Inner Mongolia, northern China, is one of the largest Ge deposits in the world. Although the origin, modes of occurrence, and spatial distribution of Ge in this deposit have been investigated by several studies, the provenance and pathways of Ge from the source to the deposit are largely unknown. In this study, we investigated the 87Sr/86Sr values in the high-Ge coal of the Wulantuga deposit and the stratigraphically-equivalent low-Ge coal of the No. 1 Pit, both from the Shengli Coalfield, Inner Mongolia, northern China. In addition to an organic association, Sr and Ca in the high-Ge and low-Ge coals also occur in gypsum. The water-soluble Sr (i.e., in gypsum) in the high-Ge coal (Ge concentrations: 45–1170 ppm, 273 ppm on average, whole coal basis) has 87Sr/86Sr values in the range of 0.710411 to 0.710633 (with an average of 0.710478). In contrast, the low-Ge coal (Ge concentrations: up to 4.23 ppm, 0.45 ppm on average, whole coal basis) has lower 87Sr/86Sr values in two sub-groups, a low range of 0.709896–0.71005 (with an average of 0.709736) and a high range of 0.710173–0.710547 (with an average of 0.710329 and dominantly in the range of 0.710173–0.710406). The higher 87Sr/86Sr values in the high-Ge coals indicate that the highly-elevated concentration of Ge is associated with a local source of radiogenic Sr. The enrichment of Ge in the coal is due to several consecutive processes. Surface waters penetrated deeply into granite and dissolved at least partially more soluble phases of the granite. The Ge-rich solution flowed over ground or underground into the Shengli Coalfield and Ge precipitated in the peat, the precursor of the coal investigated in the coalfield. The 87Sr/86Sr values of the water-soluble fraction, the elemental compositions of high-Ge and low-Ge coals, and the geomorphological setting of the coalfield point to the Hercynian granodiorite intrusion on the nearby SE margin of the Shengli Coalfield as the primary source of Ge in the Wulantuga coal-hosted Ge deposit. In addition to serving as an indicator of the mode of formation of the coal-hosted Ge deposit, the 87Sr/86Sr values and their spatial distribution can provide an indication for the hydrological pathways of the mineralising fluid.

Coal Petrology Effect on Nanopore Structure of Lignite: Case Study of No. 5 Coal Seam, Shengli Coalfield, Erlian Basin, China

The pore structure of lignite reservoirs is affected mainly by the maceral composition of coal and depositional conditions due to geothermal effects without thermogenic hydrocarbon generation. Low-temperature nitrogen adsorption (LT-NA) and low-temperature carbon dioxide adsorption (LT-CA) were used to characterize nanopore structure. Sub-maceral identification allowed characterization of coal petrology features. The coal samples were rich in huminite—mainly attrinite and densinite—and had medium inertinite content, dominated by fusinite. The micropore volume varied from 0.036 to 0.077 cm3/g, controlling the pore specific surface area. Three pore types were identified from LT-NA isotherms. Hysteresis coefficients were used to describe quantitatively the pore types. Low tissue preservation index and vegetation index, moderate gelification index, and groundwater influence values indicate that the No. 5 coal seam (Shengli coalfield, Erlian basin, China) was deposited in limnic to limno-telmatic environments with relatively high levels of reduction and supply of marginal aquatic/herbaceous vegetation. Poor preservation of plant structure and hydrodynamic conditions, more developed marginal aquatic/herbaceous vegetation, and high ratio of huminite to inertinite contributed to high micropore content and low mesopore content. Based on sharp variations in coal macerals, coal facies indices, dried ash yield (Ad), and organic sulfur (So,d), three sedimentary cycles were distinguished. Pore structures were controlled by the sedimentary environment. Micropores increased with enhanced reduction and reduced oxidation. When the redox of the sedimentary environment showed little variation, mesopores increased with rising hydrodynamic conditions.

Mapping Annual Land Disturbance and Reclamation in a Surface Coal Mining Region Using Google Earth Engine and the LandTrendr Algorithm: A Case Study of the Shengli Coalfield in Inner Mongolia, China

The development and utilization of mining resources are basic requirements for social and economic development. Both open-pit mining and underground mining have impacts on land, ecology, and the environment. Of these, open-pit mining is considered to have the greatest impact due to the drastic changes wrought on the original landform and the disturbance to vegetation. As awareness of environmental protection has grown, land reclamation has been included in the mining process. In this study, we used the Shengli Coalfield in the eastern steppe region of Inner Mongolia to demonstrate a mining and reclamation monitoring process. We combined the Google Earth Engine platform with time series Landsat images and the LandTrendr algorithm to identify and monitor mining disturbances to grassland and land reclamation in open-pit mining areas of the coalfield between 2003 and 2019. Pixel-based trajectories were used to reconstruct the temporal evolution of vegetation, and sequential Landsat archive data were used to achieve accurate measures of disturbances to vegetation. The results show that: (1) the proposed method can be used to determine the years in which vegetation disturbance and recovery occurred with accuracies of 86.53% and 78.57%, respectively; (2) mining in the Shengli mining area resulted in the conversion of 89.98 km2 of land from grassland, water, etc., to barren earth, and only 23.54 km2 was reclaimed, for a reclamation rate of 26.16%; and (3) the method proposed in this paper can achieve fast, efficient identification of surface mining land disturbances and reclamation, and has the potential to be applied to other similar areas.

New Data and Evidence on the Mineralogy and Geochemistry of Wulantuga High-Ge Coal Deposit of Shengli Coalfield, Inner Mongolia, China

The mode of occurrence and origin of highly-enriched trace elements, especially Ge, in Wulantuga high-Ge coal deposit have been widely reported. In this study, coal samples and several coalified trunks embedded within the roof strata are collected, which provides a good opportunity to further confirm if Ge is mainly associated with organic matter. Minerals in coal samples are mainly quartz, kaolinite, montmorillonite, pyrite, and gypsum, along with trace albite, barite, chlorite, and Fe-oxide, while those in coalified trunk samples include melanterite, pyrite, and gypsum, with traces of chlorite and magnesiocopiapite. Germanium, As, W, Sb, Hg, Be, and Cs are enriched in coal samples, and these elements are also enriched in the coalified trunks and roof glutenite. The elevated contents of Ge, As, W, Sb, and Hg were almost exclusively derived from the influx of hydrothermal fluids as evidenced by the presence of pyrite veins and chamosite as well as enhanced elemental associations of Ge-W and As-Sb-Hg in the studied lignite samples. The coalified trunks in the study area should be taken into consideration due to the high contents of hazardous elements that cause potential environmental impacts during mining waste disposal and land reclamation.

Formation Environment of Main Brown Coal Seam in Xi-2 Minefield of Shengli Coalfield Based on Coal Ash Phase Analysis

Abstract The formation environment of the main coal seam in Shengli coal mine is analyzed, and the effect of coal ash parameters on the coal-forming environment is mainly discussed according to gray component parameters combined with other coal quality test analysis data. Results show that the hydrodynamic conditions of the main coal during coal accumulation have a general pattern of strong northeast and weak southwest, and lakeside swamp is generally in the retrograde process from south to north. The No.5 coal seam is a water entry cycle, and the No.5lower coal is a water withdrawal cycle. The No.6 thick coal seam is formed in the peat swamp environment where the water is shallow and the groundwater activity is weak. The input of terrestrial debris material was most abundant in the formation period of No.5lower coal, followed by No.5 coal, and that in No.6 coal is the least. Vertically, the peat swamp environment changed from weak reduction to weak oxidation to strong reducing environment. The ash yield was low to high to low from bottom to top. The organic sulfur is the main type of sulfur in the main coal seam. The weaker the hydrodynamic condition, the higher the organic sulfur content in the reduction environment, while lower organic sulfur content in the oxidation environment. The peat swamp water of No.5lower coal is medium alkaline, and the peat swamp water of No.5 and No. 6 coals is weakly alkaline or acidic.

Peat-Forming Environments and Evolution of Thick Coal Seam in Shengli Coalfield, China: Evidence from Geochemistry, Coal Petrology, and Palynology

Due to the importance of the wide occurrence of thick coal seams for Chinese coal resources, the origins of these seams have received considerable attention. Using the Early Cretaceous No. 5 coal seam with a thickness of 16.8 m in Inner Mongolia as a case study, this paper presents a systematic investigation of the coal petrology, geochemistry, and palynology of 19 coal samples to explain the origin and evolution of peat accumulation. The results indicate that the No. 5 coal seam is generally characterized by low rank (lignite), dominant huminite (average = 82.3%), intermediate ash yield (average = 16.03%), and sulfur content (average = 1.12%). The proportion of spores generally increases from the bottom to the top of the coal seam, whereas the proportion of pollen decreases. The vegetation in the coal seam is dominated by gymnosperms at the bottom and by ferns at the top. The paleographic precursor peat was most likely accumulated in the lakeshore where herbaceous and bushy helophytes were dominant. The total sulfur content was positively related to the huminite content. The sulfur content was possibly derived from bacterial action with sulfur brought in via marine incursions. Three overall declining-increasing values of carbon isotopes within the No. 5 coal seam possibly indicated three general cooling trends during peat accumulation. The environment of peat accumulation included three cycles, including one drying-wetting-drying in the bottom part and two drying-upwards cycles in the upper part. These cycles of the peat-accumulation environment could likely be ascribed to climate change because of their good agreement with humidity signals from plant types at that stage.

Bacterial removal of sulfur from the China lignite by a newly isolated bacterium, Sinomonas flava XL4

The lignite coal collected from Shengli coalfield of Inner Mongolia Autonomous Region in China contains about 5.22% by mass total sulfur with a gross calorific value of 6329 cal g−1. In the present work, the coal sample was subjected to desulfurization by using a new bacterium isolated from the native coal mine site. The native bacterium was identified to be Sinomonas flava XL4 based on the 16S rDNA gene sequence analysis, and reported first time for the capability to remove about 44% of total sulfur from the lignite coal. The influence of various process parameters such as medium pH, incubation time, pulp density, particle size, incubation temperature on sulfur removal from the lignite after S. flava XL4 treatment was investigated, and the experimental results showed that the total sulfur content of lignite coal was reduce to 2.92% under optimum reaction conditions. In addtion, the calorific value of lignite coal after bacterium desulfurization increased from 6329 to 6678 cal g−1, and the ash content was eliminated. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 374–379, 2016

Petrological, geochemical, and mineralogical compositions of the low-Ge coals from the Shengli Coalfield, China: A comparative study with Ge-rich coals and a formation model for coal-hosted Ge ore deposit

To better understand the formation mechanism of coal-hosted Ge ore deposits, this paper reports on the petrological, mineralogical, and geochemical compositions of the low-Ge coals in the Shengli Coalfield (Inner Mongolia, China), using optical microscopy, field emission-scanning electron microscopy, X-ray fluorescence, X-ray diffraction, and inductively coupled plasma mass spectrometry. The samples in the present study closely neighbor the previously-reported Wulantuga coal-hosted Ge ore deposit (both No. 6 Coal). In comparison with the Wulantuga Ge-rich coals, the low-Ge coals of the Shengli field display higher moisture (27.59% on average) and lower pyritic sulfur contents (0.53%). Both the low-Ge and Ge-rich coals are generally high in inertinite, and have varying but relatively low huminite contents. Preservation of fecal pellets as macrinite is notable in both the low-Ge and Ge-rich coals, and the position of the fecal pellets appears to be within tunnels or chambers within the wood. Quartz, kaolinite, pyrite, and gypsum are the major crystalline phases identified in most of the Ge-rich and low-Ge coals, but the low-Ge coals contain significantly less pyrite and are more abundant in non-mineral Ca and Mg. Ca-oxalate of authigenic origin is observed, generally occurring as cell-fillings in the low-Ge coals. Otherwise mineral-free organic matter in the low-Ge coals would be expected to have an inherent ash yield of around 6%, derived from the inorganic elements (mainly non-mineral Ca and Mg) that occur either in the organic matter or as dissolved ions in the pore water and form the sulfate species in low-temperature (oxygen-plasma) ash residues. The highly-elevated trace elements, including Be, Ge, As, Sb, W, Hg, and Tl, that occur in the Ge-rich coals of the Wulantuga deposit, are significantly depleted in the low-Ge coals. Lateral migration of Ge–W- and As–Hg–Sb–Tl-rich solutions through the original peat swamp for the Wulantuga Ge ore deposit has led to significant enrichment of Ge on the margin of the coal basin but decreasing Ge concentrations toward to the inner part of the basin. Such a migration direction is different to those in the previously-reported for the hydrothermal solutions in the Lincang (Yunnan of China) and Spetzugli (Russian Far East) Ge ore deposits, where the solutions migrated vertically from granite to peat along faults and led to a dome-shaped Ge distribution in the relevant coal seam.

Evolution of Organic Sulfur in the Thermal Upgrading Process of Shengli Lignite

Thermal upgrading is a promising way to improve the quality and broaden the range of use of lignite. This paper investigated the characteristics of organic sulfur evolution in a Chinese lignite from Shengli coalfield in the process of thermal upgrading by a fluidized-bed reactor under different atmospheres. The results showed that 5 min of fluidization of feed coal within the temperature range from 200 to 500 °C was capable to obtain a preferable upgraded coal with the increase of the calorific value and the decrease of the moisture. The removal of total sulfur via thermal upgrading, reaching the top at about 60%, was attributed to the evolution of organic sulfur. X-ray photoelectron spectroscopy results showed that aliphatic, aromatic and thiophene, and sulfone sulfur were the major organic sulfur species in Shengli lignite (SL). Aliphatic sulfur was the most unstable organic sulfur and began to release at 200 °C. Aromatic sulfur was found to release at 300 °C. Thiophene sulfur was most stable and could ...

Based on the Visual Modflow Surge Water Numerical Simulation Study

The detailed analysis in shengli coalfield, two East open-pit coal mine geological ， hydro-geological characteristics and groundwater recharge, Runoff, drainage patterns. And on the analysis results of this analysis are mining areas of conceptual models of hydrogeology, numerical calculation method based on Visual Modflow first mining district 4 coal mine water water-bearing rock group. This article by multiple regression method using logging parameter estimation of permeability coefficient, solved in numerical simulation used in hydrological study on permeability coefficient of hole to determine does not meet the need of traditional issues.

Ge distribution in the Wulantuga high-germanium coal deposit in the Shengli coalfield, Inner Mongolia, northeastern China

Abstract The geological and geochemical controls of the Ge distribution in the Cretaceous Wulantuga high-Germanium coal deposit in the Shengli coal field, Inner Mongolia are investigated. This paper focuses mainly on the spatial distribution of the Ge contents in coal. The high-Ge coals mainly occur in three splits of the #6 coal in the southwestern part of the Shengli coal field. Mean germanium contents in the coal range from 32 to 820 μg/g, with a mean value of 137 μg/g, on a bulk coal basis (mean of 939 coal samples from 75 boreholes in the #6 coal seam) in an area of 2.2 km 2 . The highest Ge content occurs SW of #6 coal seam, close to the margins of the coal basin, decreasing with a fan-shaped trend towards NW, the direction of the coal basin. There is an negative correlation between the mean Ge content and the thickness of the coal seam. Different distribution patterns of Ge content were found in vertical profiles. High Ge concentrations may occur in the middle parts of coal seams, at the bottom and/or the top of thick coal seams and inconspicuous variation. A major organic affinity was determined for Ge, with a special enriched in the banded bright and semibright coal. The high-Ge coals and the coalified wood in the sandstone overlaying the #6-1 coal highly enriched in Ge, As, Sb, W, Cs, Tl, Be, and Hg. The Late Jurassic silicified volcanic rocks in the NW of the Ge coal deposit relatively high enriched in Ge, Ga, Sb, As, Cs, Be, Ge and Hg. The correlation coefficients among the elements enriched showed marked variations at close sites in this deposit, suggesting a possible diagenetic origin of the geochemical anomaly. The main Ge anomaly was attributed to early Cretaceous hydrothermal fluids circulating through the fault systems and porous volcanic rocs, probably from the subjacent granitoid rocks. The fault systems, the porous coarse clastic rocks overlying coal seam and the lithotype of coal played an important role in the transport and trapping of Ge. A main diagenetic origin (overlapping a slight synsedimentary accumulation) is deduced for the Ge anomaly.

Research on Element Geochemical Characteristics of Coal-Ge Deposit in Shengli Coalfield, Inner Mongolia, China

The newly found coal-germanium deposit in Shengli Coalfield in Inner Mongolia is a super-scale germanium deposit. It is the largest coal-germanium in the world with 1805 ton proven resource of germanium. In this deposit, the elemental geochemical characteristics show that the alkaline elements, such as Ca, K, Na, Mg, Al, and so on are enriched, and positively correlated to germanium; that with increasing germanium content, LREE enrichment is gradually weakened and HREE is gradually enriched; that the germanium content is negatively correlated to ∑REE and LREE, while positively to LREE/HREE and δEu, and negatively to La/Yb, La/Sm, (La/Yb) n, (La/Sm) n and δCe; that the content of germanium is negatively correlated to ash index of coal. The coal-forming swamp with sluggish water favored the sufficient absorption of germanium from solution by organic matters. The coal-germanium deposit of Shengli Coalfield is formed in the weaker alkaline and stronger reductive environment. REE geochemical characteristics in coal-germanium deposit have inheritance, and REE mainly comes from inorganic materials in the source area. And, the rocks from the southwest margin of the basin are rich in germanium, and probably become the original source of germanium of this coal-germanium deposit. The supply of germanium from the source area and the hydrologic geology conditions for germanium coming into coal forming swamps are the controlling factors for germanium enrichment.

REE Geochemistry of the Cretaceous lignite from Wulantuga Germanium Deposit, Inner Mongolia, Northeastern China

The Wulantuga Germanium Deposit (WGD), hosted in coal seams with Ge resources up to 1600 Mt, is located in the Shengli Coalfield in Xilingol, Inner Mongolia, China. Forty-two channel samples of Ge-bearing lignites of the No. 6-1 coal seam (Lower Cretaceous Bayanhua Formation) were collected and their REE compositions were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The modes of occurrence of REE in selected lignite samples were studied by scanning electron microscope with energy-dispersive X-ray spectrometer (SEM-EDX) and statistical methods. The distribution of REE and Y in all 42 samples from WGD are in accordance with the log normal distribution, the total rare earth element content (∑REE) of most lignite samples from WGD range from 9.02 to 118 ppm, only four samples show relatively higher (149–533 ppm) ∑REE concentration. The average REE contents of 42 lignite samples from WGD are slightly higher than those of the USA coals, world wide coals, sandstone from WGD, and the contemporary Ge-barren lignite from Hongqi Coal Mine. The lignite samples from WGD have shale-like Chondrite or NASC-normalized REE patterns similar to those of sandstone overburden and Ge-barren lignite from Hongqi Coal Mine. REE contents of most lignite samples are highly positive correlated with ash yields, indicating a mainly detrital source and association with syngenetic mineral matter. REE-rich phosphates (monazite) were identified by SEM-EDX in some medium-to high-ash (ash yields range from 23.58% to 38.18%) lignite samples with high ∑REE + Y contents from WGD. REE can be concentrated in the upper and lower proportions of the No. 6-1 coal seam. The vertical profiles of REE mainly follow that of TiO 2 , and the average REE/TiO 2 ratio of lignite sample in three sections is very close to that of the sandstone from WGD or lignite from Hongqi Coal Mine. It was determined that most REE in the lignite from WGD were derived from a detrital source and associated with syngenetic mineral matter. However, when normalized to the overlying sandstone, some lignite samples from WGD display a small but distinct enrichment in middle-to heavy-REE, indicating small quantity of middle-to heavy-REE may be added and/or retained during epigenesis. The lignite samples from WGD are characterized by higher ratios of LREE/HREE and Eu/Eu*, and horizontal NASC-normalized REE patterns, and distinguished from those of the Ge-bearing lignites from Lincang Germanium Deposit, Yunnan, China and Ge deposits of Russian Far East. There is no distinct correlations between Ge and any individual REE or ∑REE + Y content of lignite from WGD.