Operating a Large-Scale Opencast Mine in the Rhenish Lignite-Mining Area – Tasks and Challenges in Operating the Hambach Mine

2015 ◽  
pp. 263-282
Author(s):  
Hans-Joachim Bertrams
Keyword(s):  
Large Scale ◽  
Mining Area ◽  
Lignite Mining ◽  
Opencast Mine

scholarly journals Three-Dimensional Regularized Focusing Migration: A Case Study from the Yucheng Mining Area, Shandong, China

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 471
Author(s):  
Yidan Ding ◽  
Guoqing Ma ◽  
Shengqing Xiong ◽  
Haoran Wang
Keyword(s):  
Large Scale ◽  
Mineral Exploration ◽  
Gravity Data ◽  
Three Dimensional ◽  
Mining Area ◽  
Model Parameters ◽  
Step Size ◽  
Migration Direction ◽  
Migration Imaging ◽  
Imaging Results

Gravity migration is a fast imaging technique based on the migration concept to obtain subsurface density distribution. For higher resolution of migration imaging results, we propose a 3D regularized focusing migration method that implements migration imaging of an entire gravity survey with a focusing stabilizer based on regularization theory. When determining the model parameters, the iterative direction is chosen as the conjugate migration direction, and the step size is selected on the basis of the Wolfe–Powell conditions. The model tests demonstrate that the proposed method can improve the resolution and precision of imaging results, especially for blocky structures. At the same time, the method has high computational efficiency, which allows rapid imaging for large-scale gravity data. It also has high stability in noisy conditions. The developed novel method is applied to interpret gravity data collected from the skarn-type iron deposits in Yucheng, Shandong province. Migration results show that the depth of the buried iron ore in this area is 750–1500 m, which is consistent with the drilling data. We also provide recommendations for further mineral exploration in the survey area. This method can be used to complete rapid global imaging of large mining areas and it provides important technical support for exploration of deep, concealed deposits.

scholarly journals Water Preservation and Conservation above Coal Mines Using an Innovative Approach: A Case Study

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2818
Author(s):  
Yujun Xu ◽  
Liqiang Ma ◽  
Yihe Yu
Keyword(s):  
Coal Mining ◽  
Water Conservation ◽  
Large Scale ◽  
Influencing Factor ◽  
Mining Area ◽  
Mining Operations ◽  
Narrow Strip ◽  
Geological Conditions ◽  
The Impact

To better protect the ecological environment during large scale underground coal mining operations in the northwest of China, the authors have proposed a water-conservation coal mining (WCCM) method. This case study demonstrated the successful application of WCCM in the Yu-Shen mining area. Firstly, by using the analytic hierarchy process (AHP), the influencing factors of WCCM were identified and the identification model with a multilevel structure was developed, to determine the weight of each influencing factor. Based on this, the five maps: overburden thickness contour, stratigraphic structure map, water-rich zoning map of aquifers, aquiclude thickness contour and coal seam thickness contour, were analyzed and determined. This formed the basis for studying WCCM in the mining area. Using the geological conditions of the Yu-Shen mining area, the features of caved zone, water conductive fractured zone (WCFZ) and protective zone were studied. The equations for calculating the height of the “three zones” were proposed. Considering the hydrogeological condition of Yu-Shen mining area, the criteria were put forward to evaluate the impact of coal mining on groundwater, which were then used to determine the distribution of different impact levels. Using strata control theory, the mechanism and applicability of WCCM methods, including height-restricted mining, (partial) backfill mining and narrow strip mining, together with the applicable zone of these methods, were analyzed and identified. Under the guidance of “two zoning” (zoning based on coal mining’s impact level on groundwater and zoning based on applicability of WCCM methods), the WCCM practice was carried out in Yu-Shen mining area. The research findings will provide theoretical and practical instruction for the WCCM in the northwest mining area of China, which is important to reduce the impact of mining on surface and groundwater.

Evidence for Iron- and Sulfur-Oxidizing Bacteria and Archaea in a Currently Active Lignite Mining Area of Lusatia (Eastern Germany)

2009 ◽  
Vol 71-73 ◽  
pp. 97-100 ◽  
Author(s):  
H.M. Siebert ◽  
Thore Rohwerder ◽  
Wolfgang Sand ◽  
M. Strzodka ◽  
K.P. Stahmann
Keyword(s):  
16S Rrna ◽  
Mining Area ◽  
16S Rrna Genes ◽  
Open Pit ◽  
Rrna Genes ◽  
Published Data ◽  
Lignite Mining ◽  
Two Samples ◽  
Pure Cultures ◽  
Sulfur Oxidizing

The largest lignite mining area in Europe is located 150 km southeast of Berlin. Acidic lakes exist in this area, known to be caused by marcasite oxidation. Thirty-two samples from the open-pit brown coal-mine Jaenschwalde were analyzed for microorganisms. Cell numbers determined after separation from sand particles revealed concentrations of 102 to 107 microorganisms per g sample. In samples exposed to the air within an hour, up to 4x107 cells were counted. Measurement of metabolic activity by microcalorimetry showed for such samples up to 50 µW per g sand, whereas in heap samples (with low moisture) low or even no activity was measurable. DNA extraction was successful for 28 samples. In 26 samples microbial 16S rRNA genes were amplified by PCR. Acidithiobacillus ferrooxidans and At. thiooxidans specific amplificates were detected by nested PCR in 23 and 10 cases, respectively. A specific signal indicating Leptospirillum ferrooxidans was obtained with nine samples. Random samples were sequenced and showed 96 to 99 % identity with published data of all three species. Surprisingly, in four samples archaeal 16S rRNA genes were amplified by PCR. Sequencing of two samples showed 99 % identity with unidentified or uncultured archaea found in NCBI-databases. Molecular biology results for At. ferrooxidans as well as for At. thiooxidans were supported by successful isolations of pure cultures in 23 cases. Cultivation of the archaea failed so far. These data indicate that iron- and sulfur-oxidizing microorganisms occur at these sites in large numbers. If in addition the evidence for archaea can become verified, a screening for hot spots as the sites of their occurrence would become interesting.

scholarly journals Study on the mechanism of water inrush in the arid western mining area

2019 ◽  
Vol 118 ◽  
pp. 03008
Author(s):  
Chao Zheng ◽  
Lan Yu ◽  
Jiangyi He ◽  
Fengfeng Yang ◽  
Jufeng Zhang
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Water Inrush ◽  
Hydrodynamic Pressure ◽  
Mining Area ◽  
Mining Areas ◽  
Isolation Layer ◽  
Working Face ◽  
Combined Action ◽  
Tension Fracture

The analysis found that the coal mining process in the western mining area has the mining loss and disaster effect of the water-rich aquifer of the coal seam roof, which is mainly manifested by the overburden water in the roof. On this basis, the formation and development of the separation water of the roof is proposed, and the mechanism of the water inrush from the layer is revealed. It is found that there is hydrostatic pressure and hydrodynamic pressure in the separated water, under the combined action of bed separation water pressure, the mining-induced fracture and water-isolation layer tension fracture are connected, which causes water inrushing in the coal working face of the mine, and provides a theoretical guarantee for the large-scale development of coal resources in western mining areas.

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