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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Added value of using real-time resource reconciliation in coal mining

Yüksel, Cansin, Benndorf, Jörg 28 September 2017 (has links) (PDF)
Recently, an efficient resource model updating framework was proposed with the aim of improving the raw material quality control and process efficiency in any type of mining operation. This includes the integration of online-sensor measurements that are obtained during the production into the resource model. The concept has been applied in a coal mining environment with the aim of identifying local impurities in a coal seam and to improve the prediction of coal quality attributes in neighbouring blocks. The goal of this presentation is to demonstrate how the use of the resource model updating framework can provide added value for the mining industry. Both economical and environmental considerations are taken into account when the added value is investigated.
2

Integrierte Bewertung altbergbaulicher Risikoobjekte des Steinkohlenbergbaus der RAG Aktiengesellschaft

Hager, Stefan 06 September 2023 (has links)
Aktuelle Risikomanagementsysteme verfolgen primär das Ziel, die Vielzahl notwendiger Maßnahmen zur Verwahrung altbergbaulicher Risikoobjekte objektiv und eindeutig zu priorisieren. Unterschiedliche Objektarten werden in separaten Systemen behandelt, auch wenn sich deren Auswirkungen an der Tagesoberfläche regelmäßig überlagen. In der Praxis zeigt sich dies, wenn in großflächigen Maßnahmen viele Objekte gemeinsam bearbeitet werden. Die Limitierung vorhandener interner und externer Ressourcen und die daraus resultierende lange Dauer bis zur Verwahrung aller Risikoobjekte ist der Grund für die Vorgehensweise. Auch wenn die operative Verwahrung schon wegen des Aufwands prioritär erscheint, ist das Ziel die maximale Reduzierung des Gesamtrisikos bei optimaler Nutzung vorhandener Ressourcen. In diesem Beitrag wird eine ganzheitliche Behandlung der altbergbaulichen Risiken vorgestellt. Die Einführung einer linearen Superposition ermöglicht eine modulare Vorgehensweise zur Integration unterschiedlicher Sachverhalte und Objekte in einem System. Neue Erkenntnisse können eingeführt werden, auch wenn sie nur einzelne Risikosachverhalte betreffen. Dabei reichen oft wenige geometrische Parameter, die aus dem markscheiderischen Risswerk oder Sanierungsmaßnahmen abgeleitet werden können. Eine rasterbasierte Berechnung des Risikos aus dem übertägigen Gefährdungspotenzial (= Stärke des Ereignisses) und der Sensibilität der Oberfläche (= Schadensausmaß) ermöglicht es, sinnvolle Bearbeitungsbereiche abzugrenzen. Dabei berücksichtigt eine normalverteilte Nachbarschaftsfunktion die Mobilität der Menschen, um deren Schutz es ja letztlich geht. Die flächennormierte Risikozahl wird zentraler Parameter für eine stets eindeutige Priorisierung. Die im vorliegenden Beitrag vorgestellte Lösung zur ganzheitlichen Bearbeitung altbergbaulicher Risiken wurde ausführlich in der Dissertation (S. Hager, 2022: Integrierte Bewertung altbergbaulicher Risikoobjekte des Steinkohlenbergbaus der RAG AG, TU Freiberg) beschrieben und war Gegenstand eines Vortrags beim Altbergbaukolloquium 2022 in Freiberg.
3

Added value of using real-time resource reconciliation in coal mining

Yüksel, Cansin, Benndorf, Jörg 28 September 2017 (has links)
Recently, an efficient resource model updating framework was proposed with the aim of improving the raw material quality control and process efficiency in any type of mining operation. This includes the integration of online-sensor measurements that are obtained during the production into the resource model. The concept has been applied in a coal mining environment with the aim of identifying local impurities in a coal seam and to improve the prediction of coal quality attributes in neighbouring blocks. The goal of this presentation is to demonstrate how the use of the resource model updating framework can provide added value for the mining industry. Both economical and environmental considerations are taken into account when the added value is investigated.
4

Surface movement due to coal mining and abandoned mine flooding

Zhao, Jian 12 July 2022 (has links)
To better understand the issues about the surface movements in the coal mining region Lugau-Oelsnitz, Germany, small-scale numerical models are firstly utilized for verifications via analytical solutions, to explore the simulation schemes, and for parameter sensitivity analysis. 1D rock column numerical models shows that simulated surface movements are consistent with analytical solutions. The investigations via 2.5D profile numerical models also show that uplift is linear related to water level rise under confined mine water conditions, while a quadratic function is valid for unconfined mine water. Geodetic survey in the Lugau-Oelsnitz district shows that at the end of the active mining period (1844 to 1971), general subsidence is about 5 - 10 m, with a maximum of 17 m in the southern mining area. General uplift velocity after abandoned mine flooding between 1972 and 2014 is about 0.5 - 2.0 mm/year. Based on numerical simulation results, predicted general uplift velocity vary between 0.5 - 3.0 mm/year, while maximum uplift position is moving toward south.:1 Introduction 2 State of the art 2.1 Overview 2.1.1 Coal mining induced settlements 2.1.2 Flooding induced uplift 2.2 Approaches to predict subsidence 2.2.1 Empirical approaches 2.2.2 Influence function methods 2.2.3 Physical models 2.2.4 Numerical simulation methods 2.3 Approaches to predict uplift 2.3.1 Empirical approaches 2.3.2 Numerical simulation methods 2.4 Comparison and conclusions 2.4.1 Comparison of research methods 2.4.2 Conclusions 3 Numerical simulation approaches 3.1 Continuum mechanical simulations with FLAC3D 3.1.1 Mining induced subsidence 3.1.2 Flooding induced uplift 3.2 Discontinuum mechanical simulations with 3DEC 3.2.1 Self-weight induced settlement in jointed rock column model 3.2.2 Uplift for jointed and fully saturated rock column 3.3 Parameter sensitivity study 3.3.1 Parameter effect on subsidence 3.3.2 Parameter effect on uplift 3.4 Interface and volume element representation of faults 3.4.1 Simulation schemes 3.4.2 Parameter sensitivity analysis of fault 3.4.3 Discussion 3.5 Conclusions 4 Case study: Coal mining region Lugau-Oelsnitz 4.1 Background information 4.1.1 Mining background 4.1.2 Geological and hydrogeological situation 4.2 In-situ monitoring data 4.2.1 Groundwater level data 4.2.2 Surface movement data 4.2.3 Discussion of data analysis 4.3 Continuum based numerical modelling 4.3.1 Introduction 4.3.2 Model set-up 4.3.3 Calculation results 4.3.4 Surface movement predictions 4.4 Discontinuum based numerical modelling 4.4.1 Model set-up 4.4.2 Calibration results 4.4.3 Surface movement prediction 4.5 Conclusions 5 Conclusions and prospects 5.1 Conclusions 5.2 Main contributions of thesis 5.3 Inadequacies and prospects

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