Longwall Mining, 3rd Edition

1 US longwall mining 
1.1 Introduction 
1.2 Requirements and constraints for high production longwalls 
1.3 Panel layout 
1.4 Mining technique 
1.5 Features and trends of US longwall mining 
1.6 Summary of US longwall development trends 
1.7 Management and human factors in high production longwalls 
2 Longwall mine design 
2.1 Introduction 
2.2 General consideration of panel layout 
2.3 Ground control consideration 
3 Strata mechanics 
3.1 Introduction 
3.2 Overburden movement 
3.3 Abutment pressures, gob caving, and gateroad convergence 
4 Panel development 
4.1 Introduction 
4.2 Distribution and comparison of gateroad development systems 
4.3 Methods and equipment used for gateroad development 
4.4 Rapid development 
4.5 Survey of types of pillar systems in gateroad development 
4.6 Design of chain pillars and barrier pillars 
4.7 Roof support 
4.8 Factors affecting the development rate 
4.9 Determination of required daily panel development footage 
4.10 Examples of gateroad development systems 
4.11 Calculation of coal recovery rate in a longwall panel 
5 Shield support – general 
5.1 Introduction 
5.2 Two-leg shields 
5.3 Elements of shield supports 
5.4 Electrohydraulic control system 
5.5 Performance of shield supports 
6 Shield support – design/selection 
6.1 Introduction 
6.2 Elements of shield design 
6.3 Preliminary determination of the overall dimensions of shield components 
6.4 Determination of external loadings 
6.5 Resultant load on the canopy and floor 
6.6 Determination of floor and roof bearing capacity 
6.7 Torsional strength of shield subject to bias loading 
6.8 Static structural analysis of shield support 
6.9 Testing of full-sized prototype shields and electronic and hydraulic units 
7 Coal extraction by the shearer 
7.1 Introduction 
7.2 Layout of longwall face equipment using the shearer 
7.3 Monorail system 
7.4 Double-ended ranging drum shearer 
7.5 Cutting drums and performance of the shearer 
7.6 Installed power of the shearer 
7.7 Haulage of the shearer 
7.8 Cutting methods of the shearer 
7.9 Coal loading of the shearer 
8 Coal transportation 
8.1 Introduction 
8.2 Layout of coal transportation system 
8.3 Major components of the armored chain conveyor 
8.4 Selection of armored flexible chain conveyor 
8.5 Coal transfer system 
8.6 Operation and maintenance of the armored flexible chain conveyor 
9 Automation of longwall components and systems 
9.1 Definition 
9.2 Automation of three face machines 
9.3 Automation of longwall system 
9.4 The first modern longwall mining system standard 
9.5 Real-time mining condition analysis and problem solving 
9.6 Automated health and safety technologies since the mid-1990s 
9.7 Discussion 
9.8 Summary 335
10 Application issues of longwall mining 
10.1 Factors to be considered in increasing panel width 
10.2 Longwall compatibility test 
10.3 Life cycle management, expert solutions, and equipment re-use services 
10.4 Basic performance requirements for shields 
10.5 Control of adverse roof conditions 
10.6 Two-leg shields vs. four-leg shields and chock shields 
10.7 How to accurately measure the shield hydraulic leg pressure 
10.8 Pre-driven recovery room and mining through open entries 
10.9 Longwall mining under hard-to-cave roof 
10.10 Cutting through a fault 
10.11 Pillar design for gas/oil wells 
10.12 Cyclic failure of strong roof strata and seismic events 
10.13 Faster or slower longwall advancing rate 
10.14 Bottom coal, hard face, soft floor, and AFC creeping – causes, problems, and solutions 
10.15 Stability of gateroad T-junctions subject to high horizontal stresses 
11 Ventilation and methane, dust, and noise controls 
11.1 Introduction 
11.2 Longwall specific ventilation 
11.3 Methane control 
11.4 Dust control 
11.5 Noise control 
12 Longwall face move 
12.1 Introduction 
12.2 Pre-move preparation 
12.3 Move preparation 
12.4 Move 
12.5 Installation of the new face at the set-up room 
13 Longwall power distribution and system control 
13.1 Introduction 
13.2 Electrical power distribution 
13.3 Longwall system control 
14 Surface subsidence 
14.1 Introduction 
14.2 Characteristics of surface movement 
14.3 Effects of geological and mining factors 
14.4 Subsidence prediction, assessment, and mitigation 
14.5 Surface and groundwater effects 
15 Longwall top coal caving mining 
15.1 Introduction 
15.2 Panel and equipment layouts 
15.3 Face equipment 
15.4 LTCC mining technique 
15.5 Automation of LTCC 
15.6 Health and safety issues 
15.7 Theory of withdrawn body in LTCC