th is paper addresses the evolut ion of longwal l mining in the United States from the initial "longwall" method, utilizing hand loading and manual haulage to the progress ive mechanizat ion of the face equipment . An analysis of accident information for specific benchmark dates in United States longwall evolution and a review of productivity (for the period of 1963 1973) are provided to demons...

Methane emissions from a longwall ventilation system are an important indicator of how much methane a particular mine is producing and how much air should be provided to keep the methane levels under statutory limits. Knowing the amount of ventilation methane emission is also important for environmental considerations and for identifying opportunities to capture and utilize the methane for ener...

There are two major design problems for upper seam longwall gateroads operating in a multi-seam environment. The first is to determine the location, magnitude and duration of stress transferred from lower seam mines; and the second is to predict the effect of stress transferred from lower seam mines on opening stability. To solve these problems for both longwall and room-and-pillar mines, case ...

Effective gas management is vital to the success of the longwall mining in the Bulli seam, in the Southern Coalfield, Sydney Basin, NSW, Australia. The evolution of gas drainage methods and practices are discussed with respect to gas type, gas drainage lead time and prevailing geological conditions. Both underground to inseam drilling and surface to inseam drilling techniques are described at b...

This paper describes successful industrial research and development in the area of underground coal mining equipment automation. A brief background to underground coal mining is given, and the process of longwall mining is detailed. Some of the major limitations and issues impacting on the productivity and safety of the longwall mining process are highlighted, which serve to motivate the automa...

Comprehensive assessments of the need for additional methane control capacity beyond ventilation often require both an empirical and theoretical approach for an adequate or timely control of increased methane emission levels. Thus, the prediction of methane emissions and optimization of methane control systems prior to starting a new mining operation will be a major improvement towards eliminat...

Methane emissions from the active face areas and from the fractured formations overlying the mined coalbed can affect safety and productivity in longwall mines. Since ventilation alone may not be sufficient to control the methane levels on a longwall operation, gob vent boreholes (GVB), horizontal and vertical drainage boreholes, and their combinations are drilled and used as supplementary meth...

This paper presents technical and application aspects of a new software suite, MCP (Methane Control and Prediction), developed for addressing some of the methane and methane control issues in longwall coal mines. The software suite consists of dynamic link library (DLL) extensions to MS-Access written in C++. In order to create the DLLs, various statistical, mathematical approaches, prediction ...

In advance longwall mining, the safety of mine network, production rate, and consequently, economic conditions of a mine are dependent on the stability conditions of gate roadways. The gate roadway stability is a function of two important factors: 1) characteristics of the excavation damaged zone (EDZ) above the gate roadway and 2) loading effect due to the caving zone (CZ) above the longwall w...

Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the a...