Two Lift Longwall Mining Method For Mid-Continent Resources, Inc. 28-Foot Thick Seam (Joint DOE/MCR Project)

INTRODUCTION The United States has an abundance of coal reserves in thick seams. Most of these resources are in the West. Surface mining operations in thick seams are highly efficient, particularly in the West, but methods for mining thick seams underground are very limited. The percentage of resource recovery in deep mining of thick seams is often as low as 30 percent. It is estimated that there are 45 billion tons of coal reserves for underground mining in seams greater than 10-ft thick in the western states alone. With such a large available reserve base and low rates of recovery, the need to develop the technology to mine these thick reserves is quite evident. As the definition of a thick seam varies widely from country to country, a thick seam is defined here as any seam where the height is such that it is not minable in a single pass with available mining equipment.