An economic evaluation of backfilling in Virginia's coal mines

Abstract

Backfilling is a technique used to place material in the voids created by underground mining. This technique has been used extensively abroad to reduce surface subsidence, fire hazards, and temperatures in underground workings. It can also help to eliminate environmental problems caused by coal waste dumps, improve coal recovery, and improve mine ventilation. However, backfilling is an additional operation in the coal mining cycle that can reduce productivity and increase production costs. This thesis identifies the backfilling methods applicable for coal mines in southwest Virginia. Following identification of variables that can affect the selection of a backfilling method, a multi-attribute decision analysis technique is developed. This technique is applied to a mine model which is representative for the mining conditions in southwest Virginia. An evaluation of the two most Suitable backfilling methods using coal refuse as fill material is then made and compared to the surface disposal of coal refuse.