Coal dust explosions in underground coal mines are pre­ vented by a generous application of rock dust (usually lime­ stone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents fl ame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of ex­ plosion experiments using various coal dust and limes...

iran has high potential and unique stone reserves in terms of variety of color, texture, quality, and economic value; nevertheless, in spite of growing mine production during the past decade, in many instances this potential has been overlooked. therefore it is necessary to investigate strategic factors of these mines. the purpose of this study is to evaluate and determine the best strategies f...