With the rapid increase of fuel prices in the last two years, there has recently been reconsideration of the application of crushing and conveying in open pit mines. This presentation examines their potential role in hard rock base metal and gold mines.

Gangue is the solid waste in the process of coal mining & washing with the main component of alumina, silicon oxide, iron oxide, calcium oxide, magnesium oxide, sodium oxide, etc. The gangue emissions occupy 10%-15% of the total coal emissions.