Another important application for bacterial bioleaching is the removed of the sulphur-containing pyrite from high-sulphur coal. Little use is now mate of high-sulphur coal because of the sulphur dioxide pollution that occurs with burning. However, as more and more reserves of coal are brought into use, high-sulphur coals cannot be overlooked. Thus the bacterial removal of pyrite (which contains most of the sulphur) from high-sulphur coal could well have huge economic and environmental significance.