System design and safety considerations for grinding high volatile coal

In the last three decades high volatile coal usage as the primary fuel source in cement kilns and calciners has increased. The increase in use of this coal type is primarily due to reduced operating costs. In Germany, almost all cement and lime plants are operating with lignite as their primary fuel. In the United States, South America and Far East the number of cement plants using up to 100% lignite as fuel has risen dramatically. The purpose of this paper is to describe how to safely design and operate a coal grinding, storage and transport system for firing high volatile solid fuels. This paper will include a description of the conditions causing spontaneous ignition in coal, the causes of coal dust explosions, and the necessary precautions needed to counteract the explosiveness of high volatile coal in storage, drying and grinding and transport systems.