What is a dust explosion?

Wu Chunping, senior engineer at Beijing General Research Institute of Mining and Metallurgy, said a dust explosion is the combustion of particles suspended in air in an enclosed space. There are seven types of explosive particles, including coal dust, grains and feeds and powdered metals such as aluminum. A spark or flame, such as a fire, an overheated surface or an electrical discharge from machinery, can trigger a blast, Wu said.