I don't have any real information about this. The video title and some of the comments on various websites talk about a Chinese coal mine using steam (still?), and igniting coal dust in the air. The video gets more spectacular towards the end. <iframe width="560" height="315" src="" frameborder="0" allowfullscreen></iframe>
Rocket, your post, and the follow-on videos are wonderful for steam foamers like myself. Thanks so much for finding and sharing it.
I doubt that it is coal dust, as such. I would believe the way the firebox drafts, grates function, soot in flues igniting....