Certain lumps that didn't burn well reduced to very white lumps of ash. As opposed to normal coal that disintegrated as it fell to ash. We called those lumps "bats".
When I was installing a weighing machine at the Grimethorpe Colliery they scooped up the dust on wet days and sold it to power station for their fluidised beds. Such power stations had to crush coal into small pieces anyway. Fluidised beds were coal infused with air. It made it easier to transport to the furnace and with the extra surface surrounded by air area it burned more efficiently.
By clicking on the User Name, you will requery the forum for that user. You will see everything that he or she has posted with that Mudcat name.
By clicking on the Thread Name, you will be sent to the Forum on that thread as if you selected it from the main Mudcat Forum page.
By clicking on the Subject, you will also go to the thread as if you selected it from the original Forum page, but also go directly to that particular message.
By clicking on the Date (Posted), you will dig out every message posted that day.
sj