‘you have to keep turning it to keep it from igniting’
I didn’t know that. Is it due to moisture?
Spontaneous combustion. You have to compact it. It’s not a big deal usually. Coal handlers keep a watch on it. They can smother it by working it. I read once where the coal pile was neglected a portion of of it collapsed when they tried working it (too little too late) and they lost a dozer and operator but that is rare.
I don’t know if its like rags that have oil, gas etc on them where they spontaneously combust if you pile them together or what but I had a friend & that was his job was to work a front loader & keep turning the coal.