Re: Quality of CH coals?
Thank you all for your answers. I have noticed that the coals that tend to crumble are the ones taken from the top or the bottom of the box. It is possible that pressure or shock may have caused "microfractures" that turn into a disaster as the coal combusts.
Tonight, I will examinate a few samples of CH coals with a magnifier and try to spot anomalies or corruption in their physical structure.