Post
by lsayre » Sun. Dec. 02, 2018 7:12 am
I'm going to presume that many people feel that if one anthracite coal weighs more for a given volume than another anthracite coal, it is better coal by virtue of its greater weight (density).
In actuality, the lighter that anthracite is with respect to weight by volume, the higher its pure carbon concentration is likely to be, and the lower its ash and impurities are likely to be, and the greater its heat value will likely be.
My reasoning in this is that breakers float coal in order to allow for rocks and impurities to sink and thereby be separated and removed. So carbon must be lighter than rocks and other impurities. The more carbon, the better it floats. The more carbon, the lighter it is.
To be honest, this one has been debated heavily over the years, and I'm not certain that it has been definitively resolved.....