| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Humic coals | Mining | A. A group of coals, including the ordinary bituminous varieties, that have been formed from accumulations of vegetable debris that have maintained their morphological organization with little decay. The majority of them are banded and have a tendency to develop jointing or cleat. Chemically, humic coals are characterized by hydrogen varying between 4% to 6% b. Coals in which the attritus may be composed predominately of transparent humic degradation matter c. Introduced in 1906 by H_ Potonie to describe coals, the original organic matter of which underwent change chiefly by humification; i.e, through the process of peat formation in the presence of oxygen. Most seams of coal consist principally of humic coal and the technological properties vary with their rank, with their petrographic composition, and with the manner of distribution of mineral inclusions i.e, through the process of peat formation in the presence of oxygen. Most seams of coal consist principally of humic coal and the technological properties vary with their rank, with their petrographic composition, and with the manner of distribution of mineral inclusions. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
