In industrial contexts, a number like usually serves one of three purposes:
: In rare cases, it can denote a specific blend or grade of coal (e.g., thermal vs. metallurgical) that meets certain BTU or sulfur content standards. The Economic & Industrial Context ALEX COAL 306
: Moving coal from a mine to a furnace involves a handoff between extraction teams, transport operators, and environmental regulators. In industrial contexts, a number like usually serves
: It may refer to a specific mine portal or "section" within a larger mining complex owned by the company. In industrial contexts