Iron ore: energy, labor, and capital changes with technology.

摘要: Resource gathering is depending on leaner crude ores. Iron ore mining typifies this trend. To make lean taconite iron ores useful required a technologic breakthrough—pelletization. The shift to pellets has the advantage that they require less energy and labor per ton of molten than high-grade naturally concentrated Increased reliance causes geographic some jobs environmental effects from blast furnaces mines.