Henderson Mill, Colorado

The Henderson Molybdenum Mill process the rock that comes out of the Henderson Mine, 15 miles east, via a ten mile long underground tunnel. The mill crushes the rock into powder and uses flotation and other methods to produce concentrated forms of molybdenum. The material is shipped from here to a finishing plant in Iowa, and to other processors, who use it in lubricants and metals. Waste material from the mill, including tailings (leftover unused parts of the rock) flow in a slurry further downslope from the plant, into a two-mile long impoundment reservoir. The Henderson Mine and Mill is one of two major molybdenum operations on the Continental Divide, both of which are operated by Climax Molybdenum, part of the Freeport-McMoRan mining company, based in Phoenix, Arizona. The Henderson operation is the the largest source of Molybdenum in the nation.