At the moment the United States Economic Reduction company, using bromination, is in operation on ore from the Cripple Creek district.

The cooler is a hollow cylinder, 6 ft. diameter and 16 ft. long, with a spiral vane on its inner surface. The major portion of its weight is borne by the water in which it rotates, although it has roller supports at the ends. A spray of water plays on the cooler from above to keep the surface always wet and prevent the accumulation of steam in the mill building.
The machine requires but little power, as it can be turned by hand. At its present capacity of 35 tons per twenty-four hours, the ore is cooled sufficiently in half the length of the cylinder, and is discharged at a temperature of about 100 deg. Fahr.
This type of cooler is in use at the works of the United States Zinc Company, Pueblo, Col., and was also used in the old Economic mill at Florence during the days when chlorination of Cripple Creek ore was practiced.