November/December 1997
—Robert J. Garino, ReMA director of commodities
Cadmium was discovered in 1817, but it was not used commercially until the beginning of the 20th century. Though cadmium occurs naturally in the mineral greenockite in the form of cadmium sulfide, it is principally recovered as a coproduct of zinc mining and refining. Annual Western World production is believed to be in the neighborhood of 15,000 to 17,000 mt, while U.S. production in 1996 was estimated at 1,450 tons, making it the fourth-largest producer behind Japan, Canada, and Belgium.
Applications: In powder form, cadmium is used in rechargeable nickel-cadmium batteries, plating for corrosion protection, and low-melting-point and brazing alloys, as well as an alloying addition to copper to improve its hardness. Cadmium is also used in the manufacture of pigments, plastic stabilizers, phosphors, and semiconductor compounds. Among its features, the metal is capable of taking a high polish.
Cadmium demand and consumption has shifted in recent years from use in the protective electroplating of iron and steel to use in the nickel-cadmium battery sector. By 2000, batteries are expected to account for around three-fourths of total cadmium consumption.
Scrap Facts: Although most cadmium is produced from primary mining operations, secondary cadmium is also recovered, principally from the recycling of nickel-cadmium batteries. Spent batteries are generally recycled using either pyrometallurgical or hydrometallurgical processes. According to U.S. EPA estimates, the nickel-cadmium battery recycling rate—encompassing both industrial and consumer batteries—was 23 percent in 1995.
Pricing Info: Cadmium is not traded on the LME or Nymex, and there is no published producer quotation. For a price reference, the U.S. Geological Survey looks to Platt’s Metals Week’s New York dealer price.
In 1996, cadmium’s monthly price averages ranged from a high of $1.90 a pound in January to monthly lows of 80 cents a pound in November and December, ending with an annual average of $1.24 a pound. The metal has continued its price downtrend in 1997, averaging 61 cents a pound through midyear. •
Cadmium was discovered in 1817, but it was not used commercially until the beginning of the 20th century. Though cadmium occurs naturally in the mineral greenockite in the form of cadmium sulfide, it is principally recovered as a coproduct of zinc mining and refining. Annual Western World production is believed to be in the neighborhood of 15,000 to 17,000 mt, while U.S. production in 1996 was estimated at 1,450 tons, making it the fourth-largest producer behind Japan, Canada, and Belgium.