| |
In pure form, the rare earths appear as solid, iron-gray to silvery, lustrous metals. They are soft, malleable and ductile and are usually reactive, especially at high temperatures or when finely divided. There are seventeen rare earth elements. These are the elemental lanthanide series starting with lanthanum and ending with lutetium, plus yttrium and scandium. Although scandium bears a physical resemblance to yttrium and the fifteen lanthanides, it is rarely found with them in nature in economically recoverable deposits. Even though the lanthanide series (plus yttrium) elements are neither "rare" nor "earths," the industry prefers to use the term rare earth.
The production and consumption of rare earth minerals constitute a relatively small but diverse and dynamic segment of the industrial minerals, metallurgical and chemical industries. World production of rare earth minerals was valued at about $130 million in 1998, with U.S. production accounting for approximately $35 million. Production and consumption worldwide in 1998 were about 66 thousand and 70 thousand metric tons, respectively. The difference between production and consumption illustrates a unique feature of this industry - consumption is stronger for some specific rare earths than for others that are coproduced, a situation that leads to stockpiling of the less desired products. As much as 10-15% losses can occur in processing rare earth minerals, but this figure is not counted as mineral production.
The various markets for rare earths, as mixtures, individual elements or compounds, have developed in a very sporadic manner. Several markets have developed that initially gave promise of consuming major amounts of rare earths, only to have the rare earths displaced by less costly alternatives. Rare earth-exchanged fluidized catalytic cracking (FCC) catalysts continue to be a major market for rare earths, rebounding in the early 1990s with the introduction of reformulated gasolines.
New markets are growing for individual high-purity rare earths, particularly for neodymium for use in high-performance permanent magnets. As a result of these changes, the rare earth oxide (REO) industry has developed into a two-tiered industry. The mixed REOs, which constitute the bulk of the business, show stagnant demand, while the purified, specialized REOs show strength and good prospects. Conventional large-volume applications for bulk rare earths are declining, thus lowering prices, while special, relatively small-volume applications are showing vigorous growth and correspondingly higher prices.
Although there are eleven countries with the ability to produce significant quantities of rare earth minerals, the majority of the world's production has become concentrated in just two countries. If viewed as a single entity, the state-owned rare earth-producing mining companies of China are the dominant world supplier, followed distantly by Molycorp, Inc., subsidiary of Unocal Corporation, United States. Together, these two producers accounted for roughly 90% of the world rare earth mineral supply in 1998, with China alone accounting for 75% of world production.
In refined rare earth product value terms, the world's leading producer is Rhodia, a subsidiary of Rhône-Poulenc. The largest share of its production is at the La Rochelle, Poitou, France facility, followed by its sites at Freeport, Texas and Phoenix, Arizona in the United States. Additional production capacity is located in Baotou, China at the Baotou Rhodia Rare Earths subsidiary.
The United States is the largest consumer of rare earths. Approximately 39% of the rare earths used in the United States are consumed in catalysts. Within the catalysts segment, more than 50% of the rare earths are consumed in automotive emission control catalysts and roughly 47% are FCC catalysts used in crude petroleum refining. Other catalyst uses include those for air pollution control and chemical production. The catalyst markets will continue to grow through 2003, though not as rapidly as in the early 1990s.
Currently, the most important environmental issues for producers and consumers of rare earths are the problems posed by the radioactivity of thorium-containing monazite and xenotime ores. Australian monazite exports declined precipitously between 1989 and 1992 in part because of the radioactivity concern. Since 1992, Rhodia, the world's largest value-added rare earth company, has used Chinese instead of Australian rare earth concentrates for production of individual rare earth oxides and other rare earth compounds in France. Malaysian production of xenotime ore ceased in 1994, following environmental regulatory compliance problems related to the mineral's radioactivity, as well as the collapse of market prices for xenotime.
Consumption of rare earths in automotive and industrial emission catalysts is directly dependent on environmental regulations for air pollution control. Use and composition of rare earth-containing refinery FCC catalysts are functions of both the feedstock and the fuel quality required, both of which also relate back to air pollution regulations.
|
